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1.1 Hopes and concerns about nanoscience and nanotechnologies 1 Nanoscience and nanotechnologies are widely seen as having huge potential to bring benefits in areas as diverse as drug development, water decontamination, information and communication technologies, and the production of stronger, lighter materials. They are attracting rapidly increasing investments from governments and from businesses in many parts of the world; it has been estimated that total global investment in nanotechnologies is currently around 5 billion, 2 billion of which comes from private sources (European Commission 2004a) (see also Table 1.1). The number of published patents in nanotechnology increased fourfold from 1995 (531 parents) to 2001 (1976 patents) (3i 2002). Although it is too early to produce reliable figures for the global market, one widely quoted estimate puts the annual value for all nanotechnologies-related products (including information and communication technologies) at $1 trillion by 2011–2015 (NSF 2001). Although many people believe that nanotechnologies will have an impact across a wide range of sectors, a survey of experts in nanotechnologies across the world identified hype (‘misguided promises that nanotechnology can fix everything’) as the factor most likely to result in a backlash against it (3i 2002). 2 Against this background of increased research funding and interest from industry, several non- governmental organizations (NGOs) and some nanotechnologists have expressed concerns about current and potential future developments of nanotechnology. These include uncertainties about the impact of new nanomaterials on human health, questions about the type of applications that could arise from the expected convergence, in the longer term, of nanotechnologies with technologies such as biotechnology, information technology (IT) and artificial intelligence, and suggestions that future developments might bring self-replicating nano-robots that might devastate the world (Joy 2000; ETC 2003a). Others have questioned the adequacy of current regulatory frameworks to deal with these new developments, and whether applications will benefit or disenfranchise developing countries (Arnall 2003). 3 The media has reflected the hopes and concerns about nanoscience and nanotechnology. 4 In January 2003 the Better Regulation Task Force (BRTF) published its report Scientific Research: Innovation with Controls (Better Regulation Task Force 2003), which included a consideration of nanotechnologies. Its first recommendation was that the UK Government should enable the public, through debate, to consider the risks of nanotechnologies for themselves. Other recommendations advocated openness in decision making, involving the public in the decision-making process, developing two-way communication channels and taking a strong lead over the handling of any issues of risk to emerge from nanotechnologies. In its response to the first recommendation, the Government stated that there was currently no obvious focus for an informed debate, but that it was initiating work that would ‘examine whether there were any areas of nanotechnology which raise or will raise specific safety, environmental or ethical issues’ that would warrant further study (UK Government 2003). The Royal Society & The Royal Academy of Engineering Nanoscience and nanotechnologies | July 2004 | 1 1 Introduction Table 1.1 Examples of public funding for research and development (R&D) in nanoscience and nanotechnology (source: European Commission 2004a). Country Expenditure on nanoscience and nanotechnologies Europe Current funding for nanotechnology R&D is about 1 billion euros, two-thirds of which comes from national and regional programmes. Japan Funding rose from $400M in 2001 to $800M in 2003 and is expected to rise by a further 20% in 2004. USA The USA’s 21st Century Nanotechnology Research and Development Act (passed in 2003) allocated nearly $3.7 billion to nanotechnology from 2005 to 2008 (which excludes a substantial defence-related expenditure). This compares with $750M in 2003. UK With the launch of its nanotechnology strategy in 2003, the UK Government pledged £45M per year from 2003 to 2009.

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Page 1: sciencescitoyennes.org · 1.1 Hopes and concerns about nanoscience and nanotechnologies 1 Nanoscience and nanotechnologies are widely seen as having huge potential to bring benefits

1.1 Hopes and concerns about nanoscienceand nanotechnologies

1 Nanoscience and nanotechnologies are widely seenas having huge potential to bring benefits in areas asdiverse as drug development, water decontamination,information and communication technologies, and theproduction of stronger, lighter materials. They areattracting rapidly increasing investments fromgovernments and from businesses in many parts of theworld; it has been estimated that total global investmentin nanotechnologies is currently around €5 billion, €2 billion of which comes from private sources(European Commission 2004a) (see also Table 1.1). The number of published patents in nanotechnologyincreased fourfold from 1995 (531 parents) to 2001(1976 patents) (3i 2002). Although it is too early toproduce reliable figures for the global market, onewidely quoted estimate puts the annual value for allnanotechnologies-related products (includinginformation and communication technologies) at $1 trillion by 2011–2015 (NSF 2001). Although manypeople believe that nanotechnologies will have animpact across a wide range of sectors, a survey ofexperts in nanotechnologies across the world identifiedhype (‘misguided promises that nanotechnology can fixeverything’) as the factor most likely to result in abacklash against it (3i 2002).

2 Against this background of increased researchfunding and interest from industry, several non-governmental organizations (NGOs) and somenanotechnologists have expressed concerns aboutcurrent and potential future developments ofnanotechnology. These include uncertainties about theimpact of new nanomaterials on human health,

questions about the type of applications that could arisefrom the expected convergence, in the longer term, ofnanotechnologies with technologies such asbiotechnology, information technology (IT) and artificialintelligence, and suggestions that future developmentsmight bring self-replicating nano-robots that mightdevastate the world (Joy 2000; ETC 2003a). Others havequestioned the adequacy of current regulatoryframeworks to deal with these new developments, andwhether applications will benefit or disenfranchisedeveloping countries (Arnall 2003).

3 The media has reflected the hopes and concernsabout nanoscience and nanotechnology.

4 In January 2003 the Better Regulation Task Force(BRTF) published its report Scientific Research:Innovation with Controls (Better Regulation Task Force2003), which included a consideration ofnanotechnologies. Its first recommendation was that theUK Government should enable the public, throughdebate, to consider the risks of nanotechnologies forthemselves. Other recommendations advocatedopenness in decision making, involving the public in thedecision-making process, developing two-waycommunication channels and taking a strong lead overthe handling of any issues of risk to emerge fromnanotechnologies. In its response to the firstrecommendation, the Government stated that therewas currently no obvious focus for an informed debate,but that it was initiating work that would ‘examinewhether there were any areas of nanotechnology whichraise or will raise specific safety, environmental or ethicalissues’ that would warrant further study (UKGovernment 2003).

The Royal Society & The Royal Academy of Engineering Nanoscience and nanotechnologies | July 2004 | 1

1 Introduction

Table 1.1 Examples of public funding for research and development (R&D) in nanoscience and nanotechnology(source: European Commission 2004a).

Country Expenditure on nanoscience and nanotechnologies

Europe Current funding for nanotechnology R&D is about 1 billion euros, two-thirds of which comesfrom national and regional programmes.

Japan Funding rose from $400M in 2001 to $800M in 2003 and is expected to rise by a further 20%in 2004.

USA The USA’s 21st Century Nanotechnology Research and Development Act (passed in 2003)allocated nearly $3.7 billion to nanotechnology from 2005 to 2008 (which excludes asubstantial defence-related expenditure). This compares with $750M in 2003.

UK With the launch of its nanotechnology strategy in 2003, the UK Government pledged £45Mper year from 2003 to 2009.

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1.2 Terms of reference and conduct of thestudy

5 In June 2003, following its response to the BRTF,the UK Government commissioned the Royal Societyand the Royal Academy of Engineering (the UK’snational academies of science and of engineering,respectively) to conduct an independent study onnanotechnology. The terms of reference of our study,jointly agreed by the Office of Science and Technologyand the two Academies, were as follows:

· define what is meant by nanoscience andnanotechnology;

· summarise the current state of scientific knowledgeabout nanotechnology;

· identify the specific applications of the newtechnologies, in particular where nanotechnology isalready in use;

· carry out a forward look to see how the technologymight be used in future, where possible estimating thelikely time-scales in which the most far-reachingapplications of the technology might become reality;

· identify what environmental, health and safety, ethicalor societal implications or uncertainties may arise fromthe use of the technology, both current and future;

· identify areas where regulation needs to be considered.

6 The two academies convened a multidisciplinaryworking group of experts in science and engineering,medicine, social science, consumer affairs, ethical issuesand the environment to conduct this study (see Annex Afor a list of Working Group members). The study wasconducted independently of Government, which wasnot involved in the selection of the working groupmembers or its methods of working, and which did notview the report before it was printed. We received muchwritten evidence, and we held a series of oral evidencesessions and workshops with a range of stakeholdersfrom the UK and overseas. The volume of evidence thatwas sent in for the Working Group to consider andfollow up extended the time taken to complete thisproject beyond that originally anticipated. At the outsetof the study it was agreed that the report should includepublic concerns and that data should be collected aboutpublic awareness of nanotechnology, which could formimportant baseline data. The market research companyBMRB International was commissioned to researchpublic attitudes to nanotechnology, which took theform of two workshops and a short market survey. Theevidence was published as the project progressed andcomments were invited through a dedicated website(www.nanotec.org.uk). A detailed description of the

conduct of the study can be found in Annex B. We areextremely grateful to all those organisations andindividuals who contributed to the study; they are listedin Annex C. Their contributions can be found on ourwebsite and are available on the CD at the back of thehardcopy version of this report. In the report thesecontributions have been referred to as evidence. Thereport was peer reviewed by a small group of Fellowsfrom the two academies (listed in Annex A) beforebeing considered by the two academies. It has beenendorsed by the Council of the Royal Society andapproved for publication by the Royal Academy ofEngineering.

1.3 Report overview

7 In Chapter 2 we introduce nanoscience andnanotechnologies, and explain the definitions of eachthat we used during the study. In Chapter 3 we giveexamples of key current research, and current andpotential future advances in: nanomaterials;nanometrology; electronics, optoelectronics and ICT;and bio-nanotechnology. We also look at the benefitsthey are currently providing and might provide in theshort, medium and longer term. In Chapter 4 we look atcurrent and possible future industrial applications ofnanotechnology, and examine some of the barriers to itstake-up by industry. In Chapters 3 and 4 we haveprovided an overview (rather than a detailedassessment) of current and potential futuredevelopments in, and applications of, nanoscience andnanotechnologies, against which health, safety,environmental, social and ethical implications (addressedlater in the report) could be considered. The Taylorreport (DTI 2002) reviewed the state of nanotechnologyapplications in industry in the UK and proposed a seriesof actions to accelerate and support increased industrialinvestment in the exploitation of nanotechnology in theUK. It was not our intention to critique or update theTaylor report or to identify research priorities fornanoscience and nanotechnology. The House ofCommons Science and Technology Committee hasrecently evaluated the implementation of therecommendations of the Taylor report (House ofCommons 2004a).

8 In Chapter 5 we evaluate the potential health, safetyand environmental implications of nanotechnologies,and in Chapter 6 we consider the potential social andethical implications. In both chapters we identify themain gaps in knowledge related to the potential impactsof nanotechnologies. Chapter 7 outlines the results ofour commissioned research into public attitudes tonanotechnology in Great Britain, and considers the roleof multi-stakeholder dialogue in the future developmentof nanotechnologies. The implications of ourconclusions for the current regulatory framework are

The Royal Society & The Royal Academy of Engineering2 | July 2004 | Nanoscience and nanotechnologies

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outlined in Chapter 8. Finally, Chapters 9 and 10contain our overall conclusions and list ourrecommendations.

1.4 Next steps

9 We look forward to the response to this reportfrom the UK Government and from the other parties atwhom the recommendations are targeted. This studyhas generated a great deal of interest among a widerange of stakeholders, both within the UK and

internationally. As far as we are aware it is the first studyof its kind, and we expect its findings to contribute tothe responsible development of nanoscience andnanotechnology globally. The two academies willcontinue to participate in this important area. The issuesraised and conclusions reached in this report can bedebated through the discussion section of the dedicatedwebsite (www.nanotec.org.uk). We will hold an openmeeting in London to discuss the report’s findingsshortly after its publication.

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1 The first term of reference of this study was to definewhat is meant by nanoscience and nanotechnology.However, as the term ‘nanotechnology’ encompassessuch a wide range of tools, techniques and potentialapplications, we have found it more appropriate to referto ‘nanotechnologies’. Our definitions were developedthrough consultation at our workshop meeting withscientists and engineers and through commentsreceived through the study website.

2 Although there is no sharp distinction betweenthem, in this report we differentiate betweennanoscience and nanotechnologies as follows.

3 The prefix ‘nano’ is derived from the Greek wordfor dwarf. One nanometre (nm) is equal to one-billionthof a metre, 10–9m. A human hair is approximately80,000nm wide, and a red blood cell approximately 7000nm wide. Figure 2.1 shows the nanometre incontext. Atoms are below a nanometre in size, whereasmany molecules, including some proteins, range from ananometre upwards.

4 The conceptual underpinnings of nanotechnologieswere first laid out in 1959 by the physicist RichardFeynman, in his lecture ‘There’s plenty of room at thebottom’ (Feynman 1959). Feynman explored thepossibility of manipulating material at the scale ofindividual atoms and molecules, imagining the whole ofthe Encyclopaedia Britannica written on the head of apin and foreseeing the increasing ability to examine andcontrol matter at the nanoscale.

5 The term ‘nanotechnology’ was not used until1974, when Norio Taniguchi, a researcher at theUniversity of Tokyo, Japan used it to refer to the abilityto engineer materials precisely at the nanometre level(Taniguchi 1974). The primary driving force forminiaturisation at that time came from the electronicsindustry, which aimed to develop tools to create smaller(and therefore faster and more complex) electronicdevices on silicon chips. Indeed, at IBM in the USA a

technique called electron beam lithography was used tocreate nanostructures and devices as small as 40–70nmin the early 1970s.

6. The size range that holds so much interest istypically from 100nm down to the atomic level(approximately 0.2nm), because it is in this range(particularly at the lower end) that materials can havedifferent or enhanced properties compared with thesame materials at a larger size. The two main reasonsfor this change in behaviour are an increased relativesurface area, and the dominance of quantum effects.An increase in surface area (per unit mass) will result ina corresponding increase in chemical reactivity, makingsome nanomaterials useful as catalysts to improve theefficiency of fuel cells and batteries. As the size ofmatter is reduced to tens of nanometres or less,quantum effects can begin to play a role, and these cansignificantly change a material’s optical, magnetic orelectrical properties. In some cases, size-dependentproperties have been exploited for centuries. Forexample, gold and silver nanoparticles (particles ofdiameter less than 100 nm; see section 3.2) have beenused as coloured pigments in stained glass and ceramicssince the 10th century AD (Erhardt 2003). Depending ontheir size, gold particles can appear red, blue or gold incolour. The challenge for the ancient (al)chemists was tomake all nanoparticles the same size (and hence thesame colour), and the production of single-sizenanoparticles is still a challenge today.

7. At the larger end of our size range, other effectssuch as surface tension or ‘stickiness’ are important,which also affect physical and chemical properties. Forliquid or gaseous environments Brownian motion, whichdescribes the random movement of larger particles ormolecules owing to their bombardment by smallermolecules and atoms, is also important. This effectmakes control of individual atoms or molecules in theseenvironments extremely difficult.

8. Nanoscience is concerned with understandingthese effects and their influence on the properties ofmaterial. Nanotechnologies aim to exploit these effectsto create structures, devices and systems with novelproperties and functions due to their size.

9. In some senses, nanoscience and nanotechnologiesare not new. Many chemicals and chemical processeshave nanoscale features – for example, chemists havebeen making polymers, large molecules made up of tinynanoscalar subunits, for many decades.Nanotechnologies have been used to create the tinyfeatures on computer chips for the past 20 years. Thenatural world also contains many examples of nanoscalestructures, from milk (a nanoscale colloid) tosophisticated nanosized and nanostructured proteins

Box 2.1 Definitions of nanoscience and nanotechnologies

Nanoscience is the study of phenomena andmanipulation of materials at atomic, molecular andmacromolecular scales, where properties differsignificantly from those at a larger scale.

Nanotechnologies are the design, characterisation,production and application of structures, devices andsystems by controlling shape and size at nanometrescale.

The Royal Society & The Royal Academy of Engineering Nanoscience and nanotechnologies | July 2004 | 5

2 What are nanoscience and nanotechnologies?

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that control a range of biological activities, such asflexing muscles, releasing energy and repairing cells.Nanoparticles occur naturally, and have been created forthousands of years as the products of combustion andfood cooking.

10 However, it is only in recent years that sophisticatedtools have been developed to investigate andmanipulate matter at the nanoscale, which have greatlyaffected our understanding of the nanoscale world. Amajor step in this direction was the invention of thescanning tunnelling microscope (STM) in 1982, and theatomic force microscope (AFM) in 1986. These tools usenanoscale probes to image a surface with atomicresolution, and are also capable of picking up, sliding ordragging atoms or molecules around on surfaces tobuild rudimentary nanostructures. These tools arefurther described in Box 3.1. In a now famousexperiment in 1990, Don Eigler and Erhard Schweizer atIBM moved xenon atoms around on a nickel surface towrite the company logo (Eigler and Schweizer 1990)(see Figure 2.1), a laborious process which took a wholeday under well-controlled conditions. The use of thesetools is not restricted to engineering, but has beenadopted across a range of disciplines. AFM, for example,is routinely used to study biological molecules such asproteins.

11 The technique used by Eigler and Schweizer is onlyone in the range of ways used to manipulate andproduce nanomaterials, commonly categorised as either‘top-down’ or ‘bottom-up’. ‘Top-down’ techniquesinvolve starting with a block of material, and etching ormilling it down to the desired shape, whereas ‘bottom-

up’ involves the assembly of smaller sub-units (atoms ormolecules) to make a larger structure. The mainchallenge for top-down manufacture is the creation ofincreasingly small structures with sufficient accuracy,whereas for bottom-up manufacture, it is to makestructures large enough, and of sufficient quality, to beof use as materials. These two methods have evolvedseparately and have now reached the point where thebest achievable feature size for each technique isapproximately the same, leading to novel hybrid ways ofmanufacture.

12 Nanotechnologies can be regarded as genuinelyinterdisciplinary, and have prompted the collaborationbetween researchers in previously disparate areas toshare knowledge, tools and techniques. Anunderstanding of the physics and chemistry of matterand processes at the nanoscale is relevant to all scientificdisciplines, from chemistry and physics to biology,engineering and medicine. Indeed, it could be arguedthat evolutionary developments in each of these fieldstowards investigating matter at increasingly small sizescales has now come to be known as ‘nanotechnology’.

13 It will be seen in Chapters 3 and 4 that nanoscienceand nanotechnologies encompass a broad and variedrange of materials, tools and approaches. Apart from acharacteristic size scale, it is difficult to findcommonalities between them. We should not thereforeexpect them to have the same the same health,environmental, safety, social or ethical implications orrequire the same approach to regulation; these issuesare dealt with in Chapters 5 – 8.

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3 Science and applications

3.1 Introduction

1 In this chapter we provide an overview of some keycurrent developments in nanoscience andnanotechnologies, and highlight some possible futureapplications. The chapter is informed by evidence fromscientists and engineers in academia and industry. Itillustrates the wide-ranging interest in these areas andprovides a background to the later chapters, whichaddress health, environmental, social, ethical andregulatory implications of nanotechnologies. It does notconsider in detail the developments in nanoscience andnanotechnologies in all scientific and engineering fields.

2 As nanoscience and nanotechnologies cover such awide range of fields (from chemistry, physics andbiology, to medicine, engineering and electronics), wehave considered them in four broad categories:nanomaterials; nanometrology; electronics,optoelectronics and information and communicationtechnology; and bio-nanotechnology andnanomedicine. This division helps to distinguishbetween developments in different fields, but there isnaturally some overlap.

3 Where possible, we define the development offuture applications as short term (under 5years),medium term (5–15 years), and long term (over20years). It may be that some of the potentialapplications that we identify are never realised, whereasothers that are currently unforeseen could have a majorimpact. We also identify potential in environmental,health and safety, ethical or societal implications oruncertainties that are discussed further in later chapters.

4 Current industrial applications of nanotechnologiesare dealt with in Chapter 4, as are the factors that willinfluence their application in the future.

3.2 Nanomaterials

3.2.1 Introduction to nanomaterials

5 A key driver in the development of new andimproved materials, from the steels of the 19th centuryto the advanced materials of today, has been the abilityto control their structure at smaller and smaller scales.The overall properties of materials as diverse as paintsand silicon chips are determined by their structure at themicro- and nanoscales. As our understanding ofmaterials at the nanoscale and our ability to controltheir structure improves, there will be great potential tocreate a range of materials with novel characteristics,functions and applications.

6 Although a broad definition, we categorisenanomaterials as those which have structuredcomponents with at least one dimension less than100nm. Materials that have one dimension in thenanoscale (and are extended in the other two dimensions)are layers, such as a thin films or surface coatings. Someof the features on computer chips come in this category.Materials that are nanoscale in two dimensions (andextended in one dimension) include nanowires andnanotubes. Materials that are nanoscale in threedimensions are particles, for example precipitates, colloidsand quantum dots (tiny particles of semiconductormaterials). Nanocrystalline materials, made up ofnanometre-sized grains, also fall into this category. Someof these materials have been available for some time;others are genuinely new. The aim of this chapter is togive an overview of the properties, and the significantforeseeable applications of some key nanomaterials.

7 Two principal factors cause the properties ofnanomaterials to differ significantly from othermaterials: increased relative surface area, and quantumeffects. These factors can change or enhance propertiessuch as reactivity, strength and electrical characteristics.As a particle decreases in size, a greater proportion ofatoms are found at the surface compared to thoseinside. For example, a particle of size 30 nm has 5% ofits atoms on its surface, at 10 nm 20% of its atoms, andat 3 nm 50% of its atoms. Thus nanoparticles have amuch greater surface area per unit mass compared withlarger particles. As growth and catalytic chemicalreactions occur at surfaces, this means that a given massof material in nanoparticulate form will be much morereactive than the same mass of material made up oflarger particles.

8 In tandem with surface-area effects, quantumeffects can begin to dominate the properties of matteras size is reduced to the nanoscale. These can affect theoptical, electrical and magnetic behaviour of materials,particularly as the structure or particle size approachesthe smaller end of the nanoscale. Materials that exploitthese effects include quantum dots, and quantum welllasers for optoelectronics.

9 For other materials such as crystalline solids, as thesize of their structural components decreases, there ismuch greater interface area within the material; this cangreatly affect both mechanical and electrical properties.For example, most metals are made up of smallcrystalline grains; the boundaries between the grainslow down or arrest the propagation of defects whenthe material is stressed, thus giving it strength. If thesegrains can be made very small, or even nanoscale insize, the interface area within the material greatly

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increases, which enhances its strength. For example,nanocrystalline nickel is as strong as hardened steel.Understanding surfaces and interfaces is a key challengefor those working on nanomaterials, and one wherenew imaging and analysis instruments are vital.

10 Nanomaterials are not simply another step in theminiaturization of materials. They often require verydifferent production approaches. As introduced inChapter 2, and discussed further in Chapter 4, there areseveral processes to create nanomaterials, classified as‘top-down’ and ‘bottom-up’. Although manynanomaterials are currently at the laboratory stage ofmanufacture, a few of them are being commercialised.

3.2.2 Nanoscience in this area

11 Below we outline some examples of nanomaterialsand the range of nanoscience that is aimed atunderstanding their properties. As will be seen, thebehaviour of some nanomaterials is well understood,whereas others present greater challenges.

a) Nanoscale in one dimension

Thin films, layers and surfaces12 One-dimensional nanomaterials, such as thin filmsand engineered surfaces, have been developed andused for decades in fields such as electronic devicemanufacture, chemistry and engineering. In the siliconintegrated-circuit industry, for example, many devicesrely on thin films for their operation, and control of filmthicknesses approaching the atomic level is routine.Monolayers (layers that are one atom or molecule deep)are also routinely made and used in chemistry. Theformation and properties of these layers are reasonablywell understood from the atomic level upwards, even inquite complex layers (such as lubricants). Advances arebeing made in the control of the composition andsmoothness of surfaces, and the growth of films.

13 Engineered surfaces with tailored properties such aslarge surface area or specific reactivity are used routinelyin a range of applications such as in fuel cells andcatalysts (see section 3.2.3b). The large surface areaprovided by nanoparticles, together with their ability toself assemble on a support surface, could be of use in allof these applications.

14 Although they represent incremental developments,surfaces with enhanced properties should find applicationsthroughout the chemicals and energy sectors. Thebenefits could surpass the obvious economic andresource savings achieved by higher activity and greaterselectivity in reactors and separation processes, toenabling small-scale distributed processing (makingchemicals as close as possible to the point of use). Thereis already a move in the chemical industry towards this.Another use could be the small-scale, on-site productionof high value chemicals such as pharmaceuticals.

b) Nanoscale in two dimensions

15 Two dimensional nanomaterials such as tubes andwires have generated considerable interest among thescientific community in recent years. In particular, theirnovel electrical and mechanical properties are thesubject of intense research.

Carbon nanotubes16 Carbon nanotubes (CNTs) were first observed bySumio Iijima in 1991 (Iijima 1991). CNTs are extendedtubes of rolled graphene sheets. There are two types ofCNT: single-walled (one tube) or multi-walled (severalconcentric tubes) (Figure 3.1). Both of these are typicallya few nanometres in diameter and several micrometres (10-6m) to centimetres long. CNTs have assumed animportant role in the context of nanomaterials, becauseof their novel chemical and physical properties. They aremechanically very strong (their Young’s modulus is over1 terapascal, making CNTs as stiff as diamond), flexible(about their axis), and can conduct electricity extremelywell (the helicity of the graphene sheet determineswhether the CNT is a semiconductor or metallic). All ofthese remarkable properties give CNTs a range ofpotential applications: for example, in reinforcedcomposites, sensors, nanoelectronics and displaydevices.

Figure 3.1a Schematic of a single-walled carbon nanotube (SWNT)

Figure 3.1b Schematic of a multi-walled carbon nanotube (MWNT)

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17 CNTs are now available commercially in limitedquantities. They can be grown by several techniques,which are discussed in section 4.3.1b. However, theselective and uniform production of CNTs with specificdimensions and physical properties is yet to be achieved.The potential similarity in size and shape between CNTsand asbestos fibres has led to concerns about their safety,which we address in detail in sections 5.3.1b and 5.3.2a.

Inorganic nanotubes18 Inorganic nanotubes and inorganic fullerene-likematerials based on layered compounds such asmolybdenum disulphide were discovered shortly afterCNTs. They have excellent tribological (lubricating)properties, resistance to shockwave impact, catalyticreactivity, and high capacity for hydrogen and lithiumstorage, which suggest a range of promisingapplications. Oxide-based nanotubes (such as titaniumdioxide) are being explored for their applications incatalysis, photo-catalysis and energy storage.

Nanowires19 Nanowires are ultrafine wires or linear arrays ofdots, formed by self-assembly. They can be made from awide range of materials. Semiconductor nanowiresmade of silicon, gallium nitride and indium phosphidehave demonstrated remarkable optical, electronic andmagnetic characteristics (for example, silica nanowirescan bend light around very tight corners). Nanowireshave potential applications in high-density data storage,either as magnetic read heads or as patterned storagemedia, and electronic and opto-electronic nanodevices,for metallic interconnects of quantum devices andnanodevices. The preparation of these nanowires relieson sophisticated growth techniques, which include self-assembly processes, where atoms arrange themselvesnaturally on stepped surfaces, chemical vapourdeposition (CVD) onto patterned substrates,electroplating or molecular beam epitaxy (MBE). The‘molecular beams’ are typically from thermallyevaporated elemental sources.

Biopolymers20 The variability and site recognition of biopolymers,such as DNA molecules, offer a wide range ofopportunities for the self-organization of wirenanostructures into much more complex patterns. TheDNA backbones may then, for example, be coated inmetal. They also offer opportunities to link nano- andbiotechnology in, for example, biocompatible sensorsand small, simple motors. Such self-assembly of organicbackbone nanostructures is often controlled by weakinteractions, such as hydrogen bonds, hydrophobic, orvan der Waals interactions (generally in aqueousenvironments) and hence requires quite differentsynthesis strategies to CNTs, for example. Thecombination of one-dimensional nanostructuresconsisting of biopolymers and inorganic compoundsopens up a number of scientific and technologicalopportunities.

c) Nanoscale in three dimensions

Nanoparticles21 Nanoparticles are often defined as particles of lessthan 100nm in diameter. In line with our definitions ofnanoscience and nanotechnologies (see Box 2.1), weclassify nanoparticles to be particles less than 100nm indiameter that exhibit new or enhanced size-dependentproperties compared with larger particles of the samematerial. Nanoparticles exist widely in the natural world:for example as the products of photochemical andvolcanic activity, and created by plants and algae. Theyhave also been created for thousands of years asproducts of combustion and food cooking, and morerecently from vehicle exhausts. Deliberatelymanufactured nanoparticles, such as metal oxides, areby comparison in the minority. In this report we willrefer to these as natural, pollutant and manufacturednanoparticles, respectively.

22 As described in Chapter 2, nanoparticles are ofinterest because of the new properties (such as chemicalreactivity and optical behaviour) that they exhibitcompared with larger particles of the same materials.For example, titanium dioxide and zinc oxide becometransparent at the nanoscale, however are able toabsorb and reflect UV light, and have found applicationin sunscreens. Nanoparticles have a range of potentialapplications: in the short-term in new cosmetics, textilesand paints; in the longer term, in methods of targeteddrug delivery where they could be to used deliver drugsto a specific site in the body. Nanoparticles can also bearranged into layers on surfaces, providing a largesurface area and hence enhanced activity, relevant to arange of potential applications such as catalysts.

23 Manufactured nanoparticles are typically notproducts in their own right, but generally serve as rawmaterials, ingredients or additives in existing products.Although their production is currently low comparedwith other nanomaterials we have given them aconsiderable amount of attention in this report. This isbecause they are currently in a small number ofconsumer products such as cosmetics and theirenhanced or novel properties may have implications fortheir toxicity. The evidence submitted during the courseof our study indicates that for most applications,nanoparticles will be fixed (for example, attached to asurface or within in a composite) although in othersthey will be free or suspended in fluid. Whether they arefixed or free will have a significant affect on theirpotential health, safety and environmental impacts. Weaddress these issues in detail in Chapter 5.

Fullerenes (carbon 60)24 In the mid-1980s a new class of carbon material wasdiscovered called carbon 60 (C60) (Kroto et al 1985). Adiagram of carbon 60 can be found in Figure 2.1. Theseare spherical molecules about 1nm in diameter,comprising 60 carbon atoms arranged as 20 hexagons

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and 12 pentagons: the configuration of a football. TheC60 species was named ‘Buckminsterfullerene’ inrecognition of the architect Buckminster Fuller, who waswell-known for building geodesic domes, and the termfullerenes was then given to any closed carbon cage. In1990, a technique to produce larger quantities of C60 wasdeveloped by resistively heating graphite rods in a heliumatmosphere (Krätschmer et al 1990). Several applicationsare envisaged for fullerenes, such as miniature ‘ballbearings’ to lubricate surfaces, drug delivery vehicles andin electronic circuits.

Dendrimers25 Dendrimers are spherical polymeric molecules,formed through a nanoscale hierarchical self-assemblyprocess. There are many types of dendrimer; the smallestis several nanometres in size. Dendrimers are used inconventional applications such as coatings and inks, butthey also have a range of interesting properties whichcould lead to useful applications. For example,dendrimers can act as nanoscale carrier molecules andas such could be used in drug delivery. Environmentalclean-up could be assisted by dendrimers as they cantrap metal ions, which could then be filtered out ofwater with ultra-filtration techniques.

Quantum dots26 Nanoparticles of semiconductors (quantum dots)were theorized in the 1970s and initially created in theearly 1980s. If semiconductor particles are made smallenough, quantum effects come into play, which limitthe energies at which electrons and holes (the absenceof an electron) can exist in the particles. As energy isrelated to wavelength (or colour), this means that theoptical properties of the particle can be finely tuneddepending on its size. Thus, particles can be made toemit or absorb specific wavelengths (colours) of light,merely by controlling their size. Recently, quantum dotshave found applications in composites, solar cells(Gratzel cells) and fluorescent biological labels (forexample to trace a biological molecule) which use boththe small particle size and tuneable energy levels.Recent advances in chemistry have resulted in thepreparation of monolayer-protected, high-quality,monodispersed, crystalline quantum dots as small as2nm in diameter, which can be conveniently treatedand processed as a typical chemical reagent.

3.2.3 Applications

27 Below we list some key current and potential short-and long-term applications of nanomaterials. Mostcurrent applications represent evolutionarydevelopments of existing technologies: for example, thereduction in size of electronics devices.

a) Current

Sunscreens and cosmetics28 Nanosized titanium dioxide and zinc oxide are

currently used in some sunscreens, as they absorb andreflect ultraviolet (UV) rays and yet are transparent tovisible light and so are more appealing to the consumer.Nanosized iron oxide is present in some lipsticks as apigment but it is our understanding that it is not usedby the European cosmetics sector. The use ofnanoparticles in cosmetics has raised a number ofconcerns about consumer safety; we evaluate theevidence relating to these concerns in section 5.3.2b.

Composites29 An important use of nanoparticles and nanotubesis in composites, materials that combine one or moreseparate components and which are designed to exhibitoverall the best properties of each component. Thismulti-functionality applies not only to mechanicalproperties, but extends to optical, electrical andmagnetic ones. Currently, carbon fibres and bundles ofmulti-walled CNTs are used in polymers to control orenhance conductivity, with applications such as anti-static packaging. The use of individual CNTs incomposites is a potential long-term application (seesection 3.2.3c). A particular type of nanocomposite iswhere nanoparticles act as fillers in a matrix; forexample, carbon black used as a filler to reinforce cartyres. However, particles of carbon black can range fromtens to hundreds of nanometres in size, so not allcarbon black falls within our definition of nanoparticles.

Clays30 Clays containing naturally occurring nanoparticleshave long been important as construction materials andare undergoing continuous improvement. Clay particlebased composites – containing plastics and nano-sizedflakes of clay – are also finding applications such as usein car bumpers.

Coatings and surfaces31 Coatings with thickness controlled at the nano- oratomic scale have been in routine production for sometime, for example in MBE or metal oxide CVD foroptoelectonic devices, or in catalytically active andchemically functionalized surfaces. Recently developedapplications include the self-cleaning window, which iscoated in highly activated titanium dioxide, engineeredto be highly hydrophobic (water repellent) and anti-bacterial, and coatings based on nanoparticulate oxidesthat catalytically destroy chemical agents (Royal Society2004a). Wear and scratch-resistant hard coatings aresignificantly improved by nanoscale intermediate layers (ormultilayers) between the hard outer layer and thesubstrate material. The intermediate layers give goodbonding and graded matching of elastic and thermalproperties, thus improving adhesion. A range of enhancedtextiles, such as breathable, waterproof and stain-resistant fabrics, have been enabled by the improvedcontrol of porosity at the nanoscale and surfaceroughness in a variety of polymers and inorganics.

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Tougher and harder cutting tools32 Cutting tools made of nanocrystalline materials,such as tungsten carbide, tantalum carbide and titaniumcarbide, are more wear and erosion-resistant, and lastlonger than their conventional (large-grained)counterparts. They are finding applications in the drillsused to bore holes in circuit boards.

b) Short-term

Paints33 Incorporating nanoparticles in paints could improvetheir performance, for example by making them lighterand giving them different properties. Thinner paintcoatings (‘lightweighting’), used for example on aircraft,would reduce their weight, which could be beneficial tothe environment. However, the whole life cycle of theaircraft needs to be considered before overall benefitscan be claimed (see section 4.5). It may also be possibleto substantially reduce solvent content of paints, withresulting environmental benefits. New types of fouling-resistant marine paint could be developed and areurgently needed as alternatives to tributyl tin (TBT), nowthat the ecological impacts of TBT have beenrecognised. Anti-fouling surface treatment is alsovaluable in process applications such as heat exchange,where it could lead to energy savings. If they can beproduced at sufficiently low cost, fouling-resistantcoatings could be used in routine duties such as pipingfor domestic and industrial water systems. It remainsspeculation whether very effective anti-fouling coatingscould reduce the use of biocides, including chlorine.Other novel, and more long-term, applications fornanoparticles might lie in paints that change colour inresponse to change in temperature or chemicalenvironment, or paints that have reduced infra-redabsorptivity and so reduce heat loss.

34 Concerns about the health and environmentalimpacts of nanoparticles (which we address in detail inChapter 5) may require the need for the durability andabrasion behaviour of nano-engineered paints andcoatings to be addressed, so that abrasion products takethe form of coarse or microscopic agglomerates ratherthan individual nanoparticles.

Remediation35 The potential of nanoparticles to react withpollutants in soil and groundwater and transform theminto harmless compounds is being researched. In onepilot study the large surface area and high surfacereactivity of iron nanoparticles were exploited totransform chlorinated hydrocarbons (some of which arebelieved to be carcinogens) into less harmful endproducts in groundwater (Zhang 2003). It is also hopedthat they could be used to transform heavy metals suchas lead and mercury from bioavailable forms intoinsoluble forms. Serious concerns have been raised overthe uncontrolled release of nanoparticles into theenvironment; these are discussed in section 5.4.

Fuel Cells36 Engineered surfaces are essential in fuel cells, wherethe external surface properties and the pore structureaffect performance. The hydrogen used as the immediatefuel in fuel cells may be generated from hydrocarbonsby catalytic reforming, usually in a reactor moduleassociated directly with the fuel cell. The potential useof nano-engineered membranes to intensify catalyticprocesses could enable higher-efficiency, small-scale fuelcells. These could act as distributed sources of electricalpower. It may eventually be possible to producehydrogen locally from sources other than hydrocarbons,which are the feedstocks of current attention.

Displays37 The huge market for large area, high brightness,flat-panel displays, as used in television screens andcomputer monitors, is driving the development of somenanomaterials. Nanocrystalline zinc selenide, zincsulphide, cadmium sulphide and lead telluridesynthesized by sol–gel techniques (a process for makingceramic and glass materials, involving the transitionfrom a liquid ‘sol’ phase to a solid ‘gel’ phase) arecandidates for the next generation of light-emittingphosphors. CNTs are being investigated for low voltagefield-emission displays; their strength, sharpness,conductivity and inertness make them potentially veryefficient and long-lasting emitters.

Batteries38 With the growth in portable electronic equipment(mobile phones, navigation devices, laptop computers,remote sensors), there is great demand for lightweight,high-energy density batteries. Nanocrystalline materialssynthesized by sol–gel techniques are candidates forseparator plates in batteries because of their foam-like(aerogel) structure, which can hold considerably moreenergy than conventional ones. Nickel–metal hydridebatteries made of nanocrystalline nickel and metalhydrides are envisioned to require less frequentrecharging and to last longer because of their largegrain boundary (surface) area.

Fuel additives39 Research is underway into the addition ofnanoparticulate ceria (cerium oxide) to diesel fuel toimprove fuel economy by reducing the degradation offuel consumption over time (Oxonica 2003).

Catalysts40 In general, nanoparticles have a high surface area,and hence provide higher catalytic activity.Nanotechnologies are enabling changes in the degree ofcontrol in the production of nanoparticles, and thesupport structure on which they reside. It is possible tosynthesise metal nanoparticles in solution in thepresence of a surfactant to form highly orderedmonodisperse films of the catalyst nanoparticles on asurface. This allows more uniformity in the size andchemical structure of the catalyst, which in turn leads to

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greater catalytic activity and the production of fewer by-products. It may also be possible to engineer specific orselective activity. These more active and durablecatalysts could find early application in cleaning upwaste streams. This will be particularly beneficial if itreduces the demand for platinum-group metals, whoseuse in standard catalytic units is starting to emerge as aproblem, given the limited availability of these metals.

c) Longer-term applications

Carbon nanotube composites41 CNTs have exceptional mechanical properties,particularly high tensile strength and light weight. Anobvious area of application would be in nanotube-reinforced composites, with performance beyondcurrent carbon-fibre composites. One current limit tothe introduction of CNTs in composites is the problem ofstructuring the tangle of nanotubes in a well-orderedmanner so that use can be made of their strength.Another challenge is generating strong bondingbetween CNTs and the matrix, to give good overallcomposite performance and retention during wear orerosion of composites. The surfaces of CNTs are smoothand relatively unreactive, and so tend to slip through thematrix when it is stressed. One approach that is beingexplored to prevent this slippage is the attachment ofchemical side-groups to CNTs, effectively to form‘anchors’. Another limiting factor is the cost ofproduction of CNTs. However, the potential benefits ofsuch light, high strength material in numerousapplications for transportation are such that significantfurther research is likely.

Lubricants42 Nanospheres of inorganic materials could be usedas lubricants, in essence by acting as nanosized ‘ballbearings’. The controlled shape is claimed to make themmore durable than conventional solid lubricants andwear additives. Whether the increased financial andresource cost of producing them is offset by the longerservice life of lubricants and parts remains to beinvestigated (along the lines of the methodologyoutlined in section 4.5). It is also claimed that thesenanoparticles reduce friction between metal surfaces,particularly at high normal loads. If so, they should findtheir first applications in high-performance engines anddrivers; this could include the energy sector as well astransport. There is a further claim that this type oflubricant is effective even if the metal surfaces are nothighly smooth. Again, the benefits of reduced cost andresource input for machining must be compared againstproduction of nanolubricants. In all these applications,the particles would be dispersed in a conventional liquidlubricant; design of the lubricant system must thereforeinclude measures to contain and manage waste.

Magnetic materials43 It has been shown that magnets made ofnanocrystalline yttrium–samarium–cobalt grains possess

unusual magnetic properties due to their extremelylarge grain interface area (high coercivity can beobtained because magnetization flips cannot easilypropagate past the grain boundaries). This could lead toapplications in motors, analytical instruments likemagnetic resonance imaging (MRI), used widely inhospitals, and microsensors. Overall magnetisation,however, is currently limited by the ability to align thegrains’ direction of magnetisation.

44 Nanoscale-fabricated magnetic materials also haveapplications in data storage. Devices such as computerhard disks depend on the ability to magnetize smallareas of a spinning disk to record information. If thearea required to record one piece of information can beshrunk in the nanoscale (and can be written and readreliably), the storage capacity of the disk can beimproved dramatically. In the future, the devices oncomputer chips which currently operate using flows ofelectrons could use the magnetic properties of theseelectrons, called spin, with numerous advantages.Recent advances in novel magnetic materials and theirnanofabrication are encouraging in this respect.

Medical implants45 Current medical implants, such as orthopaedicimplants and heart valves, are made of titanium andstainless steel alloys, primarily because they are bio-compatible. Unfortunately, in some cases these metalalloys may wear out within the lifetime of the patient.Nanocrystalline zirconium oxide (zirconia) is hard, wear-resistant, bio-corrosion resistant and bio-compatible. Ittherefore presents an attractive alternative material forimplants. It and other nanoceramics can also be madeas strong, light aerogels by sol–gel techniques.Nanocrystalline silicon carbide is a candidate material forartificial heart valves primarily because of its low weight,high strength and inertness.

Machinable ceramics46 Ceramics are hard, brittle and difficult to machine.However, with a reduction in grain size to thenanoscale, ceramic ductility can be increased. Zirconia,normally a hard, brittle ceramic, has even been renderedsuperplastic (for example, able to be deformed up to300% of its original length). Nanocrystalline ceramics,such as silicon nitride and silicon carbide, have beenused in such automotive applications as high-strengthsprings, ball bearings and valve lifters, because they canbe easily formed and machined, as well as exhibitingexcellent chemical and high-temperature properties.They are also used as components in high-temperaturefurnaces. Nanocrystalline ceramics can be pressed intocomplex net shapes and sintered at significantly lowertemperatures than conventional ceramics.

Water purification47 Nano-engineered membranes could potentially leadto more energy-efficient water purification processes,notably in desalination by reverse osmosis. Again, these

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applications would represent incremental improvementsin technologies that are already available. They woulduse fixed nanoparticles, and are therefore distinct fromapplications that propose to use free nanoparticles.

Military battle suits48 Enhanced nanomaterials form the basis of a state-of-the-art ‘battle suit’ that is being developed by theInstitute of Soldier Nanotechnologies at MassachusettsInstitute of Technology, USA (MIT 2004). A short-termdevelopment is likely to be energy-absorbing materialsthat will withstand blast waves; longer-term are thosethat incorporate sensors to detect or respond tochemical and biological weapons (for example,responsive nanopores that ‘close’ upon detection of abiological agent). There is speculation thatdevelopments could include materials which monitorphysiology while a soldier is still on the battlefield, anduniforms with potential medical applications, such assplints for broken bones. In section 6.7 we consider thepossible social implications of the exploitation ofnanotechnologies for military purposes.

3.3 Nanometrology

3.3.1 Introduction to nanometrology

49 The science of measurement at the nanoscale iscalled nanometrology. Its application underpins all ofnanoscience and nanotechnologies. The ability tomeasure and characterise materials (determine theirsize, shape and physical properties) at the nanoscale isvital if nanomaterials and devices are to be produced toa high degree of accuracy and reliability and theapplications of nanotechnologies are to be realised.Nanometrology includes length or size measurements(where dimensions are typically given in nanometres andthe measurement uncertainty is often less than 1nm) aswell as measurement of force, mass, electrical and otherproperties. As techniques for making thesemeasurements advance, so too does the understandingof nanoscale behaviour and therefore the possibility ofimproving materials, industrial processes and reliabilityof manufacture. The instruments for making suchmeasurements are many and varied; a description ofsome key instruments is given in Box 3.1. Thecharacterisation of materials, particularly in theindustrial context, is discussed further in Chapter 4.

50 As with all measurement, nanometrology isessentially an enabling technology. Nanotechnologies,however defined, cannot progress independently ofprogress in nanometrology. Apart from their directinfluence on scientific research and its application, thesolutions developed for nanometrology problems canoften be exploited elsewhere. For example, the conceptof the AFM, a key nanometrology tool, has had a directinfluence on lithographic processes and techniques formolecular manipulation. Conversely, it is likely that

continuing research into nanodevices will suggest newmeasurement methods.

51 Making measurements with nanoscale precisionposes several major difficulties. Environmentalfluctuations such as vibration or temperature changehave a large effect at the nanoscale. For example, anyexternal change to the large machines used inmanufacturing microelectronics components will affectthe creation of nanoscale features and their cruciallyimportant alignment to each other. The ability tomeasure these influences, and thereafter to minimisethem, is therefore vital.

52 Currently, instruments are available that can makesufficiently precise measurements to support laboratoryresearch. There are a number of sensor technologiesand instruments with nanometre, or better, sensitivityfor measuring length that repeat well if used carefully,including the scanning probe and electron microscopesand some optical devices (see Box 3.1). However,universal measurement standards have not yet beenestablished. Data published recently from thePhysikalisch-Technische Bundesanstalt in Germany (Breilet al 2002) shows that even apparently sophisticatedusers of atomic force microscopes can produce largevariations in their measurements of the same artefacts.Without agreed standards, tools or machines cannot becalibrated at the nanometre scale. It is therefore not yetpossible for laboratories and manufacturing plants toexchange or compare data or physical components.Also, health and safety standards cannot be set for legalrequirements. Nanoparticle characterization for size, sizedistribution and shape is also lacking formal methods.

53 Evidence presented at our industry workshophighlighted that good comparative metrology is provingdifficult to develop. There is no particular difficulty withworking at the nanoscale within a single laboratory ororganization in the sense artifacts (either universal or in-house ‘gold standards’ such as the spacing of the siliconlattice) can be used to calibrate instruments so thatthere is self-consistency across a set of measurements.In doing this there must naturally be levels of protectionagainst vibration, thermal changes, etc that arebecoming increasingly stringent. However, thedetermination of absolute measurements of length atthe nanometer scale and below is very difficult andexpensive.

3.3.2 Length measurement

54 Although there is not currently an internationalstandard that can be applied to them, calibrationartefacts are becoming available for AFMs for lengthmeasurement calibration in each of the threedimensions. Such artefacts can also be used for tipcharacterization, as the exact shape of the fine tipwhich scans across the surface can strongly influencelength measurements, particularly when the tip

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becomes blunt. The National Physical Laboratory (NPL)in the UK has a considerable reputation in formalmetrology and has done much to develop measurementcapability as well as to take responsibility for the UK’snational standards. It also has excellent realisations ofthe metre, mainly through optical and x-rayinterferometry, that can calibrate transfer standards withuncertainties of the order of nanometres when workingwith sufficiently large wave-fronts. However,comparative methods (akin to the interferometricmeasurement of optical lenses and mirrors) becomeineffective when working with very small objectscomparable to the wavelength of the photons beingused. Hence, it is not yet possible to accuratelydetermine dimensions or shape in all axes. Manysurface characterization methods (especially for theelectronics industries) directly exploit comparison via x-ray (occasionally optical) reflection or diffraction. It islikely that the practice of length metrology would beimproved through better, more easily-used calibrationsystems and improved instrument design, relative to thecurrent commercial versions. Undoubtedly, bettereducation in best practice for nanometrology would alsopartly address this issue.

3.3.3 Force measurement

55 Along with length measurement, forcemeasurement (measured in Newtons (N)) is likely tobecome an important area of nanometrology. Thecontrol of probe stiffness and geometry will need toimprove if truly quantitative measurements of surfacemechanical properties can be made, particularly whenmeasuring biological and other soft materials. There isalso likely to be an increasing need to accuratelymeasure the elasticity of protein and nucleotidemolecules, to determine bond strength and otherproperties of the molecules. Currently, there is a largecapability gap in this field. There is a large, and growing,need for force characterisation in the pico- tomicronewton (10–12–10–6N) range. Currently, no fullysatisfactory techniques are available either for secondarystandards or transfer artefacts, although a few researchprojects are in progress (NPL and the National Institutefor Standards and Technology (NIST), USA, are bothlooking at methods based on electrostatic forces).Several groups, mainly within or sponsored by nationallaboratories (such as NPL and Warwick University in theUK, and NIST in the USA), are investigating systems thatrelate force to electrical properties and so to quantumstandards. However, so far all of them remainexperimental and a great deal more work is urgentlyneeded into fundamental and transfer standards forforces much smaller than millinewtons. Unlike lengthmeasurement, there is also a lack of readily availableand applicable force or mass instrumentation withsensitivity adequate for engineering on the nanometrescale. AFM cantilevers have nanonewton forcesensitivity, but their calibration tends to be throughindirect calculation from their dimensions, and batch-to-

batch repeatability may be poor. Some nano-indentationinstruments for hardness measurement use micro-electromechanical systems (MEMS), with broadly similarquestions over traceability. Thus there is urgent need forresearch into basic laboratory and industrial nanoforceinstrumentation alongside that for standards.

3.3.4 Measurement of single molecules

56 In the longer term, development in measurement atthe scale of the single molecule is expected.Measurements of single organic molecules and ofstructures such as single-wall nanotubes are alreadymade, providing the molecules can be anchored to asubstrate. Electron microscope and AFM/STMdeterminations of shape are relatively routine in manyresearch laboratories. Increasingly, there is interest inmolecule stiffness, in effect producing a tensile testcurve in which jumps indicate the breaking and byinference the location of various types of bond in foldedproteins and nucleotides. AFM manufacturers arestarting to offer options that can do this without theneed for the skills of a large research team.

3.3.5 Applications

57 Metrology forms the basis of the semiconductorindustry and as such is enormously advanced. TheInternational Technology Roadmap for Semiconductors(ITRS) roadmap (see also section 3.4) highlights a seriesof challenges for nanometrology if it is to keep pacewith the reduction in feature size of semiconductordevices. Shrinking feature sizes, tighter control of deviceelectrical parameters and new interconnect materialswill provide the main challenges for physical metrologymethods. To achieve desired device scaling, metrologytools must be capable of measurement of properties atatomic distances. Compounding these is the uncertainnature of the development of device design, making itdifficult to predict metrology needs in the long term andin particular the necessary metrology for manufacturingto ensure reliability. A major need is to integratemetrology data into the manufacturing process.

58 The developing capabilities of semiconductorprocessing, particularly the ever-reducing dimensionsthat can be defined using lithographic tools, are beingcombined with the techniques developed for MEMSdevice fabrication to enable the manufacture of electro-mechanical components with sub-100nmdimensions. The exploitation of these structures innano-electromechanical systems (NEMS) devices hasproduced some interesting and exciting developments inthe field of nanometrology. For example, Schwab et al(2000) have made a NEMS device that has enabled themeasurement of the quantum of thermal conductance.

59 Another group has made ultra-thin siliconcantilevers with attonewton (10–18N) sensitivity. Thesedevices have potential applications in the

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characterisation of single molecule properties and areexamples of how the field of NEMS is increasing thecapabilities of nanometrology.

60 The role of nanometrology and in particular theneed for the standardisation of measurement at thenanometre scale is explored further in section 8.4.3.There is a need to develop agreed standards that can beused to calibrate equipment that will be used by bothindustry and regulators. We believe that this can best beaddressed through existing programmes such as theDepartment of Trade and Industry (DTI) NationalMeasurement System Programme and should beundertaken in collaboration with industry.

We recommend that the DTI supports thestandardisation of measurement at the nanometrescale required by regulators and for quality controlin industry through the adequate funding ofinitiatives under its National Measurement SystemProgramme, and that it ensures that the UK is inthe forefront of any international initiatives forthe standardisation of measurement.

61 We are pleased to learn that initial steps in this areaare being undertaken by the British StandardsInstitution, as part of the European Committee forStandardisation Technical Board working group onnanotechnology.

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Box 3.1 Instruments used in nanometrology

a) Electron beam techniquesTransmission electron microscopy (TEM) is used to investigate the internal structure of micro- and nanostructures.It works by passing electrons through the sample and using magnetic lenses to focus the image of the structure,much like light is transmitted through materials in conventional light microscopes. Because the wavelength of theelectrons is much shorter than that of light, much higher spatial resolution is attainable for TEM images than fora light microscope. TEM can reveal the finest details of internal structure, in some cases individual atoms. Thesamples used for TEM must be very thin (usually less than 100nm), so that many electrons can be transmittedacross the specimen. However, some materials, such as nanotubes, nanocrystalline powders or small clusters, canbe directly analysed by deposition on a TEM grid with a carbon support film. TEM and high-resolutiontransmission electron microscopy (HRTEM) are among the most important tools used to image the internalstructure of a sample. Furthermore, if the HRTEM is adequately equipped, chemical analysis can be performed byexploiting the interactions of the electrons with the atoms in the sample.

The scanning electron microscope (SEM) uses many of the basic technology developed for the TEM to provideimages of surface features associated with a sample. Here, a beam of electrons is focused to a diameter spot ofapproximately 1nm in diameter on the surface of the specimen and scanned back and forth across the surface.The surface topography of a specimen is revealed either by the reflected (backscattered) electrons generated orby electrons ejected from the specimen as the incident electrons decelerate secondary electrons. A visual image,corresponding to the signal produced by the interaction between the beam spot and the specimen at each pointalong each scan line, is simultaneously built up on the face of a cathode ray tube similar to the way that atelevision picture is generated. The best spatial resolution currently achieved is of the order of 1nm.

b) Scanning probe techniquesScanning probe microscopy (SPM) uses the interaction between a sharp tip and a surface to obtain an image. Thesharp tip is held very close to the surface to be examined and is scanned back-and-forth. The scanning tunnellingmicroscope (STM) was invented in 1981 by Gerd Binnig and Heinrich Rohrer, who went on to collect the NobelPrize for Physics in 1986. Here, a sharp conducting tip is held sufficiently close to a surface (typically about0.5nm) that electrons can ‘tunnel’ across the gap. The method provides surface structural and electronicinformation with atomic resolution. The invention of the STM led directly to the development of other ‘scanningprobe’ microscopes, such as the atomic force microscope. The atomic force microscope (AFM) uses a sharp tip onthe end of a flexible beam or cantilever. As the tip is scanned across the sample, the displacement of the end ofthe cantilever is measured, usually a laser beam. Unlike the STM, where the sample has to be conductive, an AFMcan image insulating materials simply because the signal corresponds to the force between the tip and sample,which reflects the topography being scanned across.

There are several different modes for AFM. In contact mode, the tip touches the sample; this is simple toimplement but can lead to sample damage from the dragging tip on soft materials. Tapping mode mitigates thisdifficulty: the tip is oscillated and only touches intermittently, so that dragging during scanning is minimized.Non-contact mode is where the tip senses only the attractive forces with the surface, and causes no damage. It istechnically more difficult to implement since these forces are weak compared with contact forces. In non-contactmode at larger tip-surface separation, the imaging resolution is poor, and the technique not often used.However, at small separation, which requires specialized AFM apparatus to maintain, true atomic resolution canbe achieved in non-contact mode AFM.

c) Optical tweezers (single beam gradient trap)Optical tweezers use a single laser beam (focused by a high-quality microscope objective) to a spot on a specimenplane. The radiation pressure and gradient forces from the spot creates an ‘optical trap’ which is able to hold aparticle at its centre. Small interatomic forces and displacements can then be measured. Samples that cananalysed range from single atoms and micrometre-sized spheres to strands of DNA and living cells. Opticaltweezers are now a standard method of manipulation and measurement. Numerous traps can be usedsimultaneously with other optical techniques, such as laser scalpels, which can cut the particle being studied.

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3.4 Electronics, optoelectronics and informa-tion and communication technology (ICT)

3.4.1 Introduction to electronics, optoelectronics and ICT

62 The past 30 years has seen a revolution ininformation technology (IT) that has impacted the livesof many people around the world. At the heart of thisrevolution is the desire to share information, whetherthe printed word, images or sounds. This requires atechnology that can absorb and process information onone side of the planet and deliver it almostinstantaneously to the other in a form that is immediatelyaccessible. Such a technology places enormous pressureon advances in processing and storing information, andon transmitting it and converting it from and to a humanreadable form. It also increasingly requires secureencryption of information so that access to informationcan ultimately be restricted to particular individuals.

63 The market size of the IT industry is currently around$1000 billion, the order of $150 for every human beingon the planet, with an expectation that it will reach$3000 billion in 2020. In no other industry sector is thetrend for miniaturisation so apparent. This is perhapsmost obvious by charting the number of transistors, thebuilding blocks of computer chips, over the past30years. In 1971 there were just 2300 transistors onIntel’s 4004, their first computer chip, with a clockspeed (a measure of how fast the chip could operate) of0.8 million cycles per second. By 2003 the Intel Xeonprocessor had 108 million transistors operating at clockspeeds in excess of 3,000 million cycles per second.Remarkably, the physical size of the computer chip hasremained virtually unchanged over this time; it is thetransistor and all the circuitry associated with it that hasshrunk dramatically. The increase in the number oftransistors on a chip coupled with increased speed havefuelled the economics of the IT industry; in 1971 thefabrication of a single transistor cost about 10 cents; itis currently less than one-thousandth of a cent. Thisevolutionary progression of technology is charted andanticipated in the ITRS roadmap, a worldwideconsensus-based document that predicts the maintrends in the semiconductor industry 15 years into thefuture (ITRS 2003) The roadmap which defines in detailall elements of technology that have to be realised foreach step change improvement in manufacturingprocess. This roadmap is used by all industries that aredirectly or indirectly involved in the manufacture ofsilicon chips. It identifies material, architecture,metrology and process challenges as well as addressingenvironmental and heath issues in manufacturing.

3.4.2 Nanoscience in this area

64 Nanoscience research in ICT shares many of the samegoals as for other applications of nanotechnologies: animproved understanding of nanoscale properties of

materials and devices, advances in fabrication andprocess technology to satisfy increasingly stringentdimensional tolerances, and exploration of alternativetechnologies that may offer economic or performancebenefit. There is no doubt that the ICT sector haseffectively driven a large proportion of nanoscience.Indeed, the first use of the word nanotechnology was inrelation to ultra thin layers of relevance to the then up-and-coming semiconductor industry. Since then, theresearch into all aspects of semiconductor devicefabrication, from fundamental physics to processtechnology, has dominated the nanoscience landscapeand will continue so to do. Decreasing device scales willadd further impetus to the truly nanoscalar aspects ofthis global research activity. The ICT sector is, and forhistorical and economic reasons is likely to remain,heavily silicon-based for the foreseeable future.However, the end of the ITRS roadmap, currently set at2018 (commonly referred to as the end of Moore’s Law)has prompted intensive research into alternative orhybrid technologies for electronics such as conductingpolymers, which are discussed further below.

3.4.3 Current applications

Computer chips65 The dominant role of miniaturisation in the evolutionof the computer chip is reflected in the fact that the ITRSroadmap defines a manufacturing process standard – atechnology node – in terms of a length. The current130 nm technology node that produces the Intel Xeonprocessor defines the size of the DRAM (dynamicrandom access memory) half-pitch (half the distancebetween two adjacent metal wires in a memory cell).This is turn places a requirement on the lithography,process technology and metrology required tomanufacture a working device to this tolerance. As acomparison, the 1971 Intel 4004 chip used 10,000 nmtechnology; the chips of 2007 and 2013 will require65nm and 32nm technology, respectively. In the broadestsense, computer chips in current manufacture aretherefore already using nanotechnologies and havebeen so doing for over 20years. Furthermore, it is notsimply the DRAM half-pitch that is on the nanometrescale. All the technology that goes into the research,metrology and production of chips has been working, insome cases, at the sub-nanometre atomic level. Thevariety of tools that support the IT industry includescomputer modelling of advanced devices and materialsatom by atom, microscopies that can image single atoms,metrologies that can define the absolute position of asingle atomic defect over a 30cm diameter wafer (thesubstrate used for computer chips), thin-film growthprocesses that can produce layers of material with atomicprecision, and lithographies that can ‘write’ features,such as the DRAM cell, with an accuracy of sub-10nm.

Information storage66. A technology that has necessarily developed intandem with IT is that of memory for data storage. This

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can be divided into two quite different types: solid-statememory such as DRAM that a processor chip would useor flash memory for storing images in a digital camera;and disk-based memory such as the magnetic harddrives as found in all computers. Solid-state memoryessentially uses the same processes and technology asthe computer chip, with very similar design rules and asimilar emphasis on packing more memory into a givenarea to increase total memory per device. Thedevelopment of the hard disk drive, however, has takena quite different route in evolution as it is based onreading and writing information magnetically to aspinning disk. It is therefore primarily mechanical, ormore strictly electro-mechanical, and presents quitedifferent technical challenges. Once again, however, theimportance of length scales is paramount as the idealdisk drive is one that has the minimal physical size witha massive ability to store data. This is reflected in theevolution of the disk drive over the past 50years. Thefirst magnetic hard drive was developed by IBM in 1956and required fifty 24 inch disks to store five megabytes(million bytes) of data. In 1999 IBM introduced a73gigabyte (thousand million bytes) drive that could fitinside a personal computer; that is, over 14,000 timesthe available data storage in a device less than one-thousandth the size of the 1956 drive. Although theindividual bits of magnetic information that are writtenonto the disk drive to give it the high-density storageare currently smaller than 100nm, the constraintsrelated to this nanotechnology on other aspects of thedrive require fabrication of components with evengreater precision. The importance of thisnanotechnology in the related compact disk (CD) anddigital versatile disk (DVD) drives that are nowcommonplace is equally ubiquitous.

Optoelectronics67 The other crucial element of the IT revolution,optoelectronics, relates to devices that rely onconverting electrical signals to and from light for datatransmission, for displays for optical-based sensing and,in the future, for optical-based computing. Technologyin this sector is strongly associated with those describedabove, and relies substantially on the tools developedthere. Although some optoelectronic devices do notdepend so critically on miniaturisation as computerchips do, there is nevertheless a similar trend towardsminiaturisation, with some existing components, such asquantum-well lasers and liquid crystal displays, requiringnanometre precision in their fabrication.

3.4.4 Applications anticipated in the future

68 The future development of hardware for the ITindustry can be conveniently separated into two paths:a path that is following the well-established ITRSroadmap (which projects out to 2018); and a path thatexplores alternative technologies and materials that maysupersede the roadmap.

69 For the roadmap, miniaturisation remains a keydriving force, so that a 22nm technology node isenvisaged for manufacture in 2016. Having set thistechnology target, it is possible to anticipate all thechallenges associated with realising it. Such challengesare detailed extensively in the roadmap but includeenhancing performance by introducing new materialssuch as low dielectrics and higher-conductivityinterconnects (wiring), developing lithographies capableof fabricating structures in the sub-50nm range, andintegrating advanced metrology tools into themanufacturing process capable of detecting and sizingdefects down to the nanometre size. As such,nanoscience and nanotechnologies will continue tohave a pivotal role in developing new generations ofchips. Related technology such as flash memory willevolve in a similar fashion, with the aim of maximisingmemory capacity in the smallest possible device.

70 Hard disk technologies, although not explicitly partof the ITRS roadmap, will continue to increase in memorydensity. However, there are prospects for some stepchanges in technology that may significantly change thedata storage industry. One obvious potential trend is forsolid-state memory to replace disk-based memory. Thisis already obvious in, for example, personal musicplayers where, as solid-state memory increases indensity, hard-disk-based storage is competing with thejog-proof solid-state players. It is likely that the harddisk, whether magnetic or optical, will still be the choicefor large volume data storage for the foreseeable future,especially as the bit size shrinks even further. This is anactive area of nanoscience research.

71 Optoelectronics, although not as dependent uponlength-scale tolerances as computer chips and datastorage, will nevertheless have challenges of its own.Integration of optical components into silicon deviceshas started and can be expected to evolve further. Someof the challenges where nanotechnologies will have animpact will be in the area of photonic band-gapmaterials, where the propagation of light through adevice can be controlled with the aim of computingwith light. Photonic crystals, fabricated either through alithographic process or through a self-assemblytechnique, confine light into precisely controlledpathways in a device structure so that both transmissionand functionality can be combined into a singlestructure. A typical photonic crystal would consist of anarray of holes in a dielectric material, fabricated withsub-10nm accuracy, so that the periodicity of the holesdetermines the ability of the material to transmit thelight at any given wavelength. The development ofphotonic crystals could mean that optical integratedcircuits are shrunk further, making a significant impactin areas such as communications and optical computing.

72 Quantum computing and quantum cryptographywill also benefit from advances in optoelectronics. Bothtechnologies rely on the fact that discrete energy

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(quantum) levels increasingly dominate as electromagneticenergy is confined into smaller and smaller structures.Assuming that the considerable technological challengesof making nanostructures from complex materials canbe solved, in some cases by designing at the level of thesingle atom, then on a 10year time-scale quantumcryptography (a much more secure encryptiontechnology) will replace current encryption methods. Ona similar time-scale, quantum computing will start toprovide solutions to complex problems that are difficultor impossible to solve by conventional computing.

73 Once controlling where, how and when lightinteracts is possible by the advances in technology alludedto above, there is the potential for developing new typesof optical spectroscopy at the level of the single molecule,assembling nanostructures by arrays of optical tweezersplacing objects into patterns on surfaces, new opticallithographic methods for fabricating computer chips, andoptical devices that act as biosensors with detection ofsingle molecules. The last type of sensor, able to detectthe presence of a single molecule in, say, a drop of blood,represents one of the greatest challenges fornanotechnologies. Not only does it require precision inmanufacture, but it also requires a unique mixture ofelectronics, optics, chemistry, biochemistry and medicineto make devices that can be used routinely, cheaply andreliably to monitor the state of human health. Anexample of this is in point-of-care health screening wherea single drop of blood placed on a sensor chip would bealmost instantaneously analysed to provide data to aid adiagnosis. This will require the processing power of asilicon chip with biochemical sensitivity to identify manyblood components. This type of monitoring could alsobegin to be incorporated within the body to provideconstant monitoring of health, such as in the control ofdiabetes or in critical care. There are many otherpotential applications of such devices in medicine, makingthis an area of increasing investment.

74 Alternative, ‘off-roadmap’ technology will have asimilar reliance on nanoscience and nanotechnologies asthat of the IT sector described above, but with far greaterfreedom to explore materials and architectures that mayhave little resemblance to existing technology. Plastic-based electronics is an example of an alternativetechnology. It does not directly compete with silicon-based devices but, because of its vastly cheaperfabrication, offers a far cheaper alternative. Forinexpensive electronic and optoelectronic applicationswhere speed and high memory density are less important,such as smart cards, plastic offers a new approach tobuilding electronics. Plastic-based electronics is alreadymoving into the commercial sector with potential forconsiderable growth. Similarly, the use of single moleculesas functional elements in future circuits will continue tobe an important element of nanoscience where the sizeof the molecule, typically less than 1nm, offers theultimate in miniaturisation. In fact, the goal of shrinkingfunction down to single molecules and atoms, foreseen

by Richard Feynman in 1959, is the only way to gobeyond the currently foreseen evolutionary limit of theITRS roadmap; conventional silicon transistors have a sizelimit of the order of tens of nanometres. Nanoscience isstill pursuing the concept of storing and processinginformation at the atomic scale with the hope of, forexample, quantum computing and atomic memorywhere each bit of data is stored on a single atom.

Sensors75 Nanotechnologies play several important roles indeveloping sensor technology. First, the ideal sensor willbe minimally invasive and therefore as small as possible.This includes the power supply, the sensing action,whereby the detected property is converted into anelectrical signal, and the transmission of the sensingsignal to a remote detector. Combining these actions intoa device that is smaller than 1mm2 will certainly requirenanofabrication techniques, similar to those employed bythe IT industry. The second role for nanotechnologies willbe in designing the sensing element to be as specific andaccurate as possible; as the sensor dimension decreasesthe area of the sensor available to effect detection willalso decrease, making increasing demands on sensitivity.In the limit of, say, chemical detection this may requiredetection at the single molecule level; close to the bottomend of the nanotechnology length scale and a significanttechnical challenge.

76 Nanotechnologies are therefore expected to enablethe production of smaller, cheaper sensors with increasingselectivity, which can be used in a wide range ofapplications. These include monitoring the quality ofdrinking water, measuring mechanical stresses in buildingsor vehicles to monitor for structural damage, detectingand tracking pollutants in the environment, checking foodfor edibility, or continuously monitoring health.Developments could also be used to achieve greatersafety, security, and individualised healthcare, and couldoffer advantages to business (for example in tracking andother monitoring of materials and products). However,there are concerns that the same devices that are used todeliver these benefits might also be used in ways that limitprivacy of groups or individuals; these are consideredfurther in section 6.4. Other potential applications varyfrom monitoring the state and performance of productsand materials to give early warning of the need for repairor replacement to enhancing human capabilities byextending physical performance.

3.5 Bio-nanotechnology and nanomedicine

3.5.1 Introduction to bio-nanotechnology andnanomedicine

77 Without doubt the most complex and highlyfunctional nanoscale machines we know are thenaturally occurring molecular assemblies that regulateand control biological systems. Proteins, for example,

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are molecular structures that possess highly specificfunctions and participate in virtually all biologicalsensory, metabolic, information and molecular transportprocesses. The volume of a single molecule bio-nanodevice such as a protein is between one-millionthand one-billionth of the volume of an individual cell. Inthis respect the biological world contains many of thenanoscale devices and machines that nanotechnologistsmight wish to emulate.

78 Bio-nanotechnology is concerned with molecular-scale properties and applications of biologicalnanostructures and as such it sits at the interfacebetween the chemical, biological and the physicalsciences. It does not concern the large-scale productionof biological material such as proteins or the specificgenetic modification of plants, organisms or animals togive enhanced properties. By using nanofabricationtechniques and processes of molecular self-assembly,bio-nanotechnology allows the production of materialsand devices including tissue and cellular engineeringscaffolds, molecular motors, and biomolecules forsensor, drug delivery and mechanical applications. Bio-nanotechnology can be used in medicine to provide asystematic, as well as a screening, approach to drugdiscovery, to enhance both diagnostic and therapeutictechniques and to image at the cellular and sub-cellularlevels, at a much higher resolution than that ofmagnetic resonance imaging (MRI).

3.5.2 Nanoscience in this area

79 The primary aim of much current research is to obtaina detailed understanding of basic biochemical andbiophysical mechanisms at the level of individualmolecules. This knowledge will allow the design rules ofnaturally occurring molecular machines to be determined,which may lead to new technological applications. As wesaw in section 3.3, several tools have developed in recentyears, such as SPM, that allow the direct observation ofthe behaviour of single molecules within biologicalsystems. Examples range from the relatively large (45nm)rotary molecular motors that power bacterial flagella‘propellers’ to the tiny enzymes such as ATP-synthase(9nm) that catalyse energy conversion in biologicalprocesses. The intricate sequence of changes in molecularstructure that forms the basis of such biomolecularmachines can now be measured directly by using AFMand ‘optical tweezers’. The recent development of high-speed AFM has enabled real-time molecular movementwithin a molecular motor to be observed directly. Futurebio-nanotechnology and nanomedicine devices mayexploit many classes of functional biological materials.One particular group of proteins that is attractingattention are the membrane proteins; these are anotherclass of protein-based machine that regulate manyphysiological processes. They include ion channels thatenable rapid yet selective flux of ions across the cellmembrane, hormone receptors that behave as moleculartriggers, and photoreceptors that switch between

different conformational states by the absorption of asingle photon of light, the process that is the basis ofvision and photosynthesis. That approximately one-quarter of all genes code for membrane proteins providesevidence of their immense biological importance; it isestimated that they will be the target of up to 80% of allnew drugs. Single molecule techniques for bothobservation and manipulation are now being usedroutinely to study the selectivity and gating mechanisms ofion channels, and their response to drugs.

3.5.3 Current and future applications

80 Bio-nanotechnology is regarded by many experts asa longer-term prospect: much fundamental science mustfirst be investigated, and many applications, especially inthe medical field, will by necessity have to undergo stricttesting and validation procedures. The time-scale forsuch applications is 10years and beyond. In the shorterterm it may be possible to use proteins, DNA and otherbio-polymers directly in nanoelectronics and biosensorapplications, but factors such as biocompatibility androbustness may prove to be serious obstacles.Alternatively, bio-mimetic structures may be devised thatare based on naturally occurring machines: examplesinclude catenanes and rotaxanes, compounds thatbehave as rotary or linear molecular motors, respectively.

81 Applications in the field of medicine are especiallypromising. Areas such as disease diagnosis, drugdelivery and molecular imaging are being intensivelyresearched. Medical-related products containingnanoparticles are currently on the market in the USA.Examples that exploit the known antimicrobialproperties of silver include wound dressings containingnanocrystalline silver, which release ionic silver over asustained period of time to provide a claimed extensiveantimicrobial spectrum of 150 different pathogens.

a) Array technologies

82 The enormously powerful array technologies, whichuse relatively large biological samples at the micrometrescale, are continuously being enhanced for sensitivity,size and data analysis. The original DNA chip approach,which carries an array of DNA molecules on an inertcarrier, is now routinely used in gene and proteinanalysis. The push towards higher resolution and smallersample volume makes this an emerging nanotechnology.Lab-on-a-chip technologies, which are used for sensingand supporting disease diagnosis, are also currently inthe micrometre range, but progress in nanofluidicsystems will potentially lead to integrated nanoscalesystems becoming available. These could have a rangeof applications, for example in improved devices fordetection of biological and chemical agents in the field(Royal Society 2004a).

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b) Electronics and information and communicationtechnology

83 One of the objectives of bio-nanotechnologyresearch is to use the highly specialised functionality ofproteins in devices such as molecular sensors. One ofthe greatest challenges is to understand thefundamental electronic properties of such moleculesand the mechanisms by which electronic charge istransferred between them and metals, semiconductorsand novel nanoelectronic components such as CNTs.Progress in this area could allow these ‘smart’ moleculesto be integrated into devices and networks for specificor indeed ICT applications: the realisation of a protein-based transistor is a major scientific challenge. DNAitself may turn out to be a useful electronic material,although the weight of experimental evidence indicatesthat it is not a good electrical conductor; however, usedas a template, gold or silver ‘coated’ DNA nanowirescan be produced, and integrated circuits using DNAinterconnects have already been realised which use theinformation coded in the DNA.

84 Thin films and crystals of the membrane proteinbacteriorhodopsin have already been demonstrated tohave potential photonics applications such as opticallyaddressable spatial light modulators, holographic

memories and sensors. The photosynthetic reactioncentre in this protein, which is only 5nm in size, behavesas a nanometre diode and so it may be useful in singlemolecule optoelectronic devices. For example, itsintegration with electrically conducting CNTs andnanometre electrodes could lead to logic devices,transducers, photovoltaic cells, memories and sensors.

c) Self-assembly

85 The top-down approach to nanofabrication has theadvantage that almost any pre-determined structure canbe produced. However, much attention is now beingfocused on processes that involve some degree ofmolecular self-assembly, and in this respect biologicalmaterials have remarkable advantages over inorganicmaterials in the diversity of self-assembled structuresthat they can produce. Evolution in the natural worldhas produced an astonishing variety of biomoleculardevices, and compared with conventional technologies,many natural molecular devices display enormousfunctionality. Among the most outstanding examples ofsynthetic structures now being fabricated are DNA-based geometrical structures (including artificial crystals)and functioning DNA-based nanomachines (andexample of which can be seen in Figure 3.2).

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Figure 3.2 DNA nanomachine (a) A simple device composed of three short single strands of DNA can be made tooperate as a tweezer that opens and closes on the addition of another strand. The base sequences are chosen tomake parts of A and B and parts of A and C complementary with each other so that double strands form; thisproduces the tweezer that is initially in the open state. (b) The addition of a strand F that is complementary to theunpaired sections of B and C causes the tweezer to close when pairing occurs. The tweezer opens again when astrand Fbar is added that is complementary to F: Fbar pairs with F to form a doubled stranded DNA by-product.The energy source for the machine is the hybridisation energy of the FFbar by-product. (Yurke et al 2000).

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86 Hybrid nanomachines, composed of biologicalmaterial with inorganic components, have beensuggested as posing a threat if they are able to replicate.There are ongoing investigations into the application ofbiological machines that involve incorporation ortransport of non-biological components or material, butthese are basic molecular constructions compared witheven a simple cell. Although they have the ability tomove when chemical fuel is added, the working groupfound no convincing evidence that self-replication, acharacteristic of a living organism, is possible.

d) Drug delivery

87 There is enormous potential for nanotechnology tobe applied to gene and drug delivery. The vehicle mightbe a functionalised nanoparticle capable of targetingspecific diseased cells, which contains both therapeuticagents that are released into the cell and an on-boardsensor that regulates the release. Different stages of thisapproach have already been demonstrated, but thecombined targeting and controlled release have yet to beaccomplished. In this event the way will be opened up forinitial trials, and the eventual approval of such techniqueswill be fully regulated as for any new pharmaceutical.

88 A related approach already in use is that of polymer-based drug therapies: they include polymeric drugs,

polymer–drug conjugates, polymer–protein conjugates,polymeric micelles to which the drug is covalently bound,and multi-component complexes being developed asnon-viral vectors for gene therapy. An illustration of hownanoparticles target cells for drug or gene delivery canbe seen in Figure 3.3. Many of these materials are nowundergoing clinical trials for a variety of disease states.Gene therapy, where the DNA has been packaged into ananometre-scale particle, holds much promise for thetreatment of genetic defects such as cystic fibrosis andimmune deficiencies. Gene therapy using viral vectorshas been successfully used to treat ten children withsevere combined immunodeficiencies. These are lifethreatening diseases for which there is no alternativetreatment. Unfortunately two of the childrensubsequently developed leukaemia leading to atemporary moratorium on all gene therapy trials in 2003.After intensive risk assessments most trials have nowresumed. Alternative non-viral approaches bio-nanotechnology approaches are being activelyresearched although none has reached clinical trials.Advantages of these approaches include the versatility ofsynthetic chemistry, which allows tailoring of molecularweight, addition of biomimetic features to the man-made construct and even the possibility to include bio-responsive elements. The safety implications ofnanoparticles in the body are discussed in section 5.3.

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Fig 3.3 An illustration of how nanoparticles target cells for drug or gene delivery. Liver cells (stained blue) sur-rounded by 200nm semiconductor nanoparticles that have been coated with the outermost protein (E2) of thehepatitis C virus (HCV) which is believed to be the main binding protein. The nanoparticle is the same size as thevirus and so it targets cells in the same way as the HCV. (Reproduced by permission James F Leary, University ofTexas Medical Branch).

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e) Drug discovery

89. Nanotechnology techniques offer the possibility ofstudying drug–receptor interactions at the singlemolecule level, for example by using optical tweezersand AFM, so that a more direct approach to drugdiscovery becomes feasible. This approach might alsoallow, for example, the discovery of disease at the singlecell level, long before physical symptoms aremanifested. This has been achieved by monitoringchanges in atomic forces or ion conductance of a singlereceptor or ion channel when a drug molecule attaches.However, the industrial process will require thedevelopment of large arrays of such instrumentsworking in parallel to create a high-throughputscreening capability.

f) Medical Imaging

90 Non-invasive imaging techniques have had a majorimpact in medicine over the past 25years or so. Thecurrent drive in developing techniques such asfunctional MRI is to enhance spatial resolution andcontrast agents. Nanotechnologies already afford thepossibility of intracellular imaging through attachmentof quantum dots or synthetic chromophores to selectedmolecules, for example proteins, or by the incorporationof naturally occurring fluorescent proteins which, withoptical techniques such as confocal microscopy andcorrelation imaging, allow intracellular biochemicalprocesses to be investigated directly.

g) Nanotechnologies and cancer treatment

91 In the USA the National Nanotechnology Initiativehas claimed that nanotechnology has potential in thetreatment of cancer. It has been stated that ‘It isconceivable that by 2015, our ability to detect and treattumors in their first year of occurrence might totallyeliminate suffering and death from cancer’ (Roco 2004).We have, however, seen no evidence to support thenotion that nanotechnologies will eliminate cancer inthe short- to medium term, and feel that such a claimdemonstrates an over-simplistic view of the detectionand treatment of cancer. Although it is reasonable to

hope that some measures based on nanotechnologiesmay make contributions to detection and treatment ofsome forms of cancer, other factors such as a greaterunderstanding of environmental causes of cancer, publichealth measures, and advances in surgical,pharmacological and radiological management areimportant in the reduction of incidence of and deathfrom cancer.

h) Implants and prosthetics

92 As discussed in section 3.2, some nanomaterialssuch as nanocrystalline ceramics have certain properties– such as hardness, wear resistance and biocompatibility– that may make them of use as implants in the longterm. The development of nanoelectronic systems withhigh detector densities and data processing capabilitymight allow the development of an artificial retina orcochlea. Important progress is already being made inthis area, but many issues must be resolved before theycan become viable treatments. Similarly, theintroduction of nanoelectronics will allow biologicalneural processing to be investigated at much enhancedspatial resolution. Neurons of rodents have already beengrown on nanofabricated surfaces to form elementaryneural networks in which electrical signalling can bemeasured. By sending and receiving electrical impulsesfrom the network, it might begin to be possible tounderstand how neurons create memory by theirresponses to different patterns of stimuli.

93 It is hoped that this research might help somevisually impaired people regain their sight, or thatmuscle function might be restored to sufferers ofParkinson’s disease. However, these developments raisepotential ethical concerns about human enhancementand the convergence of technologies, in particularwhether the availability of body alterations that enhancehuman performance might diminish the role of disabledpeople in society, and whether progress in informationprocessing and data storage technologies combinedwith developments in neurophysiology could lead to thepossibility of non-therapeutic enhancement of humanperformance. These concerns are explored in section 6.5.

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4.1 Introduction

1 In the previous chapter, we saw many examples ofnanoscience and some current and potentialapplications of nanotechnologies. Current industrialapplications of nanotechnologies are mainly in thecharacterisation of materials, the production ofchemicals and materials, precision manufacturing andICT. In general, these applications represent incrementalrather than truly disruptive advances; however, in thelonger term it is likely that many manufacturingprocesses will be influenced by nanotechnologies, justas they are today by ICT.

2 In this chapter we outline how nanotechnologiesare being realised in industry, focusing on the genericmethods of nanomaterial manufacture, production ratesand applications in some key industry areas. We indicatehow nanoscience and nanotechnologies might impacton industry in the longer term, and highlight some ofthe factors that will affect the commercialisation ofnanotechnologies. A detailed consideration of theseissues for the UK can be found in the Taylor report (DTI2002). Our aim, in particular, is to provide anappropriate background for Chapter 5, in which wediscuss the health, environmental and safety impacts ofnanotechnologies. We have focused disproportionatelyon the manufacture and use of nanoparticles andnanotubes, because they raise particular concerns, but itshould be noted that nanoparticles and nanotubes onlyaccount for a small fraction of the predicted globalmarket for nanotechnologies.

4.2 Characterisation

3 The characterisation of materials – thedetermination of their shape, size, distribution,mechanical and chemical properties – is an important

part of the industrial process. It serves two broadpurposes: as quality control, and as part of the researchand development of new processes, materials andproducts. Evidence taken during our industry workshopsuggested that many areas of industry did not considernanotechnologies to be new (for example, nanoscalestructures have been important to the catalyst industryfor over 100years). However, the industrialists believedthat a nanotechnology ‘breakthrough’ had occurred inthe tools used to observe and measure properties andprocesses at the nanoscale level. Sophisticated tools,such as the STM, AFM and TEM (see Box 3.1), enablesurface and interfacial characterisation of materials atthe nanoscale, allowing individual atoms to be observedand analysed. This is leading to greater understandingof the relationship between form and materialproperties, and enabling the control of processes at thenanoscale and the design materials with specificproperties. However, the commercialisation of suchadvanced functional materials requires that they can bemade in a predictable, reliable way, and in sufficientquantities. Until that is achieved production will belimited to academia and R&D departments withinindustry.

4.3 Fabrication techniques

4 There are a wide variety of techniques that arecapable of creating nanostructures with various degreesof quality, speed and cost. These manufacturingapproaches fall under two categories (first introduced inChapter 2): ‘bottom-up’, and ‘top-down’. In recentyears the limits of each approach, in terms of featuresize and quality that can be achieved, have started toconverge. A diagram illustrating some of the types ofmaterials and products that these two approaches areused for is shown below in Figure 4.1.

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4 Nanomanufacturing and the industrial application of nanotechnologies

Figure 4.1 The use of bottom-up and top-down techniques in manufacturing

Bottom-up Top-down

Chemical synthesis Self-assembly Positional assembly Lithography Cutting,Etching, Grinding

Particles Crystals Experimental atomic Electronic devices Precision engineeredMolecules Films,Tubes or molecular devices chip masks surfaces

Cosmetics, Displays Quantum High quality optical mirrorsFuel additives well lasers

Computer chipsMEMS

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Figure 4.2 The generic processes that are involved in the production of nanoparticles

Precursor Reaction Product

Solid Creation Liquid Transformation Separation

Liquid Vapour SolidGas Primary

Secondary Drying HarvestingGeneration Calcination

Chemistry

4.3.1 Bottom-up manufacturing

5 Bottom-up manufacturing involves the building ofstructures, atom-by-atom or molecule-by-molecule. Thewide variety of approaches towards achieving this goalcan be split into three categories: chemical synthesis,self-assembly, and positional assembly. As discussedbelow, positional assembly (with its many practicaldrawbacks as a manufacturing tool) is the onlytechnique in which single atoms or molecules can beplaced deliberately one-by-one. More typically, largenumbers of atoms, molecules or particles are used orcreated by chemical synthesis, and then arrangedthrough naturally occurring processes into a desiredstructure.

a) Chemical synthesis

6 Chemical synthesis is a method of producing rawmaterials, such as molecules or particles, which canthen be used either directly in products in their bulkdisordered form, or as the building blocks of moreadvanced ordered materials, produced using thetechniques outlined in sections (b) and (c) below.

7 A generic process by which nanoparticles may beproduced by chemical synthesis is shown in Figure 4.2.

8 The precursor phase is the starting point, and thematerial can be in any physical state (or multiphase) orspatial arrangement to other components. The first step isthe creation of a new phase or state where thenanoparticles either form or can be formed by a chemicalstep. In other words, the phase change itself could bringabout nanoparticle formation (rare but possible) althoughgenerally the circumstances are created wherebynanoparticles can be made, for example vaporisation of aprecursor mixture. Once in a state where nanoparticlescan be made, usually a chemical reaction of somedescription is performed to generate the desired material.A further phase transformation or even solid-statereaction may be necessary to produce the final product.

9 Potential exposure of the workforce to nanoparticlesis likely to be greatest when these materials are processed

in a gaseous environment; in such cases worker exposurewill need to be monitored closely. However, nanoparticleshave a tendency to agglomerate, and are therefore oftenmanufactured from a liquid phase as this enables surfaceenergies to be better controlled, reducing agglomeration.This also reduces the potential exposure level of workers.The expected health impacts of nanoparticles and theimplications for regulation in the workplace are discussedin sections 5.3 and 8.3, respectively. Processing andhandling ability is very important for nanomaterials:mixing nanoscale particles together before agglomeratingand (for example) sintering can generate wholly newcomplex nanophase materials which could not be madeby any other method. Most genuinely nanoscale andnanostructured materials, however, are still at thelaboratory scale of synthesis (kilograms per day scale ofoperation or even less).

10 Table 4.1 gives our estimates of current and futureproduction of nanomaterials. Metal oxides, such astitanium dioxide, zinc oxide, silicon dioxide, aluminiumoxide, zirconia and iron oxide, are currently the mostcommercially important nanoparticles. They are availableas dry powders or liquid suspensions. The quantitiescurrently used in the skincare market sectors (titaniumdioxide etc.) amount to 1,000–2,000 tonnes per annumworldwide, with the nanoscalar component materialsworth approximately $10 to $100,000 per tonne.Although the world market for nanoparticles is expectedto increase during the next few years, to provideperspective, it is worth noting that the global productionrate of all chemicals is around 400M tonnes per annum(European Commission 2001), and so chemicals innanoparticulate form account for only a tiny fraction ofthe total (around 0.01%) currently produced. Nanoscalarinorganic, metallic or semiconductor material often willhave multifunctionality, which enables it to be usedacross many industry sectors. Zinc oxide, for example, willhave more commercial use as an optoelectronic material(for displays or advanced solar and photovoltaic cells)where it will be fixed in the final product, than as aningredient for skincare products, where particles will befree.

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b) Self assembly

11 Self assembly is a bottom-up production techniquein which atoms or molecules arrange themselves intoordered nanoscale structures by physical or chemicalinteractions between the units (see Chapter 2). Theformation of salt crystals and snowflakes, with theirintricate structure, are examples of self-assemblyprocesses. Although self assembly has occurred innature for thousands of years, the use of self assemblyin industry is relatively new. There is an economic andenvironmental interest in processes through whichmaterials or product components essentially formthemselves, creating less waste and using less energy.However, current understanding extends only to thecreation of fairly rudimentary systems. Improvedunderstanding of thermodynamic and kinetic processesat the nanoscale, enabled through advances in thecharacterisation techniques described in section 4.2 andBox 3.1, and improved computer modelling, are

expected to aid the development of more complexsystems. One potential processing technique involvesthe use of an external force or field (for example,electric or magnetic) to accelerate the often slow self-assembly process, which is attractive in an industrialcontext. This is known as directed self assembly.

12 As we saw in section 3.2.3, CNTs are generatinginterest within industry because of their remarkableproperties. Potential applications include composites,conductive plastics, sensors, batteries and fuel cells.CNTs can be grown by several techniques, such as thelaser ablation of metal-doped graphite targets, carbonarc discharge, and the pyrolysis of hydrocarbons overmetal catalysts. However, because of a lack ofunderstanding of the growth mechanism, the selectiveand uniform production of CNTs with specificdimensions and physical properties has yet to beachieved (as, indeed, has an industrial process forseparation of the spaghetti-like bundles that are

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Application Material/device Estimated production rates (tonnes/annum)

Present 2005–2010 2011–2020

Structural Ceramics, catalysts, 10 103 104–105

applications composites, coatings,thin films, powders, metals

Skincare products Metal oxides 103 103 103 or less(titanium dioxide, zinc oxide, iron oxide)

ICT Single wall nanotubes, 10 102 103 or morenano electronics,opto-electro materials (titanium dioxide, zinc oxide, iron oxide),organic light-emittingdiodes (OLEDs)

Biotechnology Nanoencapsulates, less than 1 1 10targeted drug delivery,bio-compatible,quantum dots,composites, biosensors

Instruments, sensors, MEMS, NEMS, SPM, 10 102 102–103

characterisation dip-pen lithography,direct write tools

Environmental Nanofiltration, 10 102 103–104

membranes

Table 4.1 Estimated global production rates for various nanomaterials and devices based on internationalchemical journals and reviews (2003–2004), and market research (BCC 2001). These rates are intended forguidance only, as validated numbers are commercially confidential.

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Figure 4.3 Estimated future global production of nanotubes (Cientifica 2004)

currently produced). This is an area of intense research.Current production capacity for CNTs is estimated to bearound 100 tonnes per annum (Cientifica 2004); theactual production output remains commerciallyconfidential, but is expected to be lower. Most of thecapacity is estimated to be multi-walled tubes, withsingle-wall tubes accounting for about 9 tonnes ofcapacity. Estimated future global production ofnanotubes is outlined in Figure 4.3.

c) Positional assembly

13 The final bottom-up technique is positionalassembly, whereby atoms, molecules or clusters aredeliberately manipulated and positioned one-by-one(see Chapter 2). Techniques such as SPM for work onsurfaces, or optical tweezers in free space, are used forthis. Positional assembly is extremely laborious and iscurrently not suitable as an atomic-scale industrialprocess. As described in Chapters 2 and 3, the utilityand strength of SPM in industry lie in their ability tocharacterise and measure surfaces with atomic-levelprecision, rather than as fabrication tools.

14 The fact that (albeit very rudimentary) structurescan be fabricated atom-by-atom has lead to speculationthat tiny nanoscale machines could be made whichcould be used in parallel to manufacture materialsatom-by-atom. The idea is to fabricate one or a fewmachines (or assemblers) that would first make copiesof themselves, and then go on to make materials inparallel, in principle solving the problem of slowproduction speed. This speculation has led someindividuals to voice fears of uncontrollable self-replication, known as ‘grey goo’, which are discussed inAnnex D. Such concerns currently belong in the realmof science fiction. We have seen no evidence of the

possibility of such nanoscale machines in the peer-reviewed literature, or interest in their developmentfrom the mainstream scientific community or industry.Indeed, the originator of concerns over grey goo, EricDrexler, has since retracted his position (Phoenix andDrexler 2004).

4.3.2 Top-down manufacturing

15 Top-down manufacturing involves starting with alarger piece of material and etching, milling ormachining a nanostructure from it by removing material(as, for example, in circuits on microchips). This can bedone by using techniques such as precision engineeringand lithography, and has been developed and refinedby the semiconductor industry over the past 30years.Top-down methods offer reliability and devicecomplexity, although they are generally higher in energyusage, and produce more waste than bottom-upmethods. The production of computer chips, forexample, is not yet possible through bottom-upmethods; however, techniques using bottom-up (orhybrid top-down/bottom-up) methods are underexploration (see sections 3.4.4 and 4.3.3).

a) Precision engineering

16 In general, ultra-precision engineering andmanufacture underpin much of the micro-electronicsindustry in everything from the production of the flatlow-damage semiconductor wafers used as substratesfor computer chips, to the mechanical stages used toposition the wafers, to the manufacture of the precisionoptics used to print the patterns on the wafers. Inaddition, the techniques of ultra-precision engineeringare used in a variety of consumer products such ascomputer hard disks, CD and DVD players.

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17 Ultra-precision machine tools can now achieve veryhigh performance in terms of both the accuracy withwhich form can be defined (up to 1 part in 107, orbetter than 100nm over distances of tens ofcentimetres) and the surface finishes that can beachieved (0.5–1nm root mean square surfaceroughness), although these are currently on simpleshape surfaces and with low output levels. Thiscapability, which is bringing benefits in several areas (see(b) below), has been achieved through a combination ofadvances. These include: the use of advanced materialsfor cutting tools, based on diamond or cubic boronnitride; very stiff, precise machine tool structures; newlinear and rotary bearing designs employing fluid films;and sensors for size control combined with numericalcontrol and advanced servo-drive technologies. Veryprecise process and temperature control is needed toachieve this performance (the latter being of the orderof ±0.01ºC).

b) Lithography

18 As discussed in section 3.4, manufacturing in theICT sector predominantly involves lithographic processesthat pattern a semiconductor wafer in a sequence offabrication steps. Lithography involves the patterning ofa surface through exposure to light, ions or electrons,and then subsequent etching and/or deposition ofmaterial on to that surface to produce the desireddevice. The ability to pattern features in the nanometrerange is fundamental to the success of the IT industryand the ITRS roadmap. The main lithographic tools canbe conveniently separated into methods that use afocused beam of electrons or ions to write patterns, andthose that rely on the projection of light through a maskto define a pattern over a complete semiconductorwafer. Electron- and ion-based methods are bothcapable of making sub-10nm structures (with electronbeam lithography having the greatest routineresolution), but they are too slow to be used directly inproduction. Optical lithography is used for production ofsemiconductor devices. Although it does not have theresolution of the beam-based techniques, it providesrapid throughput and cost-effective manufacture.Electron beam lithography is primarily used to fabricatethe masks used for optical lithography, and ion beamtechniques are mostly used to repair masks and forspecialist device applications.

19 The requirement for ever-shrinking device structureshas placed enormous technical demands on opticallithographic process, as the nanostructures have lengthscales similar to or less than the wavelength of theilluminating light (ultraviolet). Despite these difficulties,the ITRS roadmap implicitly expects optical lithographyto keep track of future device dimensions until 2016when the target critical device dimension reaches 22nm.

20 Techniques developed in the microelectronicsindustry have also enabled the miniaturisation of smallmechanical moving devices (MEMS), which in turn havelead to research into NEMS. MEMS technology seeks toexploit and extend the capabilities that have beenprovided by silicon integrated circuit manufacturingfrom one of making chips for electronic signalprocessing to the provision of on-chip sensing and/oractuation through the use of moving mechanical parts.Some MEMS technologies are starting to attain maturityin manufacture (for example, MEMS accelerometers areused widely in air-bag sensors). However, there arecurrently difficulties in the reproducible large-scalemanufacture of more complex MEMS systems. Althoughnot strictly a ‘nanotechnology’ as defined in this report,MEMS, NEMS and the technologies used to make themare used extensively in techniques that can access andexploit the nanoscale (such as SPMs or lab-on-a-chipand biosensing). The reducing dimensional tolerances(less than 100nm) being provided by modernlithographic patterning techniques are now enabling theproduction of structures of such small dimensions thatthey are becoming a legitimate part ofnanotechnologies in their own right.

4.3.3 Convergence of top-down and bottom-uptechniques

21 The relationship between top-down and bottom-upmanufacturing is illustrated in Figure 4.4. The ‘top-down’ section is an updated version of the diagramproduced by Norio Taniguchi, which showed thedevelopment in the accuracy of artefact definition fromthe early 20th century to 1974, extrapolated to the endof the century. The ’bottom up’ section illustrates howbottom-up processes have evolved to control ever-largerstructures through advances in chemical processing.Now the dimensions that can be controlled by eitherapproach are of a similar order, and this is leading toexciting new hybrid methods of manufacture.

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4.4 Visions for the future

4.4.1 Precision Engineering

22 There are strong drivers to reduce tolerances inengineering, including miniaturisation, improved wearand reliability characteristics, automated assembly andgreater interchangeability, reduced waste andrequirement for re-work. As the trend towardsminiaturisation continues, research and the industrialapplication of energy beam processing methods willincrease, driven in particular by the electronics andcomputer industries. Techniques such as electron beamlithography (EBL), focused ion beam (FIB), reactive ionetching (RIE) and femtosecond pulsed laser ablation arebecoming more accurate and cheaper to apply in aproduction context. Some examples of futureapplications of high-precision engineering are givenbelow.

· ICT: the machines used to fabricate chips dependfundamentally upon the use of ultra-high precisiontechniques for their manufacture and nanometrologytechniques for their operation. The manufacture oflarger-diameter semiconductor wafers with improvedflatness and reduced sub-surface damage should leadto improved device yields and reduced costs.

· Optics: innovative ductile-mode grinding processes,together with electrolytic in-process dressing (ELID),

should result in the elimination of polishing in theproduction of high-quality optical devices. This is likelyto be of particular importance in the production of theoptics for extra-large astronomical telescopes such asthe proposed 50m and 100m systems (Euro50 andOWL), which will consist of many individually figuredsegments (Shore et al 2003).

· Transport: precision-machined parts should be morereliable, because of reduced wear, requiring fewerreplacement parts and less energy consumption. Forexample, the ability to produce surfaces withcontrolled textures through finishing to 10nm averageroughness followed by laser surface treatment isexpected to lead to improved power transmissiontrains with losses through slip reduced by up to 50%.Precision manufacturing is predicted to lead to weightreductions in airframe wings and to improve theperformance of internal combustion chambers.

· Medical: it is hoped that the use of ultra-precisionmachining techniques to produce improved surfacefinishes on prosthetic implants should lead to lowerwear and better reliability.

23 It is hoped that advances in precision engineeringwill enable the reduction of environmental impacts by,for example, reducing the use of lubricants. However,for any particular product, the whole life cycle needs tobe taken into account before it can be established

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Figure 4.4 The convergence of top-down and bottom-up production techniques (Whatmore 2001)

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whether there is a net environmental benefit. This isdiscussed further in section 4.5.

4.4.2 The chemicals industry

24 The long-term goal within the chemicals industry isto use nanoscale ‘building blocks’ to assembleorganised nanostructures, that can in turn bemanufactured into commercially useful products. Froman understanding of the chemistry and physics ofnanoscale materials, and top-down/bottom-upmodelling and measurement, industry will concentrateon processes that use manufacturing at the nanoscale ina way that preserves the desired effect and function asnanoscale components are combined into macroscalematerials and products. This will involve thedevelopment of technologies based on self-assemblingmaterials, or more probably on directed-assemblymethods, which allow for some form of massivelyparallel production, along with modelling andmeasuring tools. The vision is the manufacture ofreproducible, accurate and designable nanomaterials.

25 The time-scale for the commercial exploitation ofthese types of highly organised structures or quantummaterials is approximately 2020 and beyond, for use inthe biotechnology and IT sectors. These materials will beextremely valuable, in excess of $1,000,000 per tonne,with the production rates of the order of 10–10,000tonnes a year. The price is expected to remain relativelyhigh because, though the effect of the nanomaterial willbe to add value to consumer products, it will only forma tiny fraction of the final product as sold.

26 The desired functionality is created throughexploiting structure – property relationships.Measurement, modelling and simulation are essentialfor the characterisation and subsequent control ofproperty and functional performance and therefore theproduction of desirable materials. The development ofmeasurement tools for use at the nanoscale will movefrom laboratory-based characterisation to in-line andon-line methods of monitoring and controlling accuracyat the 6-sigma level (99.9997% accurate) in terms ofreproducible structure, texture and surface properties.The use of computer simulation based on advancedstructure – property – process predictor codes willbecome the key technology for manufacture-by-design,where the characteristics of the material are effectively‘dialled up’ through morphology, texture, structure andreactivity based on the interaction of materials acrossmolecular- and nano-length scales. The structure orform of the material then dictates the processingoptions for economic, reliable and reproducibleoperation. The combination of measurement, modellingand manufacturing technologies will be the basis forintelligent material systems. It is also hoped that it willbe possible to produce materials with less waste.

27 The synthesis and control of micro- and nano-scale

structures may yield unprecedented control of meso-and macro-scale properties in functional materials foruse in applications of direct relevance to industry. It hasbeen predicted (Chemical Industry 2003) that over thecourse of the century, many of the needs of commerceand society may be satisfied through a materials revolutioninvolving synthesis and smart fabrication. Because ofsome of the barriers outlined in section 4.6 it is difficultto predict when these developments might occur, butwe provide some estimated timeframes in Box 4.1.

4.4.3 The information and communication technology industry

28 Although the future of device fabrication is stillcentred around the lithographic processes described insection 4.3.2, there are other techniques that areincreasingly being applied both to on-roadmapdevelopments and to alternative approaches to devicematerials. Soft lithography techniques where a flexiblemaster is used to stamp out patterns on a range ofsurfaces have been available for several years. Theaccuracy demands imposed by the silicon-based industryhave, until now, prohibited the use of soft lithographiesas the elastic nature of the stamp can cause small, butstill unacceptable, physical distortions across a wafersurface. However, for small-area device fabrication andfor applications where spatial tolerances are lessrestrictive, they offer a real alternative to conventionalmethods, although the fabrication of the master stillrequires optical or electron beam methods. Softlithographies can be used for plastic electronics, as canalternative ink-jet based methods which use essentiallythe same technology as desk-top printers. Althoughplastic electronics are not truly in the nano-range interms of critical dimensions, a relatively simple

Box 4.1 Estimated timeframes for developments innanomanufacturing

Short term (next 5years): opportunities will arrivethrough the exploitation of equipment capable ofimaging, analysing and fabricating simple materialsand devices at the nanoscale.

Medium term (5–15years): nanoscience andtechnology will give rise to nanomanufacture-by-design, using self-assembly and directed assemblymethodologies to create a sustainable knowledge-based industry capable of addressing simplebio–info–nano material needs.

Longer term: it is hoped that the idea ofnanomanufacturing will encompass genuine ‘green’concepts of zero waste and little or no solvent useincorporating life cycle (sometimes referred to as‘cradle to grave’) concepts of responsible productscoupling biology with inorganic materials.

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manufacturing technique that can deal with wetchemistries will enable cheap electronic and photonicdevices. Such developments, combined with advances indirected self-assembly, may bring the semiconductor,materials and chemical industries closer together, inorder to create novel alternative methods for chipproduction as the end of the roadmap approaches.

4.5 Resource management and environmentalissues

29 It has been claimed that several nanotechnology-based applications and processes will bringenvironmental benefits, for example through fewerresources required in manufacture or improved energyefficiency in use. It is important to substantiate suchclaims by checking that there are indeed net benefitsover the life of the material or product.

30 The potential benefits of nanotechnologies shouldbe assessed in terms of life cycle assessment (LCA)(sometimes referred to as ‘cradle-to-grave’ analysis).LCA is the systematic analysis of the resource usages(for example, energy, water, raw materials) andemissions over the complete supply chain from the‘cradle’ of primary resources to the ‘grave’ of recyclingor disposal. For example, one of the areas of applicationforeseen for nanomaterials is in photovoltaic (PV) energyconverters in order to increase efficiency. An LCA wouldinvestigate the extent to which the additional energyyield over the service life of a PV device would be offsetby any additional energy used in manufacturing thedevice and in recovering or disposing of its materialcontent at the end of its life.

31 To illustrate the importance and associatedcomplexity of such analyses, an example can be takenfrom the possible use of nanotechnologies in the transportsector. As we have seen in section 3.2.3b, reducing theweight of aircraft is a foreseeable application, for examplethrough use of CNT composites and thinner (that is,lighter) paints and coatings. Available LCA studies onaircraft show that the resource use and environmentalimpacts of aircraft in flight currently outweigh those fromaircraft construction by several orders of magnitude(Energy Technology Support Group 1992). The firstassumption has therefore been that technologicaldevelopments towards ‘lightweighting’ are alwaysbeneficial. This assumption would need to be tested fornanoengineered materials where end-of-life disposal mayhave an adverse environmental impact. Also, the basis onwhich reducing aircraft weight is assessed needs to bedefined carefully to avoid reaching simplistically optimisticconclusions. In practice, it is likely that reductions inaircraft weight will be exploited by increasing payload, i.e.carrying more passengers, which if the market were fixedwould bring environmental benefits due to fewer flights.However, if this is used to decrease ticket costs, it couldstimulate additional passenger movements, albeit using

less fuel per passenger–kilometre flown. The true trade-offto be considered is between the benefits of additionalpassenger movements rather than the environmentalperformance of the aircraft and the impacts of producingnano-engineered materials. Thus the superficially simpleenvironmental assessment ends up involving social andethical issues.

32 LCA is now a standardised and accepted tool,covered by a set of international standards (ISO14040–14044) and is the basis of much Europeanenvironmental policy including the End-of-Life Directives(see section 8.3.5). We are aware of only one study (inprogress at Carnegie Mellon University, USA, funded bythe US Environmental Protection Agency) applying LCAapproaches to nanotechnology-enabled products andprocesses, and we welcome the inclusion of LCA in arecent Communication from the EC (EuropeanCommission 2004a). We recommend that a series oflife cycle assessments be undertaken for theapplications and product groups arising fromexisting and expected developments innanotechnologies, to ensure that savings inresource consumption during the use of theproduct are not offset by increased consumptionduring manufacture and disposal. To have publiccredibility these studies need to be carried out orreviewed by an independent body.

33 Where there is a requirement for research toestablish methodologies for life cycle assessmentsin this area, we recommend that this should befunded by the research councils through thenormal responsive mode.

4.6 Barriers to progress

34 There are several factors that will influence whethernanotechnologies will be used routinely within industrialprocesses. Some of these are economic or social, othersare technical.

35 Any new process or technology must be able toexceed (in terms of economic value) what is already inplace, and it must be of value (or perceived value) to theconsumer, to be adopted by industry. As we have heardin evidence from Don Eigler and others, the technologyused in current industrial processes is already generallyvery advanced, and so nanotechnologies will only beused where the benefits are high. This economic realitymay well act to moderate their rate of introduction.

36 The technical barriers should not beunderestimated: as well as the difficulty in scaling aprocess up from the laboratory to an industrialoperation, more fundamental barriers stem from a lackof understanding of nanoscale properties and thetechniques to characterise and engineer them to formuseful materials and products. Figure 4.5 summarises the

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generic technical steps that needed to be undertaken toproduce a material with designed functionality.

37 The current technical barriers to achieving the stepsoutlined in Figure 4.5 are as follows:

· Inadequate characterisation and measurement toolsand capabilities to enable on-line and in-linemonitoring and processing control based onnanoscalar features.

· Insufficient understanding to enable the design andproduction of desired material properties through thedevelopment of multi-phase, multiple length-scalemathematical models that are capable of linkingeffectively across structure–property–processingboundaries. This is crucial if we are to preservefunctionality from the nanoscalar synthesis through tothe creation of macroscopic functional materials.

· Insufficient knowledge to synthesize complexheterogeneous nanostructured large-scale, self-assembled monolayers (SAMs) and directed assemblyof monolayers (DAMs). Of great practical interest areDAMs whereby scale-out (reliable replication of aprocess) will be key to the development of continuousnanomanufacturing processes (NSF 2001; DTI 2002).

38 Alongside purely technical barriers to progress arethose relating to regulation such as classification andstandardisation of nanomaterials and processes, and themanagement of any health, safety and environmentalrisks that may emerge. Appropriate regulation andguidance informed by scientific evidence will help toovercome some of these barriers, and there are alreadydiscussions between industry and regulators on theabove issues. Until these regulatory measures are inplace, industry will be vulnerable to reduced consumerconfidence, uncertainty over appropriate insurancecover (Swiss Re 2004) and litigation should some

nanomaterials prove to be harmful. These issues will beof particular importance to the smaller, more innovativecompanies. Health, safety and environmental impacts ofsome nanomaterials are discussed in Chapter 5 andregulatory issues are discussed further in Chapter 8.

39 Naturally, the development and exploitation of newtechnologies or techniques cannot proceed without asufficiently trained workforce. This point has been madestrongly for the UK in the Taylor report (DTI 2002), bythe EC in its recent communication on nanotechnology,and by the House of Commons Science and TechnologyCommittee report on UK Government investment innanotechnology (House of Commons Science andTechnology Committee 2004a). However, it is not partof the remit of our study.

4.7 Summary

40 In their widest sense, nanotechnologies have beenused by industries for decades (semiconductors), and insome cases considerably longer (chemicals). However,developments over the past 20years in the tools used tocharacterise materials have led to an increasedunderstanding of the behaviour and properties ofmatter at very small size scales. Increased knowledge ofthe relationship between the structure and properties ofnanomaterials has enabled the production of materialsand devices with higher performance and increasedfunctionality. This progress has taken place steadily overseveral years; so, at least so far, the influence ofnanotechnologies on industry can be described asevolutionary rather than revolutionary. This is alsoevident in the current production rates of nanoparticlesand nanomaterials which, although increasing, arenegligible compared with bulk chemicals and materials.

41 True nanomanufacturing is therefore very much inits infancy; however, there are strong economic, societal

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Figure 4.5 The generic steps that are undertaken to manufacture nanomaterials, from identification of propertiesthrough to production

IDENTIFY CHARACTERISE PROCESS PRODUCT

Unique effects Synthesise Fabricate Createcreated through Measure functional sustainable Nanoscalar & Model materials through value Nanostructured Simulate new ground adding Behaviour breaking advanced

technologies functionalmaterial

All this done with consideration of health, safety and environmental impacts

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and environmental reasons why its development iscurrently the focus of so much attention. At the sametime, there are uncertainties about the direction thetechnology may take and about the hazards to humans

or the environment presented by certain aspects ofnanotechnologies. The health, environmental and safetyaspects of nanoparticles and nanotubes are discussed inChapter 5.

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5.1 Introduction

1 In Chapters 3 and 4 we have outlined the ways inwhich researchers and industry hope to exploit theunique properties of nanomaterials and the processes ofnanomanufacturing for medical applications and todeliver environmental benefits. Current medicalapplications of nanotechnologies include anti-microbialwound dressings, and it is anticipated that futureapplications will include more durable and betterprosthetics and new drug delivery mechanisms. Currentresearch into applications of nanotechnology includesefforts to reduce the amount of solvents and otherharmful chemicals in manufacturing, to improve energyefficiency and energy storage capabilities, and to removepersistent pollutants from soil and water supplies, all ofwhich offer hope of benefiting the environment andincreasing sustainability. In section 4.5 we highlighted theneed to incorporate a life cycle assessment approach intothe research and development of products and processesarising from nanotechnologies to ensure that they do notresult in a net increase in resource use. In this chapter weconsider potential adverse health, environmental andsafety impacts of nanotechnologies.

2 Whereas the potential health and environmentalbenefits of nanotechnologies have been welcomed,concerns have been expressed that the very propertiesthat are being exploited by researchers and industry(such as high surface reactivity and ability to cross cellmembranes) might have negative health andenvironmental impacts and, particularly, that they mightresult in greater toxicity. The public who participated inthe market research that we commissioned expressedworries about possible long-term side effects associatedwith medical applications and whether nanomaterialswould be biodegradable. Analogies were made withplastics, which were once hailed as ‘the future’ butwhich have proved to have accompanying adverseeffects on individuals and the environment (BMRB 2004).

3 Almost all the concerns expressed to us, in evidenceand during our workshop on health and environmentalimpacts of nanotechnologies, related to the potentialimpacts of manufactured nanoparticles and nanotubes(in a free rather than fixed form) on the health and safetyof humans, non-human biota and ecosystems. The factthat nanoparticles are on the same scale as cellularcomponents and larger proteins has led to the suggestionthat they might evade the natural defences of humansand other species and damage cells. It is important to setthese concerns in context by noting that humans havealways been exposed to some types of nanoparticlesarising from natural sources such as atmosphericphotochemistry and forest fires, and exposures tomillions of pollutant nanoparticles per breath have beencommonplace since the first use of fire.

4 Manufactured nanoparticles and nanotubes areimportant because they are among the first nanoscaletechnologies used in consumer products, but as Table 4.1makes clear, the production rates of these materials is onlya small fraction of the predicted potential fornanotechnologies. The IT industry also usesnanotechnologies, both in techniques used and theminimum feature size of devices; however, in contrast tomanufactured nanoparticles and nanotubes, it does notpresent any unique hazards. There is an importantdistinction between applications that use nanoscalar activeareas on larger objects (for example, nanometre-scalejunction regions in transistors, which form part of amillimetre-sized chip and are therefore fixed), andchemicals or pharmaceuticals in which the nanometre-scale ‘active area’ is a discrete nanoparticle or nanotube.Although a computer chip with 100 millionnanostructures presents a potential hazard formanufacture, disposal or recycling, these issues are relatedto the bulk materials, which make up the chips (forexample, gallium), rather than to the nanostructureswithin them. Although nanoscience and nanotechnologiesmay involve individual scientists and other workers usingor being exposed to a range of chemical reagents andphysical processes that could imply harm to their health,such exposures to substances and materials other thannanoparticles are covered by existing understanding andregulation. They are not considered further in this reportexcept in that they may be in the form of discrete particlesincorporated into materials in the nanometre size range.

5.2 Assessing and controlling risk

5 The general approach to assessing and controllingrisk involves identification of hazard (the potential of thesubstance in question to cause harm) and then astructured approach to determining the probability ofexposure to the hazard and the associated consequences.Risk is usually controlled in practice by reducing theprobability of exposure, although the first principle of riskmanagement is to substitute less hazardous for morehazardous substances where possible. An appreciation ofhazard (for example, toxicity or likelihood of explosion) isrequired to determine to what extent exposure should becontrolled. Risk is controlled by limiting release of thematerial to air or water, and/or by interrupting thepathways by which the substance reaches the receptorwhere it could cause harm (for example an organ in thebody), making an understanding of exposure pathwaysand likely quantities essential to risk management. In anynew technology, foresight of possible risks depends on aconsideration of the life cycle of the material beingproduced. This involves understanding the processes andmaterials used in manufacture, the likely interactionsbetween the product and individuals or the environmentduring its manufacture and useful life, and the methods

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5 Possible adverse health, environmental and safety impacts

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used in its eventual disposal. Some of the definitionsused in this chapter are outlined in Box 5.1.

6 Manufactured nanoparticles might be used inproducts where they are not fixed (such as sunscreens),be used to form composites from which they might laterbe released, be formed during the self-assembly ofnanomaterials (again from which they might later bereleased), or be created if nanomaterials are damagedor break down. For physical harm to occur, humans orother organisms must come into contact with thematerials or be involved in the processes in such a waythat the material contacts or enters the body and takespart in reactions with cells, leading to tissue-damagingreactions. Any such damage might be anticipated if thematerial has toxic properties and reaches the targetorgan in sufficient dose (defined in Box 5.1). Some ofthe possible routes by which exposure might occur nowand in the future after release of a nanoparticle areillustrated in Figure 5.1. If the material is released intothe air, it may be inhaled directly. This is the dominantpathway for humans exposed to manufacturednanoparticles released in the workplace, and for allorganisms exposed to nanoparticles from sources suchas combustion. In addition to inhalation by air-breathingorganisms, exposure to nanoparticles could occur fromsurface contact (for example in cosmetic skinpreparations) or from ingestion (if nanoparticles are to

be added to food or drink in the future). In the future,medicinal applications may result in particles beinginjected into the body. Other organisms such as bacteriaand protozoa may take in nanoparticles through theircell membranes, and thus allow the particles to enter abiological food chain.

7 In this chapter we examine the possible hazardsfrom nanoparticles before going on to consider theexposure pathways, any current exposure levels andhow these might be managed to reduce the risk frommanufactured nanoparticles and nanotubes. We addressthe important gaps in scientific understanding ofpossible interactions between nanoparticles, theenvironment and people, and outline the areas ofresearch necessary to reduce these uncertainties. Waysin which regulation might be used to manage any riskspresented by free nanoparticles or nanotubes arediscussed in Chapter 8.

5.3 Human health

5.3.1 Understanding the toxicity of nanoparticlesand fibres

8 To understand the potential risks to humans fromnanoparticles, it is necessary first to consider briefly thebody’s defences against particles in general and theproperties that particles require to overcome thesedefences. Throughout much of their evolutionaryhistory, humans have been exposed to small particles,often in very high concentration, and the mechanismsevolved for defence against micro-organisms are alsoused to defend the body against such particles. Accessto the human body can occur through the lungs, theskin or the intestinal tract. Each organ presents a barrierto penetration by micro-organisms or other particles.Nevertheless, despite the defence mechanisms outlinedin Box 5.2, certain particles have proved to have toxiceffects on humans, just as have certain micro-organisms. In general this is a consequence of propertiesthat either allow them to evade or cause damage todefensive mechanisms. An understanding of thesemechanisms is of importance to estimate the possibletoxic effects of nanoparticles or nanotubes. Three typesof particle in particular have provided relevantinformation: the minerals quartz and asbestos, and theparticles associated with air pollution.

a) Evidence from exposure to quartz

9 Quartz is a mineral to which many millions ofworkers have been exposed, for example in mining andstone working. Exposure for a few years to micrometre-sized particles, in concentrations of the order of amilligram per cubic metre of air, leads to a potentiallyfatal form of lung fibrosis (Seaton 1995). Toxicologicalstudies have shown that relatively low exposure tomicrometre-sized particles of quartz causes severe lung

Box 5.1 Definitions

Hazard is defined as the potential to cause harm:hazard is typically assessed by toxicology, forexample testing harmful potential on cultured cellsor isolated organs (in vitro) or directly on laboratoryanimals or humans (in vivo). Another hazard is thepotential for clouds of combustible nanoparticles toexplode.

Exposure is the concentration of the substance inthe relevant medium (air, food, water) multiplied bythe duration of contact.

Dose is defined here as the amount of a substancethat will reach a specific biological system, and is afunction of the amount to which the individual isexposed, namely the exposure, taking account ofthe fact that a proportion is eliminated by the body’snatural defences and does not reach the targetorgan.

Risk is a quantification of the likelihood of suchharm occurring: risk is assessed from considerationof the likelihood of exposure, the dose and theinherent toxicity of the substance to which people orother organisms may be exposed. Sometimes, in thecase of materials to which exposure has alreadyoccurred, risk may be measured directly by thetechniques of epidemiology.

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Figure 5.1 Some possible exposure routes for nanoparticles and nanotubes based on current and potential futureapplications. Very little is known about exposure routes for nanoparticles and nanotubes and this figure should beconsidered with this in mind (Adapted from National Institute for Resources and Environment, Japanhttp://www.nire.go.jp/eco_tec_e/hyouka_e.htm).

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inflammation, cell death, fibrosis and tumours in rats(Vallyathan 1994). This has been demonstrated to berelated to the surface of the quartz crystal, which ishighly reactive and generates free radicals (reactiveatoms or molecules), leading to oxidative damage tothe defensive cells that take up the particles. It is likelythat this surface activity is a fundamental aspect of thetoxicity of particles but one that varies considerablybetween different types of particle. Other mineralparticles encountered in industry, such as coal andvarious silicates, are less toxic but are still capable ofcausing similar diseases when inhaled in higher doses. Itis now believed that inhaled particles in general, evenwhen they have a low intrinsic toxicity to cells, maycause disease of the lungs if the dose is sufficiently highby overloading the lung defences, and that this propertyrelates to the total surface area of the particles inhaled(Faux et al 2003). Thus studies of mineral particles havedemonstrated that the toxic hazard is related to thesurface area of inhaled particles and their surfaceactivity. The risk relates to the dose inhaled.

b) Evidence from exposure to asbestos

10 The effects of asbestos have also been studied ingreat detail (Mossman et al 1990). Inhalation byworkers of this natural fibrous mineral is known tocause several different diseases of the lung and its lining(the pleura), most of which prove fatal. Fibres aredefined as particles with a length at least three timestheir diameter. Fibres narrower than about 3µm haveaerodynamic properties that allow them to reach thegas-exchanging part of the lung when inhaled, whereasthose longer than about 15µm are too long to bereadily removed by macrophages (Figure 5.2). Oncelodged in the deep lung, their toxicity depends upon anability to initiate an inflammatory reaction, involvingattraction of macrophages and other defensive cells,which, if sufficiently widespread, may eventually lead toscarring (asbestosis) and lung cancer. Over decades,migration of fibres through the lung to the pleura insufficient numbers leads to the development ofmesothelioma, a fatal tumour. Studies in rats haveshown that the likelihood of a fibre, be it asbestos orsome other natural or man-made fibre, to cause these

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diseases depends critically on its solubility. Fibres thatdissolve readily are likely to break into shorter particlesthat are easily removed by macrophages, and so areunlikely to persist long enough to cause such diseases(Mossman et al 1990). This has been supported bystudies of human lungs, which have shown differentialpersistence of different fibre types in exposed workerswith asbestos-related diseases (Wagner et al 1982).Asbestos is present in the fabric of many buildings andin cities, and all of us have some in our lungs. Incontrast, those who develop asbestos-related diseasesusually prove to have millions of fibres in every gram oflung tissue as a consequence of cumulative exposure toconcentrations of several hundred fibres in every breathwhen they are exposed to the mineral at work overmonths or, more often, years (Wagner et al 1982). Thus,studies of asbestos and other fibres have shown thattheir toxicity depends on the two physical factors,length and diameter, and two chemical factors, surfaceactivity and durability (ability to resist degradation).Again, the risk relates to the dose reaching the targetorgan.

c) Evidence from exposure to air pollution

11 Whereas studies of mineral dusts and asbestos haveshown the importance of particle size, surface reactivityand dose in the causation of lung disease, the mostdirect evidence on nanoparticles comes from studies ofair pollution. Any combustion process producesnanoparticles in vast numbers from condensation ofgases. Initially only about 10nm in diameter, theserapidly coalesce to produce somewhat larger aggregatesof up to about 100nm, which may remain suspended inthe air for days or weeks (Figure 5.3). The sources ofsuch combustion nanoparticles range from volcanicactivity and forest fires, to the use of fires for heatingand cooking, and more recently industrial and trafficpollution (Dennekamp et al 2002). Modern scientificinterest in air pollution started after the disastrousLondon smog episode in December 1952, when some4000 excess deaths occurred over a two-week period.Particle concentrations were as high as severalmilligrams per cubic metre, and most of these particleswere in the nanometre size range. Reductions inpollution as a result of legislation to restrict coal burninghave prevented such serious episodes from occurring

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Box 5.2 Human defences against particles

LungsIn the lung, small particles may be filtered out of the inhaled air by deposition on the airway wall and removal tothe throat by the rhythmical beating action of microscopic protrusions (cilia) from the lining cells of the airways,or they may reach the gas-exchanging tissues and be engulfed by phagocytic cells called macrophages. Thesecells then carry the particles up the airways or through the lungs to lymphatic vessels and thence to lymph nodes.Both mechanisms tend to remove the particles from areas where they have the potential to cause harm and toneutralise their toxicity. However, an overwhelming dose may lead to excessive inflammation, scarring anddestruction of lung tissue, as exemplified by bacterial pneumonia or industrial lung diseases such as asbestosis.

SkinThe skin is protected by a layer of dead cells (the epidermis or stratum corneum), covered by a hydrophobic(water-repelling) lipid layer. Beneath the epidermis is a layer of living cells supplied by nerves and blood vessels,the dermis. Within the dermis are glands that produce sweat and the protective secretion, sebum. The bloodsupply of the dermis allows recruitment of inflammatory cells when the skin is attacked by bacteria or otherwisedamaged, enabling protective inflammation and tissue repair. Prolonged or repeated inflammation, such as maybe induced by certain chemicals or by sunlight, may lead to skin damage and cancer. The epidermis is normallyimpermeable to particles and micro-organisms but is readily damaged (for example, by cuts and abrasions) orperforated (for example, by specialised insects or by therapeutic injections). Several skin diseases such as allergiescan also impair its ability to withstand toxic agents.

GutThe epithelium of the gut differs from the other external epithelia in that its primary function is to allowabsorption of substances into the body. However, unless diseased, it is impermeable to large molecules such asproteins (the largest of which are tens of nanometres in size), which it needs to break down before absorption,and to particles and micro-organisms. The high acidity of the stomach has an important microbicidal function, aswell as a digestive one, and may dissolve some particles and affect toxins in various ways. The lower gut has ahighly specialised secretory and absorptive epithelium that produces mucus and digestive enzymes and is richlysupplied with blood and lymphatic vessels, allowing it to recruit defensive cells and remove penetrating micro-organisms if necessary. Research into better formulations for drug delivery has shown that some nanoparticlesmay be taken up by gut lymphatic vessels (Hussain et al 2001). Much disease of the gut relates to infections andto adverse reactions to foods. Environmental and occupational causes of diseases of the gut, other than these,are uncommon.

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Figure 5.2 Four macrophages attempting to ingest an asbestos fibre (approximately 80µm long). (Reproduced bypermission of Professor Ken Donaldson, University of Edinburgh).

subsequently in UK cities. Nevertheless, from the 1980s, aseries of epidemiological studies has provided evidencethat exposure to the particulate fraction of air pollution isassociated with both heart and lung disease and is stillresponsible for measurable morbidity and mortality inurban areas as outlined in Box 5.3 (Brook et al 2004). Thisseems to be the case despite the fact that concentrationsin western cities are now measured in concentrations ofonly a few tens of micrograms per cubic metre.

12 Air pollution is caused by a complex mix of particlesand gases. However, there appear to be consistentassociations between exposure to the particulate fractionand adverse health effects. In seeking to explain these,two difficult facts have had to be considered. First, theconcentrations associated with measurable effects onhealth in populations are extraordinarily low – forexample, rises of only 10µg/m3 are consistently associatedwith an increase in cardiac deaths of about 1%. Secondly,the particles comprise chemicals generally believed to benon-toxic, mostly carbon and simple ammonium salts. Itseemed unlikely that inhalation of less than a milligram ofnon-toxic particles over 24 hours (a human breathesabout 20m3 per day and urban concentrations averageabout 20–30µg/m3) could cause a heart attack.Consideration of this problem led to the hypothesis thatthe adverse heart and lung effects are due to the action

of the nanoparticulate component of the pollution onsusceptible individuals, reflecting the point made abovefor quartz: that the total surface area and the surfaceactivity hold the key to toxicity (Seaton et al 1995).Although the mass concentration of nanoparticles is low,it still amounts to some tens of thousands ofnanoparticles per millilitre of urban particle counts (Figure5.4). This concentration implies that one inhalation of300ml will contain several million such particles, over halfof which will be retained within the lungs. Activities suchas cooking, driving in traffic or being in the presence ofsmokers entail breathing much higher concentrations.Since all are exposed yet few suffer adverse effects, it isgenerally believed that air pollution exerts its adverseeffects on a minority of individuals who, because of priorillness, are particularly susceptible.

13 These studies of air pollution have therefore shownthat although we are all exposed to very many, verysmall, apparently non-toxic particles on a regular basis,only relatively few of us succumb to their effects, butsuch effects may occur at very low mass concentrations.The concept that nanoparticles in air pollution might beresponsible for the observed adverse health effects haspromoted interest in their toxicology, and this interest isexpanding rapidly. Review of in vivo animal studiessupports the hypothesis that there may be a generaleffect of low-toxicity particles of all sizes that dependson the total surface area inhaled (Faux et al 2003);further investigation has shown that, weight for weight,finely divided particles of a material, such as titaniumdioxide or carbon black, are more toxic than largerparticles of the same material (Ferin et al 1990;Oberdörster 1996). This toxicity is largely explained bythe presence of transition metals on the surfaces ofsome types of nanoparticle and their subsequent abilityto promote release of free radicals in contact with bodytissues (Donaldson et al 2001) However, othernanoparticles with no transition metals appear toachieve their effects by their large surface area and theability of this surface to generate oxidative stress oncultured cells or isolated organs (in vitro) or directly onlaboratory animals or humans (in vivo) by as yet

Box 5.3 Observed epidemiological associationsbetween particulate air pollution and health

· Death from and exacerbation of heart disease invulnerable people.

· Death from and exacerbation of chronic lungdisease in vulnerable people.

· Exacerbations of asthma.· Long-term increase in risk of death from heart

attack and lung cancer.· Possibly, precipitation of cot death and stroke in

vulnerable individuals.

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unknown mechanisms (Brown et al 2000). In bothcases, nevertheless, the observed effects are related tothe total surface area of inhaled particles and to thechemical reactivity of that surface, a sufficient dose tothe lungs leading to inflammation and secondary effectson the blood that in turn lead to increased risk of lungand heart illness in susceptible individuals.

14 Owing to universal exposure to air pollution, anddespite the defence mechanisms outlined in Box 5.2,many particles of all sizes do in fact enter the bodymainly through the lungs, having been taken up bymacrophages and transferred into the interstitial tissues.Some remain in the lung while some are removedthrough draining lymphatic vessels to lymph nodes andthe blood stream. After death it is usually possible tofind traces of the minerals to which workers have beenexposed in their lungs (Seaton et al 1981), and verysmall amounts may be found in other tissues.Nanoparticles are probably removed from the lung moreefficiently than somewhat larger ones, although inter-species differences are known to occur (Churg andBrauer 1997; Bermudez et al 2004). It is likely that aproportion of this removal is by the blood stream.

15 A few specifically designed epidemiological studieson human populations have investigated the cellularreactions demonstrated by in vitro and in vivo toxicology(Seaton et al 1999; Schwartz 2001). However, it is oftendifficult to attribute responsibility to one or othercomponent of the air pollution (Seaton and Dennekamp2003), and air pollution particles themselves are ofdiffering chemistry and likely to include metallic atomsand molecules that will influence their toxicity. Ingeneral, epidemiological studies of air pollution pointtowards the finer particles rather than the coarsercausing harm, although gases such as nitrogen oxides

(which correlate closely with particle number) also showassociations with several negative health impacts(Seaton and Dennekamp 2003).

16 Observations linking air pollution episodes withcardiac responses (Peters et al 2000) and with changesin heart rhythm and sometimes blood pressure (Peters etal 1999) have led to suggestions that, as well as ahumoral (or blood-borne) response, a short-term neuralresponse to air pollution may occur. The mechanism fora response by the nervous system is not clear and iscurrently an area of active research. Nanoparticles wouldbe a strong candidate (though not the only one: gasesmight have such an effect) for the role of initiator of theneural reflex; viruses may use nerves for transmission(Bodian and Howe 1941), and recent work hassuggested that manufactured nanoparticles maypenetrate and pass along nerve axons and into the brain(Oberdörster et al 2004b). There is also some evidencethat metals characteristic of air pollutants may be foundin the brains of urban dogs (Calderón-Garcidueñas et al2003), and it is possible that transfer of particles alongthe nerves concerned with smell may provide atransport mechanism. More research on theneurotransmission of nanoparticles is needed.

17 The most significant finding from research into airpollution particles for the hazard of nanoparticles is thatcells and organs may demonstrate toxic responses evento apparently non-toxic substances when they areexposed to a sufficient dose in the nanometre sizerange.

d) Evidence from medical applications of nanoparticles

18 Further information on the effects of nanoparticleson the human organism comes from the pharmaceutical

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Figure 5.3 Soot nanoparticles viewed using Field Emission Scanning Electron Microscopy. (Reproduced by permissionof Professor Roy Richards, University of Cardiff).

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industry. For many years pharmaceutical scientists havestudied the fate of nanometre-scale particles with theaim of developing novel drug delivery systems forpharmaceutical compounds (see section 3.5). Thesestudies have been undertaken on spherical particles andhave explored different routes of delivery includinginhalation, ingestion, injection and transdermal delivery.Given the barriers to uptake of particles in the lungs,gut and skin, much of the knowledge on the fate ofnanoparticles has been derived from studies of drugdelivery by injection. It is known that after suchadministration the nanoparticles are taken up bymacrophages in the liver and spleen. Ultimately,depending on their solubility and surface coating, theymay be excreted by the kidneys (Borm and Kreyling2004). In general, the options for removal of all foreignmatter are excretion in urine or breath, through the gutby bile excretion, or in dead cells shed from the body.The use of surface coatings has enabled some particlesto influence these disposal mechanisms and allowedthem to be selectively deposited in particular organs orcells (Illum et al 1987). This suggests that surfacecoating might allow some nanoscale material to bedirected to specific organs and that tests for toxicityneed to take account of these coatings. It also impliesthe possibility that less desirable nanoparticles maypenetrate into cells or cross natural barriers, such asthose between the blood and the brain, that serve asimportant defences against harm.

5.3.2 Manufactured nanoparticles and nanotubes

19 In this section we consider the health impacts ofmanufactured nanoparticles and nanotubes, current andpotential exposure routes and levels, and discuss waysof managing any potential risks.

20 The understanding derived from studies of airpollution, mineral dusts and pharmaceuticals has led tothe general conclusion that the principal determinantsof the toxicity of nanoparticles are:

· the total surface area presented to the target organ;

· the chemical reactivity of the surface (including anysurface components such as transition metals andcoatings), and particularly its ability to take part inreactions that release free radicals;

· the physical dimensions of the particle that allow it topenetrate to the organ or into cells or that prevent itsremoval;

· possibly, its solubility, in that soluble particles such assalts may disperse before initiating a toxic reaction.

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Figure 5.4 Exposure to particles over the course of a four hours spent in Aberdeen City centre.Measurements were taken using a PTrak continuous particle counter which counts all particles below500nm, though in ambient air the very large majority are below 100nm. (Data collected by MartineDennekamp, University of Aberdeen)

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a) Inhalation

21 The small size of nanoparticles ensures that a highproportion inhaled from the air reaches and is depositedin the deep lung. The size of nanoparticles appears toinfluence their uptake into cells. Specialised phagocyticcells such as tissue macrophages and leukocytes in theblood generally take up larger particles. This is amechanism evolved in higher animals for removal ofpotentially harmful bacteria, and is analogous to thefeeding method of unicellular organisms. Nanoparticlesin contrast, because of their small size, may pass intocells directly through the cell membrane with thepossibility of interfering with important cell functionssuch as motility and ability to remove bacteria (Renwicket al 2001).

22 Small size alone is not the critical factor in thetoxicity of nanoparticles; the overall number and thusthe total surface area (essentially the dose) are alsoimportant. Based on the evidence we have reviewed itfollows that, although nanoparticles may imply a toxicthreat because of their small size and therefore largesurface area per unit mass, any toxicity would beexpected to be dependent upon inhalation orabsorption into the body of a very large number. Fornanoparticles with low surface reactivity, potentialtoxicity to humans and, presumably, other animals,should be considered in relation to the likely dose androute of exposure. From the point of view of the lung,inhalation of small numbers of particles is unlikely torepresent a significant risk. Inhalation of very largenumbers, as may occur in a manufacturing process,should be controlled by regulation. For specific types ofnanoparticle that may be expected to have a morereactive surface, perhaps because of a higher proportionor different combination of transition metals, greatercaution would be advised and exposure should beminimised. Toxicological studies, both in vitro and in vivo, will be required for the investigation of any suchsubstances to which people might be exposed.

23 Only a few types of manufactured nanoparticle,such as titanium dioxide, carbon black, zinc oxide andiron oxide are currently in industrial production (seeChapter 4). There is, however, a realistic prospect ofindustrial production of other nanoparticles fortherapeutic or diagnostic use, often based on metalswith chemical coatings that confer particular propertieswith respect to uptake into the body, across naturaltissue barriers, and into cells (Borm and Kreyling 2004).There is also considerable interest in the possibleproduction of nanotubes: some pilot manufacturingplants exist for CNTs, and nanotubes made of carbonand other elements are being extensively investigated inresearch laboratories. The greatest potential forexposure therefore over the next few years will be in theworkplace, both in industry and in universities.

24 Workplace exposure will depend on productiontechniques (outlined in Chapter 4): for example,production and storage in liquid will reduce the risks ofairborne exposure but fugitive emissions as vapour orwet aerosol may occur. Manufacturers must takeaccount of the differences in toxic potential betweenlarger and nano-sized particles and until the toxicologyof the nanoparticles is better known, they should beassumed to be harmful and such workers seekprotection by the usual methods of industrial hygiene,including provision of personal respiratory protectionand appropriate hazard information, together withappropriate procedures for cleaning up accidentalemissions and for making repairs to machinery. Severalissues require further research. In particular, standard,validated methods of measurement and monitoring willbe required to control airborne concentrations ofnanoparticles in industry and academic laboratories, andthe efficiency of various filter materials and respiratorcartridges with respect to nanoparticles requiresinvestigation. Toxicological research should be directedat assessing the hazard of new manufacturednanoparticles, particularly investigating the surfaceproperties that alter toxicity.

25 As outlined in Chapter 3.2, nanotubes are ofinterest because they are mechanically strong, flexibleand can conduct electricity. So far, most research hasfocused on CNTs but nanotubes made from otherelements and molecules are also being developed.Perceived similarities with asbestos and other disease-causing fibres have led to concern about their safety.Technology exists that allows production of nanotubesthat can have remarkable predicted dimensions of a fewnanometres in diameter and micrometres in length(although currently they can only be produced asagglomerates, not as single nanotubes). These couldrepresent a hazard because of their combination offibrous shape and nanometre dimensions. It is also likelythat such tubes are sufficiently robust to resistdissolution in the lung, and their dimensions suggestthat they could reach the deep lung if inhaled asindividual fibres. The presence of iron or other metalswithin them from its use as a catalyst in their productionsuggests that they may also have free-radical-releasing,pro-inflammatory properties. This has been borne out byone study that has investigated the effects of what musthave been heavy doses in terms of numbers (60–240µg,dimensions unspecified) of single-wall nanotubes oncultured skin epithelial cells (Shvedova et al 2003). Inthis case the effects were probably due to the iron, andthe tubes are likely to have been relatively short andclumped into masses. It is unlikely that such structureswould remain as individual fibres in the air; rather,electrostatic forces probably cause them to clump intomasses that are less easily inhaled to the deep lung.However, little is known of their aerodynamic propertiesand indeed whether they can be present in the air insufficient numbers to constitute a risk.

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26 If nanotubes were to intertwine and becomeairborne as ‘ropes’, these might pose a risk equivalentto a conventional fibre. If they combined as ‘balls ofwool’ their aerodynamic diameter would be critical:greater than 10µm diameter they would not beinhalable, whereas less than that they would act likelarger particles. It is recognised, however, that oneobjective of current research is to find structures orcoatings that enable the nanotubes to remain separate.In whatever final format, if they are inhalable, theirtoxicity is likely to be determined, at least in part, bytheir surface activity. The published mammalian studiesrelating to lung toxicity cannot be easily extrapolated, asof necessity the tubes were instilled (injected as a massinto the trachea rather than inhaled in a naturalmanner) as tangles rather than as individual fibres. Thehigh masses instilled resulted in blockage of airways andintra-airway fibrosis - a not unexpected result in thecircumstances (Maynard et al 2004). Preliminary studiesin several workplaces suggest that single-wallnanotubes are difficult to disperse as an aerosol andtend to clump into large masses (Warheit et al 2004).Nevertheless, inhalation of small clumps may also implyproblems for normal lung defences, with the possibilityof them acting as large surface area, non-fibrousparticles or being separated into single fibres by theaction of lung surfactant.

27 If the barriers to producing single nanotubes (ratherthan clumps) are overcome, we would expect to seethem used in many products such as electronic devices(as outlined in Chapters 3 and 4) and the potentialexposure to manufacturing workers would increase.There are obvious difficulties in measuring aerosols ofnanotubes against a background of normal laboratoryor workplace air. The fact that they are currently difficultto disperse suggests that the escape of large numbersof individual fibres into the air is unlikely in normalprocesses. Given previous experience with asbestos, webelieve that nanotubes deserve special toxicologicalattention; the types of studies that are required arelisted in Box 5.4. The aim of such a programme wouldbe to characterise as far as possible the potential forharm to occur by assessing possible human exposures inthe laboratory and the workplace, and by performingsimple tests of solubility and toxicity in vitro, assessingthe validity of these tests by in vivo studies in smallmammals. In the meantime, we believe that there issufficient concern about possible hazards to thoseinvolved in the research and early industrialdevelopment of nanotubes to control their exposure.The role of regulation in controlling the exposure tonanoparticles and nanotubes in the workplace isdiscussed in Chapter 8.

b) Dermal contact

28 Currently, dermal exposure is limited to peopleapplying skin preparations that use nanoparticles.Before and during this study, concerns were raised

about the use of nanoparticles (particularly oftitanium dioxide) for cosmetic purposes. Nanoparticlesof titanium dioxide are used in some sunscreens, asthey are transparent to visible light while acting asabsorbers and reflectors of ultraviolet. Iron oxide isused as a base in some products, including lipsticks,although we understand that in Europe only sizesgreater than 100 nm are used. It is clear thatnanoparticles have different properties to the samechemical at a larger scale, and the implications ofthese different properties for long-term toxicity to theskin require rigorous investigation on a case-by-casebasis.

29 Although the use of sunscreens reduces the risk ofacute sunburn, the evidence that it prevents skin cancerin humans is far from established. There have even beensuggestions that, perhaps by changing patterns ofbehaviour, the use of sunscreens may actually increaserisks (IARC 2001). Some of the preparations used insunscreens, including organic chemicals and particles,may themselves be photoactive in some conditions, soparticular care is necessary in assessing their effects onthe human skin. We have examined the concernsexpressed to us that nanoparticles might penetrate theskin, that titanium dioxide is photoactive and that if it is

Box 5.4 Assessment of likely risks to health of novelfibres such as nanotubes

Exposure studies· Occupational hygiene study of production and

use/disposal to determine the sizes andconcentrations of fibres likely to be present in theworkplace

· Are fibres longer than about 15µm (preventingtheir removal by macropahges)?

· Can fibres reach the part of the lung responsiblefor gas-exchange (ie are they narrower than 3µm)?

In vitro studies· Are fibres durable (an indication that they might

persist in the lung)?· Do fibres kill cells, provoke inflammation and

release free radicals?· What is the effect of removal of metals on their

toxicity?

Small mammal (in vivo) studies· Do fibres persist in rat lung during following

inhalation or instillation?· Do fibres cause an inflammatory response

following inhalation or instillation?· Do fibres cause fibrosis and/or cancer after long-

term inhalation?· Do fibres cause mesothelioma (a cancer) after

injection into rat pleura/peritoneum (membranes ofthe lung and abdominal cavity, respectively)?

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able to penetrate the skin it has the potential togenerate free radicals that are known to cause damageto DNA. Limited toxicology so far on animal and humanskin appears to indicate that the nanoparticles oftitanium dioxide used currently in sunscreens do notpenetrate beyond the epidermis (SCCNFP 2000) andthat organic components of sunscreens are more likelyto penetrate the skin than are the nanoparticles. TheScientific Committee on Cosmetic and Non-foodProducts (SCCNFP), which advises the EuropeanCommission, considered the safety of nanoparticles oftitanium dioxide when used as a UV filter. They declaredit safe for use at any size, uncoated or coated (SCCNFP2000).

30 One of the concerns expressed to us was that thesafety dossier submitted to the SCCNFP remainsconfidential to the industries supplying it, although theevidence supplied is referenced in the final opinion ofthe Committee. Although we recognise that industryhas legitimate concerns about commercialconfidentiality, we consider that this should not preventdata on the safety testing of cosmetic ingredients beingaccessible to the scientific community and otherinterested parties. We expect it to be possible for this tobe done in a way that does not reveal proprietaryinformation about the composition of individualproducts. Therefore, we recommend that the termsof reference of scientific advisory committees(including the SCCNFP or its replacement) thatconsider the safety of ingredients that exploit newand emerging technologies like nanotechnologies,for which there is incomplete toxicologicalinformation in the peer-reviewed literature, shouldinclude the requirement for all relevant datarelated to safety assessments, and themethodologies used to obtain them, to be placedin the public domain.

31 Cosmetics (including sunscreens) are intended foruse on undamaged skin, and most skin penetrationtests appear to have been designed with this in mind.Few reported studies indicate whether these particlespenetrate skin that might have been damagedpreviously, for example by severe sunburn from sunlightexposure or by disease such as eczema. Uncoatednanoparticulate titanium dioxide is photoactive but thecoatings used on titanium dioxide in sunscreens toprevent agglomeration also reduce the formation of freeradicals (Bennat and Müller-Goymann 2000); so even ifthe titanium dioxide used in sunscreens were able topenetrate the skin it would probably not exacerbate freeradical damage. Based on our concerns aboutsunscreens being used on damaged skin, our initialinstinct was to recommend that all products containingsunscreens be regulated as medicines, as they are in theUSA. However, we recognise that this poses challenges,including deciding how many and which types ofproduct would fall into this category. We note that theUK has a total ban on the testing of cosmetic products

and ingredients on animals and that the EU is in theprocess of moving incrementally towards a completeban on all animal testing effective from 2013. Althoughtests on human skin and on cells are available, it is notclear that suitable non-animal models will be availablefor testing nanoparticles by 2013.

32 The SCCNFP has also considered the safety ofnanoparticulate zinc oxide for use as a UV filter incosmetic products and issued an opinion that theyrequire more information from manufacturers to enablea proper safety evaluation (SCCNFP 2003a). In doing sothey highlight evidence that zinc oxide (200nm andbelow – referred to as microfine) has phototoxic effectson cultured mammalian cells and their DNA in vitro.They recommend that the relevance of these findings beclarified by appropriate investigations in vivo. Inaddition, they commented on the lack of reliable dataon the absorption through the skin of zinc oxide andnoted that the potential for absorption by inhalationhad not been considered (SCCNFP 2003a). The US Foodand Drug Administration (FDA) has approved zinc oxidefor use in sunscreens without restrictions on the sizethat can be used, although it is not clear if specificconsideration was given to whether its properties weredifferent at the nanoscale (FDA 1999). The uncertaintiesraised by SCCNFP about microfine zinc oxide as a UVfilter are also relevant to its use in cosmetics and otherskin preparations. In Europe, whereas all cosmetics mustundergo a safety assessment by the manufacturer, onlysome categories of ingredients (such as UV filters) mustbe assessed by the SCCNFP before they can beapproved for use.

33 The regulatory implications of our concerns relatingto skin preparations containing free nanoparticles areaddressed in Chapter 8.

c) Other exposure routes

34 Several therapeutic and investigative options for theuse of nanoparticles are under development, with thebroad aim of them being injectable and able totransport active chemicals to diseased cells. It is likelythat such applications, when realised, will use relativelyfew particles that are biodegradable. As therapeuticsubstances, they should be subject to rigorous safetyand toxicological testing before general release, and thistesting will need to take account of their size as well astheir chemistry. It is apparent that there has been littlecommunication between pharmaceutical scientistsinvestigating nanoparticles for their properties inevading cell defences to target disease and toxicologistsinvestigating the properties of air pollution particles andthe means by which they may cause adverse effects onorgans distant from the lung. For example,nanoparticles are being investigated as carriers ofproteins, such as antibodies, for pharmaceuticalapplications. This ability to conjugate implies that, onceinjected, a similar effect could occur with natural

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proteins in vivo, interfering with the proteins’ functionsin the blood or within cells. It has been speculated thatthese interactions might alter a range of importantcellular functions or indeed nullify the intendedfunctions of the nanoparticles (Borm and Kreyling2004). These possible hazards would most likely apply ifnanoparticles intended for medical applications wereinjected or inhaled, and represent an area in whichfundamental toxicological research is required.

35 There are two important implications of this lack ofdialogue. First, research by pharmaceutical scientists willprovide much useful information about the potentialtoxicity of nanoparticles being developed in othersectors and about means of reducing that toxicity.Secondly, when seeking novel applications ofnanoparticles, pharmaceutical scientists need to beaware of the possible toxic properties of such particles,perhaps on organs or cells other than those targeted. Itis important that the knowledge being gathered by eachis shared with the other. Later in this chapter weconsider how this might be facilitated.

5.4 Effects on the environment and otherspecies

36 Although there is a body of literature about thehuman impacts of pollutant nanoparticles, research onthe impacts of particulate air pollution on the naturalenvironment and on non-human species within it hasprimarily been concerned with the impact of pollutantgases such as sulphur dioxide and ozone rather thanparticles. So with the exception of studies on somelaboratory mammals related to investigation of humantoxicology, there is no equivalent body of literature onnon-human animals that can be used to consider theimpacts of nanoparticles. Similarly, there is a dearth ofevidence about effects of pollution nanoparticles, if any,on plants or micro-organisms.

37 We are only aware of one small published study ofthe impact of manufactured nanoparticles on non-human species (other than laboratory mammals). In thestudy in question, small numbers of juvenile largemouthbass (between four and nine fish in the treatment levels)were exposed to carbon 60 (C60) nanoparticles(fullerenes) that had been treated to make them soluble(Oberdörster 2004a). A significant increase in lipidperoxidation (the oxidation of fats) was found in thebrains of the fish after exposure for 48 hours to 0.5 parts per million (p.p.m.) C60, but the increase wasnot significant at 1 p.p.m. The author noted clarification

of the water in the treated fish tanks, suggesting apossible effect of the nanoparticles on micro-organisms.There is a need to follow up this pilot study with a largerand more detailed investigation.

38 It is plausible that soil or water organisms couldtake up manufactured nanoparticles escaping into thenatural environment and that these particles could,depending on their surface activity, interfere with vitalfunctions. The evidence that nanoparticles may inhibitmotility and phagocytosis of macrophages, for example,suggests that similar effects might be expected onsimple soil organisms. As with human toxicology, thedose to which the organisms are exposed would beexpected to be critical in determining toxicity.

39 In common with other chemicals, nanoparticlesmay reach humans and other organisms by a widevariety of environmental routes. For example, organismsmay ingest materials that have entered the water systemor been deposited on vegetation. The criteria used toidentify chemicals that have intrinsic properties that givecause for concern about their potential to damage theenvironment (or human health through theenvironment) are based on persistence, bioaccumulationand toxicity. The criteria used by the UK ChemicalsStakeholder Forum, for example, are outlined in Box5.5. Chemicals that score highly according to all threecriteria are of particular concern. Once inhaled oringested, materials may enter the food chain, leading tothe possibility of bioaccumulation and ingestion byorganisms higher up the chain. Exposure by ingestiontherefore depends on the persistence of the material(that is, its longevity in the environment) and itspotential to accumulate, usually in lipids. Measures ofpersistence and bioaccumulation indicate when levels ofa chemical are likely to build up in the environment andhow difficult it will be to return concentrations tobackground levels if a problem is identified with thechemical. Bioaccumulation will depend on the surfaceproperties of nanoparticles, which will determinewhether they are likely to be taken up by the fattytissues, bone or proteins in the body. For example, theC60 particles used in the study on largemouth bass(Oberdörster 2004a) were lipophilic, indicating that theycould be taken up by fatty tissues. Persistence willdepend on whether the material decomposes, forexample by oxidation, and on whether the particles aremodified in the environment, for example byagglomerating or adhering to other materials so thatthey lose the particular properties that could make themhazardous as nanomaterials.

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40 For animals, simple tests for persistence andbioaccumulation are available (Royal Commission onEnvironmental Pollution 2003), and can be used forpreliminary screening to identify chemicals whose risksmay give cause for concern. In addition, there arenumerous tests for toxicity. Whether these simple testscan be adapted for nanoparticles and nanotubes needsto be established and, if not, alternatives need to bedeveloped. More generally, there is a need to establishappropriate methodologies for testing the toxicity ofsubstances in nanoparticulate form in the context ofboth the environment and human health. Currently,almost nothing is known about the behaviour ofnanoparticles in the environment (for example, whetherthey agglomerate and how this affects their toxicity); theonly information on how they are transported throughenvironmental media such as soil and water comes frominitial studies on their potential for remediation, whichindicate that nanoparticles of iron can travel with thegroundwater over a distance of 20metres and remain

reactive for 4–8 weeks (Zhang 2003).

41 A current source of environmental exposure is inthe waste streams from factories and researchlaboratories. Until more is known about theenvironmental impacts of nanoparticles and nanotubes,we are keen to manage any potential risk by avoidingtheir release into the environment as far as possible.Therefore, we recommend that factories andresearch laboratories treat manufacturednanoparticles and nanotubes as if they werehazardous, and seek to reduce or remove themfrom waste streams.

42 One of the difficulties in determining potentialfuture exposure of the environment and humans tomanufactured nanoparticles is the lack of informationabout both the extent to which they will be used inproducts and also the likelihood of such particles beingreleased from nanomaterials such as composites in aform or quantity that might cause harm to humans orthe environment. Although we expect that exposurefrom composites containing nanoparticles andnanotubes will be low – because they will typically makeup a very small fraction of the final product and thefunctionality of the material will rely on them beingretained – there is a need to test this assumption. Weexpect the ways of fixing nanoparticles and nanotubeswill be proprietary. Therefore, we recommend that, asan integral part of the innovation and designprocess of products and materials containingnanoparticles or nanotubes, industry should assessthe risk of release of these componentsthroughout the life cycle of the product and makethis information available to the relevantregulatory authorities.

43 Any widespread use of nanoparticles in productssuch as medicines (if the particles are excreted from thebody rather than biodegraded) and cosmetics (that arewashed off) will present a diffuse source ofnanoparticles to the environment, for example throughthe sewage system. Whether this presents a risk to theenvironment will depend on the toxicity of nanoparticlesto organisms, about which almost nothing is known,and the quantities that are discharged.

44 Perhaps the greatest potential source ofconcentrated environmental exposure in the near termcomes from the application of nanoparticles to soil orwaters for remediation (and possibly for soil stabilisationand to deliver fertilisers), as outlined in section 3.2. Insome cases the nanoparticles used for remediation areconfined in a matrix but, in pilot studies, slurries of ironnanoparticles have been pumped into contaminatedgroundwater in the USA (Zhang 2003). Given the manysites contaminated with chemicals and heavy metals,the potential for nanotechnologies to contribute toeffective remediation is large. But this potential use alsoimplies a question about eco-toxicity: what impact

Box 5.5 Criteria for concern of the UK ChemicalsStakeholder Forum

Persistence: Chemicals that are persistent are thosethat either take a long time to decay once they arereleased into the environment, or do not decay atall. The Forum classes a substance as persistent if itdoes not decay to half of its original quantity withintwo months (if in water) or six months (if in soil orsediment).

Bioaccumulation: Chemicals that arebioaccumulative have a strong tendency to be takenfrom solution (for example, in the stomach or fromthe blood of organisms that they enter) into thefatty tissues of the body where they remain. Asubstance is classed as bioaccumulative if, in tests todetermine its attraction to fatty tissue over water,the substance favours fatty tissue in a ratio(quantity-wise) of 10,000 to 1 or more. Anysubstance that favours fatty tissue with a ratio of atleast 100,000 to 1 is consequently considered ascause for extreme concern. Chemicals thataccumulate in bone or bind to proteins are also ofconcern.

Toxicity: Chemicals that are toxic cause directdamage to organisms that are exposed to them. TheForum's criteria for toxicity generally follow thoseoutlined in the EU Directive on dangerous substances(67/548/EEC). In addition to the Directive, asubstance is classed as being of concern if it is fatalto at least 50% of waterborne organisms in a givensample, where the concentration of the substance is0.1mg per litre or less.

Adapted from Chemicals Stakeholder Forum (2003)

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might the high surface reactivity of nanoparticles thatare being exploited for remediation have on plants,animals, microorganisms and ecosystem processes? It isof course possible that, in the concentrations used inremediation, any negative impacts on ecosystems will beoutweighed by the benefits of the clean up ofcontaminated land and waters, but this needs to beevaluated by appropriate research and further pilotstudies before deliberate release into the environment isallowed. In the UK, requests for use of nanoparticles inremediation of groundwater and other contaminatedmedia are likely to be made to the Environment Agency.We recommend that the use of free (that is, notfixed in a matrix) manufactured nanoparticles inenvironmental applications such as remediation beprohibited until appropriate research has beenundertaken and it can be demonstrated that thepotential benefits outweigh the potential risks.

45 It has also been suggested to us that thatnanoparticles might be used to increase thebioavailablity of pollutants, allowing them to be brokendown by bacteria, or that they might be used todisperse and dilute pollutants. As with the exampleabove, the very properties that researchers hope toexploit could potentially lead to unintendedconsequences for the environment, for exampleincreased bioavailability of pollutants to plants andanimals, or the transport of pollutants to sensitiveecosystems. This is clearly another area where moreresearch is required alongside the development of theseremediation systems.

5.5 Risk of Explosion

46 The explosion of dust clouds is a potential hazard inindustries such as food production (sugar, flour, custardpowder), animal feed production and places handlingsawdust, many organic chemicals, plastics, metalpowders and coal. The increased production ofnanopowders such as metals has led to questions aboutwhether there is a greater risk of explosion in the cloudsof these nanopowders that might form during theirproduction, transport or storage. Any dry, fine andcombustible powder poses an explosion or fire risk,either through spontaneous combustion or ignition. Theincreased surface area of nanoparticles might mean thatthey would be more likely to become self-charged, andbe more easily ignited. In addition, because of theirsmall size, nanoparticles may persist for longer in the air,may be harder to detect and may be invisible to thenaked eye, making crude detection difficult.

47 The UK Health and Safety Laboratory (HSL) hasrecently reviewed research in this area and found thatalthough there is a body of literature about theexplosion risk of micrometre-scale powders, noinformation exists on nanopowders (HSL 2004).Research on micrometre-scale powders reveals that

explosion severity tends to increase with decreasingparticle size, although for some substances this effectlevels off. The report recognises that the changes in thephysical and chemical properties of particles below100nm mean that results from tests at the micrometre-scale cannot be extrapolated to the nanoscale, wherethe risk of explosion could be either greater or smaller.The HSL has identified the need for research todetermine the explosion characteristics of arepresentative range of nanopowders; they believe thatthis research can be undertaken using standardapparatus and procedures already employed forassessing dust explosion hazards.

48 The risk of explosion can be avoided if combustiblenanopowders are manufactured, handled and stored inliquid. By contrast, the drying of nanopowders in rotarydriers is of particular concern. At present only a very fewnanopowders are produced in the type of quantitiesthat might present a dust explosion hazard (forexample, carbon black). Other than these, specialistnanoparticles are currently produced or used in verysmall quantities (that is, grams) and do not pose thisparticular hazard. Until the explosion hazard has beenproperly evaluated, this potential risk can be managedby avoiding large quantities of combustiblenanoparticles becoming airborne.

5.6 Addressing the knowledge gaps

49 Given the relatively small amounts of manufacturednanoparticles being produced, it is perhaps notsurprising that there is a lack of information about theirhealth, safety and environmental impacts. At present wehave to rely by analogy on research results from airpollution and occupational research, the budget forwhich in the UK is very limited. Some research on thetoxicity of new nanoparticles is underway, particularly inthe USA (Service 2004). For example, the NationalInstitute for Occupational Safety and Health in the USAis about to undertake a 5-year study into the toxicityand health risks associated with occupationalnanoparticle and nanotube exposure, and is developinga dedicated centre to coordinate activities. Some work isalso being funded by the European Commission.

50 With the exception of the research into air pollutionby the Department of Health (DH) and the Departmentfor Environment Food and Rural Affairs (DEFRA), nocoordinated programme of research into the health andenvironmental risks of nanomaterials is beingundertaken in the UK. We are pleased to hear that theUK research councils have committed to work togetherto address the issues raised in our report, and note thatthe Engineering and Physical Sciences Research Council(EPSRC) is assembling two ‘thematic networks’ in thearea of nanosafety (House of Commons 2004b). Inaddition, the environmental impact of nanotechnologiesis now on the agenda for the Environmental Funders’

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Forum, which brings together the UK's major publicsector sponsors of environmental science (including theresearch councils, DEFRA and the Environment Agency).As nanotechnologies advance, so environmental andhuman health hazard and risks should be investigated intandem, priority being given to categories of productseither in or near to the market.

51 The capacity for particle toxicology in the UK, basedas it was on the need to protect workers in heavyindustries such as those concerned with coal, steel andasbestos, has declined with the reduction in numbers ofworkers employed in such industries. However, a recentrise in interest in air pollution has allowed maintenanceof a nucleus of expertise, particularly in Edinburgh andCardiff. Traditionally, particle toxicologists have workedvery closely with the relevant industries and the researchcouncils. There is now an opportunity for a newcollaboration between nanotechnologies, environmentalscience, pharmaceutical science and toxicology, buildingon the current expertise in air pollution and fibreresearch. Fundamental questions about the interactionsof cells and their components and particle surfaces, andpragmatic questions about likely exposures andmethods of their reduction, need to be addressed. Wenote the close relationship between toxic effects on cellssuch as macrophages derived from humans or othermammals and similar effects on organisms in thegeneral environment. We also note the commoninterests of those concerned with research into possiblebeneficial effects of nanoparticles in the pharmaceuticalindustry and those concerned with toxicity. We believethat there is a strong case for a research dialoguebetween human toxicologists, pharmaceuticalnanoscientists and eco-toxicologists.

52 A fundamental aspect of assessment of risk is theability to quantify the hazard; this applies to all theabove sections. Nanoparticles and nanotubes are toosmall to be measured by most standard instrumentsused, for example, in workplaces. Those instrumentsused for their quantification, electron microscopes andscanning mobility particle size analysers, are expensiveand require a high level of expertise to use, althoughsome cheaper, portable instruments are becomingavailable. Moreover, it is not known which physicalproperty of nanoparticles is the one that correlates mostclosely with toxicity. The quantification of nanoparticlesfor regulatory purposes in mixtures such as cosmetics orin effluents would raise particular problems. There is animportant need to develop, standardize and validatemethods of measurement of nanoparticles andnanotubes in workplaces and the environment.

53 In Box 5.6, we summarise the research required toaddress some of the knowledge gaps highlighted in thischapter and to develop methodologies andinstrumentation to support the regulation of

production, use and disposal of nanoparticles (discussedfurther in section 8.4.3).

54 Much of the necessary research by its naturerequires an interdisciplinary approach. Some of therelevant research should be done by Governmentagencies or through international collaborations, but itis important for the UK to have its own centre ofexpertise, which would maintain a database ofinformation, become the centre of a network todisseminate this information, and act as a source ofadvice for industry and regulators.

55 We recommend that Research Councils UK(RCUK) establish an interdisciplinary centre(probably comprising several existing researchinstitutions) to research the toxicity, epidemiology,persistence and bioaccumulation of manufacturednanoparticles and nanotubes as well as theirexposure pathways, and to developmethodologies and instrumentation formonitoring them in the built and naturalenvironment. A key role would be to liaise withregulators. We recommend that the research centremaintain a database of its results and that itinteract with those collecting similar informationin Europe and internationally. The remit of theresearch centre is summarized in Box 5.7.

56 Initially, RCUK will need to build expertise andcollaborations in the areas outlined in Box 5.6, and itshould work with the community to assemble anappropriate centre (along the lines of EPSRC quantuminformation processing Interdisciplinary ResearchCollaboration) rather than invite competitive bids. Itsadvisory board should include industrialists andregulators as well as scientists from the UK and overseasto ensure the wider relevance of the researchprogrammes. Funding for the centre should keep pacewith the development of manufactured nanoparticles.We estimate that funding at the rate of £5-6 M perannum for 10 years is needed to perform the tasks thatwe have outlined. Although core funding would needto be provided by the UK Government, we wouldexpect to see the centre participating in European andinternationally funded projects. As methodologiesbecome established, the centre might become therecognized place for the testing of nanoparticles andnanotubes and develop a sustainable funding basewithin approximately 10 years. Because it will not bepossible for the research centre to encompass allaspects of research relevant to nanoparticles andnanotubes, we recommend that a proportion of itsfunding be allocated to research groups outsidethe centre to address areas identified by theadvisory board as of importance and not coveredwithin the centre.

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5.7 Conclusions

57 Many applications of nanotechnologies introduceno new health, environmental or safety aspects, forexample where the nanotechnology is in the scale of anode on a computer chip or of nanometre thin films indata storage devices such as hard disks. Free particles inthe nanometre size range do raise health, environmentaland safety concerns and their toxicology cannot beinferred from that of particles of the same chemical atlarger size. The difference comes largely from two size-dependent factors: the larger surface area of smallparticles compared with larger particles, given equalmass, and the probable ability of nanoparticles topenetrate cells more easily and in a different mannerthan larger ones. Exposure to natural and pollutionnanoparticles in ambient and indoor air is universal, andmost of the population and workers in many industriesare exposed to high concentrations without significantharm. Nevertheless, in recent decades it has beensuggested, though not proven, that such exposures maybe responsible for the observed relationships betweenair pollution and several diseases, particularly of theheart and the lung, in susceptible individuals.

58 Toxicological investigations, based largely on lowsolubility, low surface-activity nanoparticles, havesuggested that the ability of such particles to causeinflammation in the lung is a consequence of reactions

Box 5.7 Remit of the proposed interdisciplinaryresearch centre

· To undertake the research programmes outlined inBox 5.6.

· To act as the UK centre for advice on the potentialhealth, safety and environmental impacts ofnanomaterials.

· To hold regular dialogue meetings with appropriateregulators to exchange information on therequirements of regulators and research findings.

· To maintain a network bringing together thoseresearching into:

· epidemiology, toxicology, persistence,bioaccumulation, exposure pathways andmeasurement of manufactured nanoparticlesand nanotubes;

· medical applications of nanoparticles andnanotubes;

· epidemiology, toxicity, exposure pathwaysand measurement of nanoparticles in airpollution.

· To maintain an accessible database of results frompublicly funded research within the centre on thetoxicity of nanoparticles and nanotubes, and tointeract with those collecting similar information inEurope and internationally.

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Box 5.6 Research areas to be addressed

· Development of suitable and practical methods for measurement of manufactured nanoparticles andnanotubes in the air and other media, including those properties most likely to reflect their toxicity such assurface area and potential to release free radicals.

· Investigation of methods of measuring the exposures of workers to manufactured nanoparticles and nanotubesin current laboratories and manufacturing processes.

· Development of international agreement on measurement standards.· Establishment of protocols for investigating the long-term fate of nanoparticles as products containing them

approach the market, to determine whether, how and to what extent they might come into contact with thenatural environment.

· In conjunction with research on environmental remediation, develop an understanding of the transport andbehaviour of nanoparticles and tubes in air, water and soil, including their interactions with other chemicals.

· Epidemiological investigation of the inter-relations of exposure and health outcomes in those industrialprocesses, such as welding, carbon black and titanium dioxide manufacture, where nanoparticle exposure hasbeen known to have occurred for some time.

· Development of internationally agreed protocols and models for investigating the routes of exposure andtoxicology to humans and non-human organisms of nanoparticles and nanotubes in the indoor and outdoorenvironment, including investigation of bioaccumulation. This would include an understanding of the impact ofdifferent sizes of nanoparticles and different types of coating.

· In collaboration with pharmaceutical nanoscientists and air pollution toxicologists, fundamental studies of themechanisms of interaction of nanoparticles with cells and their components, particularly the effects on bloodvessels, the skin, heart and the nervous system.

· Development of protocols for in vitro and in vivo toxicological studies of any new nanoparticles and nanotubeslikely to go into large-scale production and which could impact people or the natural environment.

· Further investigation of the absorption through skin of different commercial nanoparticles used in dermalpreparations, in particular any changes that may occur if the skin is damaged before application.

· Determination of the risk of explosion associated with a representative range of nanopowders (assumingfunding has not already been received by HSL for this research).

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between cells and a large total particulate surface area(perhaps carrying reactive metals and other chemicals).Although it is very unlikely that new manufacturednanoparticles could be introduced into humans insufficient doses to cause the effects associated with airpollution, nevertheless it is important that precautionsare taken in the workplace in manufacturing andresearch laboratories to manage this potential risk bylimiting exposure.

59 Moreover, it seems likely that the needs of industrywill be met by development of a diverse range ofnanoparticles with differing properties, and that thesemight lead to production of nanoparticles with surfacesthat increase their reactivity and their ability to traversecells, become blood-borne or cause injury to tissue.Therefore new nanoparticles that differ substantiallyfrom those with low solubility, low toxicity physico-chemistry should be treated with caution. If they are tobe produced on a large scale they should be tested fortheir hazard and any likely human exposure assessed, sothat risk can be minimised.

60 Exposure to fibres in industry, in the form of asbestos,is a well-recognised cause of serious illness, includingcancer. The toxic properties of such fibres are dependentupon a diameter narrow enough to allow inhalationdeep into the lung, a length that prevents their removalby macrophages, resistance to dissolution in tissue fluid,and a surface able to cause oxidative damage. However,the doses of asbestos associated with disease aresubstantial, of the order of several hundred per breathat work over months or years. Any new fibre with theseproperties would be expected to cause similar problemsif inhaled in sufficient amounts to lead to similar lungburdens of long fibres. Carbon and other nanotubeshave physical characteristics that raise the possibility ofsimilar toxic properties, although preliminary studiessuggest that they may not readily be able to escape intothe air in fibrous form. Such materials require carefultoxicological assessment and should be treated withparticular caution in laboratories and industry.

61 Several nanoparticles are currently used incosmetics and sunscreens. We believe the publishedevidence on toxic hazards from some such particles forskin penetration is incomplete, particularly in individualsusing these preparations on skin that has beendamaged by sun or by common diseases such aseczema. Further careful studies of skin penetration bynanoparticles being considered for use, and the propensity of such particles to potentiate free radicaldamage, are desirable.

62 The methods of quantifying nanoparticles andespecially nanotubes pose serious problems at present.There is a need for more industrial hygiene andepidemiological evidence to guide regulation bydifferent particle metrics; this requires research intoappropriate instrumentation and standardisation ofmeasurement.

63 Until research has been undertaken and publishedin the peer-reviewed literature, it is not possible toevaluate the potential environmental impact ofnanoparticles and their behaviour in environmentalmedia. Until more is known about environmentalimpacts of nanoparticles and nanotubes, werecommend that the release of manufacturednanoparticles and nanotubes into the environmentbe avoided as far as possible. In section 5.4 we makespecific recommendations to reduce releases ofnanoparticles and nanotubes in waste streams andthose used for environmental applications in whichnanoparticles are dispersed freely (for example, inremediation and soil stabilization).

64 Our conclusions have been based on incompleteinformation about the toxicology and epidemiology ofnanoparticles and their behaviour in air, water and soil,including their explosion hazard. If nanotechnologies areto expand and nanomaterials become commonplace inthe human and natural environment, it is important thatresearch into health, safety and environmental impactskeeps pace with the predicted developments. In thischapter we recommend that RCUK establish aninterdisciplinary centre (probably comprising severalexisting research institutions) to undertake research intothe toxicity, epidemiology, biopersistence andbioaccumulation of manufactured nanoparticles, theirexposure pathways, and methods and instrumentationfor monitoring them in the environment. A key rolewould be to liaise with regulators. We recommend thatthe research centre maintain a database of its resultsand that it interact with those collecting similarinformation in Europe and internationally.

65 In this chapter we have identified several ways inwhich the risks of nanoparticles and nanotubes can bemanaged. In Chapter 8 we consider how this riskmanagement can be incorporated into some of therelevant regulatory frameworks, such as those thatrelate to the safety of employees and consumers.

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6 Social and ethical issues

6.1 Introduction: framing social and ethicalissues

1 As recent debates in the UK and elsewheredemonstrate, developments in science and technologydo not take place in a social and ethical vacuum.Widespread discussions of issues such as nuclear energy,agricultural biotechnology and embryonic stem cellsillustrate this point only too clearly.

2 Given this backdrop, it seems highly likely thatsome nanotechnologies will raise significant social andethical concerns. Such concerns seem most likely fordevelopments envisaged for the medium (5–15years)and much longer (more than 20years) time horizons.However, such issues rarely become matters of concernmerely as a result of the underlying science orengineering. More typically, they are associated withspecific applications of a technology. For example, inEurope medical or ‘red’ uses of biotechnology haveraised a very different set of concerns from those raisedby agricultural or ‘green’ applications (Gaskell and Bauer2001). As earlier chapters of this report illustrate, theterm ‘nanotechnologies’ encompasses an even widerrange of basic science, methods and engineeringapproaches than biotechnology, and so are likely to giverise to a highly diverse set of potential applications oververy different time-scales. Predicting all but the near-market applications of such a diverse effort is a difficultenough task, as a recent report from the RANDCorporation points out (Anton et al 2001), butanticipating which applications are likely to raisesignificant long-term social or ethical issues sets an evenbigger challenge. Some currently envisioned applicationsof nanotechnologies which are seen as technicallyfeasible may never be realised on a significant scale,while unanticipated scientific breakthroughs may lead torapid applications that are not currently foreseen.

3 Most of the social and ethical issues arising fromapplications of nanotechnologies will not be new orunique to nanotechnologies. However, throughout thischapter we take the view that effort will need to bespent whenever significant social and ethical issues arise,irrespective of whether they are genuinely new tonanotechnologies or not. Previous chapters havehighlighted some of the possible short-term health andenvironmental implications of certain developments innanotechnologies, each of which have their own socialand ethical dimensions. Here we discuss some of thewider social and ethical issues that these newtechnologies raise. The list is not intended to be anexhaustive treatment but to highlight what seem to us tobe significant issues. When discussing both the potentialpositive and negative impacts of nanotechnologies, wehave tried to avoid an unbalanced discourse (present insome of the more speculative writings on the subject),

which implies that major positive benefits for societyalways be accredited to the ‘new science ofnanotechnology’, while any negative social and ethicalissues are ‘just a problem of technology’ or alternativelythat the very newness of a technology is itself evidenceagainst it. Nanotechnologies, whether singly or inconvergence with other technologies, are likely to hold arange of both positive and (however unintended)negative outcomes.

4 Widespread acceptance and use ofnanotechnologies will depend upon a range of socialfactors including: specific technical and investmentfactors; consumer choice and wider public acceptability;the political and macro-economic decisions thatcontribute to the development of major technologiesand outcomes that are viewed as desirable; and legaland regulatory frameworks. Equally, just as theknowledge-base underpinning science and technologycan change rapidly and unpredictably, so can society.Forecasting people’s needs and values 20 years or moreinto the future is fraught with uncertainty. Accordingly,it is difficult to state with any confidence hownanotechnologies are likely develop in the future, ininteraction with a changing society and its shifting socialand ethical concerns. It may also be important to lookbeyond the perspective of Western industrialisedsocieties, to take account of the ways in which peoplein developing societies might respond to developmentsin nanotechnologies and their impacts.

5 Precisely which social and ethical issues become afocus of concern will hinge upon the actual trajectoriesof change in particular nanotechnologies. In their recentreport for the ESRC on the social and economicchallenges of nanotechnology, Wood et al (2003) pointout that current evaluations of the impacts ofnanotechnologies can be located on a continuumwhose extreme poles are on the one hand incrementalprogress (the view that nanotechnologies merelyrepresent a basic evolution from well-establishedprinciples and procedures), and on the other a radicaldisjunction from current science and technology (forexample, as represented by the vision of nanobotsoutlined in Annex D). According to the authors of theESRC report, most current commentary on social,economic and ethical impacts, which ranges from thehighly optimistic to the almost apocalyptic, occupies thecentre ground of this continuum. What does seem clearis that genuinely new and/or unanticipated social orethical issues are likely to be associated with radicaldisjunctions if they occur. Equally, much of what passesfor incremental nanotechnologies (for example,powerful computers networked with cheaper smallsensors) may still prove transformative in social terms.This is because the role of nanotechnologies is likely tobe an enabling one, often in convergence with other

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new technologies, bringing to fruition applications suchas pervasive sensing which have been anticipated bycommentators for many years, but are only nowbecoming a practical possibility. Much of thecommentary provided to the working group alsosuggests that many of the social and ethical issuesraised by incremental developments are unlikely toprove entirely new. For example, many concerns aboutthe overall impact of a rapidly changing science onsociety, and the governance and regulation of thetechnology, are likely to echo some of those raisedpreviously about other developments in science andtechnology that have proved controversial, such asnuclear energy, reproductive technologies orbiotechnology (Mosterín 2002). That does not makethese concerns any the less significant or worthy of theattention of policy-makers; indeed, past experience withcontroversial technologies should predispose policy-makers to pay timely and applied attention to theseconcerns rather than dismissing them as 'nothing new'.

6 This chapter provides selective comments on thesignificant claims and arguments that have beenpresented to the working group, alongside others thatare found in the published literature, to highlight someof the more difficult issues that might potentiallyemerge. Some of the issues covered here were alsoraised in the group workshops on nanotechnologies withmembers of the public that were conducted as part ofthis study; findings from these are discussed in detail insection 7.2. For the reasons outlined above, this chaptercannot pretend to be a full-scale horizon scanningexercise for social and ethical impacts. This is one of thereasons why we recommend here that at least someform of ongoing evaluation, and in section 7.6 thatcontinuing dialogue and engagement, be extended wellbeyond the lifetime of the Working Group.

6.2 Economic impacts

7 There is some disagreement about how much of aneconomic impact nanotechnologies will have. A rangeof views has been heard in evidence. Overall, it seemsthat effects will be incremental in the short term but,given the fact that nanotechnologies are likely to enablea great many products and processes, they may wellhave significant economic impact in the long-term. Asargued above, much will depend upon which particularapplications eventually come to market, and the order inwhich they are developed. Judging by experience,seemingly insignificant technological advances couldhave profound long-term economic impacts. Somecommentators appear to assume that the potentialeconomic results of nanotechnologies – greater grossdomestic product (GDP), greater efficiency and lesswastage in industrial processing – will be entirelypositive across society or across the range of developedand developing nations. However, in general theintroduction of new technologies creates both ‘winners’

and ‘losers’; for example, as employment is displacedfrom one sector to another.

8 At this stage, evidence does not suggest thatnanotechnologies raise economic issues that differsignificantly from other cases of technological innovation.However, it would contribute greatly to the wider societaldebate and to decisions about the introduction ofnanotechnologies if appropriate economic analysis ofdevelopments with widespread societal impacts, includingan assessment of the advantages and disadvantages, isundertaken at an appropriate stage. Since this cannot bedone on a systematic basis far ahead of the developmentof new technologies (for reasons given at the start of thischapter), such analysis would need to proceed on a case-by-case basis, as developments and applications comecloser to market. Such analysis should also take fullaccount of the uncertainties involved, of the case forrelying on alternative technologies and of any economicshocks and surprises.

6.3 A ‘nanodivide’?

9 Much of the ‘visionary’ literature at the radicaldisjunction end of the continuum described in the ESRCreport (Wood et al 2003) contains repeated claimsabout the major long-term impacts of nanotechnologiesupon global society: for example, that it will providecheap sustainable energy, environmental remediation,radical advances in medical diagnosis and treatment,more powerful IT capabilities, and improved consumerproducts (see many of the contributions to two recentNational Science Foundation (NSF) workshops (NSF2001, 2003)). If even a few of these predictions provetrue then the implications for global society and theeconomies of many nations are profound indeed.However, it is equally legitimate to ask who will benefitand, more crucially, who might lose out? Theapplication of science, technology and engineering hasundoubtedly improved life expectancy and quality of lifefor many in the long term. In the short-term, however,technological developments have not necessarilybenefited all of humankind, and some have generatedvery definite ‘winners’ and ‘losers’.

10 Concerns have been raised over the potential fornanotechnologies to intensify the gap between rich andpoor countries because of their different capacities todevelop and exploit nanotechnologies, leading to a so-called ‘nanodivide’. If global economic progress inproducing high-value products and services dependsupon exploiting scientific knowledge, the high entryprice for new procedures and skills (for example, in themedical domain) is very likely to exacerbate existingdivisions between rich and poor (P Healey, writtenevidence). Equally, a parallel danger that could arise ifthe more radical ‘visions’ of the promise ofnanotechnologies were realised, is that enthusiasm fordeveloping a ‘technical fix’ to a range of global and

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societal ills might obscure or divert investment fromcheaper, more sustainable, or low-technology solutionsto health and environmental problems.

11 A further concern that has been highlighted (ETC2003a; GeneWatch UK written evidence) relates topatenting in the field of nanotechnologies. Appropriateownership of intellectual property is generallyconsidered advantageous. However, as experience ingenetics shows (Nuffield 2002), patents that are toobroad or that do not strictly meet the criteria of noveltyand non-obviousness, can work against the publicgood. There is a concern that broad patents could begranted on nanotechnologies, for example on processesfor manipulating or creating materials, which wouldstifle innovation and hinder access to information, notleast by those in the developing world. As highlighted inthe Royal Society report on intellectual property (RoyalSociety 2003), it is vital that patent offices monitor thecomplex and rapidly changing developments in scienceand technology so that any patents which are grantedare appropriate and support rather than constrainresearch and innovation.

12 In evidence presented to the Working Group, DougParr of Greenpeace highlighted the potentially beneficialapplications of nanotechnologies for the developingworld and for the environment, for example by reducingcarbon dioxide emissions through improving renewableenergy technology, and expressed concern thatnanotechnologies could become another ‘opportunitylost’ for developing countries. The Joint Centre forBioethics (2004) also highlight applications such asusing nanosized quantum dots for cheaper, quickerdisease detection, and improved water purificationtechnologies, which could have benefits for the poor.There have also been suggestions thatnanotechnologies could offer new opportunities forsome developing countries to participate more directlyin global technology through their own initiatives – forexample, through the development of plastic electronicsfacilities, which are one-hundredth of the cost ofconventional silicon fabrication plants.

13 There are therefore significant risks that someshort-term developments in nanotechnologies will beexclusive to those who already own wealth and power,to the detriment of wider society. Equally, opportunity toapply nanotechnologies in ways that will benefit thedeveloping world should not be overlooked. Twofundamental questions arise in this context. First, canthe future trajectories of nanotechnologies be steeredtowards wider social or environmental goals (forexample, cheap sustainable energy generation andstorage) rather than towards meeting short-term ordeveloped world ‘market’ opportunities (for example,cosmetics)? Second, if a ‘nanodivide’ develops, whatcan governments do about it? For example, to theextent that the products of nanotechnologies becomeessential to normal participation in society, should public

authorities try to rectify the divide in an appropriateway? Where the products are luxury goods, can theirdemand and supply reasonably be left to the market?The governance of nanotechnologies must in some waybe designed to incorporate the perspectives andobjectives of governments, the market and civil society.

6.4 Information collection and the implications for civil liberties

14 As we saw in Chapter 3, nanotechnologies promiseconsiderable advances in developing small and cheapsensing devices, enabling a range of features that willmake smaller, longer-lasting sensors possible. Theconvergence of nanotechnologies with IT could providethe basis for linking complex networks of remotesensing devices to significant computational power.Some nanodevices may be widely incorporated in otherproducts. Such developments could be used to achievegreater safety, security and individualised healthcare,and could offer advantages to business (for example intracking and other monitoring of materials andproducts). However, the same devices might be used inways that limit individual or group privacy by covertsurveillance, by collecting and distributing personalinformation (such as health or genetic profiles) withoutadequate consent, and by concentrating information inthe hands of those with the resources to develop andcontrol such networks. The ETC Group claim that‘biosensors and chips…could become ubiquitous indaily life – monitoring every aspect of the economy andsociety’ (ETC 2003a).

15 These kinds of development might reinforce existingconsumer concerns about the use of radio frequencyidentification (RFID) technology to replace bar codes,currently being trialled by supermarkets and clothingretailers. A recent briefing on RFID from the NationalConsumer Council (2004) highlights concerns such as:the potential to link personal information (for example,credit card number) to a particular product, which maythen allow individuals to be profiled and tracked in storeand marketed to on an individual basis; the increasedcollection of data on an individual; and whether there isabuse if the technically unequipped cannot detectsensing devices. The Government's Foresight programmerecently completed a project on cyber trust and crimeprevention, which explored the application andimplications of next generation information technologies(including developments in nanotechnologies) in areassuch as identity and authenticity, surveillance andinformation assurance. One of the science reviews thatcontributed to this project (Raab 2004) highlighted theincreased use of surveillance, with implications forpolicing, profiling and ‘social sorting’, all of which‘continually seek to identify, classify and evaluateindividuals according to ever more refined anddiscriminating forms of personal data. Sorting is a highlypotent set of techniques with political and social-control

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implications’. These themes were also explored in theRoyal Society’s public dialogue on cybertrust andinformation security in March and April 2004.

16 This issue is clearly one where nanotechnologies playan enabling role in promoting societal changes that haveboth positive and (if the technology is abused) negativeconsequences. It seems unlikely that the underlying legaland ethical issues raised by such developments will be anydifferent in principle from those society has faced in thepast across a whole range of healthcare and consumerissues. However, as new forms of surveillance and sensingare developed, further research and expert legal analysismight be necessary to establish whether currentregulatory frameworks and institutions provideappropriate safeguards to individuals and groups insociety. We touch on this again in section 8.5.

6.5 Human enhancement

17 As noted in section 3.5.3h, nanotechnologies arecontributing to the development of some‘enhancement’ applications; the closest to developmentbeing improved cochlear and retinal implants, toimprove or restore hearing and eyesight.

18 A few disability rights groups have objected toproposed interventions that enhance human capacities,on the grounds that this might lead to stigmatisation ofthose without enhanced capacities (see, for example,Wolbring 2003). The general concern is difficult to graspwithout a clear account of the difference betweenenhancements and other interventions. The issue ofspecific human enhancements is also likely to fall,initially at least, squarely within the medical domain,where there is an established history of consideringemergent ethical issues and the societal acceptability ofparticular procedures.

19 The general issues about stigmatisation of thosewho are different in various ways is a serious one, but ithas little connection with ways in which differencesbetween people may be brought about. All successfulmedical treatment of illness, including treatment ofillness with a genetic basis, enhances the functioningand capacities of those who are treated. Even where anintervention – a drug, a prosthesis, a medical device,surgery – is not effective for all sufferers, it can hardly bewithheld from those who could benefit on the groundsthat some others cannot. There is no general case forresisting technologies or interventions that enhancehuman capacities. It would be wrong to denyappropriate treatment to patients whose impaired sightcan be improved by glasses or surgery simply becauseothers have sight impairments that cannot be improved.

20 What is important to note is that a purely ‘technicalfix’ view of disability is not unproblematic. In evidencepresented to the Working Group, Richard Light, director

of the DAART Centre for Disability and Human Rights,suggested that disabled people may prefer money to beallocated to, for example, anti-discrimination or humanrights measures, rather than technology in general andnanotechnologies in specific as a cure. He also statedthat medical technology is irrelevant unless people canafford and have access to it, and urged properconsideration of the claims that nanotechnologies willprovide benefits to the disabled: ‘any suggestion thatnanotechnologies will have an impact on their livesmust be assiduously tested; making such claims withouta demonstrable basis in fact is immoral and does little toreassure those concerned by the commercialisation ofscience.’

21 However, certain types of enhancement may bemore controversial, whether because those who lackthem would be stigmatised or (more probably) for otherreasons. For example, some have argued that allenhancement by gene therapy is an unacceptable formof eugenics, while others have argued that geneticenhancement of basic capacities such as intelligence orheight would only be acceptable only if fairly distributed(Buchanan et al 2002). Yet others hold that ifenhancement of capacities by education or training isacceptable, then enhancement of capacities by othermeans, such as cosmetic surgery or taking drugs withcognitive effects, is also acceptable. A parallel debatecan be found between those who are concerned aboutthe use of performance-enhancing drugs by athletes orothers (usually on grounds of unfairness or risk tohealth)1, and those who think that if it is acceptable toenhance performance by exercise, then it is acceptableto do so by taking drugs2.

6.6 Convergence

22 Convergence refers to the multiple ways in whichnanotechnologies will combine in the future with otherdevelopments in new technology (reflecting itsgenuinely interdisciplinary nature). Convergenceprobably presents some of the biggest uncertainties,with respect to what is genuinely plausible and whennew technologies might actually come into use. Wehave noted above how convergence ofnanotechnologies with information technologies couldraise concerns about civil liberties. However,convergence is likely to generate a range of other socialand ethical challenges, particularly in relation to longer-term applications within bio-nanotechnology thatinvolve significant interface of material systems with, orinternal modification of, the body. Some developments– although essentially physical interventions conductedprimarily for medical benefits – might well raise a rangeof fundamental psychological and sociological questionscentred around the issue of identity: that is, what weunderstand to be ‘human’, what is ‘normal’ and what isnot. As stated in the recent report from the GermanParliament Office of Technology Assessment (TAB 2004):

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1 For more on the medical consequences of taking performance-enhancing drugs in sport, see http://www.bmjpg.com/chapters/0727916068_sample.pdf.

2 For a bibliography of writing on human enhancement see http://www.ucl.ac.uk/~ucbtdag/bioethics/biblio.html.

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'In visions of nanotechnology, we repeatedly see aspectswhich dissolve the boundaries between whatconstitutes a human being, and what they can createwith the help of technological achievements andapplications. Such aspects relate for example to thepenetration and modification of the human body byattempts to supplement or replace its biologicalcomponents by nanotechnology components, and tonetwork it with external machines or other bodies orbody parts'. Developments that in some way invade orintervene with the body in the manner described aboveare also likely to raise issues of control and choice andto be particularly sensitive in relation to publicperceptions and concern. In evidence presented to theworking group, Stephen Wood and Richard Joneshighlighted that although these very extreme visions ofthe potential outcomes of nanotechnologies – includingthe possibility of greatly expanding lifespans, or even ofthe separation of human consciousness from the bodyand its relocation in a computer – may seem too far-fetched for many scientists, these visions do form abackground for discussions of the impact ofnanotechnologies by informed non-scientists.

23 An example of proposals for radical humanenhancement appears in a recent publication jointlysponsored by the US NSF and the Department ofCommerce, which maps out a possible futureconvergence of nanotechnologies with biotechnology,information and cognitive sciences for enhancinghuman performance. The editors of this report suggestthat ‘the integration of the four technologies(nano–bio–info–cogno) originates from the nanoscale,where the building blocks of matter are established’(NSF 2003). Although it is not entirely clear what isbeing said here, it appears that convergence is beingused in two senses. In addition to the definition ofconvergence as interdisciplinary research anddevelopment, convergence is used to refer to matter‘converging’ at the atomic level – ie to the fact that allmatter is made of atoms.

24 This volume provides a very good example of thedifficulty some commentators find in drawing anappropriate line between hope and hype. The authorscontributing to this report are almost universallyoptimistic about the potential of convergence for thehuman condition, and provide very little criticaldiscussion of potential drawbacks. The report alsomakes strong assumptions about the social acceptabilityof some of its implications (see Baird 2004). The bookalso places some very concrete and beneficialdevelopments that converging technologies will shortlybring (non-invasive diagnostics for example) alongsidemore fanciful visions of the future (for example, ofhuman society as one single interconnected ‘brain’).Many of the papers also advocate a highly mechanisticview of people and society, where machines andbiological systems are intersubstitutable, with very littleconsideration of some of the ethical challenges that the

more radical enhancement proposals (such as thedevelopment of direct neural-to-computer interfaces)might encounter. One would be forgiven, therefore, fordismissing many of the papers as being less aboutsound science and technology than they are aboutscience fiction (for example, the volume talks extensivelyabout the ‘human cognome project’ but contains littleby way of mainstream neuroscience). However, thevolume does pose the question of whether society hasappropriate mechanisms for anticipating anddeliberating some of the more radical enhancementproposals, currently thought possible throughconvergence, if and when they were ever to becomepractical realities.

6.7 Military uses

25 Nanotechnologies are predicted to offer significantadvances and advantages in defence capability.According to the UK Ministry of Defence (MOD 2001),nanotechnologies will present both new opportunitiesfor defence and new external threats. Echoing thepoints made above about the prospects for thedevelopment of pervasive sensing, the main initialdefence impact is predicted to be in information systemsusing large numbers new and cheap sensors, as well asin information processing and communications. Thesedevelopments might enable pervasive nanosensors tocontribute to national defence capability through earlydetection of chemical or biological releases, andincreased surveillance capability. In addition, ‘a wholerange of military equipment including clothing, armour,weapons, personal communications will, thanks to lowcost but powerful sensing and processing, be able tooptimise their characteristics, operation andperformance to meet changing conditionsautomatically’.

26 A current military example is provided by the USInstitute for Soldier Nanotechnologies at MassachusettsInstitute of Technology, which has been awarded a $50million budget from the US army to research newmaterials. Its ultimate goal is ‘to create a 21st centurybattlesuit that combines high-tech capabilities with lightweight and comfort’, focusing on soldier protection,injury intervention and cure, and human performanceimprovement. Specific features of the battlesuit weredescribed in section 3.2.3c. The Institute states thattheir research describes ‘a long-range vision for howtechnology can make soldiers less vulnerable to enemyand environmental threats’ but does not discuss aspecific time-scale for realising that vision.

27 Military developments raise several obvious socialand ethical issues, most of them once again notconfined to nanotechnologies. Manipulation ofbiological and chemical agents using nanotechnologiescould result in entirely new threats that might be hardto detect and counter. Some observers have suggested

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that refinements of both existing and new weaponssystems, through applications of nanotechnologies,might lead to a new form of arms race (see, forexample, Gsponer 2002; Arnall 2003). One can also askwhether the use of arms control frameworks developedfor existing categories of nuclear, chemical andbiological weapon will be sufficient to control futuredevelopments involving nanotechnologies.

28 A related issue arises from the fact that much ofthe basic knowledge and technology needed to achievemilitary capabilities using applications ofnanotechnologies will be produced within the civilsector, and hence is potentially available to a very widerange of parties, including non-state actors. Joy (2000)suggested that ‘The 21st-century technologies –genetics, nanotechnology, and robotics (GNR) – are sopowerful that they can spawn whole new classes ofaccidents and abuses. Most dangerously, for the firsttime, these accidents and abuses are widely within thereach of individuals or small groups. They will notrequire large facilities or rare raw materials. Knowledgealone will enable the use of them’ . This factor alsomakes proliferation of weapons developmentprogrammes much harder to detect because the linebetween non-military and military industrial activitybecomes blurred. In this way, nanotechnologies mayincrease the range of asymmetric power relations.

29 Those applications of nanotechnologies that attractmilitary funding are likely to raise other concerns: forexample considerations of secrecy will make the openpeer review of findings in these areas much moredifficult. An unintended consequence of secrecy in thedevelopment of some nanotechnologies could also beto fuel public distrust and concerns about non-militarydevelopments. This would be so particularly if the term‘nanotechnology’ as a whole became to be closelyassociated with military ends (it is not currently: see theanalysis of our research into public attitudes in section7.2). The case of nuclear energy is instructive here. Flynn(2003) in the USA argues that one of the historicalreasons for the stigmatisation of, and enduring hostilepublic attitudes towards, nuclear power was the inabilityof the civilian nuclear industry to separate itself fromdestructive uses of the atom. Government denials ofthis linkage – scarcely believed at the time – furtherserved to undermine public trust in those regulating thetechnology. There seems to be a significant danger thatpublic acceptance of a whole range of beneficialapplications of nanotechnologies, particularly in theenvironmental domain, might be threatened by tooclose an association with military applications. However,individual perceptions of the role of the military will ofcourse impact on the way that military development ofnanotechnologies will be received.

6.8 Conclusions

30 Nanotechnologies will have an impact across manybranches of science and technology and can beexpected to influence a range of areas of humanendeavour. Some applications of nanotechnologies arelikely to raise significant social and ethical concerns,particularly those envisaged in the medium (5–15 years)and longer (longer than 20 years) time-scales. However,given the difficulty of predicting any but the most short-term applications of nanotechnologies, evaluating long-term social or ethical impacts is a huge challenge.Incremental advances in nanotechnologies may play arole in enabling a number of applications, often inconvergence with other technologies, which may in thelong term prove transformative to society.

31 In the near- to medium term, many of the socialand ethical concerns that have been expressed inevidence are not unique to nanotechnologies. The factthat they are not necessarily unique does not makethese concerns any less valid. Past experience withcontroversial technologies demonstrates that effort willneed to be spent whenever significant social and ethicalissues arise, irrespective of whether they are genuinelynew to nanotechnologies or not. In this chapter wehave identified a range of social and ethical issuesrelating to the development of nanotechnologies thatwould benefit from further study. These includeconcerns about who controls nanotechnologies andwho will benefit from its exploitation in the short- andlong term. The recent report to ESRC (Wood et al 2003)raised other relevant issues. Although not all theseissues are necessarily research questions, some are andothers may be in the future, presenting a uniqueopportunity for interdisciplinary research to beundertaken between scientists and social scientists. Thecost would be small compared with the amount spenton research on nanotechnologies, the applications ofwhich could have major social and ethical impacts.Therefore, we recommend that the researchcouncils and the Arts and Humanities ResearchBoard (AHRB) fund an interdisciplinary researchprogramme to investigate the social and ethicalissues expected to arise from the development ofsome nanotechnologies. This programme wouldinclude research grants and interdisciplinary researchstudentships, which would explicitly link normative andempirical inquiry. Research studentships could involvetaught courses to familiarise students with the termsand approaches used by natural and social scientists,pooled or within institutions.

32 In the longer term we see civil liberties as a keyethical issue. The expected convergence between IT andnanotechnologies is likely to enable devices that can

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increase personal security on the one hand but might beused in ways that limit individual or group privacy bycovert surveillance, by collecting and distributing personalinformation (such as health or genetic profiles) withoutadequate consent, and by concentrating information inthe hands of those with the resources to develop andcontrol such networks. There is speculation that apossible future convergence of nanotechnologies withbiotechnology, information and cognitive sciences couldbe used for the purposes of radical human enhancement.These currently fall into the far-future/science fictioncategory, but should they be realised are likely to raisefundamental and possibly unique social and ethical issues.There is a need to monitor future applications ofnanotechnologies to determine whether they will raisesocial and ethical impacts that have not been anticipatedin this report. Later in this report we consider how thismight be facilitated for nanotechnologies (section 9.6) andfor other new and emerging technologies (section 9.7).

33 On the whole, the scientists and engineers fromwhom we have collected evidence during this studyindicated that they had considered, or were willing toconsider, the ethical and social impacts of their work.Because nanotechnologies and other advancedtechnologies have the potential for significant and

diverse impacts, which bring both benefits and risks, allresearchers engaged in these fields should give thoughtto the wider implications of their work. We note thatthe Joint Statement of the Research Councils’/AHRB’sSkills Training Requirements for Research Students doesspecify that research students should be able todemonstrate awareness of the ethical issues associatedwith their research. However, the Statement does notrequire formal training of students to raise awareness inthese areas, which in the case of advanced technologiessuch as nanotechnologies may not always be obvious,nor does the Statement apply to staff. We recommendthat the consideration of ethical and socialimplications of advanced technologies (such asnanotechnologies) should form part of the formaltraining of all research students and staff workingin these areas and, specifically, that this type offormal training should be listed in the JointStatement of the Research Councils’/AHRB’s SkillsTraining Requirements for Research Students. Theresearch councils/AHRB should support and expand theprovision of short courses, bringing together juniorresearchers and doctoral students in science,engineering and social science to address the ethicaland societal implications of technological developments.

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7.1 Introduction

1 As has been seen for other technologies, such asgenetically modified (GM) crops and food in the UK,public attitudes play a crucial role in the realisation ofthe potential of technological advances. A number ofsocial and ethical issues have been outlined in Chapter 6and, as will be seen below, through our research intopublic attitudes, which could valuably be addressedthrough stakeholder and public dialogue onnanotechnologies. In this chapter we consider currentpublic awareness of nanotechnologies in Britain (basedon market research commissioned for this study),discuss the value of public dialogue on newtechnologies, and examine possible mechanisms forfuture dialogue on nanotechnologies.

7.2 Current public awareness of nanotechnologies in Britain

2 There is currently very little research evidenceavailable on public attitudes to nanotechnologies in theUK or elsewhere. A single quantitative item appeared onthe 2002 Eurobarometer survey (Gaskell et al 2003),where over 50% of the sample answered ‘don’t know’when asked whether they thought that nanotechnologieswould improve or make worse their way of life over thenext 20 years. Of the remainder who did have an opinion,a clear majority felt that it would indeed improve theirlives. However, the extremely high level of ‘don’t know’responses indicates very low general levels of awarenessof the issue of nanotechnologies across Europe. A web-based survey conducted in 2001 in the USA jointlysponsored by the National Geographic Society and theNational Science Foundation (Sims-Bainbridge 2002)found that 57% of respondents agreed with thestatement that ‘human beings will greatly benefit fromnanotechnology, which works at the molecular level atomby atom to build new structures, materials and machines’.However, such a web-based sampling technique isinherently self-selecting in nature, drawingdisproportionately from people who have ready internetaccess as well as those who are particularly interested inscience and technology issues in the first place.Accordingly, it is impossible to extrapolate this result toattitudes among a sample of the general public. A furtherdifficulty with both surveys is that we cannot knowwhether the responses obtained reflect genuinelyconsidered beliefs about nanotechnologies, or a responseto the questions based upon beliefs about the futureimpacts of technology more generally (where attitudesare known to be highly favourable). That is, neithersurvey gives us detailed information on how peoplemight interpret a new development when it is describedto them in some detail, something that is arguably more

important as an indicator of the way in which publicattitudes to nanotechnologies might develop in thefuture. Accordingly, BMRB International Ltd wascommissioned by the Working Group to carry outpreliminary research into levels of awareness of andattitudes to nanotechnologies with samples drawn fromthe general public. This research was both quantitativeand qualitative, and comprised two strands (see BMRB2004): (a) a representative national survey using threeitems; and (b) two in-depth workshops. Sections 7.2.1and 7.2.2 outline BMRB’s findings, as presented in itsreport to the Working Group.

7.2.1 Quantitative survey findings

3 The first strand was a three-question survey with arepresentative sample of 1005 people aged 15 or overin Great Britain. This was designed to give a basicmeasure of awareness of nanotechnologies amongmembers of the general public, establish whether thosewho had heard of it could provide any definition, andwhether they thought it would have a positive ornegative effect on quality of life. The questions used areshown in Box 7.1.

4 As had been expected, there was limited awarenessof nanotechnologies among the survey respondents.

5 In response to question 1, only 29%1 of the surveyrespondents said they were aware of the term.Awareness was higher among men (40%) than women(19%), and was slightly lower for older respondents,falling from around one-third for those aged under 55,to one-fifth (20%) of those aged 65 or over. There wasalso a clear pattern by social grade, with awarenesspeaking at 42% of socio-economic group AB and fallingto 16% of socio-economic group DE.

Box 7.1 The BMRB survey questions

The first question was asked of all 1005 respondents

Q1. Have you heard of nanotechnology? (n=1005)

If the respondent answered yes at question 1 theywere then asked

Q2. What do you think nanotechnology is? (n=262)

Finally, if a person said yes at question 1 and hadnot said don’t know at question 2 they were asked

Q3. Do you think nanotechnology will improve ourway of life in the next 20 years, it will have noeffect, or it will make things worse? (n=172)

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1 262 out of 1005 respondents gave this response at the time of the interview, which is approximately 26%. However, the final data are weighted to the profile of

all adults in Great Britain. This means that those 262 respondents represent more respondents (293) in the weighted data. In terms of the estimated

percentage of all GB adults, this is 29%.

7 Stakeholder and public dialogue

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6 At question 2, just 19% (172) of the survey samplecould offer any form of definition. The most commoncentred on miniaturisation, or technology on a very smallscale. Another frequent response relied on a particularapplication such as computing, electronics or medicine.

7 At question 3, the majority (68%) of those whowere able to give a definition of the word felt that itwould improve life in the future, compared with only4% who thought it would make things worse. Thirteenper cent said unprompted that whether nanotechnologywould make things better or worse depended on how itwas used (despite the fact that this was not presentedas an option on the questionnaire). This last finding isconsistent with views presented in the qualitativeworkshops (discussed next), which also showed thatparticipants’ decisions about whether a technology is‘good’ or ‘bad’ depends on what it is used for.

7.2.2 Qualitative workshop findings

8 The second strand of research consisted of two in-depth qualitative workshops with members drawn froma broad spectrum of the general public: one held inLondon (23 participants) and one in Birmingham (27 participants). The aim was to explore participants’ideas about and attitudes towards nanotechnologies,the everyday concepts that people might use tounderstand and interpret the technology, and to identifyand discuss areas for concern and questions they mighthave. As expected (and congruent with the surveyfindings discussed above) prior awareness andknowledge of nanotechnologies among most workshopparticipants was limited. In anticipation of this, thenature of nanotechnologies was described as theworkshops progressed, and participants couldsubsequently ask questions of a member of the workinggroup who attended in the capacity of expert scientist2.The workshops also aimed to discuss the issue of thecontrol and regulation of nanotechnologies.

9 The more in-depth exploration of respondents’views that was possible in the qualitative workshopsrevealed that, although there were major concernsabout nanotechnologies, as with any new technology,there was also much that respondents thought waspositive, or potentially so. However, it was also felt thatnanotechnologies were very much untried technologies,

and as such their potential benefits and drawbackswould only become clear over time.

10 The workshop participants were concerned aboutmany aspects of nanotechnologies, including thoseoutlined in Box 7.2. They felt that reassurances werenecessary about the areas of concern, although thebalance of concerns obviously varied from individual toindividual.

11 There was also much that participants in theworkshops were positive towards. The key areas inwhich it was felt that nanotechnologies had a potentialcontribution to make, or which interested respondents,are listed in Box 7.3.

Box 7.2 Aspects of nanotechnologies that causedconcern in workshops

· Its financial implications: whether there would bean adequate return on any investment made by theUK; also whether the UK could afford not to invest;and who might make such an investment, andwith what sort of hoped-for return;

· its impact on society: employment; social freedomand control; the position of the developing worldin relation to industrialised nations; and thepossibility of corporations gaining influence;

· whether or not nanotechnologies, and devicesusing it, would work: particularly for applicationsused within the human body;

· the long-term and side-effects ofnanotechnologies: whether enough was beingdone to establish what these were, and whether ornot lessons had been learned from the past (forexample, from nuclear technology);

· whether nanotechnologies could be controlled:whether this could be done internationally as wellas nationally; whether the public would be involvedand whether they would be capable of making acontribution; also, whether the public’scontribution to the debate would be listened to.

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2 The scientist’s role was confined to providing basic information on what nanotechnologies were, scenarios of possible developments in nanotechnologies, and

then to be on hand to answer any questions raised by the group. The scientist did not take part in any other aspect of the moderating or running of the groups.

The full methodology is described in BMRB (2004).

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3 It is important to recognise that the qualitative and quantitative research yield complementary findings, rather than one being in any sense more valid than the

other. In addition, the total number of participants in the two workshops (n=50) may at first sight seem small compared with that of the survey (n=1005).

However, this number is not untypical of qualitative social science research into risk attitudes, where the main objective is to explore the views of a group of

people in depth, rather than gather a statistically representative sample of opinion. For example, the recent ‘narrow-but deep’ component of the UK GM Nation?

public debate (Public Debate Steering Board 2003) involved 77 participants, selected as here to represent a cross-section of lay views.

7.2.3 Interpreting the research into public attitudes

12 In interpreting the findings from the survey andqualitative workshops, it should be borne in mind thatboth were exploratory exercises, conducted within theremit and financial resources available to the WorkingGroup. They certainly should not be taken to representa full exploration of current British attitudes tonanotechnologies. In addition, the findings should beinterpreted in a British context only: no generalisationscan be made from these data about public attitudes tonanotechnologies in other countries, particularly tocultural contexts outside Europe.

13 Several issues are, however, worthy of comment.The fact that awareness among the British population iscurrently very low (consistent with the 2002Eurobarometer findings cited above) implies that muchwill hinge upon how attitudes to nanotechnologies areshaped over the next few years. In addition, whenattempting to define this new development, the surveyrespondents made reference to other technologies withrelatively positive associations (IT, medicines). This maywell explain in part why the majority of those who couldprovide a definition also thought that nanotechnologieswould improve the quality of life for people.

14 By contrast, in the qualitative workshops, whererespondents deliberated the issues in greater depth,responses were more mixed and at times touched alsoupon issues with more negative connotations (such as

nuclear energy and GM organisms)3. Four issues arisingfrom the qualitative workshops can be placed in relationto what is already known about public perceptions of risk.

15 First, the need for informed and accessiblecommentary on, and consideration of, any long-termuncertainties associated with nanotechnologies.Uncertainty has potentially both positive and negativeoutcomes, as the workshop participants fully recognised.However, it is known to be a significant driver of publicconcerns about technological risks, particularly wheredoubts exist over future safety or environmental impacts.Uncertainty was identified as a key factor in some of thevery first research into risk perception on nuclear energy,and subsequent studies of a wide range of risk issues(Royal Society 1992; Slovic 2000).

16 Second, questions over governance ofnanotechnologies. Like the concerns over long-termuncertainties, these issues are not specific tonanotechnologies, but arise in public discourse aboutmany other technological issues. It can be helpful toseparate governance issues into two strands. The firstinvolves the role and behaviour of institutions, and theirabilities to minimise unintended consequence andadequately regulate. Such questions are not, as Wynne(2003) points out, the product of a mis-informed or‘irrational’ public. Rather, they are legitimate questionstouching upon areas of very real potential risk, albeitones that are inherent to the way organisations andregulation operate, and as a consequence sometimesdifficult to represent in formal quantitative riskassessments. Nor should such questions be seen as theproduct of views that are anti-science or anti-technology. Many people, as the current workshopfindings also indicate, remain highly enthusiastic aboutthe general impacts that science will have on theirfuture lives (see OST/Wellcome 2000). A second strand(highlighted in Chapter 6) concerns the possibletrajectories that nanotechnologies will follow as theydevelop: who can be trusted to ensure that thesetrajectories will be socially beneficial? Can the publicplay a role in determining which trajectories arerealised? Such questions express genuine doubts thatpeople have about the ethics, social uncertainties andfuture governance of the technologies. Such concernsare likely to be key ones that will arise in any dialogueprocess involving nanotechnologies.

17 Third, the enthusiasm that many workshopparticipants expressed for the possible ways thatnanotechnologies would benefit their and others’ lives.Perhaps not surprisingly, benefits are an important part(if not the only part) of the evidence that people weighup, alongside perceived risks, when making a judgementabout the acceptability or otherwise of a hazard thatmight impact upon them (Royal Society 1992).

Box 7.3 Aspects of nanotechnologies that workshopparticipants were positive about

· The exciting nature of nanotechnologies: the sensethat it was untried and, as such, had untappedpotential, and an unknown number of ways inwhich humankind and individuals could benefit;

· the possible applications of nanotechnologies:respondents were particularly positive towardsmedical and, to a lesser extent, cosmetic applications;

· the possible creation of new materials, potentiallybeing more useful and creating less waste;

· a sense that nanotechnology was a naturaltechnological progression and that, in the future,arguments against nanotechnology developmentswill appear to be ridiculous;

· a hope that nanotechnology would improve qualityof life, both through the creation of new productsand new medical treatments.

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18 Fourth, BMRB (2004) also report that there wassome mention in the workshops of ethical concernsover ‘messing’ with the building blocks of nature, inpart in response to suggestions of scientistsmanipulating matter at the atomic level to createentirely new materials. An analogy was also drawn hereby some workshop participants betweennanotechnologies and GM. We know from bothquantitative and qualitative risk perception research thatthis issue is one determinant of uneasiness overbiotechnology (Grove White et al 1997; Gaskell et al2000; Marris et al 2002) and other issues such asradioactive waste and nuclear energy (Sjöberg 2000). Itfollows that, not only does the potential exist fornanotechnologies to be stigmatised by such generalassociation, but also some specific applications (as in theproduction of entirely new materials or properties,material/biological systems or organisms) are likely toraise significant ethical dilemmas.

19 In summary, awareness of nanotechnologies iscurrently low among the British population. In addition,the workshops reported here represent the first in-depthqualitative research on attitudes to nanotechnologies inthe published literature, as far as we are aware. Theirfindings, although limited, provide a valuable indicationof some of the wider social and ethical questions thatordinary people might wish to raise aboutnanotechnologies both now and in the future.Accordingly, we recommend that the researchcouncils build on the research into public attitudesundertaken as part of our study by funding a moresustained and extensive programme of researchinto public attitudes to nanotechnologies. Thisshould involve more comprehensive qualitativework involving members of the general public aswell as members of interested sections of society,such as the disabled, and might repeat theawareness survey to track any changes as publicknowledge about nanotechnologies develops.

7.3 Importance of promoting a wider dialogue

20 It would be easy to argue that the assessment andcontrol of the impacts of nanotechnologies – as a highlytechnical and complex subject – should be an expert-ledprocess, restricted primarily to the peer community ofscientists and engineers within academia, industry andgovernment. However, the discussion in Chapter 6, aswell as the results of the public attitudes researchdescribed above, indicates that some of the social andethical concerns that certain applications ofnanotechnologies are likely to raise stretch well beyondthe basic science or engineering of the matter. In thisrespect, we are in broad agreement with the BetterRegulation Taskforce (2003), which has recommendedthat the government communicate with, and involve asfar as possible, the public in the decision-making

process in the area of nanotechnologies. This view isalso in line with that of the European Commission, setout in their Communication ‘Towards a EuropeanStrategy for Nanotechnology’ (EC 2004a), in whichcoherent action ‘to integrate societal considerations intothe R&D process at an early stage’ is endorsed.

21 In addition, several recent UK reports haverecommended that scientists and policy makers engagein dialogue with interested parties about science andtechnology issues (House of Lords 2000; POST 2001),risk (Cabinet Office 2002; National Consumer Council2003) and the environment (Royal Commission onEnvironmental Pollution 1998; Environment Agency2004). In this respect, the events surrounding the bovinespongiform encephalopathy (BSE) crisis in the 1990smarked a turning point in the way UK science policyand risk assessment practice is viewed. The House ofLords Science and Technology Committee in particular,in its report on Science and Society, recommended ‘Thatdirect dialogue with the public should move from beingan optional add-on to science-based policy-making andto the activities of research organisations and learnedinstitutions, and should become a normal and integralpart of the process.’ (House of Lords 2000). Its rationalewas that a crisis of trust had arisen in certain areas ofUK science policy-making. To regain public trust, itrecommended greater openness and transparencyabout science policy and scientific uncertainties. Thisassertion did not go unchallenged. O’Neill (2002) hasargued that the evidence is not clear that the so-calledcrisis of trust is a response to greater untrustworthinessof officials in the UK: rather, many statements ofmistrust might actually reflect a climate of suspicion,partly fed by media reporting of issues.

22 Dialogue with a range of stakeholders about risksalso holds an increasingly important place in the work ofmany of the new advisory and regulatory bodies set upin the UK in the wake of BSE, such as the FoodStandards Agency, the Agriculture and EnvironmentalBiotechnology Commission, and the Human GenomicsCommission. Dialogue-based processes have also beenextensively used for addressing environmental and riskdecision-making across Europe (Renn et al 1995) andthe USA (Beierle and Cayford 2002). The Royal Society isundertaking its own dialogue initiatives through its 5-year Science in Society programme (see Royal Society2004b). The aims of this programme are captured bythe President of the Royal Society, in his 2001Anniversary Address: ‘Society needs to do a better jobof asking what kind of tomorrow we create with thepossibilities that science offers. Such decisions aregoverned by values, beliefs, feelings; science has nospecial voice in such democratic debates about values.But science does serve a crucial function in painting thelandscape of facts and uncertainties against which suchsocietal debates take place’.

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23 The general case for wider societal dialogue aboutnovel technologies, and with it greater openness aboutscience policy, rests upon three broad sets of argument.Fiorino (1990) characterises these as normative,instrumental and substantive. The normative argumentproposes that dialogue is a good thing in and of itselfand as such forms a part of the wider democraticprocesses through which controversial decisions aremade. The normative argument suggests, in particular,that it is important to make decisions sensitive, as far asis possible, to the ethical and value concerns of directlyaffected groups or populations. The instrumentalargument suggests that dialogue, as one means ofrendering decision-making more open and transparent,will increase the legitimacy of decisions and through thisgenerate secondary effects such as greater trust in thepolicy-making process. Many of the arguments in the2000 House of Lords Science and Society report focusupon the issue of the legitimacy of risk regulation andscience. Finally, the substantive argument is thatdialogue will help to generate better quality outcomes.In the field of environmental risk, non-technicalassessments and knowledge have been shown toprovide useful commentary on the validity or otherwiseof the assumptions made in expert assessments (Wynne1996; Yearley 2000). For upstream issues, where highlevels of uncertainty exist, there may be particularbenefits to opening up the risk characterisation processto a wide range of differing perspectives (Funtowicz andRavetz 1992; Stirling 2004). The aim here is to avoid anoverly narrow framing of the problem, through givingconsideration to as full a range of impacts as possible,including potential ‘shocks and surprises’, many ofwhich may not, initially at least, be open to formalquantitative analysis.

24 A US National Research Council report onUnderstanding Risk (Stern and Fineberg 1996) develops adetailed set of proposals for risk characterisation. Theydefine the resultant analytic–deliberative process ascombining sound science and systematic uncertaintyanalysis with deliberation by an appropriaterepresentation of affected parties, policy makers andspecialists in risk analysis. According to the authors,dialogue and deliberation should occur throughout theprocess of risk characterisation, from problem framingthrough to detailed risk assessment and then on to riskmanagement and decision implementation. Likewise, theRoyal Society’s report on risk (Royal Society 1992) arguedthat the evaluation of whether a risk is tolerable or notinvolves judgements both about basic statements of fact(what types of harm might we run, and with whatlikelihood) as well as values (what level of a particularharm should we run). Even the basic statements of factused in a risk assessment can be critically sensitive to‘framing’ assumptions (that is, decisions about whatfactors to include or exclude, as necessary, to structure arisk assessment model). For example, probabilistic risk

assessments have particular difficulty in accommodatingthe human and organisational causes of majortechnological accidents and failures, even thoughevidence from case histories shows that these are theprincipal determinants of major failures in complexengineered systems (Blockley 1980; Vaughan 1996;Turner and Pidgeon 1997). The National Research Councilreport argues here that failure to attend to dialogue atthe early stages of framing the problem can beparticularly costly, for if a key concern is missed insubsequent analysis the danger is that the whole processmay be invalidated. As we argue below, the issue offraming is particularly relevant to the upstream nature ofthe debate on nanotechnologies, and the case forstakeholder dialogue at the present time.

25 Although there is clearly a considerable momentumin the UK and elsewhere to engage in dialogue overscience and technology issues, this should not beviewed uncritically. A first challenge concerns definingwho might be involved. A useful distinction in thisregard can be made between ‘stakeholders’ and ‘thepublic’ as follows: ‘the term, stakeholder refers toorganized, official and defined interested parties in anydecision, such as NGOs, environmental groups, industry,regulators. The term public refers to individuals andcommunities who have an interest or stake in an issuebut who may be less organized and less easily definedand identified’ (Petts 2004).

26 This distinction is particularly important whendesigning engagement processes, for who needs to beinvolved will depend upon the objectives of dialogue,and in turn will have a direct bearing upon the expectedoutcomes, their efficacy and legitimacy. For many issueseven the category ‘the public’ should not be viewed as asingle undifferentiated entity, particularly in terms ofattitudes towards risk (Royal Society 1992). And asnoted in Chapter 6 of the current report, withnanotechnologies special interests might lie with veryspecific groups in society such as those who suffer fromparticular disabilities or health problems.

27 Other difficulties with dialogue processes arisebecause, as Okrent (1998) points out, we do not yetknow enough about the practicalities and impacts ofusing analytic–deliberative processes. One reason forthis is that systematic evaluation of dialogue processesand their outcomes remains relatively uncommon, beingdifficult and expensive to do properly, and often notrecognised as important by sponsors at the outset of theprocess of dialogue. In addition, a number of technicaland institutional/cultural barriers, such as regulatoryfragmentation (which may preclude discussion of allrelevant issues if these fall outside the sponsor’s legalremit), may thwart effective implementation of anotherwise well-intentioned and planned dialogueprocess (Petts 2004).

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7.4 Nanotechnologies as an ‘upstream’ issue

28 Most developments in nanotechnologies, as viewedin 2004, are clearly ‘upstream’ in nature. There are atleast three senses in which this is so: regarding currentdecisions, impacts and public acceptance, respectively.

29 First, many of the significant decisions that willaffect the future trajectory of the technology, concerningresearch funding and R&D infrastructure, have yet to bemade. As discussed in sections 6.3 and 7.2.3, one driverof the current concerns among NGOs (Arnall 2003; ETC2003a) is a scepticism over whether the technology willbe shaped in such a way that its outcomes will genuinelybenefit society, the environment and people (particularlyin the developing world) as is sometimes claimed. Atimely and very broad-based debate might thereforefocus upon which trajectories are more or less desirable,and who should be the ultimate beneficiaries of publicsector investment in R&D, before deeply entrenched orpolarised positions appear. Mehta (2004) argues that inthe Canadian context the failure to consult the publicearly over biotechnology has led to several difficulties inthe regulatory process, while Mayer (2002) also pointsout that the problematic issues that heralded the adventof biotechnology in the 1970s and 1980s did not goaway, and that the participative technology assessmentmethods only now being developed for biotechnologymight be usefully deployed in the upstream phase ofnanotechnologies.

30 Second, as also noted in Chapter 6, many of thesocial and ethical impacts of nanotechnologies are yetto be envisioned, remain hypothetical, or will dependupon nanotechnologies’ convergence with othertechnologies. Only over the medium (5–15 years) or farlonger (more than 20 years) term will its preciseoutcomes and associated ethical implications becomeclear. Achieving meaningful dialogue today willtherefore set several difficult challenges: to separatecurrent hype from what is realistically achievable withthe technology; to provide good-quality information onlikely impacts; and to scope fully the potential sources ofuncertainty. In turn, very specific applications might raiseunanticipated social or ethical questions only well intothe future or when the technology has reached amature stage of development.

31 Finally, in terms of public acceptance, the researchpresented above illustrates that nanotechnologies haveyet to gain any major place in public discourse in Britain,with awareness of the technology among the generalpopulation being extremely low. Although this has thepotential to change rapidly, research on the factors thatlead to risk issues becoming amplified or attenuated inpublic discourse shows that this rarely depends uponany single factor operating alone. Rather, this dependsupon the combined impacts of a range of factorsaccumulating over time. These include: the balance ofperceived benefits between individuals, private and the

public sectors; analogies drawn with other (bothstigmatised or accepted) technologies; patterns ofmedia coverage; position of campaigning groups; theexistence of significant scientific dispute; and attributionof blame for prominent ‘accidents’ were these to occur(Pidgeon et al 2003).

32 Viewing nanotechnologies in upstream termssuggests that lessons can and should be learned fromthe history of other similar technological innovations.Mayer (Mayer 2002) argues that the development of allmajor technologies should be viewed as socialprocesses, and that framed in this way there are clearparallels to be drawn between nanotechnologies todayand the position that biotechnology faced in the 1980s.Similarities include the levels of excitement and hype, apromise to control the future without criticalconsideration first of which futures are desirable andwho might ultimately control them, and narrowlyframed debates about risk issues not encompassingwider social and ethical issues. One can also drawparallels between nanotechnologies today and thenuclear energy industry in the 1950s. Wynne (2003)argues that a particular difficulty with the early historyof that industry, unanticipated at the time, was that theover-optimistic early claims made for the technology laidthe foundations for the deep public scepticism andopposition that was to emerge much later in the 1970s.

33 Ultimately, it is difficult at this stage to judgewhether, and which, applications of nanotechnologieswill necessarily prove more or less difficult than nuclearpower, GM or any other controversial technology(although Chapter 6 and the research into publicattitudes discussed above outlines some of thepotentially sensitive issues). One can make theargument that with many of these more maturetechnologies public dialogue has typically arrived toolittle too late, only being seen as an optional ‘add-on’when the decision-making surrounding an issue (forexample, radioactive waste siting) has become pressing,difficult or uncomfortable for regulators orgovernments. Under such circumstances the existenceof highly polarised positions can make it very difficult, ifnot impossible, to take any real dialogue forward.

7.5 Designing dialogue on nanotechnologies

34 We have reviewed, and are in broad agreementwith, a number of submissions and papers that haveargued for wider public dialogue and debate about thesocial and ethical impacts of nanotechnologies.However, the evidence presented to us also suggeststhat specifying the precise forms of such dialogue willbe no simple matter. The objectives of dialogue,alongside who needs to take part, are likely to vary overtime as the issues with nanotechnologies evolve.Equally, the methodologies available to meet dialogueobjectives vary widely. Given that nanotechnologies are

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likely to pose a wide range of issues (for example,regarding strategic direction and investment, specificapplications, or convergence with other technologies)there is no single method to draw upon. Rather,dialogue methods must be designed specifically aroundthe objectives at hand at any point in time.

35 Renn et al (1995) distinguish between three broadclasses of citizen participation: genuine deliberativemethods which allow for fair and competent debateand discussion between all parties, such as consensusconferences, citizens’ juries and planning cells;traditional consultation methods, including publicmeetings, surveys, focus groups, and mediation, wherethere is little or no extended debate; and referenda, inwhich people do have democratic power but which arenot generally deliberative in nature.

36 Although referenda are not a typical engagementmechanism in the UK (unlike some other Europeancountries such as Switzerland), government and otherorganisations have used various forms of traditionalconsultation on science and technology issues in the past,while consensus conferences occurred in the UK in 1994for plant biotechnology (POST 1995) and in 1999 forradioactive waste management (UKCEED 1999). A usefulsummary of dialogue processes has been produced bythe Parliamentary Office of Science and Technology (POST2001); Box 7.4 lists some possible approaches.

37 Often dialogue processes need to be multi-stage(Renn 1999): that is, involving different participants andmethodologies at different points in time. The GMNation? public debate on the commercialisation ofagricultural biotechnology, held in the UK in 2003, is acase in point in multi-stage design. GM Nation? hadthree main engagement components: initial issueframing (or foundation) workshops with randomlyselected members of the general public were followedby a series of open activities (public meetings,interactive website) to which anybody could contribute,and finally a set of closed ‘narrow-but-deep’ groups,again comprising randomly selected members of thepublic (Public Debate Steering Board 2003).

38 Experience with GM Nation? (Horlick-Jones et al2004) and deliberative processes elsewhere highlightsseveral key requirements that any dialogue processinvolving nanotechnologies must meet and which werecommend. First, dialogue and engagement shouldoccur early, and before critical decisions about thetechnology become irreversible or ‘locked in’. Second,dialogue is not useful in and of itself, but has to bedesigned around specific objectives. Accordingly, clarityat an early stage about the objectives for dialogue isessential. Third, at least some form of commitment fromthe sponsor (typically government or some otheragency) to take account of outcomes is required whencommissioning dialogue processes: otherwise whyshould organisers and participants bother? Fourth,stakeholder and public dialogue should be properlyintegrated with other processes of technologyassessment for nanotechnologies, as and when theyoccur. For example, the 2003 GM Nation? public debatewas conducted in parallel with, and in part providedinputs to, both a science review of GM agriculture andan economic analysis of its costs, benefits andassociated uncertainties. Finally, and not least, anydialogue process should be properly resourced,including the means for systematic evaluation (see alsoPetts 2004). Providing proper resources for dialogueprocesses is not a trivial matter, and one thatGovernment should consider very seriously. The 1999UK nuclear waste consensus conference costs were inthe order of £100,000 (POST 2001), while the overallcosts for the GM Nation? public debate totalled

Box 7.4 Possible Approaches to dialogue

· Participatory and/or constructive technologyassessment with stakeholders, particularly thatwhich takes account of the dynamic interrelationsbetween society and the development ofnanotechnologies (see, for example, Rip et al 1995).

· Scenario analysis with stakeholders to identifysignificant uncertainties that might emerge withnanotechnologies. For example, the GM ‘shocksand surprises’ seminar organised by the CabinetOffice (2003).

· Direct public engagement such as citizen juries orpanels for identifying at an early stage broad‘desired futures’ for nanotechnologies, significantethical concerns, or the acceptability of keyapplications and options. The quality of scientificand other input to such public engagementactivities is critical to their success.

· Decision analytic methods draw upon more formalapproaches for framing problems, as well as foridentifying preferred options and their attributes(see, for example, Stirling and Mayer 1999; Arvai etal 2001)

· Multi-stage methods, which combine differentapproaches to framing, option appraisal and finalchoice in a sequence of linked activities, often withdifferent groups of stakeholders and the public atvarious stages (see, for example, Renn 1999)

· Research into public attitudes, both qualitative andquantitative, to generate good quality ‘socialintelligence’ (Grove White et al 2000) aboutnanotechnologies and public concerns.

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£650,000 (Public Debate Steering Board 2003). Suchcosts, although at first sight large, must be viewed inrelation to the far greater potential economic and socialcosts of getting decisions about investments in majorareas of nanotechnologies wrong at this stage.

39 As discussed above, many of the issues currentlysurrounding nanotechnologies are ‘upstream’ in nature,providing a real opportunity for engagement to bedesigned in early. However, it seems likely that the pre-cise requirements and objectives for such forms ofengagement are much more difficult to specify, com-pared with the ‘downstream’ issues with which the UKhas more experience. Accordingly, at the moment, webelieve that we can only indicate generic areas of need.In the sections below we have applied the five genericobjectives of dialogue and public participation mecha-nisms that have been proposed by Beierle and Cayford(2002) to nanotechnologies.

7.5.1 Incorporating public values in decisions

40 For nanotechnologies, decisions will need to besensitive to public values where significant ethical issuesarise. For example, the concerns raised in Chapter 6about the nano-divide and the future trajectory of thetechnology suggest such a need. Similarly, some of theissues associated with the convergence ofnanotechnologies with other technologies, and inparticular developments in bio-nanotechnologies, arelikely to raise novel ethical questions in the futurerequiring wide public debate. This in turn suggests arequirement for periodic reflection on possible emergingethical questions, and initiating appropriate forms ofdialogue with stakeholders or the public as appropriate,as the technology matures and its tangible applicationsbecome clearer.

7.5.2 Improving decision quality

41 The arguments above suggest that for upstreamissues such as nanotechnologies the quality, as well asthe acceptability, of initial decisions will depend heavilyupon achieving appropriate framings for risk andtechnology assessments at an early stage. In particular,framing needs to incorporate both social as well astechnical outcomes and concerns. Two important issueshere, suggested by the research into public attitudes,would appear to be first the governance ofnanotechnologies (who is to control and regulatenanotechnologies, and ensure that socially desirablegoals can be identified and delivered), and second thelong-term uncertainties. At a more operational level onecould envisage the introduction of specific applicationsbeing accompanied by forms of stakeholderengagement on a case-by-case basis: one obvious issuewould be to explore labelling requirements that peoplewish to see for specific classes for products, another theprivacy implications of developments in sensing devices.

7.5.3 Resolving conflict

42 Unlike with some other issues of more maturetechnologies, nanotechnologies have so far notgenerated significant levels of conflict betweenstakeholders. However, as applications emerge anddecisions are made, this situation might well change. Thehope expressed in evidence submitted to the group isthat methods for upstream deliberation may help societyto find appropriate resolutions for potential conflicts inadvance, by better anticipation of sensitive issues.

7.5.4 Improving trust in institutions

43 Although we note above some of the difficultiessurrounding current discourses about openness andtrust, a process of early debate and dialogue wouldsignal to people a commitment by the UK Government,with the science and technology community, to ameasure of transparency in the future development ofnanotechnologies.

7.5.5 Informing or educating people

44 This is a particularly critical objective, given theupstream nature of most nanotechnologies. At a broadsocietal level there is a need for a mature debate thatcan discriminate between the many (and we notesometimes exaggerated) claims for the technology.However, information provision has to aim at more thatjust ‘educating’ the public as a presumed means ofavoiding controversy, a view embedded in the so-called‘deficit model’ of much traditional public understandingof science and science communication practice (Irwin1995). Meeting such an objective has proven unrealistictime and again: in particular because people resent orresist attempts at direct manipulation, greaterknowledge does not necessarily bring greater acceptanceof risks, and one-way communication without genuinedialogue about science issues may not address people’swider concerns (see Wynne 2003). The ESRC report onnanotechnology (Wood et al 2003) makes clear thatsome current commentary on social science andnanotechnologies runs a similar risk of assuming anunproblematic relationship between the role ofcommunication and technology acceptance. Movingbeyond the deficit model will require more innovativeapproaches to information provision, ones that involve agenuine two-way engagement between scientists,stakeholders and the public. The development andincorporation of good-quality, independent scientificinformation will also be central to the success of anyanalytic–deliberative process, such as a citizens’ jury orpublic debate, that is adopted for nanotechnologies, aswell as the design of appropriate health communicationsfor individuals potentially exposed to nanoparticles andother materials in the workplace (see Cox et al 2003).

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7.6 Conclusions

45 As has been seen with GM crops and food in theUK, public attitudes can play a crucial role in therealisation of the potential of technological advances.The research into public attitudes that we commissionedindicated that awareness of nanotechnologies amongthe British population is currently very low, whichimplies that much will depend on how attitudes tonanotechnologies are shaped over the next few years.Many of the participants in the qualitative workshopswere enthusiastic about the possible ways thatnanotechnologies might benefit their lives and those ofothers. However, reassurances were sought for long-term uncertainties about the possible impact ofnanotechnologies, and analogies were made with issuessuch as nuclear power and genetic modification.Concerns were also raised about the role and behaviourof institutions, specifically about who can be trusted toultimately control and regulate nanotechnologies.

46 The qualitative workshops reported here representthe first in-depth qualitative research on attitudes tonanotechnologies in the published literature, as far as weare aware. They provide a valuable indication of the widersocial and ethical questions that ordinary people mightwish to raise about nanotechnologies, but they were bynecessity limited. We have therefore recommended thatthe research councils fund further and ongoing researchinto public attitudes to nanotechnologies that will in turninform future dialogue work.

47 The upstream nature of most nanotechnologiesmeans that there is an opportunity to generate aconstructive and proactive debate about the future ofthe technology now, before deeply entrenched orpolarised positions appear. Our research into publicattitudes highlighted questions around the governanceof nanotechnologies as an appropriate area for earlypublic dialogue.

48 We recognize that dialogue on nanotechnologies islikely to be taken forward over the next few years in a

diversity of ways, and by a number of parties (not onlyGovernment). We welcome this and the opportunitythat diverse activities are likely to present to identify bestpractice in public dialogue, and not just as applied tonanotechnologies.

49 We see an additional and important role forGovernment in supporting early stakeholder and publicdialogue about nanotechnologies. A current particularstrategic need is to ensure that the framing forsubsequent public debate and technology assessments isdrawn as widely as possible. This is particularly true forsome of the governance questions highlighted in theresearch into public attitudes and in wider evidence,which would be appropriate for early public dialogue.Therefore, we recommend that the Governmentinitiates adequately funded public dialogue aroundthe development of nanotechnologies. Werecognise that a number of bodies could beappropriate in taking this dialogue forward. Forexample, were issues about governance ofnanotechnologies to be the subject of initial dialogue, aswe suggest in this report, the research councils might beasked to take this forward as they are currently fundingresearch into nanotechnologies. Others that could beappropriate to take forward, or co-sponsor, suchdialogue include organisations such as the BritishAssociation for the Advancement of Science, thenational academies, and major charities with experienceof public engagement processes. Industry should also beencouraged to sponsor public dialogue. An example ofthis from 2003 was the citizens’ jury on GM crops jointlyconvened by Unilever, Greenpeace, the ConsumersAssociation and the Co-op in 2003. As noted above, theprecise means of dialogue would need to be designedaround specific objectives to be agreed by anindependent steering board comprising a range ofrelevant stakeholders and experts in public engagement.Dialogue must be adequately funded (for example, aproperly conducted citizens’ jury or consensusconference would require minimum funding of the orderof £100,000–£200,000) and properly evaluated, so thatgood public dialogue practice can be built on.

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8 Regulatory issues

8.1 Introduction

1 In this chapter we discuss the impact on regulationof the issues raised in earlier chapters. It is clear fromthe preceding chapters that nanosciences andnanotechnologies span a wide array of researchinstitutions, industrial sectors and applications. Thus it islikely that several regulators will need to consider theimpacts that nanotechnologies may have on each oftheir areas of coverage.

2 It is timely to consider the effect of regulations onthe prudent development of nanotechnologies.Currently, applications are incremental in nature but ifthe broad range of nanotechnologies fulfil expectationsit is likely that progress will accelerate in the comingyears. We strongly believe that flexible andproportionate regulatory measures informed byscientific evidence are beneficial to everybody; thepublic, consumers and employees are protected fromharm while industry is able to participate in developingstandards and preparing guidance to ensure a levelplaying field and reduced risk of liability.

3 As we outline in section 5.1, many nanosciencesand nanotechnologies present no unique risks to health,safety or the environment. In this chapter we focusprimarily on the management of the potentially adversehealth, safety and environmental impacts of theproduction, use and disposal of nanoparticles andnanotubes because these (particularly in a free ratherthan fixed form) were the main area of concernidentified during the study (see Chapter 5). We stressthat exposure of humans and the environment tonanoparticles and nanotubes is currently extremely low.However, nanoparticles and nanotubes are generatinginterest within industry, several products containingthem being either in the market (for example cosmetics,anti-static packaging, self cleaning surfaces) or close toit (for example fuel cells, display screens). In section 5.6we recommended the establishment of a new researchcentre as a way of addressing the uncertainties relatingto the toxicity of and exposure to nanoparticles andnanotubes.

4 As part of our evidence-gathering process, we helda workshop with regulators in February 2004, at whichit became apparent that existing regulations may needto be adapted to accommodate the particularcharacteristics of nanomaterials. We were encouragedto find, however, that most regulators were aware ofnanotechnologies, and some (such as the Health SafetyExecutive (HSE)) had already taken initial steps towardsthis end.

8.2 Approaches to regulation

5 In general terms, regulation requires assessment ofhazard (the intrinsic harmfulness of the material) andassessment of the likelihood or duration of exposure,these factors combining to produce the risk to anyexposed biological or human population. The overallaim is to determine the risk management measuresneeded to eliminate risks or (in practice) reduce them toacceptable levels. Where possible this process isinformed by factual evidence, usually obtained fromtoxicological, environmental or epidemiological studies.The precautionary principle comes into play when thereis a lack of full scientific certainty about the threat ofharm from the substance. An assumption then has to bemade about the potential hazard on the basis of suchevidence as is available (for example by analogy withmaterials of known toxicity) and the best availablejudgements about the hazard-inducing properties of thesubstance. There must then be an assessment of the riskof exposure, for example in the workplace or to thegeneral public from the use of products.

6 The need to control the use of hazardoussubstances to prevent harm to people or theenvironment is not new. Only those substances thatimply the most serious risks to health or to theenvironment, for example certain carcinogens, arebanned. There is already extensive national andEuropean legislation covering different aspects ofhazardous substance use. In addition, severalinternational agreements have been developed that areaimed at controlling global aspects of the issue. Whereit is judged that controls are necessary, severalregulatory options are available. For example:

· workplace controls;· classification and labelling measures;· control of emissions to air, water and land;· waste disposal restrictions;· marketing and use restrictions;· prohibition.

All these options can be written into legislation. InEurope, this may take the form of a new directive orregulation or an amendment to existing legislation.Regulatory measures are not static; the regulatorcollaborates with industry in seeking to identify furthermeasures that are reasonably practicable to reduce risks.

7 Regulation within the EU and the UK operatesunder a broad framework. Current frameworks alreadyin place cover a wide range of products and processes,such as chemicals, cosmetics and medicines, whichrepresent some of the major areas that nanomaterialsare likely to impact. At least for the foreseeable futurewe believe that the present frameworks are sufficiently

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broad to encompass nanotechnologies and hence aseparate regulator or regulatory framework isunnecessary. Given the hazards outlined in Chapter 5,we believe however that specific aspects of theseframeworks such as requirements or triggers for testingwill require consideration by regulators, with thecollaboration of scientists and toxicologists. We illustratethis in the case studies presented below.

8.3 Case studies

8 In this section we present several case studies fromvarious stages in the lifecycle of products, frommanufacture and use through to disposal. Theseexamples encompass several concerns raised with usduring the evidence-gathering process. In most casesthey relate to situations where there is currently thepotential for exposure to nanoparticles or nanotubes,such as in the workplace.

8.3.1 Workplace (including research laboratories)

9 Currently, the most likely place of exposure tonanoparticles and nanotubes is the workplace, includingacademic research laboratories. The Health and Safetyat Work etc. Act (1974) sets out the responsibilities forhealth and safety that employers have towardsemployees and members of the public, and employeeshave to themselves and to each other. Detailedregulations that build on this Act allow these generalresponsibilities to be expanded and adapted in the lightof technological developments and the identification ofnew risks. Responsibility for health and safety restsprimarily with the employer whereas the HSE isresponsible for developing detailed standards andensuring compliance.

10 The regulations particularly relevant tonanotechnologies are the Control of SubstancesHazardous to Health (COSHH) regulations, which set thebroad requirements of reducing occupational ill healthby setting out a simple framework for controllinghazardous substances in the workplace. Concern hasbeen expressed about the potential risk (particularlythrough inhalation) to workers involved in theproduction and use of manufactured nanoparticles andnanotubes. Personal exposure (through inhalation) isregulated by requiring compliance with occupationalexposure limits (OELs) for individual substances. TheOELs are separately specified and are reviewed andadapted in the light of new knowledge through aprocess that involves the regulator, industry, employeesand the public interest.

11 Some materials, such as carbon black and titaniumdioxide, are being produced by industry either asmicrometre-sized or as nano-sized particles. Thesematerials, previously regarded as harmless in their largerforms, may present different toxicological characteristics

in their nanoparticulate forms. At present, theregulatory standards are based on the mass of inhaledparticles and are derived from a consideration of largersize distributions. If these mass-based standards were tobe applied to materials in nanoparticle form, this wouldimply the relative safety of inhaling vast numbers ofnanoparticles. As discussed above and in section 5.3,there is now experimental toxicological evidence thattoxicity of these nanoparticles is related to their size. Wetherefore recommend that the HSE reviews theadequacy of its regulation of exposure tonanoparticles, and in particular consider therelative advantages of measurement on the basisof mass and number. In the meantime, werecommend that it considers setting loweroccupational exposure levels for manufacturednanoparticles.

12 In many cases it is expected that high standards ofcontainment will be used to prevent the release inworkplaces of nanoparticles and that high standards ofoccupational hygiene will be in place. However, releasescan and do occur, both because of leakage fromcontainment in normal use and because of isolatedevents arising from human error or equipment failure.Minimising these possibilities is an essential part of riskmanagement. Given the greater hazard posed bysome chemicals in the form of nanoparticles werecommend that the HSE, DEFRA and the EAreview their current procedures for themanagement of accidental releases within andoutside the workplace.

13 The single current example of exposure tonanoparticles in the workplace that is regulated bynumber and not mass is that of fibres, includingasbestos. Many (but not all) such fibres are visible bylight microscopy, being above the nanometre range in atleast one dimension, and regulation is based oncounting by phase-contrast optical microscopy, using aspecially designed eyepiece graticule. This is a time-consuming process with potential for inter- and intra-laboratory variability and, as a result, is covered by UKand international quality-control schemes. Futuredevelopments in nanotechnologies may result in theintroduction into the workplace of much finer fibrousmaterials such as nanotubes that are well below 100nmin diameter yet may be longer than 10µm, and may notbe visible by existing methods. We have highlighted ourconcerns about the similarity between nanotubes andasbestos, and the need to control exposure of thoseworking with them until more is known about theirtoxicity (see sections 5.3.1b and 5.3.2a). Therefore werecommend that the HSE consider whether currentmethods are adequate to assess and control theexposures of individuals in laboratories andworkplaces where nanotubes and other nanofibresmay become airborne, and whether regulationbased on electron microscopy rather than phase-contrast optical microscopy is necessary.

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14 Until the reviews recommended above have beenundertaken, and appropriate regulation and controlmeasures are in place, there will be a need for interimguidance to ensure as far as possible the safety ofworkers in academic laboratories and industry. In thisrespect, we welcome the publication of a preliminaryinformation note from the HSE on the currentunderstanding of the health and safety issuessurrounding nanomaterials (HSE 2004). In addition tothe health risks resulting from inhalation, we haveidentified in section 5.5 the need to avoid largequantities of combustible nanoparticles becomingairborne until more information about the explosionhazard has been quantified.

8.3.2 Marketing and use of chemicals

15 The chemicals industry is likely to be the majorproducer of nanomaterials, currently in the form of bulknanoparticles such as titanium dioxide and eventuallymore advanced functional materials as research anddevelopment progresses. Although nanomaterialscurrently account for only a tiny fraction of the totalquantity of chemicals manufactured, production isexpected to increase over the coming years, albeitprobably not reaching the levels of larger particulatechemicals currently produced.

16 From the discussions in preceding chapters, it willbe clear that nanoparticles (particularly at the smallerend of the scale) often have different or enhancedproperties compared with those of the same chemical ina larger form. It is not yet known to what extent thenew or enhanced properties of nanomaterials will beassociated with differences in their toxicity but, as wehave seen in section 5.3, there is evidence that somesubstances are more toxic when in nanoparticulateform, probably caused in part by their greater surfacearea. Whether this increased toxicity poses a risk tohuman health will depend on the mode of exposureand whether the particles are coated.

17 The regulation of the marketing or use of chemicalsin the UK (which reflects European legislation) isoutlined in Box 8.1. Neither of the triggers that are usedto determine the need for and extent of testing ofchemicals take account of particle size. Existingsubstances that are produced in the form ofnanoparticles are not defined as new chemicals and thethreshold levels do not recognise the fact thatsubstances in nanoparticle form may have differenthealth and environmental impacts per unit mass. Thesedifferent properties of nanoparticles are also notconsidered in the latest version of REACH, currentlyunder negotiation. Thus present chemical regulation,and that being negotiated under REACH, implicitlyassume that toxicity will be unaffected by particle size.

18 We see this as a regulatory gap and werecommend that chemicals in the form ofnanoparticles or nanotubes be treated as newsubstances under the existing Notification of NewSubstances (NONS) regulations and in theRegistration, Evaluation, Authorisation andRestriction of Chemicals (REACH) (which iscurrently under negotiation at EU level and willeventually supersede NONS). To comply with thisrecommendation Directorate General (DG) Enterpriseand DG Environment will need to ensure that the final

Box 8.1 Regulation of the marketing and use ofchemicals

Regulation begins with a determination of whethera chemical is a new or existing substance. The ECdefines ‘existing substances’ as chemicals declaredon the market in September 1981, and ‘newsubstances’ as those placed on the market since thatdate. New substances have to undergo much strictertesting and assessment than existing chemicals eventhough existing chemicals account for more than99% of all substances on the market. At present thistakes place under the Notification of NewSubstances (NONS) regulations. The EC is currentlynegotiating a new single system called REACH(Registration, Evaluation, Authorisation ofChemicals) designed to help clear the backlog ofuntested chemicals. Aside from any possibleimplications that nanotechnologies may have, thetesting of existing industrial chemicals is alreadylagging far behind what is already in themarketplace.

The triggers currently used to determine the needfor testing and to decide the number and types oftest required under NONS are:

· New chemicals. A new chemical is defined as onethat does not appear on the EINECS (EuropeanInventory of Existing Commercial Substances)inventory. When a new chemical is produced,before introduction to the market, the producer ofthat chemical is required to conduct testing, and inthe meantime take such precautions as arepracticable. The level of testing required isdetermined by the mass produced, with the lowestmass trigger currently set at 10kg per annum. Onlychanges in chemical structure constitute a newsubstance, whereas changes in form (for examplesize or shape) do not. An exception is made forpolymers: those produced entirely from EINECS-listed monomers are exempt from notification.

· Mass (tonnage) triggers. Essentially, the more of anexisting substance that is produced, the more dataon its properties are required by regulators.

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version of REACH is sufficiently flexible to take accountof the enhanced or different properties that somenanoparticles (and nanotubes) may have compared withlarger particles of the same chemical species. Expertsconvened to produce a preliminary risk analysis for theEC reached a similar conclusion and recommended thata new Chemical Abstract Service (CAS) Registry numberbe assigned to manufactured nanoparticles (EuropeanCommission 2004b).

19 The type of research that we outline in section 5.6(and Boxes 5.6 and 5.7) will provide more informationabout the types and sizes of nanoparticulate that havean increased toxicity. It will also determine the tests thatare most appropriate for various types of nanoparticle.For example, are existing tests for persistence andbioaccumulation appropriate for nanoparticulates? Asmore information about the toxicity ofnanoparticles and nanotubes becomes available,we recommend that the relevant regulatory bodiesconsider whether the annual productionthresholds that trigger testing and the testingmethodologies relating to substances in theseforms should be revised under NONS and REACH.

20 Since we began our study, the EC has recognised

the need to revisit the mass thresholds that triggertesting (European Commission 2004b) and weunderstand that the US Environmental Protection Agencyis assessing whether nanomaterials should best beregulated as new chemicals. International co-operationin developing regulation in this area would be beneficial.

8.3.3 Consumer products incorporating freenanoparticles, particularly skin preparations

21 As we have seen in earlier chapters, somemanufacturers of consumer products, particularlycosmetics, and perhaps in the future foodstuffs, mayutilise the advantages derived from includingnanoparticulate materials in these products to giveimproved or additional functionality. Here thenanoparticles will essentially be free rather than fixed,although their reactivity (and thus toxicity) may beinfluenced by coatings. In this section we concentrateon cosmetics because this is an area wherenanoparticles of oxides of zinc, titanium and iron arebeing used, and where there are concerns (outlined insection 5.3.2b) that they might penetrate through theprotective layers of the skin and cause reactions with UVlight that result in damage to DNA in cells. Regulation ofcosmetics in the UK and EU is outlined in Box 8.2.

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Box 8.2 Regulation of cosmetics in the UK and EU and the role of the scientific advisory committee

Cosmetics include hair and skincare products, colour cosmetics and toiletries. Under the EU Cosmetics Directive(and the UK’s Cosmetic Products (Safety) Regulations 2003), the manufacturer (or the person responsible forplacing the product on the market in the European Community) is primarily responsible for ensuring thatcosmetic products do not cause damage to human health when applied under normal or reasonably foreseeableconditions of use. The definition of normal use takes into account the product’s presentation, its labelling andany instructions for its use and disposal. In assessing safety the manufacturer must take into consideration thegeneral toxicological profile of the ingredients, their chemical structure and its level of exposure.

Two annexes of the Cosmetics Directive list substances that must not be used in cosmetics or that haverestrictions on their use. Three additional annexes list the substances that are permitted for use as colourants,preservatives and UV filters. Unless listed in the various annexes, any substance can be included in a cosmeticproviding the manufacturer declares the final preparation safe.

The safety of cosmetics and non-food products intended for consumers is assessed for the European Commissionby the Scientific Committee on Cosmetic Products and Non-food Products intended for consumers (SCCNFP),which comprises independent scientific experts from across the EU. One of its roles is to assess dossiers ofevidence submitted by industry on the safety of substances used in their products and to produce an opinion onsafety. It does not conduct its own testing, but can request that further evidence be supplied by industry. TheOpinions of the SCCNFP are publicly available. Based on these Opinions, the EC’s DG Enterprise makesrecommendations to the Expert Group on Cosmetics, which comprises representatives from all member states ofthe European Union. This group votes on whether an amendment to the Cosmetics Directive is required (forexample, to add a substance to an annex). Once an amendment has been adopted, it is the obligation of thecompetent authorities within member states (DTI in the UK) to transpose it into national legislation. Memberstates can bring any issues of concern to the attention of the EC. The Scientific Committee on ConsumerProducts will shortly replace the SCCNFP.

In the UK the DH reviews the safety dossiers from the SCCNFP and can highlight any issues of concern to the DTI.Although cosmetics legislation is harmonised at EU level, the DTI can introduce temporary legislation in the UK ifit identifies a serious and immediate risk to consumers.

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22 At the request of industry, the SCCNFP consideredseparate requests to include both titanium dioxide andzinc oxide (including the nanoparticulate form) on thelist of approved UV filters. As outlined in section 5.3.2b,titanium dioxide has been approved for use at all sizesby the SCCNFP (2000), but further evidence wasrequested in June 2003 about microfine zinc oxide(200nm and below). In its opinion concerning zincoxide, the SCCNFP requested clarification as to whetherthe damage caused to DNA by microfine zinc oxideduring tests on cell cultures (in vitro) would be seen inliving animals (in vivo) and if zinc oxide could passthrough the skin (a necessary precursor to harmoccurring) (SCCNFP 2003a). Without a favourable safetyOpinion microfine zinc oxide cannot be used as a UVfilter but there are no restrictions on its use in cosmetics(including sun protection products) for other purposesproviding the manufacturer is assured of its safety. It isour understanding that nanoparticles of zinc oxide arenot much used in sun protection products in Europe.

23 We recommend that industry submit theadditional information on microfine zinc oxide thatis required by the SCCNFP as soon as reasonablypracticable so that the SCCNFP can deliver anopinion on its safety. The uncertainties about thesafety of nanoparticles of zinc oxide are not justapplicable to its use as a UV filter. Titanium dioxide innanoparticle form was judged by the SCCNFP not topose a risk, based on observations that it does notpenetrate the skin and that coatings reduced itsreactivity. Further information from industry maydemonstrate that microfine zinc oxide does notpenetrate the skin or that the activity seen in vitro doesnot occur in vivo, in which case the SCCNFP will be ableto deliver a positive opinion on its safety. However, untilthe safety dossier is provided to the SCCNFP theuncertainties remain.

24 Based on the evidence that some chemicals havedifferent properties when in their nanoparticulate form,safety assessments based on the testing of a larger formof a chemical cannot be used to infer the safety ofnanoparticulate forms of the same chemical (as outlinedin section 8.3.2). Therefore, we recommend thatingredients in the form of nanoparticles undergo afull safety assessment by the relevant scientificadvisory body before they are permitted for use inproducts. One way to implement this recommendationin the Cosmetics industry would be to add as an annexto the Cosmetics Directive a list of ingredients permittedin nanoparticlulate form. Only those ingredients thathave been assessed by the SCCNFP (or its equivalent)would be considered for addition to this list. If thisapproach is taken, titanium dioxide could be included inthe new annex (as it has received a favourableassessment) while the nanoparticulate form of zincoxide would await the SCCNFP’s assessment before adecision was made about its inclusion on the newannex. We understand that particles iron oxide below

100nm are not used as an ingredient in cosmetics inEurope. Were it to be used in Europe in the future wewould expect it to be assessed by the SCCNFP. Theassessments should pay particular attention to ourconcerns about the penetration of damaged skin; theseare of particular relevance to sun protection products asthey are used for a preventative purpose and may beused on skin already damaged by the sun. The SCCNFPshould also consider whether the tests introduced asalternatives to animal testing are appropriate for testingnanoparticles. Our recommendation from section5.3.2b, that committees considering the safety ofingredients for which there is incomplete toxicologicalinformation in the peer-reviewed literature should insistthat the data submitted to them by industry is placed inthe public domain, would apply here.

25 Except for a few categories of uses (such as UVfilters), responsibility for the assessment of the safety ofthe inclusion of free nanoparticles in products rests withthe manufacturer or supplier. The Cosmetic Directive doesnot specify the type of safety studies that must beperformed. So manufacturers must ensure that thetoxicological tests that they use recognise thatnanoparticles of a given chemical will often have differentproperties to the larger forms and may have greatertoxicity. In the UK, details of the safety assessments mustbe made available to Trading Standards, but they are notpublicly available. The guidelines on the testing ofcosmetics produced by the SCCNFP (2003b) do notspecifically refer to the use of microfine ingredients orthose in nanoparticulate form. Because of uncertaintiesabout the safety of nanoparticles in cosmetics, and whilethey are awaiting a safety assessment by the SCCNFP, werecommend that manufacturers publish details ofthe methodologies they have used in assessing thesafety of their products containing nanoparticlesthat demonstrate how they have taken accountthat properties of nanoparticles may be differentfrom larger forms. Based on our understanding that theuse of nanoparticles in the European Cosmetics sector isnot extensive we do not believe that thisrecommendation will apply to many manufacturers.

26 Although the current use of free nanoparticles inconsumer products is limited to a few cosmetic products,it is probable that in the future they will be used in otherconsumer areas such as food and pharmaceuticals.Because we believe that chemicals in the form ofnanoparticles should be treated as new chemicals, werecommend that the ingredients lists of consumerproducts should identify the fact that manufacturednanoparticulate material has been added. There is anadditional case in favour of labelling based on a desire fortransparency of information about consumer products.

27 The three EC non-food safety advisory committees,including the SCCNFP, are being replaced shortly. One ofthe new committees, the Scientific Committee onEmerging and Newly Identified Health Risks (SCENIHR)

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will examine the risks of new technologies, includingnanotechnologies. Given that nanoparticles areexpected to be used increasingly in consumer productsin the future, with various coatings (some of which mayalter their toxicity), we recommend that the new ECSCENIHR gives a high priority to the considerationof the safety of nanoparticles in consumerproducts. It should also liaise with equivalent safetyadvisory bodies relating to food and those related tomedicines and medical products in the EU andinternationally to share expertise in this area.

28 Because of the regulatory gaps that we identify werecommend that the EC (supported by the UK)review the adequacy of the current regulatoryregime for the introduction of nanoparticles intoconsumer products. In undertaking this review, theyshould be informed by the relevant scientific safetyadvisory committees in the way that we outline above.Attention should also be given to the question that weposed in section 5.3.2b about whether all sunprotection products (not just those containingingredients in nanoparticle form) should be regulated asmedicines rather than cosmetics because they are usedfor a preventative purpose and may be used on skinalready damaged by the sun.

8.3.4 Medicines and medical devices

29 Research is being undertaken to introducenanomaterials into medical diagnosis and treatment.Although such materials would be subject to thestringent regulatory regime that governs all newinterventions in medicine, the particular properties ofnanoparticles suggest the possibility of unforeseentoxicity if introduced into the body in large numbers.Therefore, we recommend that the DH review itsregulations for new devices and medicines toensure that particle size and chemistry are takeninto account in investigating possible adverse sideeffects of medicines.

8.3.5 Consumer products incorporating fixednanoparticles: end-of-life issues

30 In contrast to products such as cosmetics thatcontain free nanoparticles, those that containnanomaterials in which nanoparticles or tubes are fixedor embedded (for example in plastics) will present amuch lower likelihood of exposure. In section 5.4 wehave outlined the requirement for industry to quantifythe likelihood of release of nanoparticles or nanotubesduring the lifecycle of the product. The processesinvolved in disposal, destruction or recycling may posean increased risk of exposure to workers in recycling anddisposal industries and to the environment. We considerthis in more detail in the context of end-of-lifelegislation.

31 In Europe and Japan (but to a lesser extent in theUSA), management of products at the end of theirservice life is regarded as an aspect of extendedproducer responsibility; in effect, waste management isseen as part of the product life cycle. In the EU extendedproducer responsibility is mandated through Directivesof which those applying to Waste Electrical andElectronic Equipment (WEEE) and End-of-Life Vehicles(ELVs) already cover two of the leading potentialengineering applications of nanotechnologies. Take-back Directives require the industry – ideally, but notalways, the manufacturer – to take responsibility forrecovering used products and for recycling materials orre-using components. In addition to ensuring that suchproducts do not enter the waste stream, the take-backprinciple is intended to encourage design fordisassembly, re-use and recycling.

32 We recommend that manufacturers ofproducts that incorporate nanoparticles andnanotubes and which fall under extendedproducer responsibility regimes such as end-of-liferegulations be required to publish proceduresoutlining how these materials will be managed tominimise human and environmental exposure. TheEC’s approach to Integrated Product Policy (EuropeanCommission 2003) seeks to extend producer liability forend-of-life to other product classes. Thisrecommendation applies equally to product classes thatfall under extended producer responsibility regulationsin the future. As more information becomes availableabout the hazard and risk presented by releases at endof life, regulators will need to consider whether end-of-life regulation need to be modified to set out how suchmaterials should be managed.

33 The objective of minimising human andenvironmental exposure to free nanoparticles andnanotubes at all stages of the life cycle should also forman integral part of the innovation and design process.

8.4 Knowledge gaps

34 In the following section we discuss the mainknowledge gaps that must be addressed to support thedevelopment of appropriate regulation. These relate tohazard, exposure and measurement.

8.4.1 Hazard

35 In this report we have emphasised possible toxicand explosion hazards associated with nanoparticles andnanotubes. These hazards should be viewed in the lightof two important facts. First, such materials are currentlybeing produced in very low volumes and, aside fromtheir use in cosmetics, involve as yet little or no exposureto populations outside the workplace. Second, the well-

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publicised adverse effects of particulate air pollution arerelated to exposures of very high concentrations ofparticles, usually in susceptible individuals. Thus anyassessment of risk needs to take account not just oftoxic potential but also likely exposures of workers, ofindividuals and of organisms.

36 At present, very few studies have been published onthe potential adverse effects that nanoparticles ornanotubes may have on humans, and only one to ourknowledge on environmental effects. A detaileddiscussion of the current knowledge gaps relating to thehazards (and exposure) of nanoparticles and nanotubesis given in section 5.6 where we identify the need for thedevelopment of internationally agreed protocols andmodels for investigating the routes of exposure andtoxicology to human and non-human organisms ofnanoparticles and nanotubes in the indoor and outdoorenvironment, including investigation of bioaccumulation.As it will not be possible to test the toxicity of all sizes ofnanoparticles with all possible coatings, there is a needfor models to be developed so that results can beextrapolated and the amount of testing reduced. Insection 5.6 we recommend the establishment of a centreto undertake research to address these knowledge gapsand to provide advice to regulators.

8.4.2 Exposure

37 Even when, as at present, the magnitude andmechanisms of risks associated with the production, useand disposal of nanoparticles and nanotubes remainuncertain, it should nevertheless be possible to managethe overall level of risk through careful control ofexposure. Indeed, the history of the regulatory processshows that delays have in the past occurred from adesire to understand detailed mechanisms of toxicitybefore firm action to reduce exposures is taken. As willbe seen from the preceding case studies, we are of theview that sensible, pragmatic steps can be taken now byregulators to control possible risks from newmanufactured nanoparticles without the need for acessation of development activity, and that such stepsshould be taken alongside action to understand furtherthe possible mechanisms of toxicity.

38 Roughly spherical nanoparticles present aregulatory problem that is far removed from the hightechnology of laboratory nanoscience. Such particles arenot only present in urban air but are also generated invery large numbers by such day-to-day activities ascooking. In industry, welding, soldering and burningoperations also generate nanoparticles, and these arecurrently regulated on a mass basis. The specificproduction of useful, rather than polluting,nanoparticles of titanium and zinc oxides for paints,cosmetics and colourants involves rather fewoccupationally exposed individuals compared withthese. Nevertheless, workers are exposed to suchmaterials and it is questionable whether regulation by

mass or by another metric reflecting surface area ornumber is the more appropriate. A decision on this canonly be made on the basis of good epidemiologicalstudies, comparing different measurement metrics inrelation to health outcomes, combined with toxicologystudies. The lack of quantitative epidemiology preventedthe Expert Panel on Air Quality Standards fromrecommending a standard based on a metric other thanmass for ambient air particles in the United Kingdom in2000, and no suitable epidemiology has beenperformed so far in industrial situations wherenanoparticle exposure may occur.

39 There are difficulties in identifying the relevance ofparticles of different sizes in causing disease in industrialsituations. A programme of research that we outline insection 5.6 will address this knowledge gap and isurgently needed as a basis for regulatory exposure limits.However, all studies would have to take account of thebackground, complex mixture of nanoparticles normallyfound in outdoor and indoor air; these background levelsare likely to obscure any small escapes of manufacturedparticles from production or other processes save whenusing pollution-free clean room technology. There is aneed for the development of practical instruments tomeasure the size and surface area of industrial andambient aerosols in the nanometre range, whereparticles may have aggregated into irregular shapes andthere may be a background of nanoparticles.

40 In section 5.3.1c, we discussed research into theadverse effects of ambient air pollution on humanhealth, and the hypothesis that the nanoparticleconstituents may play a role. This has led to work byDEFRA, Department for Transport (DfT) and others intothe measurement of airborne nanoparticles in theenvironment. This includes research into vehicleemissions, which are currently also regulated by mass(DfT 2003). Important issues arise for the best metric formeasuring the toxic potential of emissions, as discussedin the report on Airborne Particles (DEFRA 2001). Forexample, manufacturers might reduce mass emissionsfrom an engine by a process that inadvertently led togreater emission of nanoparticle numbers. If the toxicityof the aerosol were due to the numbers ofnanoparticles, this could have paradoxically adverseconsequences. Because these issues are the subject ofactive research in the air pollution scientific community,we recommend that researchers and regulatorslooking to develop methods to measure andmonitor airborne manufactured nanoparticulatesliaise with those who are working on themeasurement of pollutant nanoparticles fromsources such as vehicle emissions.

8.4.3 Measurement

41 Because of the small size of manufacturednanoparticles and nanotubes, there are several technicalchallenges surrounding measurement of their physical

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and chemical properties. These challenges becomeparticularly problematic when measurement is requiredin ‘real-world’ situations, as opposed to carefullycontrollable laboratory conditions (as might be used forquality control or toxicity experiments). Suchmeasurement problems arise in the field as fluctuatingenvironmental conditions (for example wind speed,temperature, humidity) can modify readings, andbackground nanoparticles already present in theenvironment (for example from pollution) may mask themanufactured nanoparticles of interest.

a) Measurement in the workplace

42 As outlined in Table 4.1, production rates ofnanoparticles are currently estimated to be relatively low.Nevertheless, there is a need for standard validatedmethods of nanoparticle measurement and monitoring tocontrol exposure to workers and to assess the suitabilityof protective equipment. As highlighted in section 5.6 themost relevant metric for nanoparticles is unlikely to bemass, although this may be an adequate surrogate forthe time being. It is likely that particle size, surface area,chemical reactivity and shape may all play a role, andresearch should be directed at investigating this.

43 Several instruments currently exist that, at least incombination, are capable of measuring all thepotentially relevant metrics for nanoparticles. Theseinstruments are large, expensive, non-portable andrequire highly trained operators, and are thus likely tobe economically justifiable only in a few laboratories.However, a similar though perhaps less demandingrequirement applies to workplace measurement of toxicdusts such as asbestos and quartz. The normalprocedure is to collect samples under closely definedconditions for subsequent analysis in specialisedlaboratories. The extension of these procedures willrequire investigation of sampling technology that iscapable of capturing and retaining a representativesample in a manner that matches the measuringcapabilities of the laboratory instruments. Thedevelopment of a quality assurance scheme to regulatethe performance of the laboratories will also be needed.

44 We see the main technical challenges associatedwith measurement of exposure to nanoparticles asfollows:

· Geometry: measuring irregularly shaped particles andtubes.

· Simultaneous measurement of different metrics: caninformation about size, surface area, chemical speciesetc be measured at the same time?

· Specificity: the ability to differentiate (and quantify)particles of interest, from the background.

· Portability and robustness: can the apparatus be usedin workplaces?

· Validity: are the results of measurements a validrepresentation of the exposure conditions?

b) Measurement for toxicological studies

45 Toxicology requires measurement of dose given tothe target, be it a cell, an animal or a human being. Inmost initial toxicological studies relatively large doses aregiven just once or over a short period, and adequatemethods are available for measuring particle mass andnumber and for calculating surface area in thesecircumstances. In special circumstances, such as studiesof skin penetration and of distribution of particlesaround the body, validated and accurate methods needto be developed, but we do not see particular problemsin developing instrumentation.

c) Measurement standards

46 In addition to the development of measurementtechniques for regulatory purposes, there is a growingneed for international measurement standards fornanoscalar metrics. These will include but not be limitedto dimension, chemical composition, force and electricalquanta. Monitoring of nanoparticles in the workplacewill also require a high level of traceability to ensure thatany future agreed exposure levels are accuratelyadhered to. We have considered the requirement forinternationally agreed standards in detail in section 3.3and recommended that the DTI ensure that work in thisarea is adequately funded.

8.5 Conclusions

47 The research, development and commercialisationof nanotechnologies will have an impact on a diverserange of regulatory frameworks, including those relatingto health and safety at work, environmental protection,licensing of medicines and management of the end-of-life of products. We believe that for the foreseeablefuture, the present regulatory frameworks for protectinghumans and the environment are sufficiently broad toencompass nanotechnologies and that a separateregulator or regulatory framework is unnecessary.However, our very limited set of case studies hasdemonstrated that it will be necessary to modifyindividual regulations within existing frameworks ortheir supporting standards, to reflect the fact thatmaterials have new and enhanced properties at thenanoscale that in some cases may be associated with agreater toxicity than is seen in the same materials in thelarger size ranges. There is also a role for industry toprovide information about how they areaccommodating the properties of nanoparticles andnanotubes in their safety assessments.

48 Regulators need to consider the new or enhancedproperties that nanoparticles may have compared withlarger particles of the same chemical. These may affect,but not be limited to: toxicity; chemical or photo-reactivity; persistence; bio-accumulation; explosion. Wehave provided examples of some of the regulatory

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bodies that will need to be aware of the potential fornanoparticles and nanotubes to present hazards notpresent in materials at the larger scale. In section 5.4 weidentified a specific need for the EA to prohibit releasesof nanoparticles for use in remediation applications untilfurther research into their environmental impacts hasbeen undertaken but the responsibilities of the EA willgo much wider than this. In the future, nanoparticlesmay be produced for use in food; and regulators such asthe UK Food Standards Agency will need to investigatethe potential risks posed by ingestion and consider theneed for regulation. We recommend that all relevantregulatory bodies consider whether existingregulations are appropriate to protect humans andthe environment from the hazards outlined in thisreport, and publish their review and details of howthey will address any regulatory gaps.

49 It will be clear from preceding chapters that in themedium- and long-term, nanotechnologies are expectedto have a much greater impact in many sectors ofindustry. There is a need for regulators to be aware ofdevelopments and the implications for regulation at anearly stage. For example, nanotechnologies may enablethe development of new forms of sensing andsurveillance, which may raise concerns about privacy (asdiscussed in section 6.4). Although the widespread useof nano-enabled sensors is not yet a reality, thispotential raises questions about whether the currentregulatory frameworks and mechanisms for ensuringcompliance provide appropriate safeguards forindividuals and groups in society, which the UK’sInformation Commissioner's Office should be aware of.

50 It is not possible at this stage to predict all thepossible applications of nanotechnologies. Therefore, werecommend that regulatory bodies and theirrespective advisory committees include futureapplications of nanotechnologies in their horizonscanning programmes to ensure that anyregulatory gaps are identified at an appropriatestage. The identification of nanotechnologies as an issuefor the new EC SCENIHR indicates an awareness of thisrequirement at European level. From our meeting withUK regulators, it is clear that they are also becomingaware of the potential issues raised by nanotechnologies.In Chapter 9 we consider a mechanism by which theymight be alerted to significant developments in all newand emerging technologies.

51 A call has been made for a moratorium on the onlaboratory use of synthetic nanoparticles by the ETCgroup (2003b), and Greenpeace (2004) has called for amoratorium on the release of nanoparticles to theenvironment until evidence that it is safe (for theenvironment and human health) is clear. We havecarefully considered these positions, but do not believeit to be an appropriate response to the challenge posedby the emergence of new nanotechnologies and theirapplications.

52 For a moratorium to be justified, there would needto be either: (i) a sufficiently robust body of scientificevidence already available to politicians and regulatorsto warrant such a major intervention; or (ii) some kindof consensus among key protagonists that amoratorium should be imposed on a precautionarybasis, given legitimate and cogently argued concernsabout the risk of severe or irreversible damage tohuman health or the environment as a directconsequence of the continuing development ofnanomaterials.

53 Moreover, we do not believe that the body ofevidence outlined in (i) exists. Throughout this report,we have referred to such scientific studies as are alreadyin the public domain, and have carefully reviewed theirfindings. They do not provide any incontrovertibledemonstration of negative impacts on human health orthe environment, although there are some indications(which require further study) that substances in the formof nanoparticles may be more toxic than larger forms.Almost all our witnesses have commented on thepaucity of good data; the overriding imperative istherefore to fill those ‘knowledge gaps’. We haveoutlined how this might be achieved through theestablishment of a new centre to investigate the toxicityand exposure of nanoparticles.

54 We do not think a consensus for a moratorium ona precautionary basis exists either. As this reportdemonstrates, there are indeed many legitimate andcogently argued concerns about nanotechnologies ingeneral (and specific applications in particular), but therisks of severe or irreversible damage from thosetechnologies or applications (either already on themarket or near-market) seem to us to be small, if arigorous and comprehensive regulatory regime can besecured covering impacts of these new technologies andtheir applications.

55 It must, however, be acknowledged that thisjudgement is based on current knowledge, which wehave already pointed out is far from sufficient. Somehave argued that the current level of knowledge is sopoor that no regulatory approach whether based on newregulations or the adaptation of existing regulationscould possibly provide the levels of protection andassurance that the public seeks and deserves. Hence theneed for a moratorium. Although accepting that therewill be a need to modify individual regulations withinexisting frameworks or their supporting standards, wehave concluded that the regulatory gaps that we haveaddressed in our recommendations above are neitherinsurmountable nor permanent.

56 Our rejection of a moratorium is based on theassumption that governments will be minded to securean appropriate regulatory regime as rapidly andeffectively as possible. Therefore we have focused onprecautionary recommendations to ensure that

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regulations reflect the fact that nanoparticulate materialmay have greater toxicity than material in the larger sizerange, and have also recommended that all relevantregulators review regulations within their remit andensure that they keep pace with future developments.Part of the remit of the new research centre that werecommend in section 5.6 is to provide information toallow prompt and appropriate revision of regulation.

57 The combined effect of these measures will notentirely eliminate the risk of adverse impacts on humanhealth or the environment. But it will reduce those risksto the point where research into and commercialdevelopment of new nanotechnologies, with all theprospective economic and social benefits that may flowfrom this development, can be authorised bygovernments and society.

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9.1 Nanoscience and nanotechnologies andtheir industrial application

1 Nanoscience and nanotechnologies incorporateexciting areas of research and development at theinterface between biology, chemistry and physics. Theyare widely seen as having huge potential, and areattracting substantial and increasing investments fromgovernments and from industrial companies in manyparts of the world. We have defined nanoscience as thestudy of phenomena and manipulation of materials atatomic, molecular and macromolecular scales, whereproperties of matter differ significantly from those at alarger scale; and nanotechnologies as the design,characterisation, production and application ofstructures, devices and systems by controlling shape andsize at nanometre scale. As the term ‘nanotechnology’encompasses such a wide range of tools, techniquesand potential applications, we have referred to‘nanotechnologies’ in the plural throughout the report.

2 Much of nanoscience is concerned withunderstanding the properties of materials at thenanoscale and the effects of decreasing the size ofmaterials or the structured components of materials.Nanoscale particles can exhibit, for example, differentelectrical, optical or magnetic properties from largerparticles of the same material. Nanoscience is trulyinterdisciplinary, with an understanding of the physicsand chemistry of matter and processes at the nanoscalebeing relevant to all scientific disciplines, from chemistryand physics to biology, engineering and medicine.Collaborations between researchers in different areashave enabled the sharing of knowledge, tools andtechniques. Some of the benefits of this research arenear realisation – for example in improved catalysis –but most are longer-term.

3 Current examples of nanotechnologies arepredominately in the areas of characterisation, precisionmanufacturing, chemicals and materials. At this earlystage, these represent predominantly incrementaladvances, and in some cases, a re-labelling of existingtechnologies. However, it is clear to us thatnanotechnologies have the potential to substantiallyaffect manufacturing processes across a wide range ofindustries over the medium- to long term. Most productscurrently enabled by nanotechnologies utilise fixed orembedded nanomaterials, or nanoscale regions of largerobjects (for example, electronic components), whichform a small percentage of the final product. Otherapplications use free (but sometimes coated)nanoparticles, which in contrast may have the capabilityto come into contact with humans and the environment.Of the chemicals produced in the form of nanoparticles,metallic oxides (for example, titanium dioxide, zinc oxideand iron oxide) – whose uses include skincare, electrical

storage, and catalysis – dominate. Small quantities ofCNTs are being manufactured and used. For example,their electrical conductivity is being exploited in anti-static packaging. Although it is predicted that thedemand for nanoparticles and nanotubes will continueto grow, the longer-term focus of industry is expected tobe materials with specific properties for applicationswhose properties will be designed for use in a widerange of electronics, chemicals, communication andconsumer products. However, this type ofnanomanufacturing has not yet begun in any substantialway and will take decades to mature.

4 Wherever possible we have indicated the time bywhich we expect certain nanotechnologies to be realised.However it is difficult to give a detailed timescale,because most are at such an early stage of development.Moreover, potential products and applications will not berealised unless there is a market for them. Nor willnanotechnologies be incorporated into products anddevices without the development of scalable, cost-effective manufacturing techniques that retain andpreserve the properties of the nanoscalar material in thefinal product. Thus, realising the applications envisaged inthis report will require advances in R&D andnanomanufacturing, and the supply of scientists andengineers with the appropriate multidisciplinary skills.Some applications may never be realised, whereasunanticipated scientific breakthroughs may lead rapidly todevelopments not foreseen at the time of our study.

5 Nanotechnologies have the potential to impact ona wide range of applications in many industries in themedium- and long term. However, some peopleexaggerate potential benefits whereas othersexaggerate the risks. Overstated claims about benefitsand risks, neither of them based on sound science, aredoing a disservice to these emerging fields. In this reportwe have tried to separate hype from realistic hopes andconcerns. For example, significant benefits to theenvironment are being claimed from the application ofnanotechnologies. We recommend that a life cycleapproach be taken to evaluate these claims and toensure that savings in resource consumption during theuse of the product are not offset by increasedconsumption during other stages.

9.2 Health, safety and environmental risksand hazards

6 Many applications of nanotechnologies pose nonew health or safety risks – computer chips exploitingnanoscalar active areas, for example. Currently we seethe health, safety and environmental hazards ofnanotechnologies as being restricted to discretemanufactured nanoparticles and nanotubes in a free

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9 Conclusions

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rather than embedded form. Industry is beginning toexploit these because their physical and chemicalproperties differ from those of the same chemical atlarger size; although it should be stressed that freenanoparticles and tubes represents only a small subsetof nanotechnologies and there is currently very littleexposure outside the workplace. In assessing andmanaging any risk it is necessary to understand both thehazard and the exposure pathways.

7 The evidence that we have reviewed suggests thatsome manufactured nanoparticles and nanotubes arelikely to be more toxic per unit mass than particles ofthe same chemicals at larger size and will thereforepresent a greater hazard. The fundamental mechanismsof toxicity of nanoparticulates may not be very different:the capacity to induce inflammation by release of freeradicals in response to a dose that is adequate toovercome the body’s natural defences. However, thedifference comes largely from two size-dependentfactors: the relatively greater surface area ofnanoparticles, given equal mass, and their probableability to penetrate cells more easily and in a differentway. To pose a risk, these nanoparticles must come intocontact with humans or the environment in a form andquantity that can cause harm. Currently, the main risk ofhuman exposure to manufactured nanoparticles andnanotubes is in a few workplaces (including academicresearch laboratories) and through the use of a smallnumber of skin preparations that contain freenanoparticles. However the current lack of availableresearch means that the scale of this risk cannot be fullydetermined.

8 Humans inhale very many pollutant nanoparticles(millions per breath) produced as the products ofcombustion. In recent decades it has been suggested, butnot proven, that such exposures may be responsible forthe observed relationships between air pollution andseveral diseases, particularly of the heart and the lung.Industrial exposure to fibres such as asbestos is a well-recognised cause of serious illness such as cancer.Nanotubes have physical properties that raise thepossibility of similar toxic properties although preliminarystudies suggest that they do not readily escape into theair in fibrous form. Sufficient toxicological information hasbeen obtained, on both asbestos and air pollutionnanoparticles, to allow reasonable estimates of the likelyeffects of any new manufactured nanomaterials so longas they are composed of low-toxicity and low-solubilitymaterials. Shape and surface coatings of nanoparticlesand nanotubes will also influence toxicity. It is veryunlikely that manufactured nanoparticulates of low-toxicity and low-solubility materials (the characteristics ofthe materials that we have assessed in this report) wouldbe introduced into humans in sufficient doses to causethe effects associated with air pollution or asbestos.Nevertheless (depending on the way in which they aremanufactured, stored, transported or incorporated intoproducts), there is the potential for some nanopowders to

be inhaled in certain workplaces in significant amounts.

9 Currently, dermal exposure is predominatelythrough the use of cosmetics such as sunscreens thatcontain nanoparticles of titanium dioxide. Here the issueis whether they can penetrate the protective layers ofthe skin and then cause damage through theproduction of free radicals that can damage cells. Thereis little evidence in the public domain about penetrationof the skin by the nanoparticles most commonly used incosmetics. The toxicological evidence to date indicatesthat nanoparticles of titanium dioxide do not penetratethrough the skin, although there is insufficient evidenceavailable for the relevant scientific advisory committeeto provide a judgement about the likelihood of skinpenetration by zinc oxide. It is not clear whether skinpenetration will be enhanced if these preparations areused on skin that has been damaged by sun (as mightbe expected in the case of sunscreens) or by commondiseases such as eczema. We have recommendedfurther studies of skin penetration by manufacturednanoparticles and that existing information collected byindustry is placed in the public domain.

10 There is virtually no evidence available to allow thepotential environmental impacts of nanoparticles andnanotubes to be evaluated. With the exception of someexperiments on laboratory animals (designed to evaluatehuman toxicity) and one small study on one species offish, little information is available about the toxicity ofnanoparticulates to non-human species. In addition, thescarcity of published research into how nanoparticulatesbehave in the air, water, soil and other environmentalmedia makes an assessment of environmental exposurepathways difficult. Nanoparticles and nanotubes thatpersist in the environment or bioaccumulate will presentan increased risk and should be investigated. We haverecommended that the release of nanoparticulates tothe environment be minimised until these uncertaintiesare reduced. We have focused on the largest potentialsources of manufactured nanoparticles and nanotubesand recommended that until there is evidence to thecontrary, factories and research laboratories should treatmanufactured nanoparticles and nanotubes as if theywere hazardous and seek to reduce them as far aspossible from waste streams. In addition, we haverecommended that the release of free manufacturednanoparticles into the environment for remediation(which has been piloted in the USA) be prohibited untilthere is sufficient information to allow the potential risksto be evaluated as well as the benefits.

11 A wide range of uses for nanotubes andnanoparticles is envisaged that will fix them withinproducts. It is impossible to assess whether this will be asignificant source of exposure to nanoparticles andnanotubes without information about the rate at whichsuch particles might be released. Because ways of fixingnanoparticles and nanotubes will be proprietary, webelieve that the onus should be on industry to assess

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such releases throughout a product’s lifetime (includingat the end-of-life) and to make that informationavailable to the regulator.

12 The explosion of dust clouds of combustible materialis a potential hazard in several industries. There is someevidence to suggest that combustible nanoparticles mightcause an increased risk of explosion because of theirincreased surface area and potential for enhancedreaction. Until this hazard has been properly evaluatedthis risk should be managed by taking steps to avoid largequantities of nanoparticles becoming airborne.

13 Our conclusions about health, safety andenvironmental impacts have by necessity been based onincomplete information about the toxicology andepidemiology of nanoparticulates and their behaviour inair, water and soil, including their explosion hazard.There are uncertainties about the risk ofnanoparticulates currently in production that need to beaddressed immediately to safeguard workers andconsumers and support regulatory decisions. InChapters 5 and 8 we have identified a series of researchobjectives aimed at reducing the uncertainties relatingto the toxicology and exposure pathways ofnanoparticulates, as well as developing methodologiesand instrumentation for monitoring them in the builtand natural environment. We think that they can bestbe addressed by the establishment of a dedicatedresearch centre that would probably be based on one ormore existing research groups or centres. Ourpreliminary assessment of the toxicity of nanoparticles isbased on those formed from low-toxicity and low-solubility chemicals. In the future, nanoparticles may bemanufactured with surface chemistry that renders themmore toxic or more able to overcome the body’s naturaldefences. The research centre would ensure that theunderstanding of the health, safety and environmentalrisks of nanoparticulates keeps pace with developmentsin the field and might in time become a self-fundedcentre for the safety testing of nanomaterials.

9.3 Social and ethical impacts

14 In contrast to the health, safety and environmentalconcerns that have focused almost solely on a small partof nanotechnology, the social and ethical concernsrange across the breadth of nanoscience andnanotechnologies, from concerns about the strategicdirection of (and investment in) research intonanotechnologies through to those relating to specificapplications. We expect some developments innanoscience and nanotechnologies to raise significantsocial and ethical concerns, particularly those envisagedin the medium (5–15 years) and long (more than20 years) term. Depending on the economic andpolitical impacts of nanotechnologies (as yet unknown),some of these will relate to the governance ofnanotechnologies, with concerns about who will decide

and control developments and who will benefit fromtheir exploitation. Some facets of nanotechnologies,including their potential to manipulate the fundamentalbuilding blocks of materials, have raised concerns similarto those encountered in biotechnology.

15 Given that nanotechnologies are primarily enablingtechnologies, it is not surprising that, at least in theshort- to medium term, the social and ethical concernsthat have been expressed about it are similar to thoseencountered for other technologies as the applicationswill be similar. Past experience with controversialtechnologies demonstrates that these issues should betaken seriously even though they are not unique tonanotechnologies. We have therefore recommendedthat the research councils and the AHRB commissionresearch into the potential social and ethical issuesidentified in this report. There is also need forresearchers working in new technologies to consider thesocial and ethical implications of their work, and wehave recommended that this form part of their training.

16 In the longer term, we expect increasedinformation collection (for example, where sensorsincorporate developments in nanotechnologies) to haveimplications for civil liberties. The expected convergencebetween IT and nanotechnologies could enable devicesthat can increase personal security but might also beused in ways that limit privacy. There is speculation thata possible future convergence of nanotechnologies withbiotechnology, information and cognitive sciences couldbe used for radical human enhancement. This currentlyfalls into the category of the far future or science fiction,but should some of the more speculative suggestionsever be realised they would raise fundamental andpossibly unique social and ethical issues. We see a needto monitor future developments of nanotechnologies todetermine whether they will raise social and ethicalimpacts that have not been anticipated in this report.Later in this chapter we consider how this might befacilitated, both for nanotechnologies (section 9.6) andfor other new and emerging technologies (section 9.7).

9.4 Stakeholder and public dialogue

17 As has been seen with GM crops and food in theUK, public attitudes play a crucial role in the realizationof the potential of technological advances. The researchinto public attitudes that we commissioned indicatedthat awareness of nanotechnologies among the Britishpopulation is currently very low, which implies thatmuch will depend on how attitudes tonanotechnologies are shaped over the next few years.Many of the participants in the qualitative workshopswere enthusiastic about the possible ways thatnanotechnologies might benefit their lives and those ofothers. However, questions were asked about theirhealth, safety and environmental impact in the longterm, and analogies were made with issues such as

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nuclear power and genetic modification. Concerns werealso raised about the role and behaviour of institutions,specifically about who can be trusted to ultimatelycontrol and regulate nanotechnologies.

18 The qualitative workshops reported here representthe first in-depth qualitative research on attitudes tonanotechnologies in the published literature, as far as weare aware. They provide a valuable indication of the widersocial and ethical questions that ordinary people mightwish to raise about nanotechnologies, but were bynecessity limited. We have therefore recommended thatthe research councils fund a more sustained andextensive programme of research into public attitudes tonanotechnologies that will in turn inform future dialogue.

19 The upstream nature of most nanotechnologiesmeans that there is an opportunity to generate aconstructive and proactive debate about the future ofthe technology now, before deeply entrenched orpolarized positions appear. We broadly agree with thosewho have argued for wider public dialogue and debateabout the social and ethical impacts ofnanotechnologies, and we have thereforerecommended that the Government initiate adequatelyfunded public dialogue around the development ofnanotechnologies. Several bodies could be asked totake this forward, including organisations such as theBritish Association for the Advancement of Science, thenational academies, and major charities with experienceof public engagement processes. Industry should beencouraged to sponsor public dialogue. Our researchinto public attitudes highlighted questions around thegovernance as an appropriate area for early publicdialogue, with questions being raised about who can betrusted to ensure that nanotechnologies will develop ina socially beneficial way. Given that the researchcouncils are currently funding research intonanotechnologies, they might be asked to take forwarddialogue on this issue.

20 Nanotechnologies are likely to pose a wide range ofissues, so it would be inappropriate to identify a singlemethod of public dialogue. Instead, the precise meansof dialogue would need to be designed around specificobjectives and should be agreed by an independentsteering board comprising a range of relevantstakeholders and experts in public engagement. Finally,dialogue must be properly evaluated, so that goodpractice in public dialogue can be built on.

9.5 Regulation

21 Proportionate and flexible regulation (informed byscientific evidence) benefits and protects consumers,workers, industry and the environment, and alsogenerates public confidence in new technologies. Weexpect the research, development and industrialapplication of nanotechnologies to impact on a diverse

range of regulations, including those relating to healthand safety at work, environmental protection, licensing ofmedicines and the management of products at the endof their life. We believe that for the foreseeable future,the present regulatory frameworks are sufficiently broadto encompass nanotechnologies, and that a separateregulator or regulatory framework is unnecessary.Although many nanotechnologies are accommodatedwithin existing regulations, it will be necessary to modifysome regulations within existing frameworks to reflectthe hazard presented by free nanoparticles andnanotubes. Our case studies were selected to illustratehow regulation will need to be adapted to reflect the factthat the safety of substances in the form of nanoparticlescannot be inferred from knowledge of their hazard inlarger form. The examples were selected because ofconcerns raised during the study, and in most cases theyrelate to situations where there is potential for exposurein the short- or medium term.

22 We believe that chemicals in the form ofnanoparticles and nanotubes should be treatedseparately to those produced in a larger form. Given theevidence that increased surface area can lead to greatertoxicity per unit mass, regulation of exposure on a massbasis to nanoparticles and nanotubes may not beappropriate. Currently, the main source of exposure tonanoparticles and nanotubes is inhalation in theworkplace. While HSE performs a wider review of theadequacy of current regulation to assess and controlworkplace exposure to nanoparticles and nanotubes, wehave recommended that it consider setting loweroccupational exposure levels for chemicals in this form.In addition, there is a need to review procedures relatingto accidental exposure.

23 Under current UK chemical regulation (NONS) andits proposed replacement under negotiation at Europeanlevel (REACH), the production of an existing substance innanoparticulate form does not trigger additional testing.We have recommended that this regulatory gap beaddressed by treating nanoparticulates as newsubstances, thus requiring additional testing, under bothNONS and REACH. As more information about thetoxicity of nanoparticles becomes available, a reviewshould be undertaken of whether the toxicological testsrequired under NONS and REACH, and the productionamounts that trigger these tests, are appropriate tonanoparticles and nanotubes.

24 Under EU cosmetics regulations, ingredients(including those in the form of nanoparticles) can beused for most purposes without prior approval, providedthey are not on the list of banned or restricted usechemicals. Given our concerns about the toxicity ofnanoparticles if they penetrate the skin, we haverecommended that their use in products is dependenton a favourable assessment by the relevant EC scientificsafety advisory committee. Thus, nanoparticles oftitanium dioxide could be permitted for use (as its safety

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has been assessed in the context of their use as a UVfilter) but nanoparticles of chemicals such as zinc oxideand iron oxide (should manufacturers wish to use inEurope) would await a safety assessment. In addition totaking into account our concerns about the potential fornanoparticles to penetrate damaged skin, the safetyadvisory committee should consider whether the testsintroduced as alternatives to tests on animals areappropriate for the testing of the safety ofnanoparticles. In the light of the regulatory gaps that weidentify, we have also recommended that the EC(encouraged and supported by the UK Government andinformed by its scientific advisory committees) reviewthe adequacy of the current regulatory regime for theintroduction of nanoparticles into all consumerproducts, not just cosmetics. We have recommended asimilar regulatory review be performed about the use ofnanoparticles in medicines and medical devices.

25 Although we expect nanoparticles or nanotubes tohave a low likelihood of being released from materials inwhich they have been fixed, we see the risk of exposurebeing greatest during disposal, destruction or recycling.Under the European Take-back Directives, industry isresponsible for recovering used products and recyclingmaterials or re-using components from vehicles andelectrical and electronic equipment, two sectors that areexpected to use materials containing fixed nanoparticles.We have recommended that these sectors publishprocedures outlining how these materials will bemanaged to minimise human and environmentalexposure to free nanoparticles and nanotubes. Avoidingend-of-life release should form an integral part of theinnovation and design process of all components usingembedded nanoparticles and nanotubes.

26 In many cases, decisions about how regulationsshould be modified to address particular risks ofnanoparticles and nanotubes will require moreinformation than is currently available about hazard tohumans and the environment, and a betterunderstanding of exposure pathways. The enforcementof regulations will require appropriate measurementtechniques to monitor exposure. The research centre ontoxicology and epidemiology of nanoparticles andnanotubes that we recommended will address theseknowledge gaps, and one of its functions will be toadvise regulators who will also have an opportunity toinfluence its research programme. We have alsoidentified the need for adequate funding of aprogramme to develop agreed standards ofmeasurement at the nanometre scale that can be usedto calibrate equipment, which is a requirement forregulators and for quality assurance by industry.

27 Transparency of safety assessments is important inareas of new and emerging risks to human heath andthe environment. Because the responsibility forassessing the safety of a consumer product often restswith the manufacturer, some information may not be in

the public domain. We have therefore recommendedthat the terms of reference of scientific advisorycommittees considering the safety of ingredients shouldmake provision for them to place all relevant datarelated to safety assessments in the public domain. Inthe meantime we have recommended thatmanufacturers that are including nanoparticles in theircosmetic products publish information about how theyare taking account of the new properties of ingredientsin nanoparticulate form in the methodologies used intheir safety assessments. Because we believe thatnanoparticles should be treated as new chemicals wehave recommended that where ingredients are in theform of nanoparticles, they should be identified on thelists of ingredients in consumer products andpreparations. There is an additional case for labellingbased on transparency.

28 During this study we examined the appropriatenessof some of the regulations in several key areas.Consequently, we have recommended that all relevantregulatory bodies review the implications ofdevelopments in nanotechnologies for the existingregulations within their remit and make the results ofthis review publicly available. Our consideration ofregulation has focused primarily on current or near-termapplications of nanotechnologies, and particularly onnanoparticles and nanotubes. Future applications ofnanotechnologies may impact on other areas ofregulation. For example, advanced sensors enabled bynanotechnologies may present challenges to regulationrelating to privacy. We have also recommended thatregulators and their respective advisory committeesshould include future applications of nanotechnologiesinto their horizon-scanning programmes. We arepleased to learn that one of the new EC scientific safetyadvisory committees for consumer products willexamine the risks from new technologies, includingnanotechnologies.

29 We have considered the calls for a moratorium onthe development and release of new nanomaterials. Wedo not think that there is either the body of scientificevidence to warrant this intervention or a consensusthat this is necessary on a precautionary basis. We haverecommended measures that will minimise exposurewhile the uncertainties about the hazards posed bynanoparticles and nanotubes are being addressed,without the need for such a moratorium.

9.6 Responsible development of nanotechnologies

30 Nanoscience and nanotechnologies have hugepotential. It is recognised that nanotechnologies and theuses to which they might be put may raise newchallenges in the safety, regulatory or ethical domains,which will require societal debate if they are to fulfil thispotential. The implementation of our recommendations

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will address many of the potential ethical, social, health,environmental, safety and regulatory impacts, and helpto ensure that nanotechnologies develop in a safe andsocially desirable way. As part of the Government’scommitment to the responsible development ofnanotechnologies, we recommend that the Office ofScience and Technology commission anindependent group in two and five years’ time toreview what action has been taken on ourrecommendations, and to assess how science andengineering has developed in the interim andwhat ethical, social, health, environmental, safetyand regulatory implications these developmentsmay have. This group should comprise representativesof, and consult with, the relevant stakeholder groups. Itsreports should be publicly available. The academies willalso monitor the implementation of theserecommendations and would of course be willing toparticipate in this review.

31 The Working Group gave consideration to thecreation of a Nanotechnologies Commission, analogousto UK’s Agriculture and Environment BiotechnologyCommission, which would continuously monitoremerging nanotechnologies and advise on theirimplications. However, most of the Working Groupbelieved that, on balance, a commission would not beappropriate at this time. We believe that ourrecommendations, if implemented, will deal adequatelywith short- and medium-term developments. It is notclear when, if ever, some of the longer-term possibilitiesdiscussed in this report will be feasible. In addition,nanotechnologies cover such a diverse range oftechniques and applications with little commonality thatit is not clear that a single body would be appropriate tooversee them all. The 2- and 5-year reviewsrecommended above should reconsider whether there isa need for a nanotechnologies commission.

9.7 A mechanism for addressing future issues

32 Our study has identified important issues that needto be addressed with some urgency. Given the potentialimpacts that other new and emerging technologies(including nanotechnologies) may have on society, wesee it as essential that the Government establishes asystematic approach to identifying health, safety,environmental, social, ethical and regulatory issues ofnew technologies at the earliest possible stage.Therefore, we recommend that the Chief ScientificAdvisor should establish a group that bringstogether representatives of a wide range ofstakeholders to look at new and emergingtechnologies and identify at the earliest possiblestage areas where potential health, safety,environmental, social, ethical and regulatory issuesmay arise and advise on how these might beaddressed. As a minimum, we would envisage such agroup meeting bi-annually. We appreciate that there areseveral bodies across Government with horizon-scanningroles; we do not see this group as duplicating their workbut drawing on them to fulfil the following remit:

· Undertaking horizon scanning for new and emergingtechnologies and considering their potential health,safety, environmental, social and ethical implications.

· Commissioning wide-ranging evaluations of issues asthey think appropriate to identify areas where there islack of knowledge about impacts.

· Providing an early warning of areas where regulationmay be inadequate for specific applications of thesetechnologies.

33 The work of this group should be made public sothat all stakeholders can be encouraged to engage withthe emerging issues. This group would be separate to,but may contribute to, the periodic reviews ofnanoscience and nanotechnologies that we outline insection 9.6.

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10 Recommendations

The industrial application of nanotechnologies

R1 We recommend that a series of life cycleassessments be undertaken for the applications andproduct groups arising from existing and expecteddevelopments in nanotechnologies, to ensure thatthat savings in resource consumption during theuse of the product are not offset by increasedconsumption during manufacture and disposal. Tohave public credibility these studies need to becarried out or reviewed by an independent body.(Section 4.5: paragraph 32).

R2 Where there is a requirement for research toestablish methodologies for life cycle assessmentsin this area, we recommend that this should befunded by the research councils through the normalresponsive mode. (Section 4.5: paragraph 33)

Possible adverse health, safety and environmental impacts

The lack of evidence about the risk posed by manufactured nanoparticles and nanotubes is resultingin considerable uncertainty.

R3 We recommend that Research Councils UKestablish an interdisciplinary centre (probablycomprising several existing research institutions) toresearch the toxicity, epidemiology, persistence andbioaccumulation of manufactured nanoparticlesand nanotubes as well as their exposure pathways,and to develop methodologies and instrumentationfor monitoring them in the built and naturalenvironment. A key role would be to liaise withregulators. We recommend that the research centremaintain a database of its results and that itinteract with those collecting similar information inEurope and internationally. Because it will not bepossible for the research centre to encompass allaspects of research relevant to nanoparticles andnanotubes, we recommend that a proportion of itsfunding be allocated to research groups outside thecentre to address areas identified by the advisoryboard as of importance and not covered within thecentre. (Section 5.6: paragraphs 55 & 56)

R4 Until more is known about environmental impactsof nanoparticles and nanotubes, we recommendthat the release of manufactured nanoparticles andnanotubes into the environment be avoided as faras possible. (Section 5.7: paragraph 63)

R5 Specifically, in relation to two main sources ofcurrent and potential releases of free nanoparticlesand nanotubes to the environment, we recommend:

(i) that factories and research laboratories treatmanufactured nanoparticles and nanotubes asif they were hazardous, and seek to reduce orremove them from waste streams. (Section 5.4:paragraph 41)

(ii) that the use of free (that is, not fixed in amatrix) manufactured nanoparticles inenvironmental applications such as remediationbe prohibited until appropriate research hasbeen undertaken and it can be demonstratedthat the potential benefits outweigh thepotential risks. (Section 5.4: paragraph 44)

R6 We recommend that, as an integral part of theinnovation and design process of products andmaterials containing nanoparticles or nanotubes,industry should assess the risk of release of thesecomponents throughout the lifecycle of the productand make this information available to the relevantregulatory authorities. (Section 5.4: paragraph 42)

R7 We recommend that the terms of reference ofscientific advisory committees (including theEuropean Commission’s Scientific Committee onCosmetic and Non-food Products or its replacement)that consider the safety of ingredients that exploitnew and emerging technologies likenanotechnologies, for which there is incompletetoxicological information in the peer-reviewedliterature, should include the requirement for allrelevant data related to safety assessments, and themethodologies used to obtain them, to be placed inthe public domain. (Section 5.3.2b: paragraph 30)

Regulatory issues

R8 We recommend that all relevant regulatory bodiesconsider whether existing regulations areappropriate to protect humans and the environmentfrom the hazards outlined in this report and publishtheir review and details of how they will address anyregulatory gaps. (Section 8.5: paragraph 48)

R9 We recommend that regulatory bodies and theirrespective advisory committees include futureapplications of nanotechnologies in their horizonscanning programmes to ensure any regulatorygaps are identified at an appropriate stage. (Section 8.5: paragraph 50)

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Recommendations R10 to R14 are based on applyingour conclusions - that some chemicals are more toxicwhen in the form of nanoparticles or nanotubes andthat safety assessments based on the testing of a largerform of a chemical cannot be used to infer the safetyof chemicals in the form of nanoparticles - to a series ofregulatory case studies:

R10 We recommend that chemicals in the form ofnanoparticles or nanotubes be treated as newsubstances under the existing Notification of NewSubstances (NONS) regulations and in theRegistration, Evaluation, Authorisation andRestriction of Chemicals (REACH) (which is currentlyunder negotiation at EU level and will eventuallysupersede NONS). As more information regardingthe toxicity of nanoparticles and nanotubesbecomes available, we recommend that the relevantregulatory bodies consider whether the annualproduction thresholds that trigger testing and thetesting methodologies relating to substances inthese forms should be revised under NONS andREACH. (Section 8.3.2: paragraphs 18 & 19)

R11 Workplace:

(i) We recommend that the Health & SafetyExecutive (HSE) review the adequacy of itsregulation of exposure to nanoparticles, and inparticular considers the relative advantages ofmeasurement on the basis of mass and number.In the meantime, we recommend that itconsiders setting lower occupational exposurelevels for manufactured nanoparticles. (Section8.3.1: paragraph 11)

(ii) We recommend that the HSE, Department forEnvironment Food and Rural Affairs and theEnvironment Agency review their currentprocedures relating to the management ofaccidental releases both within and outside theworkplace. (Section 8.3.1: paragraph 12)

(iii) We recommend that the HSE consider whethercurrent methods are adequate to assess andcontrol the exposures of individuals inlaboratories and workplaces where nanotubesand other nanofibres may become airborne andwhether regulation based on electron microscopyrather than phase-contrast optical microscopy isnecessary. (Section 8.3.1: paragraph 13)

R12 Consumer products:

(i) We recommend that ingredients in the form ofnanoparticles undergo a full safety assessmentby the relevant scientific advisory body beforethey are permitted for use in products.Specifically: we recommend that industry

submit the additional information on microfinezinc oxide that is required by the SCCNFP assoon as reasonably practicable so that it candeliver an opinion on its safety. (Section 8.3.3:paragraph 24 & 23)

(ii) We recommend that manufacturers publishdetails of the methodologies they have used inassessing the safety of their products containingnanoparticles that demonstrate how they havetaken account that properties of nanoparticlesmay be different from larger forms. (Section8.3.3: paragraph 25)

(iii) We recommend that the ingredients lists ofconsumer products should identify the fact thatmanufactured nanoparticulate material hasbeen added. (Section 8.3.3: paragraph 26)

(iv) We recommend that the EC’s new ScientificCommittee on Emerging and Newly IdentifiedHealth risks gives a high priority to theconsideration of the safety of nanoparticles inconsumer products. (Section 8.3.3: paragraph 27)

(v) In the light of the regulatory gaps that weidentify we recommend that the EC (supportedby the UK) review the adequacy of the currentregulatory regime with respect to theintroduction of nanoparticles into consumerproducts. In undertaking this review theyshould be informed by the relevant scientificsafety advisory committees. (Section 8.3.3:paragraph 28)

R13 We recommend that the Department of Healthreview its regulations for new medical devices andmedicines to ensure that particle size and chemistryare taken into account in investigating possibleadverse side effects of medicines. (Section 8.3.4:paragraph 29)

R14 We recommend that manufacturers of products thatincorporate nanoparticles and nanotubes and whichfall under extended producer responsibility regimessuch as end-of-life regulations be required to publishprocedures outlining how these materials will bemanaged to minimise human and environmentalexposure. (Section 8.3.5: paragraph 32)

R15 Measurement:

(i) We recommend that researchers and regulatorslooking to develop methods to measure andmonitor airborne manufacturednanoparticulates liaise with those who areworking on the measurement of pollutantnanoparticles from sources such as vehicleemissions. (Section 8.4.2: paragraph 40)

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(ii) We recommend that the Department of Tradeand Industry supports the standardisation ofmeasurement at the nanometre scale requiredby regulators and for quality control in industrythrough the adequate funding of initiativesunder its National Measurement SystemProgramme and that it ensures that the UK is inthe forefront of any international initiatives forthe standardisation of measurement. (Section3.3.5: paragraph 60)

Social and ethical issues

R16 We recommend that the research councils and theArts and Humanities Research Board (AHRB) fundan interdisciplinary research programme toinvestigate the social and ethical issues expected toarise from the development of somenanotechnologies. (Section 6.8: paragraph 31)

R17 We recommend that the consideration of ethicaland social implications of advanced technologies(such as nanotechnologies) should form part of theformal training of all research students and staffworking in these areas and, specifically, that thistype of formal training should be listed in the JointStatement of the Research Councils’/AHRB’s SkillsTraining Requirements for Research Students.(Section 6.8: paragraph 33)

Stakeholder and public dialogue

R18 We recommend that the research councils build onthe research into public attitudes undertaken as partof our study by funding a more sustained andextensive programme of research into public attitudesto nanotechnologies. This should involve more

comprehensive qualitative work involving members ofthe general public as well as members of interestedsections of society, such as the disabled, and mightrepeat the awareness survey to track any changes aspublic knowledge about nanotechnologies develops.(Section 7.2.3: paragraph 19)

R19 We recommend that the Government initiatesadequately funded public dialogue around thedevelopment of nanotechnologies. We recognise thata number of bodies could be appropriate in takingthis dialogue forward. (Section 7.6: paragraph 49)

Ensuring the responsible development of nanotechnologies

R20 We recommend that the OST commission anindependent group in two and five years’ time toreview what action has been taken on ourrecommendations, and to assess how science andengineering has developed in the interim and whatethical, social, health, environmental, safety andregulatory implications these developments mayhave. This group should comprise representativesof, and consult with, the relevant stakeholdergroups. Its reports should be publicly available.(Section 9.6: paragraph 30)

R21 We recommend that the Chief Scientific Advisorshould establish a group that brings togetherrepresentatives of a wide range of stakeholders tolook at new and emerging technologies andidentify at the earliest possible stage areas wherepotential health, safety, environmental, social,ethical and regulatory issues may arise and adviseon how these might be addressed. (Section 9.7:paragraph 32)

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11 References

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The Royal Society & The Royal Academy of Engineering Nanoscience and nanotechnologies | July 2004 | iii

Contents

page

Summary vii

1 Introduction 11.1 Hopes and concerns about nanoscience and nanotechnologies 11.2 Terms of reference and conduct of the study 21.3 Report overview 21.4 Next steps 3

2 What are nanoscience and nanotechnologies? 5

3 Science and applications 73.1 Introduction 73.2 Nanomaterials 7

3.2.1 Introduction to nanomaterials 73.2.2 Nanoscience in this area 83.2.3 Applications 10

3.3 Nanometrology 133.3.1 Introduction to nanometrology 133.3.2 Length measurement 133.3.3 Force measurement 143.3.4 Measurement of single molecules 143.3.5 Applications 14

3.4 Electronics, optoelectronics, and information and communication technology (ICT) 173.4.1 Introduction to electronics, optoelectronics, and ICT 173.4.2 Nanoscience in this area 173.4.3 Current applications 173.4.4 Applications anticipated in the future 18

3.5 Bio-nanotechnology and nanomedicine 193.5.1 Introduction to bio-nanotechnology and nanomedicine 193.5.2 Nanoscience in this area 203.5.3 Current and future applications 20

4 Nanomanufacturing and the industrial application of nanotechnologies 254.1 Introduction 254.2 Characterisation 254.3 Fabrication techniques 25

4.3.1 Bottom-up manufacturing 264.3.2 Top-down manufacturing 284.3.3 Convergence of top-down and bottom-up techniques 29

4.4 Visions for the future 304.4.1 Precision Engineering 304.4.2 The chemicals industry 314.4.3 The information and communication technology industry 31

4.5 Resource management and environmental issues 324.6 Barriers to progress 324.7 Summary 33

Nanoscience and nanotechnologies: opportunities and uncertainties

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5 Possible adverse health, environmental and safety impacts 355.1 Introduction 355.2 Assessing and controlling risk 355.3 Human health 36

5.3.1 Understanding the toxicity of nanoparticles and fibres 365.3.2 Manufactured nanoparticles and nanotubes 41

5.4 Effects on the environment and other species 455.5 Risk of explosion 475.6 Addressing the knowledge gaps 475.7 Conclusions 49

6 Social and ethical issues 516.1 Introduction: framing social and ethical issues 516.2 Economic impacts 526.3 A ‘nanodivide’? 526.4 Information collection and the implications for civil liberties 536.5 Human enhancement 546.6 Covergence 546.7 Military uses 556.8 Conclusions 56

7 Stakeholder and public dialogue 597.1 Introduction 597.2 Current public awareness of nanotechnologies in Britain 59

7.2.1 Quantitative survey findings 597.2.2 Qualitative workshop findings 607.2.3 Interpreting the research into public attitudes 61

7.3 Importance of promoting a wider dialogue 627.4 Nanotechnologies as an ‘upstream’ issue 647.5 Designing dialogue on nanotechnologies 64

7.5.1 Incorporating public values in decisions 667.5.2 Improving decision quality 667.5.3 Resolving conflict 667.5.4 Improving trust in institutions 667.5.5 Informing or educating people 66

7.6 Conclusions 67

8 Regulatory issues 698.1 Introduction 698.2 Approaches to regulation 698.3 Case studies 70

8.3.1 Workplace (including research laboratories) 708.3.2 Marketing and use of chemicals 718.3.3 Consumer products incorporating free nanoparticles, particularly skin preparations 728.3.4 Medicines and medical devices 748.3.5 Consumer products incorporating fixed nanoparticles: end-of-life issues 74

8.4 Knowledge gaps 748.4.1 Hazard 748.4.2 Exposure 758.4.3 Measurement 75

8.5 Conclusions 76

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9 Conclusions 799.1 Nanoscience and nanotechnologies and their industrial application 799.2 Health, safety and environmental risks and hazards 799.3 Social and ethical impacts 819.4 Stakeholder and public dialogue 819.5 Regulation 829.6 Responsible development of nanotechnologies 839.7 A mechanism for addressing future issues 84

10 Recommendations 85

11 References 89

Annexes

A Working Group, Review Group and Secretariat 95

B Conduct of the study 97

C List of those who submitted evidence 99

D Mechanical self-replicating nano-robots and ‘Grey Goo’ 109

Acronyms and abbreviations 111

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Summary

Overview

Nanoscience and nanotechnologies are widely seen ashaving huge potential to bring benefits to many areas ofresearch and application, and are attracting rapidlyincreasing investments from Governments and frombusinesses in many parts of the world. At the same time,it is recognised that their application may raise newchallenges in the safety, regulatory or ethical domainsthat will require societal debate. In June 2003 the UKGovernment therefore commissioned the Royal Societyand the Royal Academy of Engineering to carry out thisindependent study into current and future developmentsin nanoscience and nanotechnologies and their impacts.

The remit of the study was to:

· define what is meant by nanoscience andnanotechnologies;

· summarise the current state of scientific knowledgeabout nanotechnologies;

· identify the specific applications of the newtechnologies, in particular where nanotechnologies arealready in use;

· carry out a forward look to see how the technologiesmight be used in future, where possible estimating thelikely timescales in which the most far-reachingapplications of the technologies might become reality;

· identify what health and safety, environmental, ethicaland societal implications or uncertainties may arisefrom the use of the technologies, both current andfuture; and

· identify areas where additional regulation needs to beconsidered.

In order to carry out the study, the two Academies set upa Working Group of experts from the relevant disciplinesin science, engineering, social science and ethics and fromtwo major public interest groups.2 The group consultedwidely, through a call for written evidence and a series oforal evidence sessions and workshops with a range ofstakeholders from both the UK and overseas. It alsoreviewed published literature and commissioned newresearch into public attitudes. Throughout the study, theWorking Group has conducted its work as openly aspossible and has published the evidence received on adedicated website as it became available(www.nanotec.org.uk).

This report has been reviewed and endorsed by the RoyalSociety and the Royal Academy of Engineering.

Significance of the nanoscale

A nanometre (nm) is one thousand millionth of a metre.For comparison, a single human hair is about 80,000 nmwide, a red blood cell is approximately 7,000 nm wideand a water molecule is almost 0.3nm across. People areinterested in the nanoscale (which we define to be from100nm down to the size of atoms (approximately 0.2nm))because it is at this scale that the properties of materialscan be very different from those at a larger scale. Wedefine nanoscience as the study of phenomena andmanipulation of materials at atomic, molecular andmacromolecular scales, where properties differsignificantly from those at a larger scale; andnanotechnologies as the design, characterisation,production and application of structures, devices andsystems by controlling shape and size at the nanometrescale. In some senses, nanoscience and nanotechnologiesare not new. Chemists have been making polymers,which are large molecules made up of nanoscalesubunits, for many decades and nanotechnologies havebeen used to create the tiny features on computer chipsfor the past 20 years. However, advances in the tools thatnow allow atoms and molecules to be examined andprobed with great precision have enabled the expansionand development of nanoscience and nanotechnologies.

The properties of materials can be different at thenanoscale for two main reasons. First, nanomaterials havea relatively larger surface area when compared to thesame mass of material produced in a larger form. This canmake materials more chemically reactive (in some casesmaterials that are inert in their larger form are reactivewhen produced in their nanoscale form), and affect theirstrength or electrical properties. Second, quantum effectscan begin to dominate the behaviour of matter at thenanoscale - particularly at the lower end - affecting theoptical, electrical and magnetic behaviour of materials.Materials can be produced that are nanoscale in onedimension (for example, very thin surface coatings), intwo dimensions (for example, nanowires and nanotubes)or in all three dimensions (for example, nanoparticles).

Our wide-ranging definitions cut across many traditionalscientific disciplines. The only feature common to thediverse activities characterised as ‘nanotechnology’ is thetiny dimensions on which they operate. We havetherefore found it more appropriate to refer to‘nanotechnologies’.

The Royal Society & The Royal Academy of Engineering2 | July 2004 | Nanoscience and nanotechnologies

Nanoscience and nanotechnologies:opportunities and uncertainties1

1 The full report of which this is a summary is Nanoscience and nanotechnologies: opportunities and uncertainties. London: The Royal Society & The Royal Academy ofEngineering, 2004. Available from the Royal Society Publications Sales Department, price £25; also free of charge on the Society’s website www.royalsoc.ac.uk/policyand The Royal Academy of Engineering’s website www.raeng.org.uk

2 The membership of the Working Group is given at the end of this document.

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Current and potential uses of nanoscience andnanotechnologies

Our aim has been to provide an overview of current andpotential future developments in nanoscience andnanotechnologies against which the health, safety,environmental, social and ethical implications can beconsidered. We did not set out to identify areas ofnanoscience and nanotechnologies that should beprioritised for funding.

(i) Nanomaterials

Much of nanoscience and many nanotechnologies areconcerned with producing new or enhanced materials.Nanomaterials can be constructed by 'top down'techniques, producing very small structures from largerpieces of material, for example by etching to createcircuits on the surface of a silicon microchip. They mayalso be constructed by 'bottom up' techniques, atom byatom or molecule by molecule. One way of doing this isself-assembly, in which the atoms or molecules arrangethemselves into a structure due to their naturalproperties. Crystals grown for the semiconductor industryprovide an example of self assembly, as does chemicalsynthesis of large molecules. A second way is to use toolsto move each atom or molecule individually. Althoughthis ‘positional assembly’ offers greater control overconstruction, it is currently very laborious and not suitablefor industrial applications.

Current applications of nanoscale materials include verythin coatings used, for example, in electronics and activesurfaces (for example, self-cleaning windows). In mostapplications the nanoscale components will be fixed orembedded but in some, such as those used in cosmeticsand in some pilot environmental remediationapplications, free nanoparticles are used. The ability tomachine materials to very high precision and accuracy(better than 100nm) is leading to considerable benefits ina wide range of industrial sectors, for example in theproduction of components for the information andcommunication technology (ICT), automotive andaerospace industries.

It is rarely possible to predict accurately the timescale ofdevelopments, but we expect that in the next few yearsnanomaterials will provide ways of improvingperformance in a range of products including silicon-based electronics, displays, paints, batteries, micro-machined silicon sensors and catalysts. Further into thefuture we may see composites that exploit the propertiesof carbon nanotubes – rolls of carbon with one or morewalls, measuring a few nanometres in diameter and up toa few centimetres in length – which are extremely strongand flexible and can conduct electricity. At the momentthe applications of these tubes are limited by the difficultyof producing them in a uniform manner and separatingthem into individual nanotubes. We may also seelubricants based on inorganic nanospheres; magnetic

materials using nanocrystalline grains; nanoceramics usedfor more durable and better medical prosthetics;automotive components or high-temperature furnaces;and nano-engineered membranes for more energy-efficient water purification.

(ii) Metrology

Metrology, the science of measurement, underpins allother nanoscience and nanotechnologies because itallows the characterisation of materials in terms ofdimensions and also in terms of attributes such aselectrical properties and mass. Greater precision inmetrology will assist the development of nanoscience andnanotechnologies. However, this will require increasedstandardisation to allow calibration of equipment and werecommend that the Department of Trade and Industryensure that this area is properly funded.

(iii) Electronics, optoelectronics and ICT

The role of nanoscience and nanotechnologies in thedevelopment of information technology is anticipated inthe International Technology Roadmap forSemiconductors, a worldwide consensus document thatpredicts the main trends in the semiconductor industry upto 2018. This roadmap defines a manufacturing standardfor silicon chips in terms of the length of a particularfeature in a memory cell. For 2004 the standard is 90nm, but it is predicted that by 2016 this will be just22nm. Much of the miniaturisation of computer chips todate has involved nanoscience and nanotechnologies,and this is expected to continue in the short and mediumterm. The storage of data, using optical or magneticproperties to create memory, will also depend onadvances in nanoscience and nanotechnologies.

Alternatives to silicon-based electronics are already beingexplored through nanoscience and nanotechnologies, forexample plastic electronics for flexible display screens.Other nanoscale electronic devices currently beingdeveloped are sensors to detect chemicals in theenvironment, to check the edibility of foodstuffs, or tomonitor the state of mechanical stresses within buildings.Much interest is also focused on quantum dots,semiconductor nanoparticles that can be ‘tuned’ to emitor absorb particular light colours for use in solar energycells or fluorescent biological labels.

(iv) Bio-nanotechnology and nanomedicine

Applications of nanotechnologies in medicine areespecially promising, and areas such as disease diagnosis,drug delivery targeted at specific sites in the body andmolecular imaging are being intensively investigated andsome products are undergoing clinical trials.Nanocrystalline silver, which is known to haveantimicrobial properties, is being used in wound dressingsin the USA. Applications of nanoscience andnanotechnologies are also leading to the production of

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materials and devices such as scaffolds for cell and tissueengineering, and sensors that can be used for monitoringaspects of human health. Many of the applications maynot be realised for ten years or more (owing partly to therigorous testing and validation regimes that will berequired). In the much longer term, the development ofnanoelectronic systems that can detect and processinformation could lead to the development of an artificialretina or cochlea. Progress in the area of bio-nanotechnology will build on our understanding ofnatural biological structures on the molecular scale, suchas proteins.

(v) Industrial applications

So far, the relatively small number of applications ofnanotechnologies that have made it through to industrialapplication represent evolutionary rather thanrevolutionary advances. Current applications are mainly inthe areas of determining the properties of materials, theproduction of chemicals, precision manufacturing andcomputing. In mobile phones for instance, materialsinvolving nanotechnologies are being developed for usein advanced batteries, electronic packaging and indisplays. The total weight of these materials willconstitute a very small fraction of the whole product butbe responsible for most of the functions that the devicesoffer. In the longer term, many more areas may beinfluenced by nanotechnologies but there will besignificant challenges in scaling up production from theresearch laboratory to mass manufacturing.

In the longer term it is hoped that nanotechnologies willenable more efficient approaches to manufacturingwhich will produce a host of multi-functional materials ina cost-effective manner, with reduced resource use andwaste. However, it is important that claims of likelyenvironmental benefits are assessed for the entirelifecycle of a material or product, from its manufacturethrough its use to its eventual disposal. We recommendthat lifecycle assessments be undertaken for applicationsof nanotechnologies.

Hopes have been expressed for the development and useof mechanical nano-machines which would be capable ofproducing materials (and themselves) atom-by-atom(however this issue was not raised by the industrialrepresentatives to whom we spoke). Alongside suchhopes for self-replicating machines, fears have beenraised about the potential for these (as yet unrealised)machines to go out of control, produce unlimited copiesof themselves, and consume all available material on theplanet in the process (the so called ‘grey goo’ scenario).We have concluded that there is no evidence to suggestthat mechanical self-replicating nanomachines will bedeveloped in the foreseeable future.

Health and environmental impacts

Concerns have been expressed that the very properties ofnanoscale particles being exploited in certain applications(such as high surface reactivity and the ability to cross cellmembranes) might also have negative health andenvironmental impacts. Many nanotechnologies pose nonew risks to health and almost all the concerns relate tothe potential impacts of deliberately manufacturednanoparticles and nanotubes that are free rather thanfixed to or within a material. Only a few chemicals arebeing manufactured in nanoparticulate form on anindustrial scale and exposure to free manufacturednanoparticles and nanotubes is currently limited to someworkplaces (including academic research laboratories)and a small number of cosmetic uses. We expect thelikelihood of nanoparticles or nanotubes being releasedfrom products in which they have been fixed orembedded (such as composites) to be low but haverecommended that manufacturers assess this potentialexposure risk for the lifecycle of the product and maketheir findings available to the relevant regulatory bodies.

Few studies have been published on the effects ofinhaling free manufactured nanoparticles and we havehad to rely mainly on analogies with results from studieson exposure to other small particles – such as thepollutant nanoparticles known to be present in largenumbers in urban air, and the mineral dusts in someworkplaces. The evidence suggests that at least somemanufactured nanoparticles will be more toxic per unit ofmass than larger particles of the same chemical. Thistoxicity is related to the surface area of nanoparticles(which is greater for a given mass than that of largerparticles) and the chemical reactivity of the surface (whichcould be increased or decreased by the use of surfacecoatings). It also seems likely that nanoparticles willpenetrate cells more readily than larger particles.

It is very unlikely that new manufactured nanoparticlescould be introduced into humans in doses sufficient tocause the health effects that have been associated withthe nanoparticles in polluted air. However, some may beinhaled in certain workplaces in significant amounts andsteps should be taken to minimise exposure. Toxicologicalstudies have investigated nanoparticles of low solubilityand low surface activity. Newer nanoparticles withcharacteristics that differ substantially from these shouldbe treated with particular caution. The physicalcharacteristics of carbon and other nanotubes mean thatthey may have toxic properties similar to those of asbestosfibres, although preliminary studies suggest that they maynot readily escape into the air as individual fibres. Untilfurther toxicological studies have been undertaken,human exposure to airborne nanotubes in laboratoriesand workplaces should be restricted.

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If nanoparticles penetrate the skin they might facilitatethe production of reactive molecules that could lead tocell damage. There is some evidence to show thatnanoparticles of titanium dioxide (used in some sunprotection products) do not penetrate the skin but it is notclear whether the same conclusion holds for individualswhose skin has been damaged by sun or by commondiseases such as eczema. There is insufficient informationabout whether other nanoparticles used in cosmetics(such as zinc oxide) penetrate the skin and there is a needfor more research into this. Much of the informationrelating to the safety of these ingredients has been carriedout by industry and is not published in the open scientificliterature. We therefore recommend that the terms ofreference of safety advisory committees that considerinformation on the toxicology of ingredients such asnanoparticles include a requirement for relevant data,and the methodologies used to obtain them, to be placedin the public domain.

Important information about the fate and behaviour ofnanoparticles that penetrate the body’s defences can begained from researchers developing nanoparticles fortargeted drug delivery. We recommend collaborationbetween these researchers and those investigating thetoxicity of other nanoparticles and nanotubes. Inaddition, the safety testing of these novel drug deliverymethods must consider the toxic properties specific tosuch particles, including their ability to affect cells andorgans distant from the intended target of the drug.

There is virtually no information available about the effectof nanoparticles on species other than humans or abouthow they behave in the air, water or soil, or about theirability to accumulate in food chains. Until more is knownabout their environmental impact we are keen that therelease of nanoparticles and nanotubes to theenvironment is avoided as far as possible. Specifically, werecommend as a precautionary measure that factoriesand research laboratories treat manufacturednanoparticles and nanotubes as if they were hazardousand reduce them from waste streams and that the use offree nanoparticles in environmental applications such asremediation of groundwater be prohibited.

There is some evidence to suggest that combustiblenanoparticles might cause an increased risk of explosionbecause of their increased surface area and potential forenhanced reaction. Until this hazard has been properlyevaluated this risk should be managed by taking steps toavoid large quantities of these nanoparticles becomingairborne.

Research into the hazards and exposure pathways ofnanoparticles and nanotubes is required to reduce themany uncertainties related to their potential impacts onhealth, safety and the environment. This research mustkeep pace with the future development of nanomaterials.We recommend that the UK Research Councils assemblean interdisciplinary centre (perhaps from existing research

institutions) to undertake research into the toxicity,epidemiology, persistence and bioaccumulation ofmanufactured nanoparticles and nanotubes, to work onexposure pathways and to develop measurementmethods. The centre should liaise closely with regulatorsand with other researchers in the UK, Europe andinternationally. We estimate that funding of £5-6M pa for10 years will be required. Core funding should come fromthe Government but the centre would also take part inEuropean and internationally funded projects.

Social and ethical impacts

If it is difficult to predict the future direction ofnanoscience and nanotechnologies and the timescaleover which particular developments will occur, it is evenharder to predict what will trigger social and ethicalconcerns. In the short to medium term concerns areexpected to focus on two basic questions: ‘Who controlsuses of nanotechnologies?’ and ‘Who benefits from usesof nanotechnologies?’ These questions are not unique tonanotechnologies but past experience with othertechnologies demonstrates that they will need to beaddressed.

The perceived opportunities and threats ofnanotechnologies often stem from the samecharacteristics. For example, the convergence ofnanotechnologies with information technology, linkingcomplex networks of remote sensing devices withsignificant computational power, could be used to achievegreater personal safety, security and individualisedhealthcare and to allow businesses to track and monitortheir products. It could equally be used for covertsurveillance, or for the collection and distribution ofinformation without adequate consent. As new forms ofsurveillance and sensing are developed, further researchand expert legal analysis might be necessary to establishwhether current regulatory frameworks and institutionsprovide appropriate safeguards to individuals and groupsin society. In the military context, too, nanotechnologieshold potential for both defence and offence and willtherefore raise a number of social and ethical issues.

There is speculation that a possible future convergence ofnanotechnologies with biotechnology, information andcognitive sciences could be used for radical humanenhancement. If these possibilities were ever realised theywould raise profound ethical questions.

A number of the social and ethical issues that might begenerated by developments in nanoscience andnanotechnologies should be investigated further and werecommend that the research councils and the Arts andHumanities Research Board fund a multidisciplinaryresearch programme to do this. We also recommend thatthe ethical and social implications of advancedtechnologies form part of the formal training of allresearch students and staff working in these areas.

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Stakeholder and public dialogue

Public attitudes can play a crucial role in realising thepotential of technological advances. Public awareness ofnanotechnologies is low in Great Britain. In the survey ofpublic opinion that we commissioned, only 29% said theyhad heard of ‘nanotechnology’ and only 19% could offerany form of definition. Of those who could offer adefinition, 68% felt that it would improve life in thefuture, compared to only 4% who thought it would makelife worse.

In two in-depth workshops involving small groups of thegeneral public, participants identified both positive andnegative potentials in nanotechnologies. Positive viewswere expressed about new advances in an exciting field;potential applications particularly in medicine; thecreation of new materials; a sense that the developmentswere part of natural progress and the hope that theywould improve the quality of life. Concerns were aboutfinancial implications; impacts on society; the reliability ofnew applications; long-term side-effects and whether thetechnologies could be controlled. The issue of thegovernance of nanotechnologies was also raised. Whichinstitutions could be trusted to ensure that the trajectoriesof development of nanotechnologies are sociallybeneficial? Comparisons were made with geneticallymodified organisms and nuclear power.

We recommend that the research councils build upon ourpreliminary research into public attitudes by funding amore sustained and extensive programme involvingmembers of the general public and members ofinterested sections of society.

We believe that a constructive and proactive debate aboutthe future of nanotechnologies should be undertakennow – at a stage when it can inform key decisions abouttheir development and before deeply entrenched orpolarised positions appear. We recommend that theGovernment initiate adequately funded public dialoguearound the development of nanotechnologies. The precisemethod of dialogue and choice of sponsors should bedesigned around the agreed objectives of the dialogue.Our public attitudes work suggests that governancewould be an appropriate subject for initial dialogue andgiven that the Research Councils are currently fundingresearch into nanotechnologies they should considertaking this forward.

Regulation

A key issue arising from our discussions with the variousstakeholders was how society can control thedevelopment and deployment of nanotechnologies tomaximise desirable outcomes and keep undesirableoutcomes to an acceptable minimum – in other words,how nanotechnologies should be regulated. Theevidence suggests that at present regulatory frameworksat EU and UK level are sufficiently broad and flexible to

handle nanotechnologies at their current stage ofdevelopment. However some regulations will need to bemodified on a precautionary basis to reflect the fact thatthe toxicity of chemicals in the form of free nanoparticlesand nanotubes cannot be predicted from their toxicity ina larger form and that in some cases they will be moretoxic than the same mass of the same chemical in largerform. We looked at a small number of areas of regulationthat cover situations where exposure to nanoparticles ornanotubes is likely currently or in the near future.

Currently the main source of inhalation exposure tomanufactured nanoparticles and nanotubes is inlaboratories and a few other workplaces. We recommendthat the Health and Safety Executive carry out a review ofthe adequacy of existing regulation to assess and controlworkplace exposure to nanoparticles and nanotubesincluding those relating to accidental release. In themeantime they should consider setting loweroccupational exposure levels for chemicals whenproduced in this size range.

Under current UK chemical regulation (Notification ofNew Substances) and its proposed replacement beingnegotiated at European level (Registration, Evaluationand Authorisation of Chemicals) the production of anexisting substance in nanoparticulate form does nottrigger additional testing. We recommend that chemicalsproduced in the form of nanoparticles and nanotubes betreated as new chemicals under these regulatoryframeworks. The annual production thresholds thattrigger testing and the testing methodologies relating tosubstances in these sizes, should be reviewed as moretoxicological evidence becomes available.

Under cosmetics regulations in the European Union,ingredients (including those in the form of nanoparticles)can be used for most purposes without prior approval,provided they are not on the list of banned or restricteduse chemicals and that manufacturers declare the finalproduct to be safe. Given our concerns about the toxicityof any nanoparticles penetrating the skin we recommendthat their use in products be dependent on a favourableopinion by the relevant European Commission scientificsafety advisory committee. A favourable opinion has beengiven for the nanoparticulate form of titanium dioxide(because chemicals used as UV filters must undergo anassessment by the advisory committee before they can beused) but insufficient information has been provided toallow an assessment of zinc oxide. In the meantime werecommend that manufacturers publish details of themethodologies they have used in assessing the safety oftheir products containing nanoparticles that demonstratehow they have taken into account that properties ofnanoparticles may be different from larger forms. We donot expect this to apply to many manufacturers since ourunderstanding is that nanoparticles of zinc oxide are notused extensively in cosmetics in Europe. Based on ourrecommendation that chemicals produced in the form ofnanoparticles should be treated as new chemicals, we

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believe that the ingredients lists for consumer productsshould identify the fact that manufactured nanoparticleshave been added. Nanoparticles may be included in moreconsumer products in the future, and we recommendthat the European Commission, with the support of theUK, review the adequacy of the current regulatory regimewith respect to the introduction of nanoparticles into anyconsumer products.

Although we think it unlikely that nanoparticles ornanotubes will be released from most materials in whichthey have been fixed, we see any risk of such releasebeing greatest during disposal, destruction or recycling.We therefore recommend that manufacturers of productsthat fall under extended producer responsibility regimessuch as end-of-life regulations publish proceduresoutlining how these materials will be managed tominimise possible human and environmental exposure.

Our review of regulation has not been exhaustive and werecommend that all relevant regulatory bodies considerwhether existing regulations are appropriate to protecthumans and the environment from the hazards we haveidentified, publish their reviews and explain how they willaddress any regulatory gaps. Future applications ofnanotechnologies may have an impact on other areas ofregulation as, for example, developments in sensortechnology may have implications for legislation relatingto privacy. It is therefore important that regulatory bodiesinclude future applications of nanotechnologies in theirhorizon-scanning programmes to ensure that anyregulatory gaps are identified at an appropriate stage.

Overall, given appropriate regulation and research alongthe lines just indicated, we see no case for themoratorium which some have advocated on thelaboratory or commercial production of manufacturednanomaterials.

Ensuring the responsible development of newand emerging technologies

Nanoscience and nanotechnologies are evolving rapidly,and the pressures of international competition will ensurethat this will continue. The UK Government’s ChiefScientific Adviser should therefore commission anindependent group in two years time, and again in fiveyears time, to review what action has been taken as aresult of our recommendations, to assess hownanoscience and nanotechnologies have developed inthe interim, and to consider the ethical, social, health,environmental, safety and regulatory implications ofthese developments. This group should includerepresentatives of, and consult with, the relevantstakeholder groups.

More generally, this study has highlighted again the valueof identifying as early as possible new areas of science andtechnology that have the potential to impact strongly onsociety. The Chief Scientific Adviser should thereforeestablish a group that brings together representatives of awide range of stakeholders to meet bi-annually to reviewnew and emerging technologies, to identify at the earliestpossible stage areas where issues needing Governmentattention may arise, and to advise on how these might beaddressed. The work of this group should be made publicand all stakeholders should be encouraged to engagewith the emerging issues. We expect this group to drawupon the work of the other bodies across Governmentwith horizon-scanning roles rather than to duplicate theirwork.

We look forward to the response to this report from the UKGovernment and from the other parties at whom therecommendations are targeted. This study has generated agreat deal of interest among a wide range of stakeholders,both within the UK and internationally. As far as we areaware it is the first study of its kind, and we expect itsfindings to contribute to the responsible development ofnanoscience and nanotechnology globally.

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Recommendations

The industrial application of nanotechnologies

R1 We recommend that a series of lifecycle assessmentsbe undertaken for the applications and productgroups arising from existing and expecteddevelopments in nanotechnologies, to ensure thatthat savings in resource consumption during the useof the product are not offset by increasedconsumption during manufacture and disposal. Tohave public credibility these studies need to becarried out or reviewed by an independent body.

R2 Where there is a requirement for research toestablish methodologies for lifecycle assessments inthis area, we recommend that this should be fundedby the research councils through the normalresponsive mode.

Possible adverse health, safety andenvironmental impacts

The lack of evidence about the risk posed bymanufactured nanoparticles and nanotubes is resulting inconsiderable uncertainty.

R3 We recommend that Research Councils UK establishan interdisciplinary centre (probably comprisingseveral existing research institutions) to research thetoxicity, epidemiology, persistence andbioaccumulation of manufactured nanoparticles andnanotubes as well as their exposure pathways, andto develop methodologies and instrumentation formonitoring them in the built and naturalenvironment. A key role would be to liaise withregulators. We recommend that the research centremaintain a database of its results and that it interactwith those collecting similar information in Europeand internationally. Because it will not be possible forthe research centre to encompass all aspects ofresearch relevant to nanoparticles and nanotubes,we recommend that a proportion of its funding beallocated to research groups outside the centre toaddress areas identified by the advisory board as ofimportance and not covered within the centre

R4 Until more is known about environmental impacts ofnanoparticles and nanotubes, we recommend thatthe release of manufactured nanoparticles andnanotubes into the environment be avoided as far aspossible.

R5 Specifically, in relation to two main sources of currentand potential releases of free nanoparticles andnanotubes to the environment, we recommend:

(i) that factories and research laboratories treatmanufactured nanoparticles and nanotubes as ifthey were hazardous, and seek to reduce orremove them from waste streams;

(ii) that the use of free (that is, not fixed in a matrix)manufactured nanoparticles in environmentalapplications such as remediation be prohibiteduntil appropriate research has been undertakenand it can be demonstrated that the potentialbenefits outweigh the potential risks.

R6 We recommend that, as an integral part of theinnovation and design process of products andmaterials containing nanoparticles or nanotubes,industry should assess the risk of release of thesecomponents throughout the lifecycle of the productand make this information available to the relevantregulatory authorities.

R7 We recommend that the terms of reference ofscientific advisory committees (including theEuropean Commission’s Scientific Committee onCosmetic and Non-Food Products or its replacement)that consider the safety of ingredients that exploitnew and emerging technologies likenanotechnologies, for which there is incompletetoxicological information in the peer-reviewedliterature, should include the requirement for allrelevant data related to safety assessments, and themethodologies used to obtain them, to be placed inthe public domain.

Regulatory issues

R8 We recommend that all relevant regulatory bodiesconsider whether existing regulations areappropriate to protect humans and the environmentfrom the hazards outlined in this report and publishtheir review and details of how they will address anyregulatory gaps.

R9 We recommend that regulatory bodies and theirrespective advisory committees include futureapplications of nanotechnologies in their horizonscanning programmes to ensure any regulatory gapsare identified at an appropriate stage.

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Recommendations R10 to R14 are based on applying ourconclusions - that some chemicals are more toxic when inthe form of nanoparticles or nanotubes and that safetyassessments based on the testing of a larger form of achemical cannot be used to infer the safety of chemicalsin the form of nanoparticles - to a series of regulatory casestudies:

R10 We recommend that chemicals in the form ofnanoparticles or nanotubes be treated as newsubstances under the existing Notification of NewSubstances (NONS) regulations and in theRegistration, Evaluation, Authorisation andRestriction of Chemicals (REACH) (which is currentlyunder negotiation at EU level and will eventuallysupersede NONS). As more information regardingthe toxicity of nanoparticles and nanotubes becomesavailable, we recommend that the relevantregulatory bodies consider whether the annualproduction thresholds that trigger testing and thetesting methodologies relating to substances inthese forms should be revised under NONS andREACH.

R11 Workplace:

(i) We recommend that the Health & SafetyExecutive (HSE) review the adequacy of itsregulation of exposure to nanoparticles, and inparticular considers the relative advantages ofmeasurement on the basis of mass and number.In the meantime, we recommend that itconsiders setting lower occupational exposurelevels for manufactured nanoparticles.

(ii) We recommend that the HSE, Department forEnvironment Food and Rural Affairs and theEnvironment Agency review their currentprocedures relating to the management ofaccidental releases both within and outside theworkplace.

(iii) We recommend that the HSE consider whethercurrent methods are adequate to assess andcontrol the exposures of individuals inlaboratories and workplaces where nanotubesand other nanofibres may become airborne andwhether regulation based on electronmicroscopy rather than phase-contrast opticalmicroscopy is necessary.

R12 Consumer products:

(i) We recommend that ingredients in the form ofnanoparticles undergo a full safety assessmentby the relevant scientific advisory body beforethey are permitted for use in products.

Specifically: we recommend that industry submitthe additional information on microfine zincoxide that is required by the SCCNFP as soon asreasonably practicable so that it can deliver anOpinion on its safety.

(ii) We recommend that manufacturers publishdetails of the methodologies they have used inassessing the safety of their products containingnanoparticles that demonstrate how they havetaken account that properties of nanoparticlesmay be different from larger forms.

(iii) We recommend that the ingredients lists ofconsumer products should identify the fact thatmanufactured nanoparticulate material has beenadded.

(iv) We recommend that the EC’s new ScientificCommittee on Emerging and Newly IdentifiedHealth risks gives a high priority to theconsideration of the safety of nanoparticles inconsumer products.

(v) In the light of the regulatory gaps that weidentify we recommend that the EC (supportedby the UK) review the adequacy of the currentregulatory regime with respect to theintroduction of nanoparticles into consumerproducts. In undertaking this review they shouldbe informed by the relevant scientific safetyadvisory committees.

R13 We recommend that the Department of Healthreview its regulations for new medical devices andmedicines to ensure that particle size and chemistryare taken into account in investigating possibleadverse side effects of medicines.

R14 We recommend that manufacturers of products thatincorporate nanoparticles and nanotubes and whichfall under extended producer responsibility regimessuch as end-of-life regulations be required to publishprocedures outlining how these materials will bemanaged to minimise human and environmentalexposure.

R15 Measurement:

(i) We recommend that researchers and regulatorslooking to develop methods to measure andmonitor airborne manufacturednanoparticulates liaise with those who areworking on the measurement of pollutantnanoparticles from sources such as vehicleemissions.

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(ii) We recommend that the Department of Tradeand Industry supports the standardisation ofmeasurement at the nanometre scale required byregulators and for quality control in industrythrough the adequate funding of initiativesunder its National Measurement SystemProgramme and that it ensures that the UK is inthe forefront of any international initiatives forthe standardisation of measurement.

Social and ethical issues

R16 We recommend that the research councils and theArts and Humanities Research Board (AHRB) fund aninterdisciplinary research programme to investigatethe social and ethical issues expected to arise fromthe development of some nanotechnologies.

R17 We recommend that the consideration of ethical andsocial implications of advanced technologies (such asnanotechnologies) should form part of the formaltraining of all research students and staff working inthese areas and, specifically, that this type of formaltraining should be listed in the Joint Statement of theResearch Councils’/AHRB’s Skills TrainingRequirements for Research Students.

Stakeholder and public dialogue

R18 We recommend that the research councils build onthe research into public attitudes undertaken as partof our study by funding a more sustained andextensive programme of research into publicattitudes to nanotechnologies. This should involvemore comprehensive qualitative work involving

members of the general public as well as members ofinterested sections of society, such as the disabled,and might repeat the awareness survey to track anychanges as public knowledge aboutnanotechnologies develops.

R19 We recommend that the Government initiatesadequately funded public dialogue around thedevelopment of nanotechnologies. We recognisethat a number of bodies could be appropriate intaking this dialogue forward.

Ensuring the responsible development ofnanotechnologies

R20 We recommend that the Office of Science andTechnology commission an independent group intwo and five years’ time to review what action hasbeen taken on our recommendations, and to assesshow science and engineering has developed in theinterim and what ethical, social, health,environmental, safety and regulatory implicationsthese developments may have. This group shouldcomprise representatives of, and consult with, therelevant stakeholder groups. Its reports should bepublicly available.

R21 We recommend that the Chief Scientific Advisorshould establish a group that brings togetherrepresentatives of a wide range of stakeholders tolook at new and emerging technologies and identifyat the earliest possible stage areas where potentialhealth, safety, environmental, social, ethical andregulatory issues may arise and advise on how thesemight be addressed.

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Working Group, Review Group and Secretariat members

Working Group

The two Academies are extremely grateful to the Working Group for their hard work.

Prof Ann Dowling CBE FREng FRS (Chair) Professor of Mechanical Engineering, University of Cambridge

Prof Roland Clift OBE FREng Director of the Centre for Environmental Strategy, University of Surrey

Dr Nicole Grobert Royal Society Dorothy Hodgkin Research Fellow, University of Oxford

Dame Deirdre Hutton CBE Chair of the National Consumer Council

Dr Ray Oliver FREng Senior Science and Technology Associate in the Strategic TechnologyGroup, ICI plc

Baroness Onora O’Neill CBE FBA FMedSci Newnham College, University of Cambridge

Prof John Pethica FRS SFI Research Professor, Department of Physics, Trinity College Dublinand Visiting Professor, Department of Materials, University of Oxford

Prof Nick Pidgeon Director of the Centre for Environmental Risk, University of EastAnglia

Jonathon Porritt Chair of the UK Sustainable Development Commission andProgramme Director of Forum for the Future

Prof John Ryan Director of the Interdisciplinary Research Collaboration onBionanotechnology. Based at the University of Oxford

Prof Anthony Seaton CBE FMedSci Emeritus Professor of Environmental and Occupational Medicine,University of Aberdeen and Honorary Senior Consultant, Institute ofOccupational Medicine, Edinburgh

Prof Saul Tendler Head of the School of Pharmacy and Professor of BiophysicalChemistry, University of Nottingham

Prof Mark Welland FREng FRS Director of the Interdisciplinary Research Collaboration inNanotechnology. Based at the University of Cambridge

Prof Roger Whatmore FREng Head of the Advanced Materials Department, Cranfield University

Review Group

The two academies gratefully acknowledge the contribution of the reviewers. With the exception of Sir JohnEnderby and Mr Philip Ruffles, they were not asked to endorse the conclusions or recommendations, nor did theysee the final draft of the report before its release.

Sir John Enderby CBE FRS (Chair) Physical Secretary and Vice-President of the Royal Society

Mr Philip Ruffles CBE FRS FREng (Vice-Chair) Vice-President of the Royal Academy of Engineering and Chair of itsStanding Committee on Engineering

Sir Richard Friend FRS FREng Cavendish Professor of Physics, Cambridge University

Prof Nigel Gilbert FREng Pro Vice-Chancellor and Professor of Sociology, University of Surrey

Dr James McQuaid CB FREng Previously Chief Scientist, Health and Safety Executive

Prof Anthony Segal FRS Department of Medicine, University College London

Secretariat

The core secretariat was: Sara Al-Bader, Dr Jofey Craig (June 2003 - September 2003), Dr Andrew Dunn (October2003 – August 2004) and Dr Rachel Quinn at the Royal Society and Richard Ploszek at the Royal Academy ofEngineering. Valuable administrative and web support was provided by Karen Scott-Jupp (Royal Society). Thesecretariat is grateful to the many other staff at the two Academies who contributed to the successful completion ofthis study.

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Annex A Working Group, Review Group and Secretariat members

Working Group

The two Academies are extremely grateful to the Working Group for their hard work.

Prof Ann Dowling CBE FREng FRS (Chair) Professor of Mechanical Engineering, University of Cambridge

Prof Roland Clift OBE FREng Director of the Centre for Environmental Strategy, University of Surrey

Dr Nicole Grobert Royal Society Dorothy Hodgkin Research Fellow, University of Oxford

Dame Deirdre Hutton CBE Chair of the National Consumer Council

Dr Ray Oliver FREng Senior Science and Technology Associate in the Strategic TechnologyGroup, ICI plc

Baroness Onora O’Neill CBE FBA FMedSci Newnham College, University of Cambridge

Prof John Pethica FRS SFI Research Professor, Department of Physics, Trinity College Dublinand Visiting Professor, Department of Materials, University of Oxford

Prof Nick Pidgeon Director of the Centre for Environmental Risk, University of EastAnglia

Jonathon Porritt Chair of the UK Sustainable Development Commission andProgramme Director of Forum for the Future

Prof John Ryan Director of the Interdisciplinary Research Collaboration onBionanotechnology. Based at the University of Oxford

Prof Anthony Seaton CBE FMedSci Emeritus Professor of Environmental and Occupational Medicine,University of Aberdeen and Honorary Senior Consultant, Institute ofOccupational Medicine, Edinburgh

Prof Saul Tendler Head of the School of Pharmacy and Professor of BiophysicalChemistry, University of Nottingham

Prof Mark Welland FREng FRS Director of the Interdisciplinary Research Collaboration inNanotechnology. Based at the University of Cambridge

Prof Roger Whatmore FREng Head of the Advanced Materials Department, Cranfield University

Review Group

The two academies gratefully acknowledge the contribution of the reviewers. With the exception of Sir JohnEnderby and Mr Philip Ruffles, they were not asked to endorse the conclusions or recommendations, nor did theysee the final draft of the report before its release.

Sir John Enderby CBE FRS (Chair) Physical Secretary and Vice-President of the Royal Society

Mr Philip Ruffles CBE FRS FREng (Vice-Chair) Vice-President of the Royal Academy of Engineering and Chair of itsStanding Committee on Engineering

Sir Richard Friend FRS FREng Cavendish Professor of Physics, Cambridge University

Prof Nigel Gilbert FREng Pro Vice-Chancellor and Professor of Sociology, University of Surrey

Dr James McQuaid CB FREng Previously Chief Scientist, Health and Safety Executive

Prof Anthony Segal FRS Department of Medicine, University College London

Secretariat

The core secretariat was: Sara Al-Bader, Dr Jofey Craig (June 2003 - September 2003), Dr Andrew Dunn (October2003 – August 2004) and Dr Rachel Quinn at the Royal Society and Richard Ploszek at the Royal Academy ofEngineering. Valuable administrative and web support was provided by Karen Scott-Jupp (Royal Society). Thesecretariat is grateful to the many other staff at the two Academies who contributed to the successful completion ofthis study.

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Overview

The Working Group sought a wide range of views in the ways outlined below. Written evidence, and summary reportsof workshops, meetings and other oral evidence sessions were posted on the dedicated website (www.nanotec.org.uk)as they became available, and comments on evidence was requested. The report has been prepared by the WorkingGroup (listed in Annex A) on the basis of evidence collected and their own expertise. The report has undergone arigorous peer review process by a review group comprising Fellows of both Academies (also listed in Annex A). It hasbeen endorsed by the Council of the Royal Society and approved for publication by the Royal Academy of Engineering.

Evidence gathering elements

Initial call for views (June 2003)The study was launched with an initial call for views that invited individuals and organisations to register theirinterest in this study and to identify the key issues that they thought should be considered by the Working Group.Over 90 responses were received.

Scientists/engineers workshop (30 September 2003)The Working Group used this meeting to gather evidence from the scientific community (including industry) aboutthe current state of research in nanotechnologies and both current and future applications of nanotechnologies.

Civil Societies workshop (30 October 2003 & 24 February 2004)At this small workshop the Working Group consulted and discussed issues with a range of civil societyorganisations. The Working Group prepared questions or issues they wanted to discuss and participants had theopportunity to help set the meeting’s agenda. The Working Group met with additional representatives on 24February 2004.

Health and environmental impacts meeting (8 December 2003)At this meeting the Working Group met with health and environment experts to consider the environmentalapplications of nanotechnologies as well as whether nanotechnologies might have a negative impact on humanhealth or the environment.

Public consultation (December 2003 - March 2004)To explore public attitudes to nanotechnology, the market research company BMRB International was commissionedto research public attitudes to nanotechnology. This involved two strands:· Two in-depth workshops with members of the public were held in December 2003 to explore their ideas about

nanotechnology, and to identify and discuss any potential concerns or questions that might arise.· Three questions, designed to establish public awareness of nanotechnology were included in an Access omnibus

survey in early January. The survey sought the views of 1,000 people in Great Britain aged 15+.

Workshop on regulation (11 February 2004) The Working Group met with regulators and others with expertise in regulatory issues to discuss whether or notexisting legislation is appropriate to nanosciences and nanotechnologies.

Industry meeting (3 March 2004)This half-day meeting offered the Working Group an opportunity to further explore the issues covered in the termsof reference with industry representatives.

Dedicated website (www.nanotec.org.uk)All interested parties (including the public) were able to comment via the website on any of the information postedon the website or raise issues relating to nanotechnologies in general or the about the study itself.

Independence

The study was conducted independently of Government, which was not involved in the selection of the WorkingGroup members or its methods of working, and which did not view the report before it was printed.

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Annex B Conduct of Study

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Annex C List of those who submitted evidence

On 11 June 2003, the Royal Society and Royal Academy of Engineering issued a call for written evidence for thenanotechnology study. This was followed by a number of oral evidence sessions, meetings and workshops. Reportsof these were posted on the website as they became available, and comments requested on them.

The following is a list of the individuals and organisations that gave evidence to the study in writing and/or orally.For ease of reference, evidence is listed according by individual and by organisation. The views of individuals do notnecessarily represent those of their organisations.

The Royal Society and Royal Academy of Engineering are most grateful to those who assisted the study by providingevidence, and have made every endeavour to list them all here. If any individuals or organisations have been omittedwe offer our apologies and will ensure that the web version of the evidence list is updated.

W = provided written evidence O = attended oral evidence session M = attended meeting or workshop

IndividualsAAdams, Michael Unilever (M)Aeppli, Gabriel London Centre for Nanotechnology (W &O)Alakeson, Vidhya Forum for the Future (W) Albertario, Fabio (W)Aldrich, Tim Forum for the Future (M)Allen, Geoffrey University of East Anglia (M)Allen, Ray University of Sheffield (M)Alsop, Adrian Economic and Social Research Council (W)Altmann, Juergen Experimentelle Physik II, Dortmund University (W)Andrews, Arlan (W)Arnall, Alexander Imperial College London (W)Ayres, John University of Aberdeen (W)

BBachmann, Gerd Co-worker of a German Governmental nanotechnology funding agency (O)Ball, Philip (W)Balmer, Richard Association of Liberal Democrat Engineers and Scientists (W)Barbur, Vicki Eastman Kodak Company, USA (W)Batchelor FREng, Keith (W)Besenbacher, Flemming University of Aarhus, Denmark (O)Biggs FREng, Simon University of Leeds (W)Binks, Peter Nanotechnology Victoria (W)Bosch, Wolfgang Filtronic (M)Bott, David ICI (M)Brazil, Rachel Royal Society of Chemistry (W & M)Briscoe, Brian Imperial College London (M)Broughton, Duncan (W)Brown, Mike Boots (M)Burgess, Doug MOD (O)Burgess, Jacquie University College London (O)

CCalladine FRS FREng, Chris University of Cambridge (W)Carroll, John University of Cambridge (W)Carson, Dave (W)Cass, Tony Imperial College London (M)Chadwick, Derek The Novartis Foundation (W)Chetwynd, Derek University of Warwick (M)Church, Colin Department for environment food and rural affairs (DEFRA) (M)Clarke, Andrew Kodak (M)

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Colbeck, Ian University of Essex (M)Collis, Amanda The Biotechnolgy and Biological Sciences Research Council (W)Cumpson, Peter National Physical Laboratory (M)

DDavey, Roger J (W) Davies, Graham J University of Birmingham (M) (W)Davies FREng, Stewart CEO BT Exact (W)Delic, Julian Health and Safety Executive (M)Dent, Benjamin Department for environment food and rural affairs (DEFRA) (M)Depledge, Mike Environment Agency, Head of Science (M)Devine, Steve (W)Dibb, Sue National Consumer Council (W&O)Dimmock, John Media Services Sussex Ltd (W)Dobson, Peter University of Oxford, Begbrooke Science Park (W & M)Donaldson, Ken MRC Centre for Inflammation Research, University of Edinburgh (W &M)Dowding, Peter Infinaeum (M)Downing, Steve ICI (M)Dransfield, Graham Uniqema (M)Drexler, Eric Foresight Institute (W&O)Duncan, Ruth Welsh School of Pharmacy (W)

EEigler, Don IBM (O)Ellis, John X-FAB UK Ltd (M)Evans, Barry University of Surrey (W)

FFenton, Gary (W)Festing, Michael Animal Procedures Committee (M)Fisher, Andrew University College London (M)Fitzmaurice, Donald University College Dublin (M)Fletcher, Amy L (W)Flodstrom, Anders Royal Institute of Technology, Stockholm, Sweden (O)Florence, Sandy The London School of Pharmacy (M)Foo, Joyce FCO Singapore (W)Fox-Male, Nick Eric Potter Clarkson IP Services (W)Fullam, Brian HSE (M)

GGallop, John National Physcial Laboratory (M)Gann, David Imperial College London (W)Garnett, Martin University of Nottingham (W)Gimzewski FREng, Chemistry Dept, University of James California, Los Angeles (W)Gittins, David Imerys (M)Glover, Anne University of Aberdeen (M)Golunski, Stan Johnson Matthey (W)Grant, Malcolm Agriculture and Environment Biotechnology Commission (O)Greisch, Edward R US Military (W)Griffiths, Glynis Food Standards Agency (M)Grimshaw, David ITDG (M)Gubrud, Mark Avrum Center for Superconductivity Research, Physics Dept, University of Maryland (W)

HHanson, Robin George Mason University, Fairfax, USA (W)Harper, Tim Cientifica Ltd (W & O)Harrison, Robert Rouse Patents (O)Hawksworth, Stuart HSE (M)Hayes, Emma Environment Agency (M)

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Healey, Peter Science Technology and Governance in Europe (W)Higgins, Rob Medicines and Healthcare products Regulatory Agency (M)Hilsum, Cyril University of Cambridge (W)Hinde, Julia FCO, Canada (W)Hitchcock, Julian Eversheds LLP Solicitors (W)Holister, Paul Cientifica (M)Holtum, Dave Engineering and Physical Sciences Research Council (W)Hook, David Medicines and Healthcare products Regulatory Agency (M)Hossain, Kamal National Physical Laboratory (W)Howard, Vyvyan University of Liverpool (M)Howorth, Dave (W)Howse, Mike (W)Humphreys, Colin (W)Hurley, Fintan Institute of Occupational Medicine, Edinburgh (M)Hyde, Vic Cosmetics Toiletry and Perfumery Association (M)

IIden, Ruediger BASF (M)Illsley, Derek Sun Chemical Co (M)Ion, Sue BNFL (W)Irwin, Alan Brunel University (O)

JJames FREng, Jim (W)Janzen, William Amphora Discovery Corporation (O)Jones, Richard University of Sheffield (W & O) Juniper, Tony Friends of the Earth (W)

KKarn, Barbara US Environmental Protection Agency (W)Kelly, Mike University of Cambridge (M)Khandelwal, Amit Chemical Industries Association (M)Knowland, John University of Oxford (M)Krauss, Thomas University of St Andrews (M)Kroto FRS, Harry (O)Kulinowski, Kristen M Center for Biological and Environmental Nanotechnology USA (O)Kumar, Dinesh ION IT Ltd (W)

LLeigh, Beatrice GlaxoSmithKline (M)Light, Richard DAART Centre for Disability and Human Rights (W)Loveridge, Denis Honorary Visiting Professor – PREST (W)

MMacaskie, Lynne University of Birmingham (M) (W)Martin, Philippe EC Health and Consumer Protection (M)Matthews, Kevin Oxonica (M)Maynard, Andrew National Institute for Occupational Safety and Health (W)McKeown FREng, PA (W)McLeod, Alistair Imperial College London (M)McQuaid, Jim (W)Mehta, Michael D. University of Saskatchewan (W)Meldrum, Maureen HSE (M)Merrifield, David GSK (M)Mesquida, Patrick London Centre for Nanotechnology (M)Miles, Glenn (W)Miles, Mervyn University of Bristol (M)Milner, Robin UK Computing Research Committee (W)Molyneaux, Andrea Medicines and Healthcare products Regulatory Agency (M)Mooney, Pat Etc Group (O)

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Moore, Julia National Science Foundation (M)Morris, Vic Institute of Food Research (M)Murray, Mike ABPI (M)Murrer, Barry Johnson Matthey (M)

NNorthage, Christine Health and Safety Executive (M)

OOzorio de Almeida FCO, Brazil (W)

PPacholak, Anna FCO, Poland (W)Palmer, Richard E University of Birmingham (W & M)Palmer, SB Warwick Nanosystems Group, UK (W)Parkinson, Stuart Scientists for Global Responsibility (W)Parr, Douglas Greenpeace (W&O)Parry, Vivienne (O)Pethrick, RA University of Strathclyde (W)Pham FREng, DUC University of Cardiff (W)Phillips, Ian ARMPhoenix, Chris Center for Responsible Nanotechnology (W)Pick, Martin (W)Pilkington, Ian Ilford (M)Poirier, Natalie FCO, The Netherlands (W)Polak, Julia Imperial College London (M)

QQuinn, Francis L’Oreal (M)

RRajan, Bob HSE (M)Rayner, Steve SaÏd Business School, Oxford University (O)Richards, David Technopreneur limited (W)Rickerby, David Advisory Cell for Science and Technology, European Joint Commission Centre (W)Reip, Paul Qinetiq Nanomaterials Ltd. (O)Rip, Arie University of Twente, The Netherlands (O)Rix, Sam ex pupil of Hills Road Sixth Form College (W)Roco, Mike National Science Foundation, USA, Senior advisor for nanotechnology also Chair

US Nanoscale Science and Engineering (W & O)Roos, Ursula FCO, Germany (W)

SSantoli, Salvatore International Nanobiological Testbed Ltd (W)Savage, Nora Environmental Protection Agency, USA (W)Schneemilch, Matthew Imperial College London (M)Scott, Andrew Intermediate Technology Development Group (W)Semple, Sean University of Aberdeen (M)Sloan, Jeremy University of Oxford (M)Smalley, Richard Rice University (O)Smith, George University of Oxford (M)Snape, Julian (W)Snowdon, Ken University of Newcastle (M)Southerland, David Department of trade and industry (M)Stark FREng, Jim (W)Stepney, Susan UK Computing Research Committee (W)Stewart FREng, Will (W)Stone, Vicki Napier University (M)Sutherland Olsen, Dorothy (W)Sutton, David ICI (M)

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Swan, Harry Thomas Swan & Co ltd (M)Symons, Rex Better Regulation Taskforce (M)Syms, Richard Imperial College London (M)

TTran, Lang Institute of Occupational Medicine, Edinburgh (M)Thomas, Jim Action Group on Erosion, Technology and Concentration (W & M)Tolfree, David Technopreneur limited (W)Tomlinson, Geoffrey (W)Treder, Mike Center for Responsible Nanotechnology, USA (W)Tsavalos, Alexander Health and Safety Executive (W & M)Tuppen, Chris BT (M)

VVadgama, PankajVaughan-Lee, David Editor, Asia Pacific Coatings Journal (W)Vest, Charles Massachusetts Institute of Technology (O)Visser, Germ W DSM, The Netherlands (W)

WWadey, Rita OST (M)Wakeford, Tom PEALS (M)Wang, Brian Owner of a software company, Silicon Valley (W)Ward, Professor IM University of Leeds (W)Warheit, David B. DuPont (W)Weiss, Tilo Sustech (M)Wells FRS FREng, PNT University of Bristol (W)Whitby, Raymond University of Sussex (W)White, Ian Chairman, scientific committee on cosmetic and non-food products (O)Whitesides, George Harvard University, Department of chemistry and chemical biology (O)Wiggins, Jason University of Oxford, Begbrooke Science Park (W)Wilkinson, Chris University of Glasgow (M)Willett, Steve (W)Williams, Gary (W)Williams, Martin Department for environment food and rural affairs (DEFRA) (M)Williams FREng, Richard Institute of Particle Science & Engineering (W)Williams, Simon The Patients Association (M)Wilsdon, James Demos (M)Wilson, Neil University of Warwick (M)Windle, Alan University of Cambridge (M)Winkler, Stefan FCO, USA (W)Wood, Stephen University of Sheffield (W & O)

YYeates, Steve (W)Young, Anthony R St Johns Institute of Dermatology, Kings College London

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Organisations

AAction Group on Erosion, Technology and Concentration (W & M)Advisory Cell for Science and Technology, European Joint Commission Centre David Rickerby (W)Agriculture and Environment Biotechnology Commission Malcolm Grant (O)Amphora Discovery Corporation William Janzen (O)Animal Procedures Committee Michael Festing (M)Asia Pacific Coatings Journal David Vaughan-Lee (W)Association of Liberal Democrat Engineers and Scientists Richard Balmer, Hon Secretary (W)Association of the British Pharmaceutical Industry Mike Murray (M)

BBASF group - Ruediger Iden (M)Begbroke Science Park University of Oxford - Peter Dobson

(W & M), Jason Wiggins (W)Better Regulation Taskforce Rex Symons (M)Biotechnolgy and Biological Sciences Research Council Amanda Collis (W)Boots Mike Brown (M)British Nuclear Fuels Sue Ion (W)British Telecom Chris Tuppen (M)Brunel University Alan Irwin (O)BT Exact (W)

CCenter for Biological and Environmental Nanotechnology, USA Kristen M Kulinowski (O)Center for Responsible Nanotechnology, USA Mike Treder, Executive Director (W)Chemical Industries Association Amit Khandelwal (M)Cientifica Ltd Tim Harper (W & O), Paul Holister (M)Computing Research Committee (W)Cosmetics, Toiletry and Perfumery Association Vic Hyde (M)

DDAART Centre for Disability and Human Rights Richard LightDepartment for the Environment, Food and Rural Affairs Colin Church (M), Benjamin Dent (M),MartinWilliams (M)Department for Trade and Industry David Southerland (M)Demos James Wilsdon (M)DSM, The Netherlands Germ Visser (W)DuPont David Warheit (W)

EEastman Kodak Company, USA Vicki Barbur (W)EC Health and Consumer Protection Phillippe Martin (M)Economic and Social Research Council Adrian Alsop (W)Engineering and Physical Sciences Research Council Dave Holtum (W)Environment Agency Michael Depledge (M), Emma Hayes (M)Environmental Protection Agency, USA Nora Savage (W)Eric Potter Clarkson IP Services Nick Fox-Male (W)ETC (Action Group on Erosion, Technology and Concentration) Jim Thomas, Programme Manager and

Pat Mooney (W, O & M)Eversheds LLP Solicitors Julian Hitchcock (W)

FFiltronic Wolfgang Bosch (M)Food Standards Agency Glynis Griffiths (M)Foreign and Commonwealth Office (W)

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Foresight Institute Eric Drexler (W & O)Forum for the Future Vidhya Alakeson, Principal Policy

Advisor (W), Tim Aldrich (M)Friends of the Earth Tony Juniper (W)

GGeneWatch UK (W)George Mason University, Fairfax, USA Robin Hanson (W)GlaxoSmithKline Beatrice Leigh (M), David Merrifield (M)Greenpeace Doug Parr (W & O)

HHarvard University George Whitesides (O)Health and Safety Executive Julian Delic (M), Brian Fullam (M),

Stuart Hawksworth (M), MaureenMeldrum (M), Christine Northage (M),Bob Rajan (M), Christine Northage (M),Alexander Tsavalos (W & M)

IIBM Don Eigler (O)ICI Steve Downing (M), David Bott (M),

David Sutton (M)Ilford Ian Pilkington (M)Imerys David Gittins (M)Imperial College London Brian Briscoe (M), Tony Cass (M), David

Gann (W), Julia Polak (M), MatthewSchneemilch (M), Richard Syms (M),Alistair McLeod (M)

Imperial College, Business School and Department of Civil and David Gann, Director InnovationEnvironmental Engineering Studies Centre (W)Imperial College London Centre for Energy Policy and Technology Alex Arnall (W)Infinaeum Peter Dowding (M)Institute of Food Research Vic Morris (M)Institute of Food Science and Technology (W)Institute of Occupational Medicine, Edinburgh Fintan Hurley (M), Lang Tran (M)Institute of particle science and engineering (W)Institute of Physics (W)Intermediate Technology Development Group David Grimshaw (M), Andrew Scott,

Policy and Programmes Director (W)International Nanobiological Testbed Ltd Salvatore Santoli (W)ION IT Ltd Dinesh Kumar (W)

JJohnson Matthey Dr Stan Golunski (W), Barry Murrer (M)

KKodak Andrew Clarke (M)

LL’Oreal Francis Quinn (M)London Centre for Nanotechnology Gabriel Aeppli, Director (W), Patrick

Mesquida (M)London School of Pharmacy Sandy Florence (M)

MMassachusetts Institute of Technology Charles Vest (O)Media Services Sussex Ltd John Dimmock - Technical Director (W)Medical Research Council (W)Medicines and Healthcare products Regulatory Agency Andrea Molyneaux (M), Rob Higgins (M),

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David Hook (M)Ministry of Defence Doug Burgess (O)MRC, Centre for Inflammation Research, University of Edinburgh Ken Donaldson (W & M)

NNanotechnology Victoria Peter Binks (W)National Consumer Council Sue Dibb, Senior Policy Officer (W)National Institute for Occupational Safety and Health (W)National Physical Laboratory (W)National Physical Laboratory Peter Cumpson (M), John Gallop (M),

Kamal Hossain (W)National Science Foundation US Mike Roco, Senior Adviser NSF and

Chair of US Nanoscale Science,Engineering and Technology (W & O),Julia Moore (M)

Natural Environment Research Council Deborah Cosgrove (W)Novartis Foundation Derek Chadwick (W)Ntera UK Ltd (W)

OOffice of Science and Technology Rita Wadey (M)Oxonica Kevin Matthews (M)

PPatients Association Simon Williams (M)PEALS Tom Wakeford (M)Policy, Ethics And Life Sciences Research Institute Tom Wakeford (M)Policy Research in Engineering, Science and Technology Denis Loveridge, Honorary Visiting

Professor (W)

QQinetiq Nanomaterials Paul Reip (O)

RRice University Richard Smalley (O)Rolls Royce Mike Howse (W)Rouse Patents Robert Harrison (O)Royal Institute of Technology, Stockholm, Sweden Anders Flodstrom (O)Royal Society of Chemistry Rachel Brazil, Manager, Materials

Chemistry (W & M)

SSaïd Business School, Oxford University Steve Rayner (O)Science Technology and Governance in Europe Peter Healey, Coordinator (W)Scientific committee on cosmetic and non-food product packaging (O)Scientists for Global Responsibility Stuart Parkinson, Director (W)St Johns Institute of Dermatology, Kings College London Anthony R Young (M)Sun Chemical Co Derek Illsley (M)Sustech Tilo Weiss (M)

TTechnopreneur limited David Tolfree (W)Thomas Swan & Co ltd Harry Swan (M)

UUK Computing Research Committee Robin Milner and Susan Stepney (W)Unilever Michael Adams (M)Uniqema Graham Dransfield (M) Universitat Dortmund, Experimentelle Physik III Juergen Altmann (W)Université Louis Pasteur Dorothy Sutherland Olsen (W)

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University College Dublin Donald Fitzmaurice (M)University College London Jacquie Burgess (O), Andrew Fisher (M)University of Aarhus, Denmark Flemming BesenbacherUniversity of Aberdeen Anne Glover (M), Sean Semple (M)University of Aston Peter Brett & Xianghong Ma, Peter J

Conley (W)University of Birmingham Richard E Palmer (W & M), Graham J

Davies (M), Lynn Macaskie (M & W)University of Bristol Professor PNT Wells FRS FREng (W),

Mervyn Miles (M)University of California, Los Angeles, Chemistry Dept James Gimzewski FREng (W)University of Cambridge Chris Calladine FRS FREng (W), John

Carroll (W), Cyril Hilsum (W), Mike Kelly(M), Alan Windle (M)

University of Cardiff Duc Pham FREng (W)University of East Anglia Geoffrey Allen (M)University of Edinburgh Ken DonaldsonUniversity of Essex Ian Colbeck (M)University of Glasgow Chris Wilkinson (M)University of Leeds Simon Biggs FREng (W), Professor I M

Ward (W)University of Liverpool Vyvyan Howard (M)University of Maryland, Dept of Physics Mark Gubrud (W)University of Napier Vicki Stone (M)University of Newcastle Ken Snowdon (M)University of Nottingham Martin Garnett (W)University of Oxford Peter Dobson (M), John Knowland (M),

Jeremy Sloan (M), George Smith (M)University of Saskatchewan Michael D Mehta (W)University of Sheffield (W)University of Sheffield Ray Allen (M), Richard Jones and

Stephen Wood (W & O)University of St Andrews Thomas Krauss (M)University of Strathclyde RA Pethrick (W)University of Surrey Barry Evans (W)University of Sussex Raymond Whitby (W)University of Twente Arie Rip (O)University of Warwick Derek Chetwynd (M), Mr Neil Wilson (M)US Environmental Protection Agency Barbara Karn (W)US Military Edward R Greisch (W)

WWarwick Nanosystems Group, UK SB Palmer (W)Welsh School of Pharmacy Ruth Duncan (W)

XX-FAB UK Ltd John Ellis (M)

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Annex D Mechanical self-replicating nano-robots and ‘Grey Goo’

Media coverage of nanotechnologies has invariably raised the spectre of the ‘grey goo’: a doomsday scenario inwhich nanoscale robots self-replicate out of control, producing unlimited copies of themselves, consuming allavailable material and ultimately laying waste to the planet. Whereas most of the scientific community considers thisto be science fiction, others have argued that it is a possible outcome of unregulated nanotechnology. The level ofpublic and media interest in nanotechnology therefore justifies the following question: Is ‘grey goo’ a real concern,or is it a distraction from the important issues?

The original concept of molecular manufacturing described by Dr Eric Drexler, Chairman of the Foresight Institute,imagined the synthesis of materials and objects by a mechanical ‘assembler’; that is, a machine with the ability makeany object by selecting atoms from the environment and positioning them, one at a time, to assemble the object.This assembler can be programmed and is independently powered. As it can make any object, it can reproduceitself. If the process malfunctions or is corrupted, intentionally or not, the self-replication process could continueindefinitely. Over the past 20 years or so, Drexler and his colleagues have continued theoretical studies of thefeasibility of such machines, but as far as we are aware there is no research in this field that has been supported byfunding agencies, and there has been no practical experimental progress over this period. The reason is simple:there are many serious fundamental scientific difficulties and objections, to the extent that most of the scientificcommunity believes the mechanical self-replicating nano-robot proposal to be impossible.

The scientific issues have been debated in open correspondence between Dr Drexler and Professor Rick Smalley, co-recipient of the Nobel Prize for Chemistry in 1996 for the discovery of carbon 60—so called buckyballs. In summary,there are two major difficulties: first, to lift and position atoms one needs very fine manipulators, of a similar size tothe atoms being worked with; second, the atoms being manipulated must first attach – i.e. chemically bind – to themanipulator, and then unbind from the manipulator and bind to the object. Although scientists have used atomicforce microscopes to manipulate a restricted group of individual atoms and molecules into simple structures onsurfaces, the properties of matter on this lengthscale appear to be incompatible with the requirements for amechanical self-replicating technology. These objections have been termed by Smalley as ‘thick fingers’ and ‘stickyfingers’. Professor George Whitesides has questioned the feasibility of the energy management system that wouldbe needed to handle the large energy input and release that occurs at the different stages of the constructionprocess. Because the assembler is a nanomachine, its positioning accuracy is severely limited by the intensebombardment it receives from atoms in the environment – whether gaseous or liquid – which causes Brownianmotion. It is quite clear: making a mechanical self-assembler is well beyond the current state of knowledge.

Our experience with chemistry and physics teaches us that we do not have any idea how to make an autonomousself-replicating mechanical machine at any scale, let alone nanoscale. Where we can find self-replicating machines isin the world of biology. The cell, thousands of nm in size, is the smallest unit we know that contains all the machineryessential for the process of reproduction, given a suitable environment. In fact, the planet we know today is quitedifferent from its earliest form: biology evolved and turned a desert into the ecosystem of which we are now a part.At present however, the complete details of operation of even a simple cell are far beyond our understanding.

Given the above, we have heard no evidence to suggest that mechanical self-replicating nanomachines will bedeveloped in the foreseeable future, and so would direct regulators at more pressing concerns outlined in chapter 8.

Quotations about mechanical self-replicating nano-robots and ‘grey goo’:

‘I think there is no such thing as the assembler.’ (Professor George Whitesides in evidence to the Working Group,with reference to the mechanical molecular assembler proposed by Dr Eric Drexler).

‘My argument is that I believe that it is so implausible that I wouldn’t worry about it…proving an impossibility is a verydifficult thing to do and I’ve only done it in small parts.’ (Professor Richard Smalley in evidence to the Working Group).

‘… when people say "this isn't what we should be worrying about" I think they are right. I believe it's very muchthe wrong issue to focus on for a variety of practical and sensible reasons.’ (Dr Eric Drexler in evidence to theWorking Group).

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Acronyms and abbreviations

AFM atomic force microscope

AHRB Arts and Humanities Research Board

BRTF Better Regulation Task Force (UK)

BSE bovine spongiform encephalopathy

CD compact disk

CNT carbon nanotube

CVD chemical vapour deposition

DAMs directed assembly of monolayers

DEFRA Department for Environment Food and Rural Affairs

DfT Department for Transport

DNA deoxyribonucleic acid

DH Department of Health

DTI Department of Trade and Industry

DVD digital versatile disk

EA Environment Agency

EBL electron beam lithography

EC European Commission

EINECS European Inventory of Existing Commercial Substances

ELID electrolytic in-process dressing

ELV End-of-Life Vehicles Directive

EPSRC Engineering and Physical Sciences Research Council

EU European Union

FDA Food and Drug Administration (USA)

FIB focused ion beam

GDP gross domestic product

GM genetically modified

HRTEM high-resolution transmission electron microscopy

HSE Health and Safety Executive (UK)

ICT information and communication technology

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IT information technology

ITRS International Technology Roadmap for Semiconductors

LCA life cycle assessment

µm micrometre

MBE molecular beam epitaxy

MEMS micro-electromechanical systems

mm millimetre

MOD Ministry of Defence

MOCVD metal oxide chemical vapour deposition

MRI magnetic resonance imaging

MWNT multi-walled carbon nanotube

NEMS nano-electromechanical systems

NGO non-governmental organization

NIST National Institute for Standards and Technology (USA)

NPL National Physical Laboratory (UK)

nm nanometre

NONS Notification of New Substances

NSF National Science Foundation (USA)

OEL occupational exposure limit

OLED organic light-emitting diode

OST Office of Science and Technology

POST Parliamentary Office of Science and Technology

PV photovoltaic

R&D research and development

RCUK Research Councils UK

REACH Registration, Evaluation, Authorisation of Chemicals

RFID radio frequency identification

RIE reactive ion etching

SAM self-assembled monolayer

SCCNFP Scientific Committee on Cosmetic Products and Non-food Products intended for Consumers

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SCENIHR Scientific Committee on Emerging and Newly Identified Health Risks

SEM scanning electron microscopy

SPM scanning probe microscopy

STM scanning tunnelling microscope

SWNT single-walled carbon nanotube

TBT tributyl tin

TEM Transmission electron microscopy

UV ultraviolet

WEEE Waste Electrical and Electronic Equipment Directive

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