possible risk assessment for nano-particles in food contact

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Possible risk assessment for

Nano-particles in

Food Contact Materials

4th Nanotechnology Dialogue

FoodDrinkEurope

Brussels 5th October 2011

P.K.T. Oldring Valspar Corporation

Until there is an agreed definition of „nano‟ then it is not possible to say what is and what is not „nano‟.

Today, nano materials used in Food Contact Materials (FCM) could be intended for food packaging or equipment / machinery which contacts / processes foodstuffs or articles in close proximity for food storage e.g. fridge. PROVIDED regulation permits them!!!!!!!!

Engineered nanoparticles (ENP) are the focus of attention rather than naturally occurring ones.

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• nano-composites • plastics (including biopolymers)

incorporating nanomaterials to improve

durability, temperature/ moisture

stability, barrier properties

• packaging incorporating nanosensors to monitor condition of the food

• ‘Intelligent’ & ‘Smart’ packaging

• ‘Active’ materials • plastics incorporating nanomaterials with

antimicrobial properties

Examples

• potential risks due to migration of ENPs into food and drinks Concerns

Food packaging applications

Courtesy of L. Castle & Q. Chaudry Fera

In some cases certain materials traditionally used in FCM have a particle size distribution which does or could extend into the nano range (depending on definition of nano)

Pigments are one example

The PIM (Plastic Implementation Measure) only applies to plastics.

How can non-plastics be handled?

What about inks, coatings and paper where some materials used for many years could be classified as „nano‟?

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The Plastics Implementation Measure (PIM) Regulation (EU) No. 10/2011 mentions „nano‟ in various places

Whereas (23) & (27)

Articles 9, 11 & 14

Table 1, Annex 1, lists the authorised substances with restrictions. There is only one mention of a „nano‟ substance.

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Whereas (23) New technologies engineer substances in particle size that exhibit chemical and physical properties that significantly differ from those at a larger scale, for example, nanoparticles. These different properties may lead to different toxicological properties and therefore these substances should be assessed on a case-by-case basis by the Authority as regards their risk until more information is known about such new technology. Therefore it should be made clear that authorisations which are based on the risk assessment of the conventional particle size of a substance do not cover engineered nanoparticles.


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Whereas (27) … functional barrier is a layer within

food contact materials or articles preventing the

migration of substances provided they fulfil certain

criteria and their migration remains below 0,01

mg/kg. Substances that are mutagenic, carcinogenic

or toxic to reproduction should not be used without

authorisation and are not covered by the functional

barrier concept. Nanoparticles, should be assessed

on a case-by-case basis as regards their risk until

more information is known about such new

technology. Therefore, they should not be covered

by the functional barrier concept.


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The PIM explicitly authorises the use of only one named „nano‟ material - FCM #807 titanium nitride, but with restrictions and a defined particle size. agglomerates with a diameter of 100 – 500 nm

consisting of primary titanium nitride

nanoparticles;

primary particles have a diameter of

approximately 20 nm.

There are two other substances which have

particle sizes of ENPs which are indirectly

authorised in the PIM – carbon black and fumed

silica.


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FCM #411 carbon black with a defined particle size distribution, because arguably when the SCF/EFSA evaluated the dossier the specification included a particle size distribution which covered „nano‟. This is in the specification in the PIM. Primary particles of 10 – 300 nm which are

aggregated to a size of 100 –1 200 nm which

may form agglomerates within the size

distribution of 300 nm – mm.


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FCM #504 Fumed silica - synthetic amorphous silicon dioxide:

primary particles of 1 – 100 nm which are aggregated to a size of 0,1 – 1 μm which may form agglomerates within the size distribution of 0,3 μm to the mm size.

Some clays (e.g. montmorillonite) are „nano‟ if exfoliated and can be used in polymer clay composites for improved gas barrier properties in e.g beer bottles.


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Antimicrobial nanoparticles of metals (silver, zinc oxide, magnesium oxide) can be used as „active packaging‟ to inhibit the growth of micro-organisms.

Active and Intelligent Packaging regulation EC No. 450/2009 excludes nanoparticles (substances deliberately engineered to a particle size which exhibit functional, physical and chemical properties that significantly differ from those at a larger scale).

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These antimicrobials in nano form can also be used as surface-active biocides in „non-active‟ FCMs such as conveyor belts and other repeated-use articles – where there is no intention to act on the food but rather to help keep the contact surface clean and aid „cleanability‟

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Initially „nano‟ seems to offer many advantages, both for the consumer and innovative industry.

„Nano‟ is seen by some as not natural.

Today, we seem to have a situation where emotion rules good science.

There are other examples in the EU, including GMOs.

What can be done to ally fears and emotion? Industry, politicians, regulators and scientific

advisory bodies need an agreed approach to evaluate „safety‟ of new materials or modifications of existing ones.

Risk assessment of Nanotechnology in

FCM - 1

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Risk = hazard x exposure to the hazard

Hazard = the potential to cause harm

Risk = (probability of event occurring) x (impact of event)

Emerging risk (EFSA definition):-

“An emerging risk to human, animal and/or plant health is understood as a risk resulting from a newly identified hazard to which a significant exposure may occur or from an unexpected new or increased significant exposure and/or susceptibility to a known hazard”.


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The first issue is how does one define the toxicology of nanoparticles?

The toxicology of the substance of „normal‟ size is normally known.

Does being orders of magnitude smaller increase the risk?

Only toxicologists can answer this question. However, there are circumstances where a

toxicological opinion may not be needed. Paracelsus stated that the dose makes the poison.


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If there is no exposure to nanoparticles, then there is no risk whatever their toxicological profile.

How can there be no exposure? Particles degrade on entering food Particles do not migrate (Question is the 10

µg/kg (10 ppb) LOD for functional barrier adequate for ENP?).

Particles are transformed (before ingestion or in the gastro-intestinal tract) into non-nano form, then look at non-nano tox data.

The ENP persists then then available tox data needs to be evaluated and if necessary additional testing undertaken.


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No FCM is completely inert.

We arguably lack some of the tools to measure nanoparticle migration into foods / simulants.

We lack the full understanding to interpret any migration results – what is a safe level?

Currently, we are only be able to evaluate applications that demonstrate the „no migration‟ principle.

This approach was used in the case of titanium nitride This „no migration‟ status was established using existing and new migration modelling approach


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It is generally recognised based on theoretical calculations, that when nanoparticles are incorporated into most types of plastic they are effectively immobilised and they cannot migrate by diffusion.

The Outlook For Nanotechnologies In Food. Edited by Q. Chaudhry, L. Castle & R. Watkins. Royal Society of Chemistry, 2009, in press.

Migration of engineered nanoparticles from polymer packaging to food – a physicochemical view. P. Simon, Q. Chaudhry and D. Bakos. Journal of Food and Nutrition Research, 2008, 47, 105–113.


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For many other types of FCM Thresholds are at last beginning to be recognised (e.g. ESCO/EFSA, EFSA, ILSI etc)

The questions remain as to whether Thresholds can be used for „nano‟.

It is certain that as technology advances and new materials are introduced, new approaches to assessing their safety are required rather than time consuming and sometimes ambiguous (results) animal testing.


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Conclusions* - 1

Molecules larger than 1,000 Daltons are of little (or even no) toxicological concern since they are not absorbed. But NPs are even bigger…

It will be necessary to measure NP migration into foods to confirm the „no-migration‟ predictions

Current methods can already place an upper limit on migration

Still need to decide if, e.g. 108 NPs / kg food would be of any concern or not.

* Courtesy L. Castle, Fera

Conclusions - 2

The concern about aggregation either self or with food constituents may be misplaced - the physical state / size after the food is digested is what probably matters.

The fate of the organic modifiers may be of more interest

It is clear that unless the difficulties surrounding the acceptance of nano-technology by ALL can be resolved fairly quickly, a technology which offers many advantages will disappear.

How can Exposure be estimated - 1

To evaluate exposure it is necessary to know the concentration of the substance in the foodstuffs and how much of each foodstuff is eaten.

The FACET (Flavours, Additives and food Contact materials Exposure Task) is a 7th Framework EU funded (~€6 Mio) project to estimate exposure to food flavourings, additives and food contact materials, which finishes August 2012.

The final product will be a stochastic model, freely available to all, which will run stand alone on a PC

How can Exposure be estimated - 2

If the concentration of a nano substance (i.e. food ingredient or contaminant) in a food is known, then it would be possible to estimate the exposure to it for any percentile consumer using FACET in the „advanced user‟ mode.

FACET will be a major tool in the risk manager‟s armoury

FACET WEB SITE www.ucd.ie/facet

http://www.ucd.ie/facet

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The input of Laurence Castle, Fera (UK) is acknowledged and much

appreciated.

Thank you for your attention

possible risk assessment for nano-particles in food contact

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