A F k t S t D i i M kiA Framework to Support Decision-Making: Tools for Classification, Release, and

E A t f N t h lExposure Assessment of Nanotechnology

Jeffery Steevens, Al Kennedy, Jessica Coleman, Aimee Poda, Zack Collier, Robert Moser, Chuck Weiss,

Mark Chappell, Anthony Bednar

U.S. Army Engineer Research and Development Center, y g p ,Vicksburg, MS

Overview

Life cycle approach to problem► Metallofullerene, self-decontaminating surfaces,

printed electronics, explosivesR l f lif l t Role of life cycle assessment

Framework and use of material categorization Case studies: paint, concrete, and electronics Conclusions

Army Technologies

Deployable force protection Self cleaning concrete

Nanosilver ink for printed electronics Nanotechnology will impact ALL Army platforms; will

enable dramatic improvements in: force protection, ease overburdened Soldiers, reduce logistics burden, create operational overmatch, operate in C

Runway Mats

CBRNE environment, improve operational energy, and reduce life-cycle costs

Composite food pouches

NanocelluloseRobert McElroy, Army Times

3

p

(Publicly available: www.erdc.usace.army.mil/missions/militaryengineering )

Thermites

Problem: Do Nanomaterials Pose Unacceptable Risk?

Are they safe? Engineered nanomaterials have potential to behave differently from traditional contaminants in the environment and cause biological effects

Unacceptable Risk?

biological effects Uncertainty of environmental regulations and liability are affecting the ability

for industry to manufacture and DoD to use

Mouse lung with alveolar bronchiolar Electron micrograph of self-decontaminating surface carcinoma (Sargent, 2013)releasing nanoparticles (Army ERDC, 2012)

Life Cycle ApproachTechnology Life Cycle

R M t i l P d ti M f t U Disposal /

Waste

Raw Materials Production Manufacture Use pRecycling

Releases to Environment

Nano Enabled Technologies

Conceptual Model, Characterization, Risk Analysis

Decision MakingNano Enabled Technologies• Dispersions• Coatings• Energetics• Textiles

Decision-Making• Research and Development• Management• Regulatory Compliance

• Textiles• Composites

Kennedy et al., 2013; Poda et al., 2013

Metallofullerene By-Product Streams

Soot> 90% Waste

Electric Arc Process

Graphite Rods

Gd and Cu metal recovered in processed soot

200

250

100%

120%

50

100

150

Met

als

conc

entr

atio

n (m

g/kg

)

Gd Cu

40%

60%

80%

Perc

ent S

urvi

val

MHRW

0250 1000

Soot sample (kg)

0%

20%

Control 0.001% 0.010% 0.100% 1% 10% 100%

MHRWMHRW (EDTA)

Metal Content in Processed Soot Toxicity of Leachate

Hull, M., Kennedy, A., Bednar, A., Weiss, C., and J. Steevens. 2009. NanomanufacturingEcotoxicology. Environmental Science and Technology.

Carbon Nanotube Electronics

Single-walled CNTs used in the manufacture of sensors, computer memory and flexible printed electronicscomputer memory, and flexible printed electronics.

Application requires manufacture of a stable aqueous suspension of SWCNTs.

Stable suspension is also produced for other electronics manufacturers.

CNT-Based Printed Flexible and Stretchable Circuit Board on Silicone

CNT-Based Printed Flexible and Stretchable Antenna

Carbon Nanotube Electronics

“Life Cycle Assessment” is a “cradle-to-grave” approach for comprehensively accounting the total cost of a product or technology.

1 Product or technology is considered in terms of life cycle1. Product or technology is considered in terms of life cycle phases representing points where resources are expended and emissions are created.

2 Valuable for technology developer/manufacture; Identifies2. Valuable for technology developer/manufacture; Identifies “leakages” or wasted energy in the system.

3. For risk assessment, it can be used to determine significance of NP releasesof NP releases

Eco-LCA Methodology

Dispersion, Derivatization

PrintingDerivatization

Boundaries (scope): Gate to Gate► Receipt of CNT powders (CNT synthesis not included in the calculations)

Environmental impacts overwhelmingly driven by waste incineration Ecotoxicity studies with these materials suggest little hazard; human

health? Waste volume mitigation is key to reducing environmental footprint

Self- Decontaminating Surfaces• Nano titanium dioxide based coating used for photocatalytic disinfection a o t ta u d o de based coat g used o p otocata yt c d s ect o

process in air-handling systems or coatings Address uncertainties to support technology development

► Release from substrate particle characteristics► Release from substrate, particle characteristics► Toxicity screening using mixed alveolar cell culture

Research Production Use Disposal and R li

Life-cycle Stage

and Development

Recycling

Sol-Gel process for

manufacturer of NP on site

Normal use

Stability in landfill

Scraping and Sanding

Aging

Coatings and Paints

HVAC Recycle in new materials

50

100

150

200

250

300

350

400

450

500

550

Frequency

50

Ri k b d C t l d l t id tif d t

Particulate releaseWaste from processing

Containment of NP

through Best Management

Practices

Inhalation Ingestion Dermal Contact

0

0.25

0.75

1.25

1.75

2.25

2.75

3.25

3.75

4.25

4.75

5.25

5.75

6.25

6.75

7.25

7.75

8.25

8.75

9.25

9.75

10.25

10.75

11.25

11.75

12.25

Mean Diameter (micron)

50mm

Coupon

• Exposure: Mean particle size = 1.9 µm 0.42% id d lt fi ( 100 )Risk based Conceptual model to identify data

gaps, releases, and routes of exposureare considered ultrafine (< 100 nm)

• Toxicity: No cytotoxicity or inflammation to milled surface using A549 pneumocytes and alveolar macrophages

 (a) Backscattered SEM micrograph of SDS  (b) EDS mapping of Si, Fe, Ag, and Ti 

 

p g• Risk: Low level of risk; compared to existing

NIOSH guidance(Steevens et al., Army ERDC, 2012)

Environmental Life Cycle of Nanothermites Aluminum + reducing agent (Fe2O3 , Bi2O3, or CuO) Releases and risks evaluated over life-cycle Focus on release during use: transformation, fate, exposure, toxicityg p y Enables informed decisions regarding safety and informs/proactively

addresses regulations

Research / Production Use

4000 x

Tekna plasma system for nanoscale Al (above); SEM of nanoscale aluminum (below),

Robert McElroy, Army Times

Scanning electron microscope image of Al/Fe2O3 energetic residue showing wide range

10 µm

Chris Haines, ARDEC 2 3 g g gof particle size; many greater than 1 µm

Nanotechnology Life Cycle

Study of “raw material” NP informs risk analysis

Transformation of NP in environment makes predictions of fate,

d h dexposure, and hazard challenging

From Lowry et al., 2012

Releases During Life Cycle

Carbon Soot CNT Ink Byproduct

SDS Particles Thermite Residue

Transformation of NP during processing, manufacture, use, and end of life are poorly understood.

Processes: intentional chemical and physical modification Processes: intentional chemical and physical modification, weathering and wear, and degradation

Poses a significant challenge in developing an exposure-effect relationshiprelationship

Next Steps: Development of a Framework

Safety of advanced materials goes beyond individual t i l ( b t b ) d h ld id fi lmaterial (e.g., carbon nanotube) and should consider final

technology or product (e.g., composite) Develop a framework for communicating material safety; is the p g y

material nanostructured or nanofeatured? Address regulatory requirements through development of

protocols/standard methods for assessmentp Reduce uncertainty for product liability raised by manufacturers’

insurance – supports technology transition and Army sustainability goalsg

Development of a Framework

Response to Army Problem• Regulatory guidance lags

technology development► No consistency► Uncertain sustainability

Free particle worse case Stated Army needs:

► Establish nanoEHS procedure► In context with technology;

Category (free vs. structured), Task 4Use & release scenarios

► Develop industry standards

Solution: Develop Adaptive GuidanceNano Guidance for Risk Informed Deployment (NanoGRID)

Tiered process (testing exclusions) tied to regulatory Product: Executable web tool step-wiseProduct: Executable web tool step wise

EHS process and methods

Collier et al, 2015, J. Nanoparticle Researchhttps://nanodev.erdc.dren.mil/NanoGrid/User.html

A Proposed Framework

TIER 1Screening CriteriaBased on material amount, size, properties, technology categories, and use

Screening Steps

TIER 2 Proceed through 

Release PotentialConservatively assume 100% release, determine actual amount released

Increasing  information 

& costTIER 3

process until an informed decision is possible

Environmental PersistenceDetermine free particle persistence and dissolved fraction

TIER 4Sustainability TestingBiological testing for acute and chronic toxicity

Adequate Information f D i i

TIER 5In Depth Product InvestigationMaterial specific and site specific

for Decision

Nanotechnology Categories

Nanomaterial taxonomy adapted from Hansen et al. 2007;

CATEGORY I: “BULK”A grain orientation map for single phase

B DC

A. grain orientation map for single-phase austenitic steel (category IA);

B. Silicon carbine nanocomposite including porosity and nano-scale carbon impurities (category IB);

CATEGORY II: “SURFACE” E F G

D. silicon bio-inspired hydrophobic surface (category IIA) from Vasudevan et al 2014;

E. graphene thin film on a metallic surface (category IIB);

F. nanobismuth metal over an iron oxide surface (category IIC);(category IIC);

CATEGORY III: “PARTICLES”G. Al2O3 nanoparticles adsorbed onto the surface

of Bi spheres (category IIIA); H. nanocomposite film with layered nanoclay

structures suspended in an polymeric matrix

H JI

p p y(category IIIB);

I. TiO2 nanoparticles suspended in a viscous (sunscreen) gel matrix (category IIIC);

J. freely dispersed multi-walled carbon nanotubes (category IIID).

Collier et al., 2015, J. Nanoparticle Research

Categorization Within Tiered Structure

Ecotoxicologist’s perspective: fate categories in EHS Cascading effect: categories will influence exposure and toxicity

testing

Tier I

g

Categorization of nanotechnologies / products► By physical structure Tier I

Screening

y y► By intended use

Fate categorization of nanoparticles► By composition

Tier II-ReleaseTier III-Fate

► By size► By release potential (Nano in nano out)► By dispersibility & stability (coating, charge, media)► By dissolution kinetics (and completeness)

Tier IV/V-Hazard► By dissolution kinetics (and completeness)► Toxicity► By interactions (ligands, transformations)

Solution: Develop Scientific Methods Standard Operating Procedures linked to

NanoGRID Methods: functional tests

► Preparation methods, characterization, release, fate, toxicology

Products:► Written SOPs (web)► Written SOPs (web)► Video demos (Youtube)

https://www.youtube.com/channel/UCe3wh_zmg3FATtbs5bcwnew/feed

R l t di hift

Army Nanotechnology Testing

Airfield Landing

Regulatory paradigm shift► Ingredients vs. technology

Testing by NanoGRID► Relevant categories Electric TESLA Airfield Landing

Mat -ERDC-

► Relevant categories► Relevant use► Release & transformation

Products: EHS Reports, improved EHS process

PRISTINE-GRL/CRREL-

Electric Switches-ARDEC-

Nanothermite-Air Force,

DTRA-

TESLA Primer-CERL-

Self Cleaning Concrete

-GSL-

NanocelluloseComposite

-ARL-improved EHS processDecreasing potential for release

UV& R i f ll& Rainfall

Kennedy et al 2014. Nanotechnology Environmental Health and Safety: Risks, Regulation and Management , Elsevier, 2014.

Abrasion testingHansen et al. (2007)

Nanotoxicology 1(3): 243-250

Printable Nanosilver CircuitsFl id di d t h l 2 D Surface bound technologyFluid-dispersed technology 2-D Surface-bound technology

ReleaseRelease

Size < 20 nm

LC50 = 3 g/L(C i d h i d bi )(Ceriodaphnia dubia)

AJK7

Slide 22

AJK7 Dave Martin - please update, revise as neededAl Kennedy, 3/11/2015

Self Cleaning Concrete

3D porous nano-solidtechnology

TiO2 and Pure TiO2cement phases

u e O2nanoparticles

Released concentration range: 58-120 ppb

Anticorrosive Paint

•Paint starts suspended in liquid (IIIb)

Originally developed and demonstrated in DoDCorrosion Prevention and Control ProgramDr. Susan Drozdz, ERDC-CERL

Test CouponsRaw materialsZn CNTs

•Paint starts suspended in liquid (IIIb)•Aerosolized during application (IIId)•Applied to a surface (IIIa)•Dried into a solid matrix (IIIc)

Primer & Primer

e &Topcoat

Zn particles> 1000 nm

MWCNTs

Coated fuel Tank: Fort Bragg

Identification of CNTs in raw form and onin raw form and on coated surface

Incorporating NanoGrid into DoD Decision Makingg

• DUSD (Installations & Environment), Chemical and Materials Risk Management

Developing guidance for the acquisition– Developing guidance for the acquisition community to better characterize chemicals as they are brought into DoD technologies

• Guidance Manual for the Collection of Chemical, Physical, and Toxicological Data (CPT) to Support DoD SystemsData (CPT) to Support DoD Systems Acquisition

• Coordinated by Tricia Underwood and the DoD Nanotechnology Working Group

January 2015 Collection of Chemical, Physical and Toxicological Data to y y gSupport DoD Systems Acquisition, DRAFT

Conclusions

Conclusions Understanding the form of NP released during manufacture, use,

and end of life for technolog is criticaland end of life for technology is critical Need to incorporate “life cycle approach” to the risk assessment of

nanotechnologies Categorization of materials based on range of properties will guide a

“technology based” assessment

Still questions remain:q At what point in the technology life cycle are NP being released? What is being released? Transformation? How do we improve the relationship between exposure assessment How do we improve the relationship between exposure assessment

and ecological hazard?

Acknowledgments

Collaborators at Brewer Science, Inc. Rolla, MO; Dan Janzen,Inc. Rolla, MO; Dan Janzen, Stephen Gibbons, Doyle Edwards, and Wu-Sheng Shih

U.S. Army Environmental Quality and Installations Research Program, Elizabeth Ferguson,Program, Elizabeth Ferguson, Technical Director

http://el.erdc.usace.army.mil/nano/Jeffery.A.Steevens@us.army.mil