NanoRelease Developing Methods to Measure Release of Nanomaterials from Solid Matrices

1. NanoReleaseDeveloping Methods to Measure Release of Nanomaterials from Solid Matrices A multinational public private partnership with administrative support by the ILSI Research Foundation NanoRelease@ilsi.orgwww.riskscience.org

2. NanoRelease “Consumer Products” Project Overview Goals • Identify best practices for measuring release at critical points of the life cycle of current products • Use inter-laboratory testing to advance the state of science for release measurement • Develop/refine methodologies and demonstrate transportability • Work with Standard Development Organizations to develop standard methodologies for release • Come to the point of “cross stakeholder agreed-to” methods on release detection and characterization for nanoparticles NanoRelease

3. NanoRelease Consumer ProductsSteering Committee www.riskscience.org NanoRelease@ilsi.org

4. Where are we looking for risk information on nanomaterials now? - based on NCBI citations 2011 Within the 1%, there are very few of what is actually released from real-world uses Data/Graphic Source: Shaun Clancy

5. Initial literature review on “nanorelease” measurement methods • www.ilsi.org/ResearchFoundation/Documents/NanoRelease%20Background%20Doc.pdf • Many qualitative methods available to detect, characterize or measure nanomaterials under controlled conditions • Quantification difficult and not routine • Differentiation of engineered nanomaterial particles from nanoparticles of the composite generally not addressed www.riskscience.org

6. NanoRelease@ilsi.org

7. Transformations Alter the Distributions The “Neat” nanomaterial in hazard studies is not what is released or what is in exposure media from uses In composite In product “Neat” nanomaterial Released material In exposure medium

8. Multiple Paths Make Multiple OutcomesWhere is the toxic part? What do we relate to the tox studies? Receptor population A Soil Receptor population B Released nanomaterial Air Receptor population C Water NanoRelease@ilsi.org

9. Release is the defining condition Risk depends on what is released at specific points along the life cycle Release conditions and pathways to receptor cause different and unpredictable exposures Without labeling, we may never know how to measure the real exposure at the receptor How do we measure release to assess the risk of the product? To make progress we must focus on the release as the control point for understanding risk. Not the pristine material in a controlled suspension.

10. NanoRelease General Work Plan • Phase 1: Nanomaterial/Scope Selection • The Consumer Products Steering Committee chose multi-walled carbon nanotubes in polymer for the first evaluation • Phase 2: Methods Evaluation • Expert Task Groups • Compile & catalogue database of data/info • White Papers • State of the Science Document • Workplan for Inter-laboratory Studies • Phase 3: Inter-laboratory Studies

11. Project Outputs • Separate evaluations of methods, materials, life cycle release scenarios for potential uses of MWCNT in polymers • State of the Science evaluation of release of MWCNT from polymers, including methods-needs • Measurement methods development plan for release of MWCNT from polymer for key life cycle release scenarios • Agreed-to methods to measure MWCNT release from current commercial uses in polymer composites

12. The project will translate developing science of measurement of release of nanomaterials into • best practice • infrastructure • experience, and • risk assessment confidence This will aid • development of guidance for risk assessment and management, • safe development of products, and • public confidence in the safe uses of the technology

13. Phase 2 Methods Evaluation: MWCNTs in Polymer • 3 Task Groups • Compile & catalogue database of data/info • White Papers (for publication & informing SOS) • TG1: Measurement Methods • TG2: Materials • TG3: Exposure/Release Scenarios • June 21/22 2012 Workshop at CPSC in Bethesda, MD, US • White paper presentations • Draft State of Science and Methods Workplan sections • State of the Science Team (SOST) • An independent integrative document • Inter-Laboratory Testing Group • Begin to design and coordinate inter-laboratory testing

14. Task Group 1: Measurement MethodsHow can MWCNT release from polymers be measured? • Co-chairs: Debra Kaiser (US NIST), Aleksandr Stefaniak (US NIOSH) • 13 Experts from: NIOSH, NIST, US EPA, U. Mass, U. Vienna, CSIRO, U. Iowa, Lockheed Martin NanoRelease@ilsi.org

15. The Meaning of Release Measurement Release measurement has multiple components 1) Choosing and modeling the release • Life cycle: fabrication, use/wear, destruction, environmental degradation, incineration, recycling • Air, water, dust • How to mimic the real world condition? 2) Sampling the release • Dispersion, statistics, etc 3) Analyzing the sample 4) Reporting the necessary information • Detection <==> Characterization (recursive: you need to define the nano-characteristic of interest in order to know if you have detected it) • Integration of release measurement to pathway modeling, exposure assessment, and toxicity data… • Informatics! (and interface to in silico modeling?!)

16. Findings/Challenges • Complexity of considering measurement for multiple forms of released material, the media into which it is released, and the time frame of interest (consider immediate exposure or further transformation in transport?). • It is critical to tackle “problem formulation” first in order to select between detection, characterization, and quantitative vs. qualitative methods. What do you need to decide, and what data are possible to generate that can support the decision. • Many possible methods to specifically detect and characterize released MWCNT/polymer material; however, except for simple mass and particle counts, none appear to be sufficiently selective and quantitative for specific MWCNT related exposure assessment now.

17. The materials released to a pathway can vary Source: Wendel Wohlleben

18. The release scenarios affect what is released Source: Wendel Wohlleben

19. Task Group 2: MaterialsHow do MWCNTs in polymer behave/interact with regard to measurement of release? • Co-chairs: Christopher Kingston (NRC Canada), Richard Zepp (US EPA) • 16 Experts from: NRC, US EPA, NC State, Applied Nanotech, Nano-C, Dow, BASF, Environment Canada, Lockheed Martin, Arkema

20. Initial focus on 5 polymer types To limit scope to the most commercially relevant applications of MWCNT, using expert opinion and review of market surveys the project initially focused review on MWCNT applications in: • Epoxy • Polycarbonate • Polyamide • Polyurethane • Polyethylene Even with this limitation the scope of variation is tremendous. However, the purpose of the review is to identify ranges of material characteristics that should be captured within the methods we develop, not be exhaustive in review.

21. Findings/Challenges • There is tremendous variety in materials and uses, but very little data on actual or anticipated uses • Factors considered in materials evaluation include UV exposure, changes in temperature, exposure to acids/ bases, mechanical stresses • UV stabilizers, coatings, and MWCNT functionalization and load can have a large effect on MWCNT release • “Pristine” polymer abrasion and/or degradation characteristics are informative but not necessarily indicative of MWCNT release from commercial articles

22. Task Group 3: Exposure/Release Scenarios What are the most likely MWCNTs-polymer release scenarios? • Co-chairs: Bernd Nowack (EMPA Switzerland), Charles Geraci (NIOSH), Dick Brouwer (TNO Research Group Q&S) • 17 Experts from: EMPA, NIOSH, TNO, SafeWork Australia, Northeastern U., CLF Ventures, USEPA, Lockheed Martin, Bayer, Tech. U. of Dresden, BASF, CPSC, U. Duisburg-Essen

23. Scope limiting decisions for Life Cycle Assessment evaluations • Release scenarios were selected to represent a range of situations • injection molding • mechanical stress during manufacturing, • sports equipment • electronics • non-abrasive outdoor use • small parts in automobiles • tires • end of life treatment (incineration/landfills) • Life cycle evaluations beginning at master batch • We are not considering free MWCNT prior to polymer compositing

24. Focus is release scenarios, but will discuss how findings relate to “risk relevant” exposure • It is possible in some scenarios there is essentially zero release • Polymer and scenario selections interact and will be considered in the evaluations (but the combinations are difficult to bound)

25. There are many potential sources for initiation of an exposure pathway Source: Bernd Nowack Source: Bernd Nowack

26. The likelihood of release for a given stage of life cycle varies by use • Low release potential for electronic component or car component uses in consumers hands • Higher release during industrial fabrication (but controlled conditions, so exposure can be managed) • Relatively low release potential in landfill due to binding • Potentially higher release under recycling scenarios (but again, conditions can be controlled if the materials are known)

27. Findings/Challenges • Knowledge of actual uses is limited, the material choice will matter, and theoretical combinations of materials with uses/scenarios are quite varied. • Nonetheless, some general observations can be made based on the types of uses and the polymers • For most uses evaluated, MWCNT release likelihood during “consumer” life cycle phase seems very low based on inaccessibility of the product (e.g., encased as a component in a car), so detection methods may be all that are needed (rather than spending resources on full characterization and quantification methods). • Release during fabrication and recycling would be higher and may be worthy of release quantification methods development, for conditions where control of release and exposure is uncertain.

28. State of the Science Team (SOST) • Integrate release measurement knowledge and the needs for methods development • Andrew Maynard (University of Michigan, USA) • Bernd Nowack (EMPA Swiss Federal Laboratories for Materials Science and Technology) • Maria Doa(US Environmental Protection Agency) • Richard Canady (ILSI Research Foundation) • Shaun Clancy (Evonik Degussa) • Stacey Harper (Oregon State University, USA) • WendelWohlleben(BASF Chemical Company)

29. Phase 3: Interlaboratory Testing(pilot phase beginning 2013) • To enable improvements, standardization, and widespread use of methods • Interlaboratory Testing Group (ITG) • Co-chairs: Janet Carter (US OSHA), Carolyn Cairns (Consumers Union) • ~20 Experts: OSHA, Consumers Union, CSIRO, NRC Canada, U. Iowa, NIST, US Army, U. Mass, Bayer, NERL, BASF, US EPA • Build from TG & SOS reports to create testing workplan • Phase 3 Testing: • Multi-lab participation to test methods with highest potential • Use “round-robin” approach

30. Plan for Phase 3 Inter-laboratory Methods Development (beginning 2013)

31. International Public Private Partnership • The NanoRelease platform • Established for over 2 years, • Methods for measuring release of carbon nanotubes in polymer matrices, now starting on food additives. • Over 80 experts active from industry, NGO, government, academia in US, Canada, Europe, Australia, and more • Funding is ~50/50 private/public • Pew Charitable Trusts, Health Canada, Environment Canada, US EPA, US FDA, American Chemistry Council, ILSI North America, Nanotechnology Industries Association, Institute for Food Safety and Health, and more. NanoRelease@ilsi.org Thank you www.riskscience.org

32. Sponsors • US Environmental Protection Agency, Office of Research and Development • Environment Canada, Emerging Priorities Division • Health Canada, New Substances Assessment and Control Bureau • American Chemistry Council, Nanotechnology Panel • Society of Chemical Manufacturers & Affiliates • National Institute of Standards and Technology • The Adhesive and Sealant Council • American Cleaning Institute