Good Stewardship and Safe Nanomaterial Handling Practices for Graphene Products

Transcription

1 Industrial Hygiene and Graphene Good Stewardship and Safe Nanomaterial Handling Practices for Graphene Products

2 Industrial Hygiene and Graphene This webinar will: Describe the type and characteristics of the most common forms of graphene produced and used in commercial products. Review good health and safety processes for nano-material production and handling from an Industrial Hygiene perspective. Discuss what users of this material need to know regarding handling and use.

3 About AIHA Industrial hygienists anticipate health and safety concerns and design solutions to prevent them. They are the guardians of workplace safety, applying science to identify and solve health and safety problems. Founded in 1939, AIHA is devoted to achieving and maintaining the highest professional standards for its members. More than half of the nearly 8,500 members are certified industrial hygienists (CIHs), and many hold other professional designations. AIHA administers comprehensive education programs that keep occupational and environmental health and safety (OEHS) professionals current in the field of industrial hygiene.

4 About The Graphene Council The Graphene Council is the largest community in the world for graphene professionals; producers, researchers, academics, end-users and regulators. We reach more than 50,000 materials science specialists world-wide. The Graphene Council is a formal member of the ISO/ANSI/IEC graphene standards development working groups and is a leading advocate for the commercial development of this amazing material.

5 Presenters Christine Knezevich is a certified industrial hygienist with 30 years experience and a member of the American Industrial Hygiene Association (AIHA) Nanotechnology Working Group. Her work has spanned the chemical, specialty metals, and explosives industries. She is currently an occupational health manager with the U.S. Air Force at Wright Patterson Air Force Base near Dayton, Ohio.

6 Presenters John Baker, CIH is a Principal Consultant for BSI EHS Services and Solutions. He holds a B.A. in Physics and an M.S. in Environmental Engineering with 40 years of experience in industrial hygiene and environmental management and consulting. He served as Deputy Director of the Center for Biological and Environmental Nanotechnology at Rice University. Mr. Baker is the Chair of the American Industrial Hygiene Association Nanotechnology Working Group, a member of the American Society of Safety Engineers Industrial Hygiene Special Interest Group, and a technical member of ASTM Committee E56 on Nanotechnology.

7 Forms of Graphene Types of Graphene Materials

8 Forms of Graphene Definitions Graphene is a two dimensional (i.e. one atom thick) planar sheet of sp²-bonded carbon atoms in a dense honeycomb shaped crystal lattice. Graphene has extraordinary material properties including ultimate tensile strength of 130 gigapascals, electron mobility of 15,000 cm2 V 1 s 1, thermal conductivity between W m 1K 1 and optical transparency of 97.7%. (Eric Pop, 2012) (Sheehy DE, 2009) ISO/TS :2017(en) Nanotechnologies Vocabulary Part 13: Graphene and related twodimensional (2D) materials. Recognizes material up to and including 10 carbon layers as graphene.

9 Forms of Graphene Production Graphene production methods can be classified broadly as Top Down and Bottom Up. Top Down methods start with a feedstock material such as graphite and through various methods (physical, electrical, chemical, etc.) exfoliate individual layers of carbon. Bottom Up methods start with a carbon feedstock such as methane gas that under controlled conditions (such as Chemical Vapor Deposition-CVD) is deposited on a substrate material (such as copper) in single or multiple layers.

10 Forms of Graphene Graphene Materials A wide range of materials in the commercial market are currently referred to as graphene. Number of Carbon Layers Description 1 CVD, Mono-layer or Pristine Graphene 1-3 Very Few Layer Graphene (vflg) 2-5 Few Layer Graphene (FLG) 2-10 Multi-Layer Graphene (MLG) > 10 Exfoliated graphite or Graphene nanoplatelets (GNP)

11 Forms of Graphene In addition to the number of carbon layers, additional characteristics define the material. Graphene Oxide (GO) - a compound of carbon, oxygen and hydrogen (typically approx. 65% carbon / 35% oxygen by weight). Reduced Graphene Oxide (rgo) - Graphene Oxide in which removes much of the oxygen content resulting in approximately 95% carbon by weight. Graphene Powder, Solution or Paste - Graphene material can be prepared in various physical forms including as a dry (usually black) powder, in solution (e.g. water or alcohol) or in a paste form (often as a dull reddish brown color). Graphene Nano Platelets (GNPs) - GNPs typically have thickness of between 1 nm to 3 nm and lateral dimensions ranging from approximately 100 nm to 100 µm. Functionalized Graphene - Chemical functionalization (adding specific elements to the surface of the graphene) is important in many applications where untreated graphene would be difficult or impossible to work with.

12 Graphene Applications There are more than 40 major applications areas for graphene.

13 Graphene Handling Industrial Hygiene and Issues Related to Working with Graphene

14 Occupational Exposure Limits Basis: Health, Risk, Administrative Route of exposure/ Duration OELs will NOT be set for all MNMs Options: OELs per hazard characteristic: Granular, Biopersistent Fibers Soluble or not Biopersistent Specific such as carbonaceous Hazard/Exposure/Control Banding

15 Safety Data Sheets (SDS) Globally Harmonized System for Classification and Labeling of Chemicals (GHS) in section 2 Composition/CAS number found in section 3 OELs found in section 8 Toxicology found in section 11 Results of SDS review

16 Material Characterization Graphene is not the same as Graphite Chemical composition Size distribution Shape Surface charge Functionalization Agglomeration Solubility BET surface area Raman spectra Toxicology

17 Developing Nanomaterial Products Considerations For Product Realization Christine Knezevich, CIH AIHA Nanotechnology WG

18 Objectives Product Stewardship Various considerations will be reviewed during the following product realization steps: Research & Development (R&D) Prototype Testing (alpha testing) Prototype Testing at a Customer Site (beta testing) Production

19 Industrial Hygiene Industrial Hygiene is a Continuous Process

20 Hierarchy of Controls Most Effective Approach Elimination Substitution Engineering Controls Administrative Controls Physically remove the hazard Replace the hazard Isolate people from the hazard Change the way people work PPE Protect the worker with Personal Protective Equipment

21 Product Stewardship Considerations Dependent on: Type of End Product (e.g., electronics, medical device, chemical product, etc.) Geographic Market (e.g., US, EU, etc.)

22 US Regulatory Agencies Product Chemicals Pesticides, including Antimicrobials Food, Drugs & Medical Devices List I & List II substances Chemicals of Concern Regulated By EPA (Toxic Substances Control Act/TSCA) EPA (Federal Insecticide, Fungicide & Rodenticide Act/FIFRA) FDA DOJ (Drug Enforcement Administration/DEA) Dept of Homeland Security (DHS) Conflict Minerals SEC (Frank-Dodds Act)

23 EU Requirements In Europe, chemicals, including biocides, are regulated under the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) by the European Chemical Agency (ECHA) EU Conflict Mineral Regulation 2017 was passed in May & goes into full effect January 2021 For electronics, there are also the Restriction of Hazardous Substances and Waste from Electrical and Electronic Equipment Directives

24 Research & Development Considerations Chemical Approval Forms completed for raw materials Review raw material Safety Data Sheets (SDSs) Add raw materials to lab chemical inventory Ensure proper chemical labeling (29 CFR , OSHA s Chemical Hygiene Plan) Health, Safety & Environmental (HSE) review for handling, storage, disposal, engineering controls, and personal protective equipment (PPE) considerations

25 R & D Chemical Approval Process Includes a product stewardship review for: TSCA status of raw materials (i.e., R&D exemptions & import requirements) FIFRA (domestic/import) DEA (domestic/import) DHS Chemicals of Concern Conflict Minerals REACH will finished product be shipped to the EU?

26 Nanomaterial HSE Considerations Matrix Engineering Controls Administrative Controls PPE Polymer Fume Hood Std lab practices Lab coat, safety glasses (w/side shields), gloves Liquid dispersion Dry Powder Fume Hood Wet wipe surfaces Lab coat, goggles, nitrile gloves Fume Hood HEPA vacuum surfaces Lab coat, goggles, nitrile gloves. N95 respirators outside containment Ref: UNC Chapel Hill Lab Nanomaterials Safety Policy

27 Lab Practices & Procedures

28 IH Considerations IH monitoring of lab personnel Medical surveillance of lab personnel (respirators?) Employee training Employee feedback & monitoring results may modify engineering controls, administrative procedures & PPE TSCA R&D Exemptions: document incidents, injuries and illnesses

29 Medical Surveillance & Biological Monitoring There are no specific medical surveillance or biological monitoring requirements for nanomaterials at this time.

30 Occupational Exposure Standards Agency American Conference of Government Industrial Hygienists (ACGIH) National Institute for Occupational Safety and Health (NIOSH) Occupational Safety and Health Administration (OSHA) American Industrial Hygiene Association (AIHA) Standard Threshold Limit Values (TLVs) Biological Exposure Indices (BEIs) Recommended Exposure Limits (RELs) Permissible Exposure Limits (PELs) Workplace Environmental Exposure Levels (WEELs)

31 R&D Produces Sample Batch of Product Create product SDS Create product technical information sheet Determine Dept of Transportation (DOT) class Create product label Export considerations does sample batch need to be sent out of the US for testing? Export Administration Regulations (EAR) apply. File for TSCA Pre-Manufacturing Notice (PMN) or Significant New Use Notice (SNUN) if applicable

32 Prototype Manufacturing (Alpha Testing) Complete HSE review to ensure environmental permits & control equipment are in place & valid The HSE review must include storage areas (e.g., flammable, toxic, etc.) for raw materials, products & wastes Ensure IH & medical surveillance programs are in place Train employees on HSE requirements

33 Beta Testing (at Customer Site) Ensure that IH monitoring results, medical surveillance, and employee feedback from the Alpha testing are incorporated in the production process before testing at a customer site. Incorporate any feedback from the customer site into the product SDS & technical information sheet.

34 Full Production Full production may require additional environmental permit modifications if alpha testing is considered R&D activity & exempt from operating permits. Complete a HSE review to ensure all recommendations from previous product stages are in place. If the finished product is being shipped out of the US, ensure export compliance requirements are in place (i.e., EAR, TSCA, etc.)

35 Production: Life Cycle Management Impact Environmental (air, water & waste) Energy (electricity, natural gas, etc.) Health (physical, biological & radiation) Safety (chemical, electrical & mechanical) Raw Mat l Storage Manufacture Storage & Transport *Include Team Members from Production, HSE, Marketing, Quality & Supply Chain.

36 Discussion and Questions