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January 26, 2022

OECD Tour de Table Includes Update on Nano Developments in the United States

Lynn L. Bergeson Carla N. Hutton

The Organization for Economic Cooperation and Development (OECD) has published the latest edition of the Developments in Delegations on the Safety of Manufactured Nanomaterials — Tour de Table. The Tour de Table compiles information provided by delegations on developments concerning the safety of manufactured nanomaterials. It includes the following information on developments in the United States.

  • The U.S. Environmental Protection Agency (EPA) completed review of two low volume exemptions for a modified graphene substance and a modified titanium dioxide substance. According to the Tour de Table, EPA allowed the exemptions under conditions that limited human and environmental exposures to prevent unreasonable risks. Additionally, EPA reviewed and completed a significant new use notice (SNUN) for a carbon nanotube substance. EPA regulated the new chemical substance with a consent order “owing to limited available data on nanomaterials”; the consent order limited uses and human and environmental exposure to prevent unreasonable risks.
  • The National Institute for Occupational Safety and Health (NIOSH) assessed potential health risk from occupational exposure to silver nanomaterials and derived a recommended exposure limit (REL) for silver nanomaterials (less than 100 nanometers (nm) primary particle size) of 0.9 micrograms per cubic meter (μg/m3) as an airborne respirable eight-hour time-weighted average (TWA) concentration. NIOSH published the assessment in May 2021. More information is available in our May 20, 2021, blog item.
  • Between September 2020 and May 2021, EPA received notification of one nanoscale substance that met reporting criteria pursuant to its authority under Section 8(a) of the Toxic Substances Control Act (TSCA), “bringing the total number of notifications to 78.” Reporting criteria exempted nanoscale chemical substances already reported as new chemicals under TSCA and nanoscale chemical substances that do not have unique or novel properties. According to the Tour de Table, most reporting was for metals or metal oxides.
  • The Tour de Table states that since January 2005, EPA has received and reviewed more than 245 new chemical notices for nanoscale materials, including fullerenes, quantum dots, and carbon nanotubes. EPA has issued consent orders and significant new use rules (SNUR) that permit manufacture under limited conditions. The Tour de Table notes that because of confidential business information (CBI) claims by submitters, “EPA may not be allowed to reveal to the public the chemical substance as a nanoscale material in every new chemical SNUR it issues for nanoscale materials.” EPA will continue to issue SNURs and consent orders for new chemical nanoscale materials in the coming year.
  • The Tour de Table states that because of limited data to assess nanomaterials, the consent orders and SNURS contain requirements to limit exposure to workers through the use of personal protective equipment, limit environmental exposure by not allowing releases to surface waters or direct releases to air, and limit the specific applications/uses to those described in the new chemical notification.
  • The approaches used given the level of available information are consistent with previous regulatory decisions. According to the Tour de Table, EPA’s assessments now assume that the environmental hazard of a nanomaterial is unknown unless acceptable hazard data are submitted with the nanomaterial submission.
  • New regulatory challenge(s) with respect to any action for nanomaterials:
    • Standards/methods for differentiating between different forms of the same chemical substance that is a nanomaterial;
    • Standardized testing for the physical properties that could be used to characterize/identify nanomaterials; and
    • Differentiation between genuinely new nanoscale materials introduced in commerce and existing products that have been in commerce for decades or centuries.