On October 11, 2019, the U.S. Environmental Protection Agency (EPA) published proposed significant new use rules (SNUR) for 31 chemical substances, including multiwalled carbon nanotubes (generic), that were the subject of premanufacture notices (PMN). 84 Fed. Reg. 54816. EPA notes that eight of the chemical substances are subject to orders under the Toxic Substances Control Act (TSCA) issued by EPA. The effective date of the TSCA Section 5(e) order for multiwalled carbon nanotubes (generic) was May 3, 2019. According to EPA, the PMN states that multiwalled carbon nanotubes (generic) will be used in heat transfer, heat storage, thermal emission, and general temperature management in heat-generating systems, such as electronics, to improve mechanical properties or electrical conductivities of other materials or products and for light absorption properties. The proposed SNUR states that EPA identified concerns for pulmonary toxicity based on carbon nanotube analogues and for aquatic toxicity when the substance is at low concentrations and in the presence of natural organic matter. EPA issued the consent order under TSCA Sections 5(a)(3)(B)(ii)(I) and 5(e)(1)(A)(ii)(I), based on a finding that in the absence of sufficient information to permit a reasoned evaluation, the substance may present an unreasonable risk of injury to human health and the environment. To protect against these risks, the TSCA Section 5(e) order requires:

  1. Use of personal protective equipment by workers to prevent dermal exposure where there is potential dermal exposure;
  2. Use of a National Institute of Occupational Safety and Health (NIOSH) certified respirators with an Assigned Protection Factor (APF) of at least 50 workers to prevent inhalation exposure where there is potential inhalation exposure;
  3. Refrain from using the PMN in applications that generates a dust, vapor, mist, or aerosol, unless such application method occurs in an enclosed process;
  4. Process and use of the PMN substance only as described in the PMN;
  5. No release of the PMN substance to surface waters; and
  6. Disposal only by incineration or landfill.

The proposed SNUR would designate as a “significant new use” the absence of these protective measures. Comments are due November 12, 2019.