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May 4, 2020

EPA Proposes SNUR for Carbon Nanotubes (Generic)

Lynn L. Bergeson Carla N. Hutton

On May 4, 2020, the U.S. Environmental Protection Agency (EPA) published proposed significant new use rules (SNUR) under the Toxic Substances Control Act (TSCA) for chemical substances that were the subject of premanufacture notices (PMN) and are subject to orders issued by EPA pursuant to TSCA.  85 Fed. Reg. 26419.  The SNURs require persons who intend to manufacture (defined by statute to include import) or process any of these chemical substances for an activity that is proposed as a significant new use to notify EPA at least 90 days before commencing that activity.  The substances subject to the proposed SNURs include carbon nanotubes (generic).  According to EPA, the PMN states that the use of the PMN substance will be as a chemical intermediate to manufacture functionalized carbon nanotubes by oxidation with nitric acid; an additive in rubber polymers to improve mechanical/physical/chemical/electrical properties; an additive in resin polymers to improve mechanical/physical/chemical/electrical properties; an additive in metals to improve electrical/thermal properties; an additive in ceramics to improve mechanical/electrical/thermal properties; a semi-conductor, conductive, or resistive element in electronic circuitry and devices; an electric collector element or electrode in energy devices; a photoelectric or thermoelectric conversion element in energy devices; a catalyst support element or catalytic electrode for use in energy devices; an additive for transparency and conductivity in electronic devices; and an electro-mechanical element in actuator, sensor, or switching devices.  Based on carbon nanotube analogues, data submitted for the PMN substance, and comparison to analogous respirable, poorly soluble particulates, EPA identified concerns for pulmonary toxicity and oncogenicity.  EPA notes that it issued a direct final SNUR for this PMN substance on November 17, 2016, and withdrew it on January 19, 2017, in response to the PMN submitter’s intent to submit adverse comments, which was a request to modify the original TSCA Section 5(e) Order to add more uses.  EPA states that it issued the Order (as modified) 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 Order requires:

  • Use of personal protective equipment where there is a potential for dermal exposure;
  • Use of a National Institute for Occupational Safety and Health (NIOSH)-certified respirator with an Assigned Protection Factor (APF) of at least 50 where there is a potential for inhalation exposure;
  • Use of the PMN substance other than as allowed in the TSCA Order;
  • Waste streams from manufacture, processing, and use must be disposed of only by incineration or landfill; and
  • No predictable or purposeful release of a manufacturing, processing, or use stream associated with any use of the PMN substance into the waters of the United States.

The proposed SNUR would designate as a “significant new use” in the absence of these protective measures.  According to the notice, EPA has determined that certain information about the environmental effects of the PMN substance may be potentially useful in support of a request by the PMN submitter to modify the TSCA Order, or if a manufacturer or processor is considering submitting a significant new use notice (SNUN) for a significant new use that would be designated by this SNUR.  The notice states that the results of chronic aquatic toxicity testing, with natural organic matter (NOM) as the dispersant, may be potentially useful to characterize the environmental effects of the PMN substance.  Although the TSCA Order does not require these tests, EPA notes that the TSCA Order’s restrictions remain in effect until the TSCA Order is modified or revoked by EPA based on submission of this or other relevant information.  Comments on the proposed SNURs are due June 3, 2020.