The U.S. Environmental Protection Agency (EPA) published on October 10, 2018, a direct final  rule promulgating significant new use rules (SNUR) for 28 chemical substances, including  single-walled carbon nanotubes, that were the subject of premanufacture notices (PMN).  The chemical substances are subject to orders issued by EPA pursuant to Section 5(e) of the Toxic Substances Control Act (TSCA).  The direct final rule requires persons who intend to manufacture (defined by statute to include import) or process any of the chemical substances for an activity that is designated as a significant new use to notify EPA at least 90 days before commencing that activity.  The required notification will initiate EPA’s evaluation of the intended use within the applicable review period.  Persons may not commence manufacture or processing for the significant new use until EPA has conducted a review of the notice, made an appropriate determination on the notice, and has taken such actions as are required with that determination.  The direct final rule will be effective December 10, 2018.  Written adverse comments on one or more of the SNURs must be received by November 9, 2018.  If EPA receives written adverse comments, it will withdraw the relevant sections of the direct final rule before its effective date.  In addition to the direct final rule, EPA published a proposed rule on October 10, 2018.  Comments on the proposed rule are due November 9, 2018.

According to the SNUR, the generic (non-confidential) use of the single-walled carbon nanotubes will be as an additive in composite materials for mechanical, thermal, and conductivity improvements.  According to the SNUR, based on analysis of analogous carbon nanotubes, EPA identified concerns for pulmonary toxicity, as well as potential toxicity to aquatic organisms if the PMN substance is released to water.  EPA issued an order under TSCA Sections 5(e)(1)(A)(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 PMN substance may present an unreasonable risk of injury to human health and the environment.  The order requires:

1. Submitting to EPA certain toxicity testing before manufacture (including import) by the times specified in the order;

2. Providing personal protective equipment (PPE) to workers to prevent dermal exposure where there is a potential for dermal exposure;

3. Providing National Institute for Occupational Safety and Health (NIOSH) certified respirators with an Assigned Protection Factor (APF) of at least 50 to workers to prevent inhalation exposure;

4. No use of the PMN substance in application methods that generate a dust, vapor, mist, or aerosol;

5. Use of the PMN substance only for industrial uses;

6. Use of the PMN substance only for the confidential uses specified in the order;

7. No release of the PMN substance to water; and

8. Disposal of the PMN substance only via landfill or incineration.

The SNUR designates as a “significant new use” the absence of these protective measures.  EPA states that it has determined that “certain information about the environmental and health effects of the PMN substance may be potentially useful to characterize the effects of the PMN substance in support of a request by the PMN submitter to modify the Order, or if a manufacturer or processor is considering submitting a SNUN for a significant new use that would be designated by this SNUR.”  EPA notes that the submitter has agreed not to manufacture the PMN substance without performing specific physical property and pulmonary toxicity testing.  EPA states that it has also determined that the results of specific chronic aquatic toxicity testing would help characterize the potential environmental effects of the PMN substance.  Although the order does not require these tests, the order’s restrictions remain in effect until the order is modified or revoked by EPA based on submission of this or relevant information.