On March 3, 2020, the U.S. Environmental Protection Agency (EPA) published in the Federal Register a proposed supplemental significant new use rule (SNUR) issued under Section 5(a)(2) of the Toxic Substances Control Act (TSCA) for long-chain perfluoroalkyl carboxylate (LCPFAC) chemical substances to make inapplicable the exemption for persons who import a subset of LCPFAC chemical substances as part of surface coatings on articles. 85 Fed. Reg. 12479. Under the proposed supplemental SNUR, this subset of LCPFAC chemical substances also includes the salts and precursors of these perfluorinated carboxylates. The supplemental proposal would require importers to notify EPA at least 90 days before commencing the import of these chemical substances in certain articles for the significant new use described in the proposed SNUR. The required significant new use notification would initiate EPA’s evaluation of the conditions of use associated with the intended significant new use. Manufacturing (including import) or processing for the significant new use would be prohibited from commencing until EPA has conducted a review of the notice, made an appropriate determination on the notice, and taken such actions as are required in association with that determination. Comments on the proposed supplemental SNUR are due April 17, 2020. More information is available in our February 28, 2020, memorandum, “Proposed Supplemental SNUR Would Remove Exemption for LCPFAC Chemical Substances Used as Surface Coatings on Articles.”