On January 27, 2017, US Customs and Border Protection (CBP) published in the Federal Register a document [USCBP–2016–0056; CBP Dec. 16–28] delaying the effective date of the final rule published in the Federal Register on December 27, 2016 announcing amendments to CBP regulations regarding the requirement to file a Toxic Substances Control Act (TSCA) certification when importing into the customs territory of the United States chemicals in bulk form or as part of mixtures and articles containing a chemical or mixture. That document amended the regulations to establish an electronic option for importers to file the required U.S. Environmental Protection Agency (EPA) TSCA certifications, to clarify and add certain definitions, and to eliminate the paper-based blanket certification process. The changes announced in that Final Rule were to be effective January 26, 2017. This notice announces that the effective date of the rule amending 19 C.F.R. parts 12 and 127 is delayed March 21, 2017, in accordance with the White House Chief of Staff’s memorandum of January 20, 2017.