The importation into the customs territory of the United States of a chemical substance in bulk or as part of a mixture, or article containing a chemical substance or mixture, is governed by the Toxic Substances Control Act (``TSCA'') (15 U.S.C. 2601 et seq.), and by regulations issued under the authority of section 13(b), TSCA (15 U.S.C. 2612(b)) by the Secretary of the Treasury in consultation with the Administrator, Environmental Protection Agency (``EPA'').