; and (2) the chemical described in paragraph (1) should be designated as a chemical of interest; and (3) the chemical amount, chemical concentration, and chemical threshold quantity described in paragraph (1) should be designated or modified, as applicable, under Appendix A to part 27 of title 6, Code of Federal Regulations, or any successor thereto. (c) Duration of authority (1) In general Any proposed change to Appendix A to part 27 of title 6, Code of Federal Regulations, or any successor thereto, published in an interim rule under subsection (b) shall only be in effect for the 180-day period following publication of the interim rule. (2) Rule making If, after the 180-day period described in paragraph (1), the Secretary determines that a chemical designated as a chemical of interest under an interim rule published under subsection (b) should be designated as a chemical interest, the Secretary shall issue a final rule designating the chemical as a chemical of interest in accordance with the notice and comment rule making procedures under section 553 of title 5, United States Code. . (2) Technical and conforming amendment The table of contents in section 1(b) of the Homeland Security Act of 2002 ( Public Law 107–196