; and (iii) any chemical amount, concentration, or threshold quantity described in Appendix A to part 27 of title 6, Code of Federal Regulations, or any successor thereto, should be modified; and (B) submit to Congress and publish on the internet website of the Department a report that contains the proposals of the Secretary relating to designations and modifications under subparagraph (A). . (d) Changes to Appendix A to part 27 of title 6, Code of Federal Regulations (1) In general Title XXI of the Homeland Security Act of 2002 ( 6 U.S.C. 621 et seq.) is amended by adding at the end the following: 2110. Changes to Appendix A to part 27 of title 6, Code of Federal Regulations (a) In general The Secretary shall prescribe, through notice and comment rulemaking under section 553 of title 5, United States Code, regulations relating to any proposed change to Appendix A to part 27 of title 6, Code of Federal Regulations, or any successor thereto, if the Secretary determines that— (1) a chemical should be designated as a chemical of interest; (2) a chemical designated as a chemical of interest should not be so designated; or (3) a chemical amount, concentration, or threshold quantity described in Appendix A to part 27 of title 6, Code of Federal Regulations, or any successor thereto, should be modified. (b) Interim rules Notwithstanding subsection (a), the Secretary may publish in the Federal Register an interim final rule relating to a proposed change to Appendix A to part 27 of title 6, Code of Federal Regulations, or any successor thereto, if the Secretary determines that— (1) an emergency or immediate threat directly relating to a specific chemical, chemical amount, chemical concentration, and chemical threshold quantity exists; and (2) the chemical described in paragraph (1) should be designated as a chemical of interest