; 128 Stat. 2919) after 2014 ; and (2) in paragraph (2), by striking 2014 and inserting 2018 . 11. Explosive materials (a) In general Title XXI of the Homeland Security Act of 2002 ( 6 U.S.C. 621 et seq.) is amended by striking section 2109 ( 6 U.S.C. 629 ) and inserting the following: 2109. Explosive materials The Secretary may not designate any explosive material subject to regulation by the Department of Justice under chapter 40 of title 18, United States Code, or by the Bureau of Alcohol, Tobacco, Firearms, and Explosives under part 555 of title 27, Code of Federal Regulations, as a chemical of interest under Appendix A to part 27 of title 6, Code of Federal Regulations, or any successor thereto. . (b) Technical and conforming amendment The table of contents in section 1(b) of the Homeland Security Act of 2002 ( Public Law 107–196 ; 116 Stat. 2135) is amended by striking the item relating to section 2109 and inserting the following: Sec. 2109. Explosive materials. . 12. Changes to Appendix A to part 27 of title 6, Code of Federal Regulations (a) In general Title XXI of the Homeland Security Act of 2002 ( 6 U.S.C. 621 et seq.), as amended by section 12 of this Act, 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) Definition In this section, the term Appendix A means Appendix A to part 27 of title 6, Code of Federal Regulations, or any successor thereto. (b) Notice of proposed rulemaking The Secretary shall publish a notice of proposed rulemaking in the Federal Register relating to any proposed change to Appendix A if the Secretary determines that— (1) a chemical should be designated as a chemical of interest under Appendix A; (2) a chemical designated as a chemical of interest under Appendix A should not be so designated