[Code of Federal Regulations] [Title 40, Volume 15] [Revised as of July 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR68.100] [Page 175] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 68_CHEMICAL ACCIDENT PREVENTION PROVISIONS--Table of Contents Subpart F_Regulated Substances for Accidental Release Prevention Sec. 68.100 Purpose. Source: 59 FR 4493, Jan. 31, 1994, unless otherwise noted. Redesignated at 61 FR 31717, June 20, 1996. This subpart designates substances to be listed under section 112(r)(3), (4), and (5) of the Clean Air Act, as amended, identifies their threshold quantities, and establishes the requirements for petitioning to add or delete substances from the list.