[Code of Federal Regulations] [Title 40, Volume 13] [Revised as of January 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR68.100] [Page 176] 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.