[Code of Federal Regulations] [Title 40, Volume 5] [Revised as of July 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR57.101] [Page 131] TITLE 40--PROTECTION OF ENVIRONMENT CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PART 57--PRIMARY NONFERROUS SMELTER ORDERS--Table of Contents Subpart A--General Sec. 57.101 Purpose and scope. (a) Applicability of the regulations. The regulations in subparts A through H govern: (1) The eligibility of smelters for a Primary Nonferrous Smelter Order (NSO) under section 119 of the Clean Air Act; (2) The procedures through which an NSO can be approved or issued by EPA; and (3) The minimum contents of each NSO required for EPA issuance or approval under section 119. Subpart I et seq., will contain NSOs in effect for individual smelters. (b) State authority to adopt more stringent requrements. Nothing in this part shall preclude a State from imposing more stringent requirements, as provided by section 116 of the Clean Air Act.