StacksVerified U.S. regulatory reference

40 CFR §57.109

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The Administrator will not approve or issue an NSO for any smelter unless he has approved or promulgated SIP provisions which are applicable to the smelter and which satisfy the requirements of section 110(a)(6) of the Clean Air Act.