Code of Federal Regulations > Title 40 > Chapter I > Part 421 - PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY

U.S. Code of Federal Regulations

Regulations most recently checked for updates: Sep 16, 2025

GENERAL PROVISIONS

§ 421.1 - Applicability.

§ 421.2 - [Reserved]

§ 421.3 - Monitoring and reporting requirements.

§ 421.4 - Compliance date for pretreatment standards for existing sources (PSES).

§ 421.5 - Removal allowances for pretreatment standards.

Subpart A [§ 421.10 - § 421.16] - Subpart A—Bauxite Refining Subcategory

Subpart B [§ 421.20 - § 421.27] - Subpart B—Primary Aluminum Smelting Subcategory

Subpart C [§ 421.30 - § 421.37] - Subpart C—Secondary Aluminum Smelting Subcategory

Subpart D [§ 421.40 - § 421.47] - Subpart D—Primary Copper Smelting Subcategory

Subpart E [§ 421.50 - § 421.57] - Subpart E—Primary Electrolytic Copper Refining Subcategory

Subpart F [§ 421.60 - § 421.67] - Subpart F—Secondary Copper Subcategory

Subpart G [§ 421.70 - § 421.77] - Subpart G—Primary Lead Subcategory

Subpart H [§ 421.80 - § 421.87] - Subpart H—Primary Zinc Subcategory

Subpart I [§ 421.90 - § 421.97] - Subpart I—Metallurgical Acid Plants Subcategory

Subpart J [§ 421.100 - § 421.107] - Subpart J—Primary Tungsten Subcategory

Subpart K [§ 421.110 - § 421.117] - Subpart K—Primary Columbium-Tantalum Subcategory

Subpart L [§ 421.120 - § 421.127] - Subpart L—Secondary Silver Subcategory

Subpart M [§ 421.130 - § 421.137] - Subpart M—Secondary Lead Subcategory

Subpart N [§ 421.140 - § 421.147] - Subpart N—Primary Antimony Subcategory

Subpart O [§ 421.150 - § 421.157] - Subpart O—Primary Beryllium Subcategory

Subpart P [§ 421.180 - § 421.187] -

Subpart Q [§ 421.190 - § 421.197] - Subpart Q—Secondary Indium Subcategory

Subpart R [§ 421.200 - § 421.207] - Subpart R—Secondary Mercury Subcategory

Subpart S [§ 421.210 - § 421.217] - Subpart S—Primary Molybdenum and Rhenium Subcategory

Subpart T [§ 421.220 - § 421.227] - Subpart T—Secondary Molybdenum and Vanadium Subcategory

Subpart U [§ 421.230 - § 421.237] - Subpart U—Primary Nickel and Cobalt Subcategory

Subpart V [§ 421.240 - § 421.247] - Subpart V—Secondary Nickel Subcategory

Subpart W [§ 421.250 - § 421.257] - Subpart W—Primary Precious Metals and Mercury Subcategory

Subpart X [§ 421.260 - § 421.267] - Subpart X—Secondary Precious Metals Subcategory

Subpart Y [§ 421.270 - § 421.277] - Subpart Y—Primary Rare Earth Metals Subcategory

Subpart Z [§ 421.280 - § 421.287] - Subpart Z—Secondary Tantalum Subcategory

Subpart AA [§ 421.290 - § 421.297] - Subpart AA—Secondary Tin Subcategory

Subpart AB [§ 421.300 - § 421.307] - Subpart AB—Primary and Secondary Titanium Subcategory

Subpart AC [§ 421.310 - § 421.317] - Subpart AC—Secondary Tungsten and Cobalt Subcategory

Subpart AD [§ 421.320 - § 421.327] - Subpart AD—Secondary Uranium Subcategory

Subpart AE [§ 421.330 - § 421.337] - Subpart AE—Primary Zirconium and Hafnium Subcategory