--- kind: "unit" title: "40" title_heading: "Protection of Environment" key: "chI/subchC/part63" level: "part" label: "Part 63" heading: "National Emission Standards for Hazardous Air Pollutants for Source Categories" release: "ecfr-current" date: "2026-08-27" url: "https://uscodex.org/cfr/40/chI-subchC-part63" sections_count: 2473 --- # Part 63 — National Emission Standards for Hazardous Air Pollutants for Source Categories Title 40 C.F.R. — Protection of Environment › Chapter I — Environmental Protection Agency › Subchapter C — Air Programs ## Sections - [§63.569-63.599. Reserved](/cfr/40/63.569-63.599.md) ## Contents - [Subpart A — General Provisions](/cfr/40/chI-subchC-part63-subpartA.md) - [Subpart B — Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections, Sections 112(g) and 112(j)](/cfr/40/chI-subchC-part63-subpartB.md) - [Subpart C — List of Hazardous Air Pollutants, Petitions Process, Lesser Quantity Designations, Source Category List](/cfr/40/chI-subchC-part63-subpartC.md) - [Subpart D — Regulations Governing Compliance Extensions for Early Reductions of Hazardous Air Pollutants](/cfr/40/chI-subchC-part63-subpartD.md) - [Subpart E — Approval of State Programs and Delegation of Federal Authorities](/cfr/40/chI-subchC-part63-subpartE.md) - [Subpart F — National Emission Standards for Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry](/cfr/40/chI-subchC-part63-subpartF.md) - [Subpart G — National Emission Standards for Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater](/cfr/40/chI-subchC-part63-subpartG.md) - [Subpart H — National Emission Standards for Hazardous Air Pollutants for Equipment Leaks and Fenceline Monitoring for All Emission Sources](/cfr/40/chI-subchC-part63-subpartH.md) - [Subpart I — National Emission Standards for Hazardous Air Pollutants for Certain Processes Subject to the Negotiated Regulation for Equipment Leaks](/cfr/40/chI-subchC-part63-subpartI.md) - [Subpart J — National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production](/cfr/40/chI-subchC-part63-subpartJ.md) - [Subpart K — Subpart K [Reserved]](/cfr/40/chI-subchC-part63-subpartK.md) - [Subpart L — National Emission Standards for Coke Oven Batteries](/cfr/40/chI-subchC-part63-subpartL.md) - [Subpart M — National Perchloroethylene Air Emission Standards for Dry Cleaning Facilities](/cfr/40/chI-subchC-part63-subpartM.md) - [Subpart N — National Emission Standards for Chromium Emissions From Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks](/cfr/40/chI-subchC-part63-subpartN.md) - [Subpart O — Ethylene Oxide Emissions Standards for Sterilization Facilities](/cfr/40/chI-subchC-part63-subpartO.md) - [Subpart P — Subpart P [Reserved]](/cfr/40/chI-subchC-part63-subpartP.md) - [Subpart Q — National Emission Standards for Hazardous Air Pollutants for Industrial Process Cooling Towers](/cfr/40/chI-subchC-part63-subpartQ.md) - [Subpart R — National Emission Standards for Gasoline Distribution Facilities (Bulk Gasoline Terminals and Pipeline Breakout Stations)](/cfr/40/chI-subchC-part63-subpartR.md) - [Subpart S — National Emission Standards for Hazardous Air Pollutants from the Pulp and Paper Industry](/cfr/40/chI-subchC-part63-subpartS.md) - [Subpart T — National Emission Standards for Halogenated Solvent Cleaning](/cfr/40/chI-subchC-part63-subpartT.md) - [Subpart U — National Emission Standards for Hazardous Air Pollutant Emissions: Group I Polymers and Resins](/cfr/40/chI-subchC-part63-subpartU.md) - [Subpart V — Subpart V [Reserved]](/cfr/40/chI-subchC-part63-subpartV.md) - [Subpart W — National Emission Standards for Hazardous Air Pollutants for Epoxy Resins Production and Non-Nylon Polyamides Production](/cfr/40/chI-subchC-part63-subpartW.md) - [Subpart X — National Emission Standards For Hazardous Air Pollutants From Secondary Lead Smelting](/cfr/40/chI-subchC-part63-subpartX.md) - [Subpart Y — National Emission Standards for Marine Tank Vessel Loading Operations](/cfr/40/chI-subchC-part63-subpartY.md) - [Subpart Z — Subpart Z [Reserved]](/cfr/40/chI-subchC-part63-subpartZ.md) - [Subpart AA — National Emission Standards for Hazardous Air Pollutants from Phosphoric Acid Manufacturing Plants](/cfr/40/chI-subchC-part63-subpartAA.md) - [Subpart BB — National Emission Standards for Hazardous Air Pollutants from Phosphate Fertilizers Production Plants](/cfr/40/chI-subchC-part63-subpartBB.md) - [Subpart CC — National Emission Standards for Hazardous Air Pollutants From Petroleum Refineries](/cfr/40/chI-subchC-part63-subpartCC.md) - [Subpart DD — National Emission Standards for Hazardous Air Pollutants from Off-Site Waste and Recovery Operations](/cfr/40/chI-subchC-part63-subpartDD.md) - [Subpart EE — National Emission Standards for Magnetic Tape Manufacturing Operations](/cfr/40/chI-subchC-part63-subpartEE.md) - [Subpart FF — Subpart FF [Reserved]](/cfr/40/chI-subchC-part63-subpartFF.md) - [Subpart GG — National Emission Standards for Aerospace Manufacturing and Rework Facilities](/cfr/40/chI-subchC-part63-subpartGG.md) - [Subpart HH — National Emission Standards for Hazardous Air Pollutants From Oil and Natural Gas Production Facilities](/cfr/40/chI-subchC-part63-subpartHH.md) - [Subpart II — National Emission Standards for Shipbuilding and Ship Repair (Surface Coating)](/cfr/40/chI-subchC-part63-subpartII.md) - [Subpart JJ — National Emission Standards for Wood Furniture Manufacturing Operations](/cfr/40/chI-subchC-part63-subpartJJ.md) - [Subpart KK — National Emission Standards for the Printing and Publishing Industry](/cfr/40/chI-subchC-part63-subpartKK.md) - [Subpart LL — National Emission Standards for Hazardous Air Pollutants for Primary Aluminum Reduction Plants](/cfr/40/chI-subchC-part63-subpartLL.md) - [Subpart MM — National Emission Standards for Hazardous Air Pollutants for Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills](/cfr/40/chI-subchC-part63-subpartMM.md) - [Subpart NN — National Emission Standards for Hazardous Air Pollutants for Wool Fiberglass Manufacturing at Area Sources](/cfr/40/chI-subchC-part63-subpartNN.md) - [Subpart OO — National Emission Standards for Tanks—Level 1](/cfr/40/chI-subchC-part63-subpartOO.md) - [Subpart PP — National Emission Standards for Containers](/cfr/40/chI-subchC-part63-subpartPP.md) - [Subpart QQ — National Emission Standards for Surface Impoundments](/cfr/40/chI-subchC-part63-subpartQQ.md) - [Subpart RR — National Emission Standards for Individual Drain Systems](/cfr/40/chI-subchC-part63-subpartRR.md) - [Subpart SS — National Emission Standards for Closed Vent Systems, Control Devices, Recovery Devices and Routing to a Fuel Gas System or a Process](/cfr/40/chI-subchC-part63-subpartSS.md) - [Subpart TT — National Emission Standards for Equipment Leaks—Control Level 1](/cfr/40/chI-subchC-part63-subpartTT.md) - [Subpart UU — National Emission Standards for Equipment Leaks—Control Level 2 Standards](/cfr/40/chI-subchC-part63-subpartUU.md) - [Subpart VV — National Emission Standards for Oil-Water Separators and Organic-Water Separators](/cfr/40/chI-subchC-part63-subpartVV.md) - [Subpart WW — National Emission Standards for Storage Vessels (Tanks)—Control Level 2](/cfr/40/chI-subchC-part63-subpartWW.md) - [Subpart XX — National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations](/cfr/40/chI-subchC-part63-subpartXX.md) - [Subpart YY — National Emission Standards for Hazardous Air Pollutants for Source Categories: Generic Maximum Achievable Control Technology Standards](/cfr/40/chI-subchC-part63-subpartYY.md) - [Subpart ZZ-BBB — Subparts ZZ-BBB [Reserved]](/cfr/40/chI-subchC-part63-subpartZZ-BBB.md) - [Subpart CCC — National Emission Standards for Hazardous Air Pollutants for Steel Pickling—HCl Process Facilities and Hydrochloric Acid Regeneration Plants](/cfr/40/chI-subchC-part63-subpartCCC.md) - [Subpart DDD — National Emission Standards for Hazardous Air Pollutants for Mineral Wool Production](/cfr/40/chI-subchC-part63-subpartDDD.md) - [Subpart EEE — National Emission Standards for Hazardous Air Pollutants from Hazardous Waste Combustors](/cfr/40/chI-subchC-part63-subpartEEE.md) - [Subpart FFF — Subpart FFF [Reserved]](/cfr/40/chI-subchC-part63-subpartFFF.md) - [Subpart GGG — National Emission Standards for Pharmaceuticals Production](/cfr/40/chI-subchC-part63-subpartGGG.md) - [Subpart HHH — National Emission Standards for Hazardous Air Pollutants From Natural Gas Transmission and Storage Facilities](/cfr/40/chI-subchC-part63-subpartHHH.md) - [Subpart III — National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production](/cfr/40/chI-subchC-part63-subpartIII.md) - [Subpart JJJ — National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins](/cfr/40/chI-subchC-part63-subpartJJJ.md) - [Subpart KKK — Subpart KKK [Reserved]](/cfr/40/chI-subchC-part63-subpartKKK.md) - [Subpart LLL — National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry](/cfr/40/chI-subchC-part63-subpartLLL.md) - [Subpart MMM — National Emission Standards for Hazardous Air Pollutants for Pesticide Active Ingredient Production](/cfr/40/chI-subchC-part63-subpartMMM.md) - [Subpart NNN — National Emission Standards for Hazardous Air Pollutants for Wool Fiberglass Manufacturing](/cfr/40/chI-subchC-part63-subpartNNN.md) - [Subpart OOO — National Emission Standards for Hazardous Air Pollutant Emissions: Manufacture of Amino/Phenolic Resins](/cfr/40/chI-subchC-part63-subpartOOO.md) - [Subpart PPP — National Emission Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production](/cfr/40/chI-subchC-part63-subpartPPP.md) - [Subpart QQQ — National Emission Standards for Hazardous Air Pollutants for Primary Copper Smelting](/cfr/40/chI-subchC-part63-subpartQQQ.md) - [Subpart RRR — National Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production](/cfr/40/chI-subchC-part63-subpartRRR.md) - [Subpart SSS — Subpart SSS [Reserved]](/cfr/40/chI-subchC-part63-subpartSSS.md) - [Subpart TTT — National Emission Standards for Hazardous Air Pollutants for Primary Lead Smelting](/cfr/40/chI-subchC-part63-subpartTTT.md) - [Subpart UUU — National Emission Standards for Hazardous Air Pollutants for Petroleum Refineries: Catalytic Cracking Units, Catalytic Reforming Units, and Sulfur Recovery Units](/cfr/40/chI-subchC-part63-subpartUUU.md) - [Subpart VVV — National Emission Standards for Hazardous Air Pollutants: Publicly Owned Treatment Works](/cfr/40/chI-subchC-part63-subpartVVV.md) - [Subpart WWW — Subpart WWW [Reserved]](/cfr/40/chI-subchC-part63-subpartWWW.md) - [Subpart XXX — National Emission Standards for Hazardous Air Pollutants for Ferroalloys Production: Ferromanganese and Silicomanganese](/cfr/40/chI-subchC-part63-subpartXXX.md) - [Subpart AAAA — National Emission Standards for Hazardous Air Pollutants: Municipal Solid Waste Landfills](/cfr/40/chI-subchC-part63-subpartAAAA.md) - [Subpart BBBB — Subpart BBBB [Reserved]](/cfr/40/chI-subchC-part63-subpartBBBB.md) - [Subpart CCCC — National Emission Standards for Hazardous Air Pollutants: Manufacturing of Nutritional Yeast](/cfr/40/chI-subchC-part63-subpartCCCC.md) - [Subpart DDDD — National Emission Standards for Hazardous Air Pollutants: Plywood and Composite Wood Products](/cfr/40/chI-subchC-part63-subpartDDDD.md) - [Subpart EEEE — National Emission Standards for Hazardous Air Pollutants: Organic Liquids Distribution (Non-Gasoline)](/cfr/40/chI-subchC-part63-subpartEEEE.md) - [Subpart FFFF — National Emission Standards for Hazardous Air Pollutants: Miscellaneous Organic Chemical Manufacturing](/cfr/40/chI-subchC-part63-subpartFFFF.md) - [Subpart GGGG — National Emission Standards for Hazardous Air Pollutants: Solvent Extraction for Vegetable Oil Production](/cfr/40/chI-subchC-part63-subpartGGGG.md) - [Subpart HHHH — National Emission Standards for Hazardous Air Pollutants for Wet-Formed Fiberglass Mat Production](/cfr/40/chI-subchC-part63-subpartHHHH.md) - [Subpart IIII — National Emission Standards for Hazardous Air Pollutants: Surface Coating of Automobiles and Light-Duty Trucks](/cfr/40/chI-subchC-part63-subpartIIII.md) - [Subpart JJJJ — National Emission Standards for Hazardous Air Pollutants: Paper and Other Web Coating](/cfr/40/chI-subchC-part63-subpartJJJJ.md) - [Subpart KKKK — National Emission Standards for Hazardous Air Pollutants: Surface Coating of Metal Cans](/cfr/40/chI-subchC-part63-subpartKKKK.md) - [Subpart MMMM — National Emission Standards for Hazardous Air Pollutants for Surface Coating of Miscellaneous Metal Parts and Products](/cfr/40/chI-subchC-part63-subpartMMMM.md) - [Subpart NNNN — National Emission Standards for Hazardous Air Pollutants: Surface Coating of Large Appliances](/cfr/40/chI-subchC-part63-subpartNNNN.md) - [Subpart OOOO — National Emission Standards for Hazardous Air Pollutants: Printing, Coating, and Dyeing of Fabrics and Other Textiles](/cfr/40/chI-subchC-part63-subpartOOOO.md) - [Subpart PPPP — National Emission Standards for Hazardous Air Pollutants for Surface Coating of Plastic Parts and Products](/cfr/40/chI-subchC-part63-subpartPPPP.md) - [Subpart QQQQ — National Emission Standards for Hazardous Air Pollutants: Surface Coating of Wood Building Products](/cfr/40/chI-subchC-part63-subpartQQQQ.md) - [Subpart RRRR — National Emission Standards for Hazardous Air Pollutants: Surface Coating of Metal Furniture](/cfr/40/chI-subchC-part63-subpartRRRR.md) - [Subpart SSSS — National Emission Standards for Hazardous Air Pollutants: Surface Coating of Metal Coil](/cfr/40/chI-subchC-part63-subpartSSSS.md) - [Subpart TTTT — National Emission Standards for Hazardous Air Pollutants for Leather Finishing Operations](/cfr/40/chI-subchC-part63-subpartTTTT.md) - [Subpart UUUU — National Emission Standards for Hazardous Air Pollutants for Cellulose Products Manufacturing](/cfr/40/chI-subchC-part63-subpartUUUU.md) - [Subpart VVVV — National Emission Standards for Hazardous Air Pollutants for Boat Manufacturing](/cfr/40/chI-subchC-part63-subpartVVVV.md) - [Subpart WWWW — National Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production](/cfr/40/chI-subchC-part63-subpartWWWW.md) - [Subpart XXXX — National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing](/cfr/40/chI-subchC-part63-subpartXXXX.md) - [Subpart YYYY — National Emission Standards for Hazardous Air Pollutants for Stationary Combustion Turbines](/cfr/40/chI-subchC-part63-subpartYYYY.md) - [Subpart ZZZZ — National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines](/cfr/40/chI-subchC-part63-subpartZZZZ.md) - [Subpart AAAAA — National Emission Standards for Hazardous Air Pollutants for Lime Manufacturing Plants](/cfr/40/chI-subchC-part63-subpartAAAAA.md) - [Subpart BBBBB — National Emission Standards for Hazardous Air Pollutants for Semiconductor Manufacturing](/cfr/40/chI-subchC-part63-subpartBBBBB.md) - [Subpart CCCCC — National Emission Standards for Hazardous Air Pollutants for Coke Ovens: Pushing, Quenching, and Battery Stacks](/cfr/40/chI-subchC-part63-subpartCCCCC.md) - [Subpart DDDDD — National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters](/cfr/40/chI-subchC-part63-subpartDDDDD.md) - [Subpart EEEEE — National Emission Standards for Hazardous Air Pollutants for Iron and Steel Foundries](/cfr/40/chI-subchC-part63-subpartEEEEE.md) - [Subpart FFFFF — National Emission Standards for Hazardous Air Pollutants for Integrated Iron and Steel Manufacturing Facilities](/cfr/40/chI-subchC-part63-subpartFFFFF.md) - [Subpart GGGGG — National Emission Standards for Hazardous Air Pollutants: Site Remediation](/cfr/40/chI-subchC-part63-subpartGGGGG.md) - [Subpart HHHHH — National Emission Standards for Hazardous Air Pollutants: Miscellaneous Coating Manufacturing](/cfr/40/chI-subchC-part63-subpartHHHHH.md) - [Subpart IIIII — National Emission Standards for Hazardous Air Pollutants for Mercury Cell Chlor-Alkali Plants](/cfr/40/chI-subchC-part63-subpartIIIII.md) - [Subpart JJJJJ — National Emission Standards for Hazardous Air Pollutants for Brick and Structural Clay Products Manufacturing](/cfr/40/chI-subchC-part63-subpartJJJJJ.md) - [Subpart KKKKK — National Emission Standards for Hazardous Air Pollutants for Clay Ceramics Manufacturing](/cfr/40/chI-subchC-part63-subpartKKKKK.md) - [Subpart LLLLL — National Emission Standards for Hazardous Air Pollutants: Asphalt Processing and Asphalt Roofing Manufacturing](/cfr/40/chI-subchC-part63-subpartLLLLL.md) - [Subpart MMMMM — National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication Operations](/cfr/40/chI-subchC-part63-subpartMMMMM.md) - [Subpart NNNNN — National Emission Standards for Hazardous Air Pollutants: Hydrochloric Acid Production](/cfr/40/chI-subchC-part63-subpartNNNNN.md) - [Subpart OOOOO — Subpart OOOOO [Reserved]](/cfr/40/chI-subchC-part63-subpartOOOOO.md) - [Subpart PPPPP — National Emission Standards for Hazardous Air Pollutants for Engine Test Cells/Stands](/cfr/40/chI-subchC-part63-subpartPPPPP.md) - [Subpart QQQQQ — National Emission Standards for Hazardous Air Pollutants for Friction Materials Manufacturing Facilities](/cfr/40/chI-subchC-part63-subpartQQQQQ.md) - [Subpart RRRRR — National Emission Standards for Hazardous Air Pollutants: Taconite Iron Ore Processing](/cfr/40/chI-subchC-part63-subpartRRRRR.md) - [Subpart SSSSS — National Emission Standards for Hazardous Air Pollutants for Refractory Products Manufacturing](/cfr/40/chI-subchC-part63-subpartSSSSS.md) - [Subpart TTTTT — National Emissions Standards for Hazardous Air Pollutants for Primary Magnesium Refining](/cfr/40/chI-subchC-part63-subpartTTTTT.md) - [Subpart UUUUU — National Emission Standards for Hazardous Air Pollutants: Coal- and Oil-Fired Electric Utility Steam Generating Units](/cfr/40/chI-subchC-part63-subpartUUUUU.md) - [Subpart VVVVV — Subpart VVVVV [Reserved]](/cfr/40/chI-subchC-part63-subpartVVVVV.md) - [Subpart WWWWW — National Emission Standards for Hospital Ethylene Oxide Sterilizers](/cfr/40/chI-subchC-part63-subpartWWWWW.md) - [Subpart XXXXX — Subpart XXXXX [Reserved]](/cfr/40/chI-subchC-part63-subpartXXXXX.md) - [Subpart YYYYY — National Emission Standards for Hazardous Air Pollutants for Area Sources: Electric Arc Furnace Steelmaking Facilities](/cfr/40/chI-subchC-part63-subpartYYYYY.md) - [Subpart ZZZZZ — National Emission Standards for Hazardous Air Pollutants for Iron and Steel Foundries Area Sources](/cfr/40/chI-subchC-part63-subpartZZZZZ.md) - [Subpart AAAAAA — Subpart AAAAAA [Reserved]](/cfr/40/chI-subchC-part63-subpartAAAAAA.md) - [Subpart BBBBBB — National Emission Standards for Hazardous Air Pollutants for Source Category: Gasoline Distribution Bulk Terminals, Bulk Plants, and Pipeline Facilities](/cfr/40/chI-subchC-part63-subpartBBBBBB.md) - [Subpart CCCCCC — National Emission Standards for Hazardous Air Pollutants for Source Category: Gasoline Dispensing Facilities](/cfr/40/chI-subchC-part63-subpartCCCCCC.md) - [Subpart DDDDDD — National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production Area Sources](/cfr/40/chI-subchC-part63-subpartDDDDDD.md) - [Subpart EEEEEE — National Emission Standards for Hazardous Air Pollutants for Primary Copper Smelting Area Sources](/cfr/40/chI-subchC-part63-subpartEEEEEE.md) - [Subpart FFFFFF — National Emission Standards for Hazardous Air Pollutants for Secondary Copper Smelting Area Sources](/cfr/40/chI-subchC-part63-subpartFFFFFF.md) - [Subpart GGGGGG — National Emission Standards for Hazardous Air Pollutants for Primary Nonferrous Metals Area Sources—Zinc, Cadmium, and Beryllium](/cfr/40/chI-subchC-part63-subpartGGGGGG.md) - [Subpart HHHHHH — National Emission Standards for Hazardous Air Pollutants: Paint Stripping and Miscellaneous Surface Coating Operations at Area Sources](/cfr/40/chI-subchC-part63-subpartHHHHHH.md) - [Subpart IIIIII — Subpart IIIIII [Reserved]](/cfr/40/chI-subchC-part63-subpartIIIIII.md) - [Subpart JJJJJJ — National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers Area Sources](/cfr/40/chI-subchC-part63-subpartJJJJJJ.md) - [Subpart KKKKKK — Subpart KKKKKK [Reserved]](/cfr/40/chI-subchC-part63-subpartKKKKKK.md) - [Subpart LLLLLL — National Emission Standards for Hazardous Air Pollutants for Acrylic and Modacrylic Fibers Production Area Sources](/cfr/40/chI-subchC-part63-subpartLLLLLL.md) - [Subpart MMMMMM — National Emission Standards for Hazardous Air Pollutants for Carbon Black Production Area Sources](/cfr/40/chI-subchC-part63-subpartMMMMMM.md) - [Subpart NNNNNN — National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium Compounds](/cfr/40/chI-subchC-part63-subpartNNNNNN.md) - [Subpart OOOOOO — National Emission Standards for Hazardous Air Pollutants for Flexible Polyurethane Foam Production and Fabrication Area Sources](/cfr/40/chI-subchC-part63-subpartOOOOOO.md) - [Subpart PPPPPP — National Emission Standards for Hazardous Air Pollutants for Lead Acid Battery Manufacturing Area Sources](/cfr/40/chI-subchC-part63-subpartPPPPPP.md) - [Subpart QQQQQQ — National Emission Standards for Hazardous Air Pollutants for Wood Preserving Area Sources](/cfr/40/chI-subchC-part63-subpartQQQQQQ.md) - [Subpart RRRRRR — National Emission Standards for Hazardous Air Pollutants for Clay Ceramics Manufacturing Area Sources](/cfr/40/chI-subchC-part63-subpartRRRRRR.md) - [Subpart SSSSSS — National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area Sources](/cfr/40/chI-subchC-part63-subpartSSSSSS.md) - [Subpart TTTTTT — National Emission Standards for Hazardous Air Pollutants for Secondary Nonferrous Metals Processing Area Sources](/cfr/40/chI-subchC-part63-subpartTTTTTT.md) - [Subpart UUUUUU — Subpart UUUUUU [Reserved]](/cfr/40/chI-subchC-part63-subpartUUUUUU.md) - [Subpart VVVVVV — National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources](/cfr/40/chI-subchC-part63-subpartVVVVVV.md) - [Subpart WWWWWW — National Emission Standards for Hazardous Air Pollutants: Area Source Standards for Plating and Polishing Operations](/cfr/40/chI-subchC-part63-subpartWWWWWW.md) - [Subpart XXXXXX — National Emission Standards for Hazardous Air Pollutants Area Source Standards for Nine Metal Fabrication and Finishing Source Categories](/cfr/40/chI-subchC-part63-subpartXXXXXX.md) - [Subpart YYYYYY — National Emission Standards for Hazardous Air Pollutants for Area Sources: Ferroalloys Production Facilities](/cfr/40/chI-subchC-part63-subpartYYYYYY.md) - [Subpart ZZZZZZ — National Emission Standards for Hazardous Air Pollutants: Area Source Standards for Aluminum, Copper, and Other Nonferrous Foundries](/cfr/40/chI-subchC-part63-subpartZZZZZZ.md) - [Subpart AAAAAAA — National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing](/cfr/40/chI-subchC-part63-subpartAAAAAAA.md) - [Subpart BBBBBBB — National Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry](/cfr/40/chI-subchC-part63-subpartBBBBBBB.md) - [Subpart CCCCCCC — National Emission Standards for Hazardous Air Pollutants for Area Sources: Paints and Allied Products Manufacturing](/cfr/40/chI-subchC-part63-subpartCCCCCCC.md) - [Subpart DDDDDDD — National Emission Standards for Hazardous Air Pollutants for Area Sources: Prepared Feeds Manufacturing](/cfr/40/chI-subchC-part63-subpartDDDDDDD.md) - [Subpart EEEEEEE — National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production Area Source Category](/cfr/40/chI-subchC-part63-subpartEEEEEEE.md) - [Subpart FFFFFFF and GGGGGGG — Subparts FFFFFFF and GGGGGGG [Reserved]](/cfr/40/chI-subchC-part63-subpartFFFFFFF_and_GGGGGGG.md) - [Subpart HHHHHHH — National Emission Standards for Hazardous Air Pollutant Emissions for Polyvinyl Chloride and Copolymers Production](/cfr/40/chI-subchC-part63-subpartHHHHHHH.md)