Federal rule library
NSPS, NESHAP, and GHG Reporting Subparts
Oil and natural gas
Production, gathering, processing, transmission, and storage.
40 CFR Part 60, Subpart OOOOb
NSPS Subpart OOOOb (Quad Ob)
Crude Oil and Natural Gas Facilities for Which Construction, Modification or Reconstruction Commenced After December 6, 2022
Last amended in eCFR 2026-06-08
40 CFR Part 60, Subpart OOOOc
NSPS Subpart OOOOc (Quad Oc)
Greenhouse Gas Emissions From Existing Crude Oil and Natural Gas Facilities
Last amended in eCFR 2026-06-08
40 CFR Part 60, Subpart OOOOa
NSPS Subpart OOOOa (Quad Oa)
Crude Oil and Natural Gas Facilities for Which Construction, Modification or Reconstruction Commenced After September 18, 2015 and On or Before December 6, 2022
Last amended in eCFR 2025-07-31
40 CFR Part 60, Subpart OOOO
NSPS Subpart OOOO (Quad O)
Crude Oil and Natural Gas Facilities for Which Construction, Modification, or Reconstruction Commenced After August 23, 2011, and on or Before September 18, 2015
Last amended in eCFR 2025-07-31
40 CFR Part 60, Subpart KKK
NSPS Subpart KKK
Equipment Leaks of VOC From Onshore Natural Gas Processing Plants for Which Construction, Reconstruction, or Modification Commenced After January 20, 1984, and on or Before August 23, 2011
Last amended in eCFR 2024-05-07
40 CFR Part 60, Subpart LLL
NSPS Subpart LLL
SO2 Emissions From Onshore Natural Gas Processing for Which Construction, Reconstruction, or Modification Commenced After January 20, 1984, and on or Before August 23, 2011
Last amended in eCFR 2016-12-23
40 CFR Part 63, Subpart HH
NESHAP Subpart HH
Oil and Natural Gas Production Facilities
Last amended in eCFR 2024-10-22
40 CFR Part 63, Subpart HHH
NESHAP Subpart HHH
Natural Gas Transmission and Storage Facilities
Last amended in eCFR 2024-10-22
40 CFR Part 60, Subpart Kb
NSPS Subpart Kb
Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced After July 23, 1984, and On or Before October 4, 2023
Last amended in eCFR 2024-10-15
40 CFR Part 98, Subpart W
GHGRP Subpart W (GHGRP Subpart W)
Petroleum and Natural Gas Systems
Last amended in eCFR 2025-01-01
Stationary engines
Reciprocating internal combustion engines, spark and compression ignition.
40 CFR Part 60, Subpart JJJJ
NSPS Subpart JJJJ (Quad J)
Stationary Spark Ignition Internal Combustion Engines
Last amended in eCFR 2024-08-30
40 CFR Part 60, Subpart IIII
NSPS Subpart IIII (Quad I)
Stationary Compression Ignition Internal Combustion Engines
Last amended in eCFR 2024-08-30
40 CFR Part 63, Subpart ZZZZ
NESHAP Subpart ZZZZ (RICE NESHAP)
Stationary Reciprocating Internal Combustion Engines
Last amended in eCFR 2024-08-30
Combustion turbines
Stationary gas and combustion turbines.
40 CFR Part 60, Subpart KKKK
NSPS Subpart KKKK (Quad K)
Stationary Combustion Turbines
Last amended in eCFR 2026-08-17
40 CFR Part 60, Subpart GG
NSPS Subpart GG
Stationary Gas Turbines
Last amended in eCFR 2026-08-17
40 CFR Part 63, Subpart YYYY
NESHAP Subpart YYYY (Turbine MACT)
Stationary Combustion Turbines
Last amended in eCFR 2022-03-09
Boilers and process heaters
Steam generating units, boilers, and process heaters.
40 CFR Part 60, Subpart Db
NSPS Subpart Db
Industrial-Commercial-Institutional Steam Generating Units
Last amended in eCFR 2019-08-16
40 CFR Part 60, Subpart Dc
NSPS Subpart Dc
Small Industrial-Commercial-Institutional Steam Generating Units
Last amended in eCFR 2020-10-07
40 CFR Part 63, Subpart DDDDD
NESHAP Subpart DDDDD (Boiler MACT)
Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters
Last amended in eCFR 2022-12-05
40 CFR Part 63, Subpart JJJJJJ
NESHAP Subpart JJJJJJ (Area source boiler rule)
Industrial, Commercial, and Institutional Boilers Area Sources
Last amended in eCFR 2018-07-02
Storage tanks and liquid transfer
Volatile organic liquid storage vessels and organic liquids distribution.
40 CFR Part 60, Subpart Kb
NSPS Subpart Kb
Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced After July 23, 1984, and On or Before October 4, 2023
Last amended in eCFR 2024-10-15
40 CFR Part 60, Subpart Kc
NSPS Subpart Kc
Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced After October 4, 2023
Last amended in eCFR 2024-10-15
40 CFR Part 63, Subpart EEEE
NESHAP Subpart EEEE (OLD MACT)
Organic Liquids Distribution (Non-Gasoline)
Last amended in eCFR 2024-04-04
Gasoline distribution
Gasoline dispensing facilities and bulk gasoline terminals and plants.
40 CFR Part 63, Subpart CCCCCC
NESHAP Subpart CCCCCC (6C)
Source Category: Gasoline Dispensing Facilities
Last amended in eCFR 2021-01-18
40 CFR Part 63, Subpart BBBBBB
NESHAP Subpart BBBBBB (6B)
Source Category: Gasoline Distribution Bulk Terminals, Bulk Plants, and Pipeline Facilities
Last amended in eCFR 2024-07-08
Petroleum refineries
Refinery process units and related equipment.
40 CFR Part 63, Subpart CC
NESHAP Subpart CC (Refinery MACT 1)
Petroleum Refineries
Last amended in eCFR 2024-04-04
40 CFR Part 63, Subpart UUU
NESHAP Subpart UUU (Refinery MACT 2)
Petroleum Refineries: Catalytic Cracking Units, Catalytic Reforming Units, and Sulfur Recovery Units
Last amended in eCFR 2023-03-08
40 CFR Part 60, Subpart Ja
NSPS Subpart Ja
Petroleum Refineries for Which Construction, Reconstruction, or Modification Commenced After May 14, 2007
Last amended in eCFR 2018-11-26
40 CFR Part 60, Subpart J
NSPS Subpart J
Petroleum Refineries
Last amended in eCFR 2016-10-31
40 CFR Part 98, Subpart Y
GHGRP Subpart Y (GHGRP Subpart Y)
Petroleum Refineries
Last amended in eCFR 2025-01-01
Chemical manufacturing
Organic chemical manufacturing process units.
Power plants
Electric utility steam generating units and generating plants.
40 CFR Part 60, Subpart Da
NSPS Subpart Da
Electric Utility Steam Generating Units
Last amended in eCFR 2016-10-31
40 CFR Part 60, Subpart TTTT
NSPS Subpart TTTT
Greenhouse Gas Emissions for Electric Generating Units
Last amended in eCFR 2026-09-17
40 CFR Part 63, Subpart UUUUU
NESHAP Subpart UUUUU (MATS)
Coal- and Oil-Fired Electric Utility Steam Generating Units
Last amended in eCFR 2026-06-15
40 CFR Part 98, Subpart D
GHGRP Subpart D (GHGRP Subpart D)
Electricity Generation
Last amended in eCFR 2017-01-01
Aggregates and asphalt
Nonmetallic mineral processing and hot mix asphalt plants.
Landfills
Municipal solid waste landfills.
40 CFR Part 60, Subpart XXX
NSPS Subpart XXX
Municipal Solid Waste Landfills That Commenced Construction, Reconstruction, or Modification After July 17, 2014
Last amended in eCFR 2022-02-14
40 CFR Part 60, Subpart WWW
NSPS Subpart WWW
Municipal Solid Waste Landfills That Commenced Construction, Reconstruction, or Modification on or After May 30, 1991, but Before July 18, 2014
Last amended in eCFR 2020-03-26
40 CFR Part 60, Subpart Cf
NSPS Subpart Cf
Emission Guidelines and Compliance Times for Municipal Solid Waste Landfills
Last amended in eCFR 2020-03-26
40 CFR Part 63, Subpart AAAA
NESHAP Subpart AAAA
Municipal Solid Waste Landfills
Last amended in eCFR 2022-02-14
40 CFR Part 98, Subpart HH
GHGRP Subpart HH (GHGRP Subpart HH)
Municipal Solid Waste Landfills
Last amended in eCFR 2025-09-29
Surface coating and metal work
Paint stripping, surface coating, metal fabrication, and solvent cleaning.
40 CFR Part 63, Subpart HHHHHH
NESHAP Subpart HHHHHH (6H)
Paint Stripping and Miscellaneous Surface Coating Operations at Area Sources
Last amended in eCFR 2022-11-10
40 CFR Part 63, Subpart XXXXXX
NESHAP Subpart XXXXXX (6X)
National Emission Standards for Hazardous Air Pollutants Area Source Standards for Nine Metal Fabrication and Finishing Source Categories
Last amended in eCFR 2021-01-18
40 CFR Part 63, Subpart T
NESHAP Subpart T
National Emission Standards for Halogenated Solvent Cleaning
Last amended in eCFR 2022-07-21
Greenhouse gas reporting
40 CFR Part 98 reporting requirements.
40 CFR Part 98, Subpart W
GHGRP Subpart W (GHGRP Subpart W)
Petroleum and Natural Gas Systems
Last amended in eCFR 2025-01-01
40 CFR Part 98, Subpart C
GHGRP Subpart C (GHGRP Subpart C)
General Stationary Fuel Combustion Sources
Last amended in eCFR 2025-09-29
40 CFR Part 98, Subpart D
GHGRP Subpart D (GHGRP Subpart D)
Electricity Generation
Last amended in eCFR 2017-01-01
40 CFR Part 98, Subpart Y
GHGRP Subpart Y (GHGRP Subpart Y)
Petroleum Refineries
Last amended in eCFR 2025-01-01
40 CFR Part 98, Subpart HH
GHGRP Subpart HH (GHGRP Subpart HH)
Municipal Solid Waste Landfills
Last amended in eCFR 2025-09-29
40 CFR Part 98, Subpart A
GHGRP Subpart A
General Provisions
Last amended in eCFR 2026-10-14
General provisions
Provisions that apply across a part unless a subpart says otherwise.
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