Air Toxic Standards for Crude Oil and Natural Gas Production Facilities and for Natural Gas Transmission and Storage Facilities

Background

EPA regulates emissions of hazardous air pollutants (HAPs) from oil and natural gas operations under two subparts of Clean Air Act (CAA) section 112. Subpart HH covers operations for oil and natural gas production facilities, while Subpart HHH covers operations for oil and natural gas transmission and storage facilities. 

Emissions from various processes and operations at oil and natural gas facilities and natural gas transmission and storage facilities typically contain 5 different HAPs: benzene, toluene, ethyl benzene, and mixed xylenes, and n-hexane. HAPs, also known as air toxics, are pollutants which are known or suspected to cause cancer or other serious health effects such as birth defects or reproductive effects.

For historical context of each subpart, visit the following webpages:

• Subpart HH: Oil and Natural Gas Production Facilities
• Subpart HHH: Oil and Natural Gas Transmission and Storage Facilities

April 2026 Proposal

April 17, 2026 -  EPA announced the technology review and reconsideration of the 2012 Final Rule Amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for oil and natural gas production, and transmission and storage facilities. Under this technology review and reconsideration, the agency is proposing that there are no new technologies that must be installed for existing oil and natural gas production, and transmission and storage facilities at this time. Additionally, EPA is proposing to add methanol as a regulated hazardous air pollutant (HAP) to meet our obligations under D.C. Circuit case law. Finally, EPA is proposing to change the definition of “associated equipment” when determining what is a major source to align with the proper reading of the Clean Air Act (CAA).This proposal fulfills EPA’s CAA obligation to conduct a technology review every eight years under section 112(d)(6) and works to align the NESHAP with existing oil and natural gas rules. 

• Proposed Changes to the Air Toxic Standards for Crude Oil and Natural Gas Production Facilities and for Natural Gas Transmission and Storage Facilities
• Economic Impact Analysis: Proposed Changes to the Air Toxic Standards for Crude Oil and Natural Gas Production Facilities and for Natural Gas Transmission and Storage Facilities