Energy & environment · 06/04/2026Updated: 10/16/2026 · 1 min read

Protection of Stratospheric Ozone: Listing of Substitutes Under the Significant New Alternatives Policy Program in Refrigeration and Air Conditioning and Fire Suppression; Supplemental Notice of Proposed Rulemaking

The U.S. Environmental Protection Agency proposes to list the refrigerant 2,3,3,3-tetrafluoropropene, also known as HFO-1234yf, as acceptable in motor vehicle air conditioning for heavy-duty pickup trucks and vans, supplementing a November 10, 2025, proposal with additional information and public comment opportunity.