Basis. EPA Technology Transitions programme, 40 CFR Part 84. Chillers for comfort cooling: refrigerants with GWP ≥ 700 restricted from 1 January 2025. Chillers for industrial process refrigeration with leaving fluid above −30 °C: GWP ≥ 700 restricted from 1 January 2026. IPR between −50 °C and −30 °C: GWP ≥ 700 restricted from 1 January 2028. GWP values per EPA’s regulatory reference table at 40 CFR 84.64 — these are the numbers a compliance submission is measured against. Industry literature sometimes quotes different IPCC-derived values (R-1234ze(E) is commonly cited as under 7 rather than 1); both sit far below the 700 limit, so eligibility is unchanged. DOE adds that fully assembled self-contained chillers using high-GWP refrigerants cannot be manufactured after 1 January 2025, and systems relying on them may not be installed after 31 December 2025.

R-1234ze(E) is A2L (mildly flammable) under ASHRAE 34 and is not a drop-in retrofit for an existing R-134a machine — it belongs in equipment designed around it.

Regulation is in motion. EPA opened a reconsideration of parts of this rule in October 2025. This tool reflects the position as of 2026 and is not legal advice — confirm current status with your compliance team before you specify.