The U.S. Environmental Protection Agency (EPA) has proposed revisions to the AIM Act's "Technology Transitions" rule, potentially extending compliance timelines for low-GWP refrigerants in transport refrigeration. The revisions aim to address industry concerns about equipment availability, retrofit complexity, and cost. These changes may delay mandates originally set for early 2025, impacting rollout plans for transport refrigeration manufacturers and fleet operators.
Background
The EPA's October 2023 Technology Transitions rule, enacted under the AIM Act, restricts high-GWP HFCs in multiple subsectors, including road, marine, and intermodal transport refrigeration. The original compliance date is January 1, 2025. The agency cited the availability of lower-GWP alternatives such as R-744, R-450A, R-513A, and R-452A for transport refrigeration[1]. However, stakeholders, including OEMs and logistics operators, have expressed concerns about supply constraints and limited planning timeframes[1].
In response, the agency issued a proposed reconsideration rule in October 2025, suggesting adjustments to GWP thresholds and schedule extensions across refrigeration sectors. Specific changes for the transport refrigeration sector remain under evaluation[2].
Details
The 2023 rule restricts several high-GWP HFC blends-including R-404A and R-507-in transport refrigeration, with the initial compliance date set for January 1, 2025[1]. Stakeholders have cited significant cost impacts, noting that retrofit expenses may exceed those of new system installations. They also highlight long lead times required for planning new facilities and refrigerated fleets[3].
The 2025 proposed reconsideration rule outlines substantial GWP limit adjustments for retail and cold storage sectors, such as an interim GWP of 1,400 from 2026 and eventual limits of 150 or 300 in 2032. Equivalent modifications for transport refrigeration are not yet specified[4]. The EPA has acknowledged petitions concerning transport refrigeration compliance dates and refrigerant availability, but as of the draft proposal, the January 1, 2025, compliance date remains unchanged[2].
Industry organizations have called for more transparent timelines and procurement certainty to prevent stranded inventory and ensure retrofit viability. Transport refrigeration typically involves longer deployment cycles and specialized service networks, increasing risks if refrigerant transitions occur without viable replacements. The proposed rule's adjustments for other sectors indicate EPA's willingness to consider these operational challenges, though transport-specific relief is still pending.
Outlook
The EPA is seeking further public comment on the proposed reconsideration rule, with final decisions anticipated by late 2025. The transport refrigeration sector is awaiting confirmation on possible deadline extensions or GWP limit modifications. These regulatory outcomes will shape equipment procurement, retrofit planning, service training, and supply chain strategies throughout the sector.
