US EPA proposes YF for buses and heavy vehicles, lists potential retrofits

The United States Environmental Protection Agency (EPA) has released proposed Significant New Alternatives Policy (SNAP) Rule 27, expanding the list of acceptable refrigerants for motor vehicle air-conditioning (MVAC) systems, including R1234yf for buses and heavy-duty vehicles, plus the addition of R444A, R456A, R452A, R480A and R1234yf as acceptable retrofits in certain applications.

Mobile Air Climate Systems Association (MACS) director of training and regulatory affairs Steve Schaeber said the rule proposes to list several substitutes as acceptable, subject to use conditions, in the refrigeration and air-conditioning sector.

“For motor vehicle air-conditioning, EPA proposes to list HFO-1234yf as acceptable in MVAC in new buses and heavy-duty on-highway vehicles,” Mr Schaeber said.

“It also proposes to list a number of refrigerant blends as acceptable as retrofits in certain MVAC applications, including R444A, R456A, R452A, R-480A and R1234yf.”

The proposed rule also updates use conditions for multiple refrigerants and includes two options related to equipment certification or industry safety standard requirements.

If accepted, these changes will impact manufacturers and air-conditioning workshops, as well as the broader automotive, transport and refrigeration sectors.

Although still in its proposal stage, the rule signals a clear shift toward reducing refrigerant emissions with potential global implications.

The EPA has released a detailed fact sheet and a 176-page pre-publication document containing the full proposal and technical details, available on the agency’s official website.