Effective: Hazardous Materials: Adoption of Department of Transportation Special Permit 21379

The Pipeline and Hazardous Materials Safety Administration (PHMSA) has issued a final rule adopting the provisions of DOT Special Permit 21379 into the Hazardous Materials Regulations (HMR). This action streamlines the transportation of refrigerating machines containing low-flammability refrigerant gases, specifically Category 1B refrigerants under the Globally Harmonized System (GHS) or Group A2L refrigerants under ANSI/ASHRAE Standard 34. The rule allows for the transport of up to 5,000 lbs. of these refrigerants by highway and rail without the need for a special permit. This regulatory change is intended to support the transition away from certain hydrofluorocarbon (HFC) refrigerants as mandated by the American Innovation and Manufacturing (AIM) Act. By incorporating ANSI/ASHRAE Standard 34-2024 and the 9th Revised Edition of the GHS, PHMSA aims to align domestic regulations with modern technical standards and reduce the administrative burden on shippers and the agency. PHMSA received four sets of comments during the rulemaking process from organizations including ASHRAE and the Council on Safe Transportation of Hazardous Articles (COSTHA). While the rule is largely supportive of industry needs, PHMSA declined to expand the exception to air or vessel transportation at this time, citing a lack of experience with those modes. The rule is effective 30 days after its publication in the Federal Register.