Hazardous Materials: Adoption of Department of Transportation Special Permit 21379

Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Department of Transportation Pipeline and Hazardous Materials Safety Administration 49 CFR Parts 171 and 173 [Docket No. PHMSA-2025-0102 (HM-268N)] RIN 2137-AG16 AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: This final rule removes undue regulatory burdens by adopting the provisions of U.S. Department of Transportation (DOT) special permit (SP) 21379 to streamline the transportation of refrigerating machines and components containing certain low flammability refrigerant gases. DATES: Effective date: This final rule is effective September 3, 2026. Incorporation by reference date: The incorporation by reference of certain material listed in this rule is approved by the Director of the Federal Register as of September 3, 2026. The incorporation by reference of certain other material listed in the rule was approved by the Director of the Federal Register as of January 1, 2004 and December 28, 2020. FOR FURTHER INFORMATION CONTACT: Candace Casey, Standards and Rulemaking Division, Pipeline and Hazardous Materials Safety Administration (PHMSA), 1200 New Jersey Avenue SE, Washington, DC 20590, 202-366-8553, candace.casey@dot.gov . I. PHMSA Action A. What action is PHMSA taking in this final rule? PHMSA is adopting the provisions of DOT SP 21379 into the Hazardous Materials Regulations (HMR; 49 CFR parts 171-180 ) by revising 49 CFR 173.306 to streamline the transportation of refrigerating mach…