Summary of Changes for Hazardous Materials 49 CFR Parts 100 — 185This is the most Up-To-Date DOT HAZMAT regulatory book available. The March 2024 edition of PHMSA's HazMat regulations includes updates published through March 15, 2024, including HM-219D. These changes include the following:

(a) Flexible packaging options for compressed natural gas, streamlined approval processes for cylinder repairs, and clearer filling requirements for hydrogen transport.

(b) Harmonization of U.S. regulations with international standards, particularly in the shipment of minimal amounts of poisonous substances, and simplifies hazard communication by introducing specific markings for compliance and exceptions for lithium battery shipments.

(c) Updates to definitions and incorporates by reference important documents from the Compressed Gas Association (CGA) and the Institute of Makers of Explosives (IME), facilitating the adoption of modern practices such as ultrasonic examination for cylinder requalification.