Pipeline and Hazardous Materials Safety Administration PHMSA

Federal pipeline safety regulation began with the Natural Gas Pipeline Safety Act of 1968, and the Hazardous Materials Transportation Act of 1975 set national rules for shipping dangerous goods. For decades both were handled by the Transportation Department's Research and Special Programs Administration. A 2004 law created the Pipeline and Hazardous Materials Safety Administration as a dedicated safety agency, led by an Administrator confirmed by the Senate.

PHMSA sets safety standards for more than three million miles of natural gas and hazardous liquid pipelines, along with liquefied natural gas facilities, and inspects interstate lines while certified state agencies inspect most pipelines within their borders. It also writes the hazardous materials regulations that govern how chemicals, fuels, explosives, and batteries are classified, packaged, labeled, and shipped by road, rail, air, and water, and trains emergency responders.

Pipeline accidents such as the September 9, 2010, natural gas explosion in San Bruno, California, which killed eight people, and an oil spill into Michigan's Kalamazoo River that summer drove new rules on inspection and leak detection. Newer issues include pipelines carrying carbon dioxide for storage and hydrogen, and methane leaks. In 2025 the agency began reviewing many existing rules for possible repeal. Industry groups said outdated requirements raised costs without improving safety, while safety advocates and communities near pipelines warned against weakening protections.