Which federal agency regulates hazardous materials transportation in the United States?

• A. OSHA
• B. PHMSA (Pipeline and Hazardous Materials Safety Administration) under the Department of Transportation
• C. EPA
• D. NIST

Answer: (B)

Hazardous materials transportation is overseen at the federal level by the pipeline and hazardous materials safety administration, which is part of the department of transportation. This agency sets and enforces the Hazardous Materials Regulations that cover how hazmat must be classified, packaged, labeled, documented, and transported across all modes—truck, rail, air, and pipeline. It coordinates with other DOT offices for mode-specific rules, but it is the primary regulator for hazmat transport overall.

Other agencies handle different areas: occupational safety in the actual workplace is OSHA, environmental rules are EPA, and NIST focuses on standards and measurement—none of them regulate the transportation of hazardous materials as a primary function.