The agency that regulates the transportation of compressed and liquefied gases is the:

• A. U.S. Department of Transportation (DOT).
• B. Petroleum Tank Institute (PTI).
• C. National Transportation and Safety Board (NTSB).
• D. Environmental Protection Agency (EPA).

Answer: (A)

Regulation of transporting compressed and liquefied gases is handled by the Department of Transportation because it oversees hazardous materials shipments across all modes of travel. Within DOT, the PHMSA (Pipeline and Hazardous Materials Safety Administration) writes and enforces the rules for packaging, labeling, vehicle design, handling practices, routing, training, and emergency response for hazmat—including gases that are compressed or liquefied. The other agencies have different roles: the NTSB investigates accidents and issues safety recommendations, the EPA focuses on environmental protection, and the Petroleum Tank Institute is a trade organization rather than a regulator. So the Department of Transportation is the correct regulator.