The PHMSA is responsible for writing and maintaining the hazardous materials regulations. Title 49 Parts 171 through 175 of the Code of Federal Regulations (CFR) stipulate the guidelines for transporting hazardous materials (hazmat). The regulations address transport by highway, rail, vessel and air.
The DOT has the authority to designate a material as hazardous. In doing so, the agency will assign the material to one of 9 hazard classifications. The classes are defined as follows: Class 1 explosives, Class 2 gases, Class 3 flammable liquids, Class 4 flammable solids, Class 5 oxidizers and oxidized peroxides, Class 6 poisons and infectious materials, Class 7 radioactive materials, Class 8 corrosive materials and Class 9 miscellaneous hazard.
Title 49 CFR 177.834 provides the general requirements of loading and storing hazardous materials that are transported by truck. 177.834(a) requires the following hazardous material containers to be secured to prevent them from moving during transit: flammable liquids, gases, corrosives, poisonous and radioactive. 177.834(c) states that smoking is not allowed when loading and unloading the following hazardous materials: explosives, flammable liquid, flammable solid, oxidizers, flammable gas. 177.834(d) forbids fire of any type while in or around the transport vehicle. The Federal Highway Administration is responsible for enforcing regulations for hazardous materials that are transported over the nation's highways.
Title 49 CFR 174.55 addresses the general handling and loading requirements when hazardous materials are shipped by rail. Additional subparts provide additional details for the following hazardous material classifications: Class 1 explosives (Subpart E), Class 2 gases (Subpart F), Class 3 flammable liquids (Subpart G) and Class 7 radioactive materials (Subpart K). 174.55(a) requires a manner of loading that prevents the freight from falling or sliding. Bracing may be used if needed. The regulations for shipping hazardous materials by rail are enforced by the Federal Railroad Administration.
Hazardous material enforcement for vessels is delegated to the United States Coast Guard. Title 49 CFR 176.57(a) allows hazardous materials to be on board a vessel if the materials are under the direct supervision and observation of an assigned person. The assigned person must be an officer if the vessel is traveling out of the jurisdiction of the United States.
Title 49 CFR 175.25 stipulates the notification text and the physical characteristics of the notification sign for passengers that plan to fly aboard an airplane. The notification includes notification that the passenger is permitted to board with small amounts of the specified materials for medicinal and personal use. The Federal Aviation Administration enforces the regulations for passenger and cargo flights.
