The term “tank car” is used frequently in the USDOT/PHMSA Hazardous Materials Regulations (HMR) though not clearly defined there.

The term “rail tank car” is not found in the HMR at all though it is often used by the rail industry to indicate its use for rail transport.

The term “rail car” is defined in the HMR and that is where our answer to this FAQ begins.

Rail car is defined at 49 CFR 171.8:

Rail car means a car designed to carry freight or non-passenger personnel by rail, and includes a box car, flat car, gondola car, hopper car, tank car, and occupied caboose.

So…

• A rail car is designed to carry freight or people by rail.
• It includes, but is not limited to the following:
  • Box car
  • Flat car
  • Gondola car
  • Hopper car
  • Tank car
  • Occupied caboose.
• That means that a tank car is a type of rail car.

The term tank car is used throughout the HMR regarding the transport of HazMat by rail, including:

• §173.10 Tank car shipments
• §173.31 Use of tank cars
• §174.67 Tank car unloading
• The specifications for tank cars are found at part 179 of Title 49 of the CFR.
• More…

Also, tank car is included in the definition of a transport vehicle at §171.8:

Transport vehicle means a cargo-carrying vehicle such as an automobile, van, tractor, truck, semitrailer, tank car or rail car used for the transportation of cargo by any mode. Each cargo-carrying body (trailer, rail car, etc.) is a separate transport vehicle.

Though not clearly defined in the HMR, a tank car is a type of transport vehicle used for the transport of freight – including hazardous materials – and non-passenger personnel by rail.

If you ship or receive HazMat by rail your HazMat Employee training must include the function specific responsibilities unique to those activities.  Contact me to provide you with that training.