Which of the following is permissible as fuel in an acquired live burn training structure?

• A. Natural gas
• B. Propane
• C. Diesel fuel
• D. None of these are correct

Answer: (D)

In an acquired live burn training structure, the fuel source must be controlled and designed specifically for training. NFPA 1403 requires fuels to be supplied by a listed, training-fuel system that’s part of the burn prop and managed under a formal burn plan. Using common fuels like natural gas, propane, or diesel inside an acquired structure introduces hazards that can’t be reliably controlled in an unknown, real-building environment: gas fuels can leak and ignite unpredictably, and liquid fuels can produce heavy smoke, pooling, and toxic byproducts that complicate suppression and rescue exercises. Because the standard calls for a controlled, approved fuel system rather than general-use fuels inside the structure, none of these options are permissible.