Generally, a flammable cargo restriction applies to trucks carrying hazardous material, not the everyday driver.

There is a code of regulations defining what constitutes as flammable cargo, but this generally applies to trucks transporting hazardous and flammable material, liquids and gas, like gasoline and ...

Extinguishment efforts were made difficult by stored materials including flammable liquids and gases determined to be gasoline, propane and oxy acetylene. These items intensified the fire.