When refueling a vehicle that contains hazardous materials: Question When refueling a vehicle that contains hazardous materials: Answers The engine should be left on. The engine should be turned off. The gas nozzle may be left unattended. No other vehicles should be at the refueling station. Explanation If you need to refuel a vehicle carrying hazardous materials, you must first turn off the engine. While refueling, someone must be at the nozzle and controlling the fuel flow at all times. This questions appears in the following tests: Alabama HazMat District Of Columbia HazMat Florida HazMat Indiana HazMat Indiana HazMat Mississippi Tank North Carolina HazMat West Virginia HazMat