Question Before loading or unloading flammable liquids, the engine should be: Answers Turned off. Revved up. Left on. Explanation Unless you must run the engine to operate a pump, you should always turn off the engine before loading or unloading flammable liquids. This questions appears in the following tests: Arizona Tank Arkansas HazMat Iowa HazMat Maryland HazMat Missouri HazMat New Mexico HazMat New Mexico HazMat New Mexico Tank Oklahoma HazMat Oklahoma HazMat Utah HazMat Virginia HazMat Virginia HazMat