Diesel engines are a potential source of ignition when used in areas where combustible gas, vapors, or vapor dust may exist, sometimes leading to catastrophic consequences for personnel, production facilities and the environment. Various industry regulatory agencies in several countries have therefore established regulations for their industries requiring air intake shutoff devices on diesel engines.

Diesel engine speed is governed by controlling the amount of fuel fed to the engine through its fuel system and internal speed governor. If a flammable material is drawn into the air intake system of a diesel engine it acts as an additional ungoverned fuel supply. This additional fuel source can cause the diesel engine to accelerate or overspeed out of control. This condition is referred to as diesel engine runaway. The result of a diesel engine runaway can range from engine damage to a catastrophic explosion.