Foam Fire Extinguishing System used in fire protection is an aggregate of air-filled bubbles formed from aqueous solutions, and is of lower density than the lightest flammable liquids. It is mainly used to form a coherent floating blanket on flammable and combustible liquids to prevent or extinguish fires by excluding air and cooling the fuel. It then prevents re-ignition by suppressing the formation of flammable vapours, and also adheres to surfaces, providing a degree of exposure protection from adjacent fires.