Aqueous Fire Fighting Foam

An acronym for Aqueous Film Forming Foam. It is a highly efficient type of fire suppressant agent used to attack flammable liquid fuel fires. This concentrated liquid is mixed with water and dispersed using a proportioning nozzle. The foam forms spontaneously upon ejection from the nozzle. The AFFF coats the pool of hydrocarbon fuel with a layer of foam which acts like a thermal and evaporation barrier to inhibit and eventually extinguish combustion. The "film forming" characterisits refers to the fact that even after the foam has dissipated, the aqueous layer formed from the water and concentrate mixture can coat a liquid hydrocarbon surface.

An extinguishing agent designed to flow on a burning liquid.