Aqueous Film Forming Foam (AFFF) concentrate, is also known as "light water", is synthetic-based foam concentrate and it is produced by the fluorocarbon and hydrocarbon surfactants. An aqueous film will be formed to provide a vapor-suppressing seal which helps to separate oxygen from the fuel surface and extinguishing the fire rapidly.

Alcohol resistant aqueous film-forming foam extinguishing agent is made mainly of composite
surfactant, polar film-forming agent, cosolvent,
stabilizer, antifreeze agent, preservatives and
water.
Characteristics for film forming foam are that it spreads rapidly across a fire. As a result, it is highly effective against hydrocarbon fires. Adding special polymers ensures it is also highly effective against polar solvents.