The unique extinguishing action of Aqueous Film Forming Foam (AFFF) is its what?

The unique extinguishing action of Aqueous Film Forming Foam (AFFF) lies primarily in its foam blanketing and penetrating abilities. AFFF creates a thin film that spreads over the surface of flammable liquids, effectively sealing off the fuel from the atmosphere and significantly reducing the release of flammable vapors. This film also aids in cooling the surface, helping to suppress flames and prevent re-ignition.

While the self-sealing characteristic of AFFF is valuable in certain situations, it is the combination of its foam blanketing and its ability to penetrate burning fuels that underpins its effectiveness as a firefighting agent for Class B fires, particularly those involving hydrocarbons. This distinguishes AFFF from other extinguishing agents and highlights its critical role in airport firefighting scenarios, where rapid and effective suppression of fuel fires is essential.