What type of foam is used for combating flammable liquid fires?

Aqueous Film Forming Foam (AFFF) is specifically designed to combat flammable liquid fires, making it the most suitable choice in this scenario. AFFF works by creating a film that spreads over the surface of the burning liquid, effectively smothering the fire and preventing oxygen from reaching the flames. This film also forms a barrier that suppresses the release of flammable vapors, significantly reducing the chances of re-ignition.

The effectiveness of AFFF lies in its ability to adhere to the surface of flammable liquids, providing a rapid knockdown of flames. This is particularly important in incidents involving hydrocarbons, such as gasoline or oil, where traditional extinguishing agents may not be as effective.

The other options, while useful in various firefighting scenarios, do not specifically target flammable liquid fires in the same way AFFF does. Dry chemical agents are good for a range of different fires but do not chemically interact with the flammable hydrocarbons to create a suppressive film. Carbon dioxide is effective for flammable gas fires but lacks the ability to cover a liquid surface. Water mist can cool and suppress fires but may not be effective for certain classes of flammable liquids as it can cause the fire to spread instead of suppressing