When should firefighting foam be applied?

Firefighting foam is specifically designed to combat liquid fuel fires by smothering the flames and preventing the release of flammable vapors. When applied to a liquid fire, the foam forms a blanket over the surface, interrupting the combustion process and effectively extinguishing the fire. This application is crucial because liquid fuel fires can spread rapidly and are more challenging to control due to the flammable nature of the fuel.

While foam can be effective in certain scenarios involving solid materials, it is primarily formulated for use on flammable liquids. Additionally, applying foam during uncontained fire scenarios or when the fire is supposedly under complete control would not leverage its unique properties effectively, as it is most beneficial when the liquid fuel fire is active and potentially spreading.