Which extinguishing agent is typically used for flammable liquid fires?

The use of foam as an extinguishing agent for flammable liquid fires is based on its ability to form a blanket over the surface of the burning liquid, effectively smothering the fire and cutting off the oxygen supply. Foam is particularly effective because it can encapsulate and cool the flammable liquid, preventing reignition. It is designed to float on top of the liquid, providing a barrier that suppresses vapors that could ignite, making it an excellent choice for fires involving liquids like oils and solvents.

While water is not appropriate for flammable liquid fires as it may spread the flames, dry chemical extinguishers work effectively but do not provide the same vapor suppression as foam. CO2 is also effective for certain types of fires, particularly those involving electrical equipment and flammable gases, but it does not provide the blanket effect that foam offers, which is critical when dealing with flammable liquids. Therefore, foam is the most suitable agent for tackling flammable liquid fires due to its unique properties and effectiveness in suppressing these types of hazardous situations.