Class B fires involving flammable and combustible liquids are typically extinguished through which action?

Class B fires, which involve flammable and combustible liquids, are best extinguished primarily through smothering. This method works by depriving the fire of oxygen, which is essential for combustion. When a Class B fire occurs, using materials such as foam, carbon dioxide, or dry chemical agents helps cover the fuel and create a barrier that separates it from the oxygen in the air. By limiting the available oxygen, the fire can be extinguished effectively.

Cooling can also play a role in fire suppression, but it is more relevant for solid materials, as Class B fires are more concerned with the vaporization of the liquid fuel and its ignition. Dilution may not be effective for all types of flammable liquids, as it can sometimes spread the fire further. Displacement, while useful in specific contexts, does not apply directly to the extinguishing action required for Class B fires in the way that smothering does. Thus, the focus on smothering accurately reflects the most effective strategy for dealing with these types of fires.