What primary function do Class B extinguishers serve?

Class B extinguishers are specifically designed to combat flammable liquid fires such as gasoline, oil, and grease. The primary function of these extinguishers is to deprive the fire of oxygen, which is essential for combustion.

When activated, Class B extinguishers typically use a smothering agent that creates a barrier between the fuel and the surrounding air, effectively cutting off the fire’s oxygen supply. This action is crucial because, without sufficient oxygen, the flames cannot sustain themselves, leading to the extinguishment of the fire.

This distinct method of operation distinguishes Class B extinguishers from those designed for other types of fires, which may focus on cooling down the flames or providing barriers without primarily addressing the oxygen component of combustion.