Which fire extinguisher agents are most effective for Class B fires?

The most effective fire extinguisher agents for Class B fires, which involve flammable liquids such as grease, oil, gasoline, and solvents, are dry chemical and foam.

Dry chemical extinguishers work by interrupting the chemical reaction of the fire, making them highly effective against flammable liquid fires. They are versatile and can be used on various types of combustible materials, specifically designed to handle Class B fires. Foam extinguishers, on the other hand, act by forming a blanket over the burning liquid, which prevents oxygen from reaching the fire and cools the flames. Foam is particularly effective for smothering flammable liquid fires and preventing re-ignition.

In contrast, water and CO2 are less effective for Class B fires. While CO2 extinguishers can be employed for Class B fires in some circumstances, they are not as effective as dry chemical agents because they do not cool the burning liquids, which might lead to re-ignition. Although water can be used in some situations for cooling purposes, it is generally not advised for Class B fires, especially with flammable liquids, since it can spread the fire.

Wet chemical extinguishers are primarily designed for Class K fires (cooking oils and fats) and