Which fire extinguishing agent is most effective for Class B fires?

Dry chemical agents are the most effective for Class B fires, which involve flammable liquids such as gasoline, oil, and solvents. These agents work by interrupting the chemical reaction of combustion, effectively suppressing the fire.

Dry chemical extinguishers often contain agents like monoammonium phosphate or sodium bicarbonate, which can quickly smother the flames and prevent re-ignition. They are particularly advantageous in these scenarios because they are versatile and can be used on other fire classes as well.

While foam agents can also be effective for Class B fires by suffocating the flames and forming a barrier between the fuel and the fire, their effectiveness can depend on the type of fuel and the surface area involved. Water is not suitable for Class B fires since it can cause the flames to spread by floating the burning liquid. Carbon dioxide extinguishers can be effective against Class B fires, especially in confined spaces, but they may not provide the same level of immediate and comprehensive suppression as dry chemical agents.