What is an example of a Class B fire extinguisher?

A Class B fire primarily involves flammable liquids such as gasoline, oil, and other combustible liquids. Therefore, fire extinguishers specifically designed to combat these types of fires typically use agents that can effectively smother or eliminate oxygen to extinguish the flames.

The use of foam or dry chemical agents in extinguishers categorized as Class B is particularly effective because these agents create a barrier between the fuel and the fire, or interrupt the combustion process. Foam can spread over the surface of burning liquids, preventing the release of flammable vapors, while dry chemicals can disrupt the chemical reaction occurring during combustion.

This distinction is essential for firefighting practices since using the wrong type of extinguisher on a Class B fire can lead to increased severity of the fire or even exacerbate the situation. The other options, such as water-based extinguishers or those designated specifically for Class A fires, would not be as effective against Class B fires, as they can either fail to extinguish the flames or may cause the flammable liquid to spread.