What is the primary function of Class B foam?

The primary function of Class B foam is to separate fuel from fire, which is essential in controlling flammable liquid fires. This type of foam forms a barrier between the burning fuel and the oxygen in the atmosphere, effectively smothering the flames and preventing the fire from reigniting. The foam also helps to suppress the vapor emissions from the fuel, further reducing the chance of explosive re-ignition.

By creating this insulating layer, Class B foam enables firefighters to suppress fires involving flammable liquids more efficiently than water alone, which may not adequately address the unique hazards presented by these types of fires. Therefore, understanding the primary function of Class B foam as a separation agent is crucial for effective fire suppression operations involving flammable and combustible liquids.