Class B fires can be extinguished by shutting off the supply of fuel or by what method?

Class B fires involve flammable liquids and gases, which require specific methods for effective extinguishment. One effective approach is using foam to exclude the oxygen from the fire. Foam creates a blanket over the burning liquid, effectively smothering the fire by cutting off the necessary oxygen that fuels combustion. This method not only prevents the fire from reigniting but also suppresses the release of flammable vapors, ensuring a safer environment for both firefighters and bystanders.

While cooling the fuel and other methods may seem plausible, they are not the most effective strategies specifically for Class B fires. Foam is particularly advantageous because it both adheres to the fuel's surface and provides a barrier against oxygen, making it a crucial technique in firefighting for these types of fires.