What characteristic defines a Class B fire?

A Class B fire is primarily characterized by the involvement of flammable liquids, gases, or greases. This includes substances such as gasoline, oil, solvents, and paints, all of which can ignite and cause a fire that spreads rapidly. Under this classification, the handling of Class B fires requires specific types of extinguishing agents, like foam, dry chemical, or carbon dioxide, which are effective in smothering the flames and preventing re-ignition.

Understanding this classification is critical, especially in fire safety training, because the strategies for extinguishing a Class B fire differ from those for other classes, such as Class A, which focuses on ordinary combustibles like paper and wood, or Class C, which involves energized electrical equipment. Each class has its unique hazards and requires tailored approaches for effective fire management.