What is a Class B fire extinguisher primarily used for?

A Class B fire extinguisher is primarily designed to extinguish fires that involve flammable liquids, such as gasoline, oil, grease, and solvents. These types of fires are characterized by their ability to spread rapidly and are often fueled by liquids that can ignite easily. The agents within a Class B extinguisher, like foam or dry chemical, work by creating a barrier between the burning material and the oxygen in the air, effectively suffocating the flames and preventing re-ignition.

This extinguishing capability is essential for dealing with fires in environments where flammable liquids are present, such as garages or service stations. Understanding the specific use of each class of extinguisher is crucial for effective fire safety. While other classes are designated for different types of fires—such as electrical (Class C), flammable metals (Class D), and ordinary combustibles like paper and wood (Class A)—the Class B extinguisher’s unique formulation makes it particularly effective at handling liquid fires without the risk of spreading the flames or causing explosions.