Which method is commonly used to extinguish Class B fires?

The method commonly used to extinguish Class B fires involves excluding the oxygen from the fire triangle. Class B fires are fueled by flammable liquids and gases, which means they primarily involve substances like gasoline, oils, paints, and solvents. These types of fires can burn rapidly, and their flames can produce a significant amount of heat that can ignite additional fuel.

By excluding oxygen, which is one of the three elements needed for combustion (fuel, heat, and oxygen), it effectively smothers the flames and prevents them from continuing to burn. This is often accomplished by using fire suppression agents like foam, carbon dioxide, or dry chemical extinguishers, which cover the fuel surface, thus cutting off the oxygen supply.

In contrast, methods that focus on cooling the fuel or interrupting the chemical chain reaction may be more applicable to other classes of fires. For instance, cooling methods work well with Class A fires (ordinary combustibles) where water can effectively reduce the temperature of the fuel to below its ignition point. However, adding water to a Class B fire can sometimes be dangerous since it can spread the flames or create additional hazards due to steam expansion. Thus, the emphasis on excluding oxygen is particularly effective and crucial for safely managing and extinguishing Class B fires