What is the primary function of a power extinguisher?

The primary function of a power extinguisher is to stop the chemical reaction that fuels the fire. Fire requires three elements to sustain itself: fuel, heat, and an oxidizing agent such as oxygen. A power extinguisher, often containing a dry chemical agent, works by interrupting this chemical chain reaction. The agent effectively coats the fuel, preventing it from releasing the vapors needed to sustain combustion.

While cooling the burning material can be an effective way to extinguish certain types of fires, and smothering a fire helps to eliminate the oxygen component, the distinguishing characteristic of a power extinguisher is its ability to disrupt the chemical process directly. This makes it particularly effective in various fire scenarios, especially those involving flammable liquids and gases where the fire might be more rapidly spreading.