What is the main function of dry chemical extinguishers?

Dry chemical extinguishers primarily work by interrupting the chemical reactions that are taking place during a fire. They release a fine powder, typically composed of agents such as sodium bicarbonate, potassium bicarbonate, or monoammonium phosphate, which act by coating the fuel and preventing the fire from receiving the oxygen it needs to sustain combustion. This interruption of the fire's chemical reaction effectively extinguishes the flames and prevents re-ignition.

Understanding this function is crucial, as it defines the effectiveness of dry chemical extinguishers in a variety of fire scenarios, especially those involving flammable liquids and electrical fires. The mechanism is distinctly different from simply cooling the area, smothering flames, or dispersing fumes, as those functions are characteristic of other types of extinguishing agents or methods.