Which fire extinguisher agent is effective on both Class B and Class C fires?

The reason dry chemical extinguishers are effective against both Class B and Class C fires lies in their composition and how they function. Class B fires involve flammable liquids, such as gasoline, oil, or grease, while Class C fires involve electrical equipment. Dry chemical extinguishers typically use agents such as monoammonium phosphate or sodium bicarbonate, which work by interrupting the chemical reaction that fuels the fire.

For Class B fires, the dry chemical forms a barrier between the fuel and the fire, effectively smothering it and preventing re-ignition. In the case of Class C fires, since the agent is non-conductive, it can be applied safely on or near live electrical equipment, effectively extinguishing the fire without the risk of electrical shock.

In contrast, water, though effective for Class A fires, is not suitable for Class B or Class C fires due to the possibility of causing flammable liquids to spread or creating electrical hazards. Foam is primarily effective on Class B fires but is not recommended for electrical fires, as it can conduct electricity. Carbon dioxide is effective on Class B fires and can be used on Class C; however, its effectiveness may vary in certain situations depending on the fire's context and configuration. Therefore