What is the best extinguishing agent for a flammable liquid fire?

The best extinguishing agent for a flammable liquid fire is dry chemical. This is primarily because dry chemical agents, such as those containing monoammonium phosphate or sodium bicarbonate, are effective at interrupting the combustion process. They work by coating the fuel surface, displacing oxygen, and preventing the vapors from igniting. This makes them particularly effective for flammable liquids, which can produce hazardous vapors that ignite easily.

While carbon dioxide is also a viable option, it is more effective against class B fires when the area is well confined but may not provide sufficient cooling for larger surface areas of flammable liquids. Water is generally not suitable for flammable liquid fires because it can spread the fire, especially if the liquid is lighter than water—leading to further hazards. Foam agents can be effective but typically require proper application techniques and may not be as readily available as dry chemical extinguishers in many situations. Dry chemical extinguishers are more versatile and widely used in various environments where flammable liquids are present.