What They Are and How They Work
Class K fire extinguishers are designed to combat kitchen fires fueled by cooking oils, fats, and greases. They use extinguishing agents that separate the fuel from oxygen and absorb heat elements of the fire triangle. These extinguishers work through a chemical reaction called saponification. This occurs when alkaline mixtures contact with fat or cooking oil, extinguishing flames completely. They create a blanket over the cooking grease to cool, block oxygen, and smother flames.
Systems and Usage
Wet chemical systems and Class K extinguishers both have a role. The system activates automatically over cooking equipment, shutting off fuel sources and dispensing agent. If a fire starts beyond system coverage, a portable Class K extinguisher is the only suppression option. Class K extinguishers supplement these systems and are better for such fires than multi-purpose ABC extinguishers.
Difference Between Class F and Class K
Class K fire extinguishers are similar to Class F, which are used in Europe and Australia. Both are intended for fires involving cooking fats and oils. The specific standards and formulations might differ slightly, but the purpose is largely the same—to fight kitchen fires effectively.
Can you use CO2 extinguisher for Class K fire?
No, CO2 extinguishers are not effective for Class K fires. Class K extinguishers use wet chemical agents for a greater firefighting and cooling effect on this type of hazard, as per the National Fire Protection Association NFPA 10 – Standard for Portable Fire Extinguishers.