The main purpose of Class K extinguishing systems is to handle fires of fats and oils in kitchens.

• A. To extinguish electrical fires
• B. To extinguish fires involving flammable liquids other than fats and oils
• C. To extinguish fires involving fats and oils in kitchens
• D. To extinguish any class of fire

Answer: (C)

Class K systems are designed specifically for fires that involve fats and oils in commercial kitchens. The key is the wet chemical extinguishing agent, typically potassium acetate, which reacts with fats to saponify them—creating a soapy, emulsified layer that cools, smothers the flames, and prevents re-ignition. This approach is tailored to high-fat cooking environments, often integrated with the kitchen’s hood and ductwork to address fires in both pans and ducts. Because this mechanism targets cooking-oil fires, it’s not used for electrical fires or for other flammable liquids, and it isn’t appropriate for fires of every class. So the main purpose is to extinguish fires involving fats and oils in kitchens.