Which class of fire extinguisher is used for kitchen grease fires?

• A. Water
• B. Foam
• C. ABC
• D. K

Answer: (D)

Grease fires from cooking oils need an extinguisher designed for fats and oils. The Class K extinguisher uses a wet chemical agent (potassium acetate) that saponifies fats, turning the oil into a soapy layer. This layer cools the oil, smothers the flame, and helps prevent re-ignition. It’s specifically formulated for kitchen cooking media found in commercial kitchens, where oil fires are common.

Water extinguishers are dangerous on hot oil because the water can rapidly turn to steam and cause the oil to splatter and flare up. Foam and multi-purpose ABC extinguishers aren’t optimized for lipid fires and can spread the oil or fail to stop re-ignition. So, the best choice for kitchen grease fires is a Class K extinguisher.