Which scenario is a typical use case for a Class K extinguisher?

• A. Electrical panel fires
• B. Fires involving cooking oils and fats in commercial kitchens
• C. Wood and paper fires
• D. Vehicle fuel fires

Answer: (B)

Cooking-oil and fat fires in commercial kitchens pose a unique hazard because oils can react violently with water and reach very high temperatures. A Class K extinguisher is specifically designed for these conditions. It uses a wet chemical agent (potassium acetate) that saponifies fats, turning the oil into a soapy layer. This layer cools the oil, smothers the flames, and helps prevent reignition by sealing the surface from air. It’s most effective around deep-fat fryers, ranges, and other cooking equipment where oils are heated. Using water or a standard ABC extinguisher on oil fires can cause the oil to splatter or spread and may not cool the oil enough to stop the flame. So fires involving cooking oils and fats in commercial kitchens are exactly where a Class K extinguisher is typically used.