Which extinguisher class is used for cooking oils?

• A. Class A
• B. Class B
• C. Class C
• D. Class K

Answer: (D)

Cooking oil fires involve fats and oils that burn at high temperatures and behave differently from ordinary combustibles or other liquids. The extinguisher designed for these fires is Class K, which uses a wet chemical agent that saponifies fats and oils. This reaction forms a soapy layer that cools the oil and creates a barrier between fuel and air, smothering the fire and helping prevent reignition. In kitchens, Class K extinguishers are preferred because they specifically address the unique properties of cooking fats and oils, while other classes target different hazards (ordinary combustibles, flammable liquids, or electrical equipment). Using water on a cooking oil fire can cause splattering and spread the fire, making non-K extinguishers ineffective for this scenario.