Class K extinguishers are specifically intended to suppress what type of fires?

• A. Electrical panel fires
• B. Fires involving cooking oils and fats, such as those from deep fat fryers, ranges, and woks.
• C. Paper and upholstery fires
• D. Metal fires

Answer: (B)

Class K extinguishers are designed for fires that involve cooking oils and fats, such as those from deep fat fryers, ranges, and woks in commercial kitchens. Cooking oil fires are dangerous because oil can reach very high temperatures and water-based agents can cause the oil to splatter or flare up. The wet chemical agent in Class K extinguishers reacts with fats to form a soapy layer that saponifies the oil, cooling the surface and creating a barrier between the fuel and the air, which helps prevent reignition. This specialized approach is necessary specifically for kitchen grease fires, unlike fires from ordinary combustibles, electrical equipment, or metals, which require different types of extinguishing agents.