A fire involving cooking fats in kitchens is classified as which fire class?

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

Answer: (D)

Fats and oils used in cooking burn differently from ordinary fuels, reaching very high temperatures and behaving in ways that require a specialized classification. In kitchens, fires involving cooking fats and oils are classified as Class K. This category exists specifically to address the hazards of cooking fats, including their tendency to reignite and to react violently if cooled or spread with inappropriate extinguishing agents. The recommended approach uses wet chemical extinguishing agents that saponify fats, creating a soapy layer that cools, smothers, and separates the fat from the air, reducing heat and preventing re-ignition. Water is dangerous on fat fires because it can cause the oil to splatter and spread the flame. Other classes cover different types of hazards: ordinary combustibles like wood and paper fall under Class A, flammable liquids under Class B, and energized electrical equipment under Class C. For kitchens, Class K is the correct designation because it targets the specific danger of cooking fats.