Which class includes combustible cooking oils and fats?

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

Answer: (C)

Fires involving cooking oils and fats require a classification that reflects their high heat and the way fatty films behave on surfaces. Class K is specifically for cooking media like vegetable oils and animal fats used in deep-fat fryers. These fires respond best to a wet chemical extinguishing agent, which saponifies the fats (turns them into a soapy layer) and cools the oil, creating a barrier to reignition. Water is dangerous here because it can cause the oil to splatter and spread the fire. So, for combustible cooking oils and fats, Class K is the correct category. The other classes cover different fuels—ordinary combustibles, flammable liquids, or metals—and do not address the unique properties of cooking-oil fires.