Which class involves cooking oils and fats?

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

Answer: (D)

Fires involving cooking oils and fats require a special approach because oils burn at high temperatures and can splash or reignite if treated with the wrong agent. The class designed for this scenario uses a wet chemical extinguishing agent that saponifies fats—potassium acetate-based solutions form a soapy layer on the oil. This layer cools, smothers the fire, and helps prevent re-ignition, which is why it’s specifically labeled for kitchen grease fires. Water-based extinguishers would just cause the oil to splatter and spread the fire, and the other classes cover different fuel types (ordinary combustibles, flammable liquids, or electrical) without addressing oil-specific behavior. So, the correct choice is the class developed for cooking oils and fats.