Which extinguisher category is specifically designed for cooking oil and fat fires?

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

Answer: (C)

Fires involving cooking oils and fats behave differently from other fuel fires, so they need a specialized extinguisher. A Class K extinguisher uses a wet chemical agent that reacts with fats to form a soapy, emulsified layer on the surface. This saponification cools the oil and creates a barrier between the fuel and the flame, effectively smothering the fire and reducing the chance of reignition. The agent is specifically formulated for high-temperature cooking media like vegetable oil and animal fats found in commercial kitchens, where these fires are most likely.

Why this is the best fit: it’s designed for the unique properties of cooking fats, addressing both the heat and the oily layer that sustain such fires. Other extinguisher types are not tailored for fats—one type targets ordinary combustibles like wood, paper, and textiles; another targets flammable liquids in general but can cause splashing or fail to suppress the oil’s heat, and a third is for electrical equipment. In a kitchen scenario, using the proper Class K system provides the most effective control with less risk of spreading hot oil or reigniting.