Class K extinguishers are designed for fires involving which substances?

Class K extinguishers are designed for fires involving which substances?

• A. Flammable Liquids
• B. Electrical Equipment
• C. Ordinary Combustibles
• D. Cooking, Greases, Fats, Oils

Answer: (D)

Fires involving cooking greases and oils require a specialized extinguisher because these fuels behave very differently from ordinary combustibles or other liquids. Class K extinguishers use a wet chemical agent (potassium acetate) that saponifies fats and oils when it contacts moisture on the surface. This creates a soapy layer that blankets the oil, rapidly cools it, and forms a barrier that helps prevent reignition. That specific action makes Class K ideal for fires in commercial kitchens rather than fires involving ordinary combustibles, flammable liquids like fuels, or energized electrical equipment.

Fires involving cooking greases and oils require a specialized extinguisher because these fuels behave very differently from ordinary combustibles or other liquids. Class K extinguishers use a wet chemical agent (potassium acetate) that saponifies fats and oils when it contacts moisture on the surface. This creates a soapy layer that blankets the oil, rapidly cools it, and forms a barrier that helps prevent reignition. That specific action makes Class K ideal for fires in commercial kitchens rather than fires involving ordinary combustibles, flammable liquids like fuels, or energized electrical equipment.