Which chemical is often found in a Class K extinguisher?

A Class K extinguisher is specifically designed to tackle fires that involve cooking oils and fats, typified by those found in commercial kitchens. Potassium acetate is the key chemical in these extinguishers. This agent works effectively to combat high-temperature fires associated with cooking oils, as it helps form a soapy film on the surface of the burning oil, effectively smothering the flames and preventing re-ignition.

The effectiveness of potassium acetate in extinguishing Class K fires is a critical aspect of its design, as it is formulated to handle the unique challenges posed by cooking-related fires. This characteristic makes it the preferred choice for environments where deep-frying and other cooking methods using oils and fats are prevalent. The other chemicals listed, while useful in different contexts—such as sodium chloride for general fires, carbon dioxide for electrical fires, and halon for specific suppression in sensitive areas—do not address the unique fire hazards presented by cooking oils and fats.