Which process do Class K extinguishers utilize to extinguish fires?

Class K extinguishers are specifically designed for kitchen fires that typically involve cooking oils and fats. The correct process they utilize to extinguish these fires is saponification. This occurs when the extinguisher's agent, which is usually a potassium-based solution, interacts with the fats and oils in the fire, causing a chemical reaction that converts the burning material into soap (saponification). This reaction not only helps to put out the fire by cooling the burning oils but also creates a barrier that prevents re-ignition.

In contrast, cooling is a method used by water-based extinguishing agents to lower the temperature of the fire and bring it below the ignition point. Chemical inhibition refers to interrupting the combustion process by disrupting the chemical reactions occurring in flames, which is a mechanism used in some dry chemical extinguishers. Smothering deprives the fire of oxygen, but this is not the primary mechanism for Class K extinguishers. Thus, saponification is unique to Class K extinguishers and is essential for effectively extinguishing kitchen fires involving oils and fats.