What is the main feature of a wet chemical extinguisher?

The main feature of a wet chemical extinguisher is that it specifically cools and suppresses fires involving cooking oils and fats, which are categorized as Class K fires. Wet chemical extinguishers employ a potassium-based solution that not only cools the flames but also forms a soapy layer on the surface of the burning oil, effectively preventing re-ignition. This mechanism is crucial in kitchen environments where cooking oils can reach high temperatures and be challenging to extinguish with conventional methods.

In contrast, creating a foam barrier is characteristic of foam extinguishers, which are designed for Class B fires involving flammable liquids but are not suitable for deep-fat fryer incidents where wet chemical extinguishers are necessary. Displacing oxygen pertains to CO2 extinguishers, which are effective in certain scenarios but do not address the needs of cooking oil fires specifically. The option of using water to cool all types of fires is misleading, as water should not be used on oil fires due to the risk of splashing and spreading the fire; hence, it is critical to understand the specialized application of wet chemical extinguishers in culinary settings.