Which extinguishing agent is approved for use in a Class K system?

The appropriate extinguishing agent for a Class K system is wet chemical. Class K fires typically involve cooking oils and fats, often found in commercial kitchens. This type of fire requires specific types of extinguishing agents that can effectively cool and suppress the flames while also preventing re-ignition.

Wet chemical extinguishers contain a specialized solution that not only puts out the fire but also creates a layer of foam on the surface of the burning oil, which helps to smother the fire and minimizes the risk of flare-ups. This chemical reaction is particularly effective for high-temperature cooking oils which can reach temperatures that ordinary extinguishers may not adequately control.

The other agents mentioned, such as aqueous film-forming foam, dry chemical, and carbon dioxide, are not designed for the unique challenges posed by Class K fires. Aqueous film-forming foam is suitable for flammable liquid fires, dry chemical is effective on many types of fires but does not provide the cooling effect necessary for cooking oil fires, and carbon dioxide lacks the ability to prevent re-ignition of hot oils. Therefore, wet chemical is the distinct and effective choice for extinguishing agents in Class K fire scenarios.