What materials are primarily used to extinguish Class K fires?

Class K fires, which are primarily caused by cooking oils and fats, typically occur in commercial kitchens and other environments where these materials are used. The best method for extinguishing these types of fires involves using specialized extinguishing agents that are effective on high-temperature cooking media.

The correct choice focuses on the very substances that fuel these fires—cooking oils and fats. In a fire involving these materials, it's critical to use agents specifically designed for this class of fire, such as wet chemical extinguishing agents that can effectively cool the burning oil and create a barrier to prevent re-ignition.

It's worth noting that water, foam, dry chemicals, and carbon dioxide are generally not effective against Class K fires. For example, using water can cause the burning oil to splatter and spread the fire, while foam and dry chemicals do not adequately cool the oils, and carbon dioxide may not penetrate the oil well enough to extinguish the flames effectively. Therefore, the optimal response to a Class K fire is indeed focused on the substances that are directly involved in creating the hazard.