Class K combustible cooking media fires typically involve kitchen appliances containing quantities of cooking greases or oils that present special hazard extinguishment and re-flash concerns. Only extinguishing agents having the ability to saponify and create a thick, heavy, long-lasting type of foam blanket upon the hot cooking media surface seal out the oxygen, cool the cooking media, and keep these fire situations out. The Class K listed fire extinguishers have effectively demonstrated the ability to address these commercial kitchen types of fire hazard situations.

Class K fires are fires in cooking appliances that involve combustible cooking media (vegetable or animal oils and fats). Fire extinguishers for the protection of Class K hazards shall be selected from types that are specifically listed and labeled for use on Class K fires.

Existing dry chemical extinguishers without a Class K listing that were installed for the protection of Class K hazards shall be replaced with an extinguisher having a Class K listing when the dry chemical extinguishers become due for either a 6-year maintenance or hydrostatic test. Class K fire extinguishers shall be provided for hazards where there is a potential for fires involving combustible cooking media (vegetable or animal oils and fats).

Maximum travel distance shall not exceed 30 ft (9.15 m) from the hazard to the extinguishers.