Class K fires involve cooking oils and fats, which are highly combustible and can ignite quickly at high temperatures. To suppress a Class K fire, a specific type of extinguishing agent is required that can separate and absorb the heat elements of the fire - the fuel, oxygen, and heat necessary to start a fire. Foam extinguishers are most suitable for Class K fires because they use a substance that turns oils into foam, effectively smothering the fire and preventing re-ignition. Water should not be used on Class K fires as it can cause the oil to splatter and spread the fire. Carbon dioxide and dry chemical extinguishers are also not recommended for Class K fires as they do not adequately remove the heat from the fire.
References: The information provided is based on standard fire safety guidelines and classifications for fire types, particularly for Class K fires involving cooking media such as oils and fats12.