Fire control

fires are classified as Class-A, Class-B, Class-C, Class-D, and Class-K; different classifications may exist in other countries.

[7] This class of fire can be started as a lightning strike that hits a tree or from a backyard campfire that releases an ash that ignites nearby material.

The most common method to control a Class-A fire is to remove heat by spraying the burning solid fuels with water.

Many Class B fires (hydrocarbons, petroleum, and similar fuels) cannot be efficiently controlled with water because fuels with a density less than water (such as gasoline or oil) float on top, resulting in the fire continuing to burn.

In addition, the heat of an intense fire may cause water to flash into steam in an explosion which can spread the flaming fuel more widely.

The configuration of some fuels, such as coal and baled waste paper, may result in a deep-seated and burrowing fire, resulting in less effective fire control by the application of water on the outer surfaces of the fuel.

Applying a combination of fire suppressant foam mixed with water is a common and effective method of forming a blanket on top of the liquid fuel, which eliminates the oxygen needed for combustion.

[8] Class-D fires include combustible or pyrophoric metals, such as potassium, uranium, sodium, lithium, calcium, and plutonium.

The main purpose for ventilating a fire is to decrease the likelihood of a flashover from occurring.