Fire control

Fire control is the practice of reducing the heat output of a fire, reducing the area over which the fire exists, or suppressing or extinguishing the fire by depriving it of fuel, oxygen, or heat (see fire triangle).

The classification below relates to the United States of America. Different classifications exist in other countries.

The most common method to control a class-A fire is to remove heat by spraying the burning solid fuels with water. Another method of controlling a class-A fire would be to reduce the oxygen content of the atmosphere in the immediate vicinity of the fire (i.e., "smother" the fire), such as by the introduction of an inert gas such as carbon dioxide.

In a wildfire, fire control includes various wildland fire suppression techniques such as defensible space, widening the fuel ladder, and removing fuel in the fire's path with firebreaks and backfires to minimize the brush fire reaching new combustible fuel and spreading further.

Some Class B fires (hydrocarbons, petroleums, and fuels on fire) cannot be efficiently controlled with water. Fuels with a specific gravity less than water, such as gasoline or oil, float on water, resulting in the fire continuing in the fuel on top of the water. The application of 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.The configuration of some fuels, such as coal and baled waste paper, 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.

Some Class-B fires can be controlled with the application of chemical fire suppressants.

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