Fire can be extinguished if any one of the three components necessary for an outbreak to occur is removed. Three basic methods are employed:
- Removal of heat (Cooling)
Water is most commonly used for cooling a fire. It has the greatest heat absorbing properties of all liquids. If the rate of heat produced by the fire is lower than the rate of heat absorbed, the fire will go out.To sum up: Cooling by water will extinguish a fire by absorbing more heat than the fire is generating.
- Removal of Fuel (Starving)
A fire will go out if deprived of its fuel supply.
A fire caused by a gas leak can be extinguished by turning off the supply of gas.
Division or removal of items can starve a fire. If pallets are staked in an open secure area rather than against a warehouse wall, and they do catch fire, the warehouse and its contents will be out of danger.To sum up: Remove a fire’s fuel supply and you extinguish it by starving.
- Removal or Limitation of Oxygen (Blanketing and Smothering)
A fire can be extinguished by removing or limiting its oxygen supply.
It is not necessary to completely prevent the contact of oxygen with the heated fuel of a fire to put the fire out. A reduction of oxygen from 21% to 15% is sufficient to extinguish flammable liquid fires.The rule applies to most solid fuels, although the degree to which the oxygen content must be reduced can vary. Solid materials may continue to burn or shoulder until the oxygen in the air is reduced to 6%.
There are also substances which carry enough oxygen within their own structure to maintain combustion.
There is no clear dividing line between blanketing and smoldering, and the two methods can be grouped together.For example:
- Snuffing out a candle.
- Placing a wooden breadboard or lid on a chip pan fire.
- Closing doors and windows. In some cases if doors and windows are shut, a fire in a room may burn itself out, smothering itself with its own by-products.
To sum up: Blanketing or Smothering will extinguish a fire by removing or limiting the oxygen supply.
