A backdraft is a situation which can occur when a fire is starved of oxygen; consequently combustion ceases but the fuel gases and smoke remain at high temperature. Fire is the heat and light energy released during a Chemical reaction, in particular a combustion reaction. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Smoke is the collection of airborne solid and liquid Particulates and Gases ref> ''Smoke Production and Properties'' - SFPE Handbook of Fire Protection Engineering If oxygen is re-introduced to the fire, eg. by opening a door to a closed room, combustion can restart often resulting in an explosive effect as the gases heat and expand.
Characteristic signs of a backdraft situation include yellow or brown smoke, smoke which exits small holes in puffs (a sort of breathing effect) and is often found around the edges of doors and windows, and windows which appear brown or black when viewed from the exterior. These darker colors are caused by incomplete combustion. Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of If the room contains a lot of soot, it indicates that the room lacks enough oxygen to permit combustion. Soot (ˈsʊt is a general term that refers to the black impure carbon particles resulting from the incomplete combustion of a hydrocarbon Firefighters often look to see if there is soot on the inside of windows and in cracks around in the room. The window might have cracked because of the heat. The windows of the structure may also have a slight vibration due to the pressure differentials. The surrounding environment (e. g. the hallway outside the suspected backdraft room) will be extremely hot.
If firefighters discover a room pulling air into itself, for example through a crack, they should evacuate immediately, because this is a strong indication that a backdraft is imminent. Due to pressure differentials, these puffs of smoke are sometimes "sucked" back into the enclosed space from which they emanate, which is where the term "backdraft" originates.
Backdrafts are very dangerous situations, often surprising firefighters, regardless of their level of experience. Firefighters are rescuers extensively trained primarily to put out hazardous Fires that threaten civilian populations and property to rescue people from car accidents collapsed The most common tactic used by firefighters in defusing a potential backdraft is to ventilate from the highest point, allowing the heat and smoke to escape without igniting explosively.
In Popular Culture
Backdrafts entered popular consciousness through the film of the same name where a serial arsonist was using them as a means of assassinating people. Backdraft is a 1991 American action - Drama film directed by Ron Howard and written by Gregory Widen.
See also
Resources
- Hall, Richard & Adams, Barbara (1998). For the 2007 documentary see Flashover (film. In Electric power transmission, a flashover is an unintended high voltage electric discharge over Backdraft is a 1991 American action - Drama film directed by Ron Howard and written by Gregory Widen. Essentials of firefighting (4th ed. ). International Fire Service Training Association. ISBN 0-87939-149-9.
- White Smoke Warning
Dictionary
backdraft
-noun
- (firefighting) An extreme fire behavior phenomena involving ignition of products of combustion (such as carbon monoxide) and pyrolysis products upon introduction of oxygen to a compartment. In this phenomena the fuel generally is at a high temperature (above 600 degrees C), but combustion is limited by a lack of oxygen. Introduction of atmospheric oxygen results in explosive combustion. Backdraft is often incorrectly referred to as a smoke explosion which is a completely different extreme fire behavior phenomena.
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