An explosive increase in the volume of fire when oxygen is suddenly allowed to enter an enclosed space where the contents have been smoldering for a period of time. Because the enclosed fire consumes the available oxygen, the air pressure inside may be lower than outside. Sometimes an incipient backdraft can be detected by observing the smoke being sucked back into the fire building, with brief puffs of smoke being forced back out periodically. A backdraft is a smoke explosion and should not be confused with a condition known as flashover, where all of the contents of a room simultaneously burst into flames because of the intense heat in the room.
Also known as a smoke explosion. A backdraft may be created when a fire burning inside an enclosed structure depletes most of the oxygen but the gases inside remain super heated. A sudden introduction of oxygen into the environmnet, such as opening a door or window, can cause the gases to ignite with explosive force. Warning signs of possible backdraft include little or no visible flame, black smoke becoming dense gray yellow, smoke stained windows, and smoke escaping in intervals, or a puffing effect.
Instantaneous explosion or rapid burning of superheated gases that occurs when oxygen is introduced into an oxygen-depleted confined space. It may occur because of inadequate or improper ventilation procedures.