1
Q
What are the backdraught signs and symptoms?
A
- Fires with limited ventilation
- Hot doors and windows
- Smoke pulsating around opening
- Soot blackened windows
- Smoke/air being drawn back into openings. (Possible whistling)
- Lack of visible flames
- Ghosting tongues of flames
- Change in fire conditions with fast moving smoke seen from exterior to exit at high velocity, as if under pressure and a steady darkening in smoke colour.
2
Q
Why is it important to recognise backdraught symptoms?
A
This is where a limited ventilation fire can lead to a fire compartment producing fire gases containing significant proportions of a partial combustion products and unburnt purplish products. With the admission of air when an opening is made this can lead to a sudden deflagration. This moving through the compartment and out the opening is called a backdraught. It Is at a subsonic speed as an explosive driven by the transfer of heat. Causing a huge danger to anyone within the vicinity.
