OPINION

Lessons from the Mountain B fire

Oped, Worsak Kanok-Nukulchai, Published on 24/08/2022

» Fire breaks out when heat, fuel, and oxygen meet. Without intervention, a fire will only come to an end under two conditions: when the fuel has run out, or when the oxygen supply is exhausted. In an enclosed space, when a fire can deplete most oxygen, the flames will die down while the fuel continues to burn in a smouldering state under pyrolysis. Pyrolysis does not require oxygen, so it can take place without fire at or above 500C and turn organic compounds into charcoal, tar, or non-condensable gases. These gases have extremely high thermal values ready to burst into fireballs as soon as fresh oxygen re-emerges from any new opening. This is called "backdraft", and is what happened in the Mountain B Pub fire.