Flash fire


 * For the Marvel comics character see Flashfire (comics); For the book by David Sherman & Dan Cragg see Flashfire

A flash fire is an unexpected, sudden intense fire caused by ignition of flammable solids (including dust), liquids, or gases. It is characterized by high-temperature, short-duration, considerable shock waves, and a rapidly moving flame front.

Flash fires may occur in environments where fuel, typically flammable gas or dust, is mixed with air in concentrations suitable for combustion.

In flash fire explosions, the flame spreads at subsonic velocity, so the overpressure damage is usually negligible and the bulk of the damage comes from the thermal radiation and secondary fires.

Clothing made of fire-retardant materials (eg. Nomex) limits the injury caused by flash fires to the unprotected body areas. Even normal clothing can provide partial protection.

When inhaled, the heated air resulting from a flash fire can cause serious damage to the tissue of the lungs, possibly leading to death by asphyxiation.

A flash fire is defined by CGSB 155.20-2000 and NFPA 2113 as:

“A rapidly moving flame front which can be a combustion explosion. Flash fire may occur in an environment where fuel and air become mixed in adequate concentrations to combust...flash fire has a heat flux of approximately 84 kW/m2 for relatively short periods of time, typically less than 3 seconds.”

Flash fires can lead to smoke burns.