Flash fire

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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.

[edit] Definition

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.”

[edit] Characterization

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. 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. Flash fires can lead to smoke burns.

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

[edit] Surgical flash fire

Small flash fires can occur in the operating room during surgery where the presence of electrical instruments, lasers, an oxygen-rich environment, and combustible material may set the stage for such an accident. While apparently smaller fires go unreported, surgical flash fires have led to burn injuries and fatalities.^[1]

[edit] References

[edit] See also

• Fuel-air explosive
• Fireball
• Trench effect
• BLEVE
• Vapor cloud fire
• Flashover
• Explosion
• Flash flood
• Air Canada Flight 797

[edit] External links

• Explosion Hazard Assessment
• Flash fire exposure analysis