What are the fire and explosion dangers associated with aluminum powder (uncoated)?
Reactive flammable solid. Bulk aluminum powder or dust in contact with water may heat spontaneously. Moist, finely divided aluminum powder may ignite in air, with the formation of flammable hydrogen gas. The hazard increases as the aluminum particle size decreases. Contact of burning aluminum with water forms flammable hydrogen gas, an extremely dangerous explosion hazard, particularly if the fire is in a confined area. Bulk aluminum metal itself is not combustible. Under certain conditions, a dust cloud of aluminum powder can explode when ignited by a spark or flame. When evaluating the explosion hazard of a specific process or sample of material, the important factors to consider include: particle size and shape, dust concentration, the nature of any impurities, oxygen concentration, humidity, and extent of containment. Explosions of aluminum dusts have occurred in industry. IGNITION SENSITIVITY: 1.4 (aluminum, atomized); 7.3 (aluminum, flake) EXPLOSION SEVERITY: 7.7 (aluminum, atomi
