White (or yellow) phosphorus is the most common and most reactive of the three allotropic forms of phosphorus.
Because of its reactivity, white phosphorus has been used as an incendiary agent by the military or as an igniter for munitions. An incendiary agent is one that is primarily designed to set fires. White phosphorus commonly is found in hand grenades, mortar and artillery rounds, and smoke bombs.
Munitions-quality white phosphorus is generally found as a waxy, yellow, transparent solid. When exposed to air, it spontaneously ignites and is oxidized rapidly to phosphorus pentoxide. Such heat is produced by this reaction that the element bursts into a yellow flame and produces a dense white smoke. Phosphorus also becomes luminous in the dark, and this property is conveyed to “tracer bullets.” This chemical reaction continues until either all the material is consumed or the element is deprived of oxygen.
Most injuries associated with white phosphorus are the result of accidents due to either human or mechanical error.
Care in handling and use of munitions should serve as the primary prevention of injuries and burns associated with white phosphorus.