Militaries use white phosphorus munitions primarily as an “obscurant” to provide visual cover for ground operations, masking the movement of troops and armor. It can also be used as an incendiary weapon to burn or “smoke out” enemy personnel or to set fire to military targets. White phosphorus can be dispersed by artillery shells, bombs, rockets, or grenades. White phosphorus is not banned by international treaty, as is mustard gas and antipersonnel landmines. It is not considered a chemical weapon, but an incendiary munition – one that causes fires.
When set to burst in mid-air, the 116 white phosphorus-coated felt wedges in a typical 155mm artillery shell can fall over an area up to 250 meters in diameter. In total, one airburst shell releases 12.74 pounds (5.78kg) of burning white phosphorus.
When white phosphorus comes into contact with people or objects, it creates an intense and persistent burn, emitting heat and absorbing liquid. It is soluble in organic material and fat, but not in water, which neutralizes it by cutting off the oxygen supply.
In addition to causing intense burns, white phosphorus can also penetrate the body and poison internal organs. According to a report prepared during the recent fighting by the office of IDF chief medical officer, “kidney failure and infections are characteristic long-term outcomes.” The report concludes that “a wound caused by explosive ordnance containing phosphorus is potentially extremely destructive to tissue.”
A report by the Israeli Ministry of Health is equally stark in its assessment of white phosphorus’s medical risks. Entitled “Exposure to White Phosphorus,” the report states that “[w]hite phosphorus can cause serious injury and death when it comes into contact with the skin, is inhaled or is swallowed.” It continues: “[b]ecause it is very soluble in fat, it quickly penetrates the skin from the surface or from an embedded fragment. Most of the tissue damage is cause by the heat accompanying the continuing oxidation of the phosphorus, and from the product of the oxidation – phosphoric acid.”
The report also mentions the “systemic poisoning” that can result. In addition to its “usual” burn effects, white phosphorus is poisonous, and has serious consequences that intensify the effects of the injury. Many laboratory studies have shown that burns covering a relatively small area of the body – 12-15% in laboratory animals and less than 10% in humans – may be fatal because of their effects on the liver, heart and kidneys. Additional effects include serious hypocalcemia and delayed healing of wounds and burns.
From "Rain of Fire: Israel’s Unlawful Use of White Phosphorus in Gaza" Human Rights Watch report, March 2009.