III. What is White Phosphorus?
White phosphorus is a chemical substance that ignites and burns on contact with oxygen, generating a dense white smoke that lasts about seven minutes, with a distinctive garlic-like odor.
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 anti-personnel 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 air-burst 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.
Israel's Use of White Phosphorus
The Israel Defense Forces (IDF) has used white phosphorus in the past, notably in the wars in Lebanon in 1982 and 2006. The IDF uses indirect-fire systems to launch white phosphorus munitions, meaning that the firing unit does not see the target, but relies on spotters to provide targeting information. To fire white phosphorus in Gaza, the IDF used 155mm artillery shells and 120mm mortar shells; Human Rights Watch researchers found the remnants of both in Gaza, many of them in residential areas. The use of air-burst white phosphorus delivered by 155mm artillery shells in populated civilian areas caused the casualties and damage that is the focus of this report.
Each 155mm shell contains a light green canister marked "WP CANISTER" that holds four metal liners. The liners hold the 116 felt wedges soaked in phosphorus. When air-burst, the canisters explode in mid-air, ejecting the felt wedges from the shell casing and scattering them over a wide area, leaving the empty shell casing to land separately. When exposed to oxygen, the wedges ignite. Human Rights Watch researchers found shell casings, unexploded white phosphorus canisters, canister liners, and felt wedges from inside the canisters in multiple sites in the Gaza Strip. Researchers saw felt wedges igniting when agitated or exposed to oxygen up to two weeks after they had landed.
All of the white phosphorus shells Human Rights Watch found in Gaza are from the same lot, manufactured in the United States and marked: THS89D112-003 155MM M825E1. THS89D is the manufacturer identification code denoting that the shells and contents were produced in April 1989 by Thiokol Aerospace, which operated the Louisiana Army Ammunition Plant at the time; 112-003 are the interfix and sequence numbers, which denote that several lots of the same ammunition were being produced simultaneously; 155mm stands for the caliber of the artillery shell. M825E1 is the US military designation for an older remanufactured M825 white phosphorus shell that has been brought up to the current M825A1 standard.
Additionally, Reuters news agency photographed an IDF artillery unit in Israel near Gaza handling M825A1 projectiles on January 4, 2009 with the lot number PB-91J011-002A, indicating that these shells were produced in the United States at the Pine Bluff Arsenal in September 1991.
One alternative to using white phosphorus as an obscurant is 155mm smoke projectiles, which also produces equivalent visual screening properties without incendiary and destructive effects. Moreover, smokescreens generated by smoke artillery can be deployed more easily over a wider area than white phosphorus. The IDF possesses smoke artillery; Israel Military Industries (IMI) manufactures the M116A1 155MM shell.
In some cases documented in this report, the evidence suggests that the IDF air-burst white phosphorus for its incendiary effect, perhaps to detonate Hamas arms caches or improvised explosive devices.
Human Rights Watch interviewed one IDF soldier who participated in Operation Cast Lead as a medic on reserve duty and had served in Gaza for more than two years prior to disengagement in 2005. He spent the last eight days of the operation in Gaza, he said, based near Zeitoun, southeast of Gaza City.
Regarding white phosphorus, the soldier, who requested anonymity, said that he saw the IDF air-burst it at an angle of about 30 degrees from 155mm artillery above houses that they suspected of being booby-trapped, based on intelligence.
"I don't know why the angle was low, but it was used to burn a house," he said. "We were told it was an empty house. We knew it was mined. It blew up [after being hit with the white phosphorus] and there were several explosions [perhaps of weapons stored there].
He continued: "I also saw conscripts using white phosphorus in Zeitoun. It was used there too at low angles. There was no specific briefing about it. But as part of our medical training we did go through the scenario of how to deal with it."
The use of air-burst white phosphorus to destroy houses suspected of having weapons or booby-traps is highly questionable when the IDF possess more effective precision weapons designed to minimize collateral damage, such as the GBU-39, a 250-pound (113 kg) guided bomb.
Hamas's Alleged Use of White Phosphorus
On January 14, Israeli police claimed that Hamas had fired a single mortar shell with white phosphorus from Gaza into Israel. Police spokesman Micky Rosenfeld said the shell had landed in a field near Sderot that morning, causing no injuries or damage. Haaretz newspaper reported that it hit an open field in the Eshkol area in the western Negev.
A Human Rights Watch researcher went to Sderot the next day to investigate, but local authorities said they were unaware of the attack. One Sderot resident said he had heard about a mortar shell, possibly with white phosphorus, landing in a field outside of town, but he did not know where. When asked for details, police spokesman Micky Rosenfeld told Human Rights Watch that "all I have is what's in the press release."
 "Identification of Explosive White Phosphorus Injury and Its Treatment," signed by Dr. Gil Hirshorn, Colonel, Head of the Trauma Unit, Headquarters of the Chief Military Medical Officer, Ref . Cast Lead SH9 01293409. Original Hebrew on file at Human Rights Watch.
 "Exposure to White Phosphorus," signed by Dr. Leon Fulls, Ministry of Health War Room, January 15, 2009, Ref. Cast Lead SH9 01393109. Original Hebrew on file at Human Rights Watch.
 In the 2006 war, Israel said it used phosphorus shells "against military targets in open ground," although Lebanese officials claimed civilians had been casualties of its use; see Meron Rapoport, "Israel Admits to Using Phosphorus Bombs in Recent Lebanon War," Haaretz, October 22, 2006, http://www.haaretz.com/hasen/objects/pages/PrintArticleEn.jhtml?itemNo=777560, accessed February 4, 2009. In the 1982 war, Lebanese medical doctors and western reporters said that white phosphorus shells had killed and wounded civilians, particularly in Beirut. See William E. Farrell, "Battered Beirut Burying Its Dead as Latest Truce Appears to Hold," New York Times, June 27, 1982, http://query.nytimes.com/gst/fullpage.html?sec=health&res=9C0CE1D7153BF934A15755C0A964948260 , accessed February 4, 2009, and Robert Fisk, Pity the Nation (New York: Atheneum, 1990), pp. 282-85.
Jane's Ammunition Handbook 2007-2008,Leland S. Ness and Anthony g. Williams, eds., (Surrey, UK: Jane's Information Group Limited, 2007), p. 644. See http://www.janes.com/extracts/extract/jah/jah_0461.html, accessed March 6, 2009. The original M825 suffered from flight instability, requiring the new A1 version. The E1 brings the old shells to A1 standard.
 The only unique benefit provided by white phosphorus is the ability to interfere with the infra-red spectrum, thus impeding the use of night vision and infra-red tracking systems used in anti-tank guided missiles (ATGMs). However, the IDF extensively used white phosphorus during the day, obviating the need to block night vision, and Human Rights Watch found no evidence that Hamas fired ATGMs.
Jane's Ammunition Handbook 2007-2008, Leland S. Ness and Anthony g. Williams, eds., (Surrey, UK: Jane's Information Group Limited, 2007), p. 644. See http://www.janes.com/extracts/extract/jah/jah_0462.html, accessed March 6, 2009.
 Human Rights Watch interview with IDF reservist, Jerusalem, February 11, 2009.
 "Israel: Hamas Fires Phosphorus Shell," Associated Press, January 14, 2009.
 Human Rights Watch interview with Israeli police spokesman Micky Rosenfeld, Sderot, January 15, 2009.