White phosphorus (weapon)


 * This article is about the military applications of white phosphorus. For more general information, see Phosphorus.

White phosphorus (WP) is a flare- and smoke-producing incendiary weapon, or smoke-screening agent, made from a common allotrope of the chemical element phosphorus. White phosphorus bombs and shells are incendiary devices, but can also be used as an offensive anti-personnel flame compound capable of causing serious burns or death. The agent is used in bombs, artillery shells, and mortar shells which burst into burning flakes of phosphorus upon impact. White phosphorus is commonly referred to in military jargon as "WP". The Vietnam-era slang "Willy(ie) Pete" or "Willy(ie) Peter" is still occasionally heard.

White phosphorus weapons are    controversial today because of their potential use against civilians. While the Chemical Weapons Convention does not designate WP as a chemical weapon, various unofficial groups consider it to be one. In recent years, the United States, Israel, Russia, and Argentina have used white phosphorus in combat.

Its use by the US has resulted in considerable controversy (see white phosphorus use in Iraq). Initial field reports from Iraq referred to white phosphorus use against insurgents, but its use was officially denied until November, 2005, when the Pentagon admitted to the use of white phosphorus while stating that its use for producing obscuring smoke is legal and does not violate the Chemical Weapons Convention. A Pentagon spokesman has also admitted that WP "was used as an incendiary weapon against enemy combatants," though not against civilians.

History


WP is believed to have been first used by Fenian arsonists in the 19th century in the form of a solution of WP in carbon disulfide. When the carbon disulfide evaporated, the WP would burst into flames, and probably also ignite the highly flammable carbon disulfide fumes. This mixture was known as "Fenian fire" and allegedly was used by disgruntled itinerant workers in Australia to cause delayed destruction of shabby sleeping quarters.

In 1916, during an intense ideological struggle over conscription for the First World War, twelve members of the I.W.W., a radical union of workers who openly opposed conscription, were arrested and convicted for using or plotting to use incendiary materials, including phosphorus. It is believed that eight or nine men in this group, known as the Sydney Twelve, had been victims of a police frameup. Most were released in 1920 after an inquiry.

World War I and II
The British Army introduced the first factory-built WP grenades in late 1916. In World War II, white phosphorus mortar bombs, shells, rockets and grenades were used extensively by American, Commonwealth, and to a lesser extent Japanese forces, in both smoke-generating and antipersonnel roles. In 1940, when the invasion of Britain seemed imminent, the phosphorus firm of Albright and Wilson suggested that the British government use a material similar to Fenian fire in several expedient incendiary weapons. The only one fielded was the Grenade, No. 76 or Special Incendiary Phosphorus grenade, which consisted of a glass bottle filled with a mixture similar to Fenian fire, plus some latex (c.f. Molotov cocktail, Greek fire). It came in two versions, one with a red cap intended to be thrown by hand, and a slightly stronger bottle with a green cap, intended to be launched from the Northover projector (a crude 2.5 inch blackpowder grenade launcher). Instructions on each crate of SIP grenades included the observations, inter alia:
 * Store bombs (preferably in cases) in cool places, under water if possible.
 * Stringent precautions must be taken to avoid cracking bombs during handling.

It was generally regarded as overly dangerous to its own operators.

At the start of the Normandy campaign, 20% of American 81 mm mortar rounds were WP. At least five American Medal of Honor citations mention their recipients using white phosphorus grenades to clear enemy positions. In the 1944 liberation of Cherbourg alone, a single U.S. mortar battalion, the 87th, fired 11,899 white phosphorus rounds into the city.

The U.S. Army and Marines used WP shells in 4.2-inch chemical mortars. WP was widely credited by Allied soldiers for breaking up German infantry attacks and creating havoc among enemy troop concentrations during the latter part of the war. American servicemen in the Pacific and otherwise (to this day) were known to call the thrown bottles "Woolly Pete" or "Willie Pete" grenades, using the same WP initials as White Phosphorus.

Incendiary bombs were used extensively by the German, British and US air forces against civilian populations and targets of military significance in civilian areas (London, Hamburg, Dresden, Area bombing etc). Late in the war, some of these bombs used white phosphorus (about 1-200 grams) in place of magnesium as the igniter for their flammable mixtures. The use of incendiary weapons against civilians was banned (by signatory countries) in the 1980 Convention on Certain Conventional Weapons Protocol III. The USA has signed Articles I and II, but not Protocols III, IV, and V.

Others
WP munitions were used extensively in Korea, Vietnam and later by Russian forces in Chechnya. According to GlobalSecurity.org, "In the December 1994 battle for Grozny in Chechnya, every fourth or fifth Russian artillery or mortar round fired was a smoke or white phosphorus round."

WP was used by the Argentine Army during the 1989 attack on La Tablada Regiment, in a violation of the Geneva Convention (according to a document presented by the human rights commission of the United Nations on January 12, 2001).

In Iraq, the Saddam Hussein regime used white phosphorus, as well as chemical weapons that are scheduled in the Chemical Weapons Convention, in the Halabja poison gas attack during the Iran-Iraq War in 1988, according to the ANSA news agency.

Another news report said "US intelligence" called WP a chemical weapon in a declassified Pentagon report from February 1991:
 * "Iraqi forces loyal to President Saddam may have possibly used white phosphorus chemical weapons against Kurdish rebels and the populace in Erbil and Dohuk. The WP chemical was delivered by artillery rounds and helicopter gunships."

but the actual declassified document contains the words "WARNING: (U) THIS IS AN INFORMATION REPORT, NOT FINALLY EVALUATED INTELLIGENCE." By "information report", the document states it is not a reviewed product of the intelligence community. Further, the document's addressee codes all start with the letter R, which means that they are in the military operational community, not the Y-community that is reserved for the intelligence community (Chapter IV, Section 11).

Use in Iraq (2004)
Use of WP against enemy areas in Fallujah were reported as early as April 2004: This U.S. Department of State website carried an addendum in November 2005, replacing the previous statement with the comment:
 * The boom kicked dust around the pit as they ran through the drill again and again, sending a mixture of burning white phosphorus and high explosives they call "shake 'n' bake" into a cluster of buildings where insurgents have been spotted all week. However, an U.S. official release of December 2004 denied any WP use:
 * U.S. forces have used [phosphorus shells] very sparingly in Fallujah, for illumination purposes. They were fired into the air to illuminate enemy positions at night, not at enemy fighters.
 * We have learned that some of the information we were provided in the above paragraph is incorrect. White phosphorus shells, which produce smoke, were used in Fallujah not for illumination but for screening purposes, i.e., obscuring troop movements and, according to an article in ... Field Artillery magazine, "as a potent psychological weapon against the insurgents in trench lines and spider holes…." The article states that U.S. forces used white phosphorus rounds to flush out enemy fighters so that they could then be killed with high explosive rounds.

The specific aspect of use against humans was highlighted after the documentary film Fallujah, The Hidden Massacre by Sigfrido Ranucci was aired on Italy's RaiNews24 and released on the internet. In the film, Giuliana Sgrena quotes city refugees testimonies from Fallujah about the reported danger of weapons effects:
 * In particular, some women had tried to enter their homes, and they had found a certain dust spread all over the house. The Americans themselves had told them to clean the houses with detergents, because that dust was very dangerous. In fact, they had some effect on their bodies, leading to some very strange things."

The film also shows U.S. soldiers on film admitting to WP use against insurgents. U.S. officials continued to deny the use of white phosphorus for antipersonnel purposes; U.S. ambassador to UK Robert Holmes Tuttle stated in November 2005, that U.S. forces "do not use napalm or white phosphorus as weapons".

However, within a week of ambassador Tuttle's statement, on November 15, Pentagon spokesman Lieutenant-Colonel Barry Venable confirmed to the BBC that WP had been used as an antipersonnel weapon, and was quoted as stating: "It has  been used as an incendiary weapon against enemy combatants". In particular,
 * Venable pointed out that WP was effective against enemy forces in covered positions that were protected from high explosives. "One technique is to fire a white phosphorus round into the position because the combined effects of the fire and smoke—and in some case the terror brought about by the explosion on the ground—will drive them out of the holes so that you can kill them with high explosives.

While WP use is legal for purposes such as illumination and obscuring smoke, the Chemical Weapons Convention does not list WP in its schedules of chemical weapons.

The March 2005 edition of the U.S. Army magazine Field Artillery, contained an article on using white phosphorus as an "effective munition" for flushing out insurgents during the Fallujah attack of November 2004:
 * “WP proved to be an effective and versatile munition. We used it for screening missions at two breeches and, later in the fight, as a potent psychological weapon against the insurgents in trench lines and spider holes when we could not get effects on them with HE (High Explosive) Rounds. We fired ‘shake and bake’ missions at the insurgents, using WP to flush them out and HE to take them out.”

On November 30, 2005, General Peter Pace defended use of WP, declaring that WP munitions were a "legitimate tool of the military", used to illuminate targets and create smokescreens, and that there were better weapons for killing people:
 * it is well within the law of war to use those weapons as they're being used, for marking and for screening... A bullet goes through skin even faster than white phosphorus does".

On June 22, 2007 New York Times correspondent Michael R. Gordon was interviewed on National Public Radio in a story called "Baquba Residents Displaced by Insurgents" by Melissa Block and Michele Norris. In this interview, Gordon was asked about civilian casualties in Baquba, Iraq. He responded by saying "Yeah, there have been civilian casualties. I was just talking to our photographer and he had seen people who are hurt by phosphorus shells." The photographer was not identified in the interview and the report was not corroborated.

2006 Israel-Lebanon conflict
During the 2006 Israel-Lebanon conflict, Israel stated that it had used phosphorus shells "against military targets in open ground" in south Lebanon. Israel stated that its use of the white phosphorus bombs was permitted under international conventions. According to a Haaretz article, President of Lebanon Émile Lahoud claimed that phosphorus shells were used against civilians in Lebanon. The first Lebanese official complaint about the use of phosphorus came from Information Minister Ghazi Aridi.

Smoke-screening properties


Weight-for-weight, phosphorus is the most effective smoke-screening agent known, for two reasons: first, it absorbs most of the screening mass from the surrounding atmosphere and secondly, the smoke particles are an aerosol, a mist of liquid droplets which are close to the ideal range of sizes for Mie scattering of visible light. This effect has been likened to three dimensional textured privacy glass&mdash;the smoke cloud does not simply obstruct an image, but thoroughly scrambles both visual and infrared radiation.

When phosphorus burns in air, it first forms phosphorus pentoxide (which exists as tetraphosphorus decoxide except at very high temperatures):
 * P4 + 5 O2 → P4O10

However phosphorus pentoxide is extremely hygroscopic and quickly absorbs even minute traces of moisture to form liquid droplets of phosphoric acid:
 * P4O10 + 6 H2O → 4 H3PO4 (also forms polyphosphoric acids such as pyrophosphoric acid, H4P2O7)

Since an atom of phosphorus has an atomic mass of 31 but a molecule of phosphoric acid has a molecular mass of 98, the cloud is already 68% by mass derived from the atmosphere (i.e. 3.2 kilograms of smoke for every kilogram of WP you started with); however, it may absorb more because phosphoric acid and its variants are hygroscopic. Given time, the droplets will continue to absorb more water, growing larger and more dilute until they reach equilibrium with the local water vapour pressure. In practice, the droplets quickly reach a range of sizes suitable for scattering visible light and then start to dissipate from wind or convection.

Because of the great weight efficiency of WP smoke, it is particularly suited for applications where weight is highly restricted, such as hand grenades and mortar bombs. An additional advantage for hand smoke grenades&mdash;which are more likely to be used in an emergency&mdash;is that the WP smoke clouds form in a fraction of a second. Because WP is also pyrophoric, most munitions of this type have a simple burster charge to split open the casing and spray fragments of WP through the air, where they ignite spontaneously and leave a trail of rapidly thickening smoke behind each particle. The appearance of this cloud forming is easily recognised; one sees a shower of burning particles spraying outward, followed closely by distinctive streamers of white smoke, which rapidly coalesce into a fluffy, very pure white cloud (unless illuminated by a coloured light source).

Various disadvantages of WP are discussed below, but one which is particular to smoke-screening is "pillaring". Because the WP smoke is formed from fairly hot combustion, the gasses in the cloud are hot, and tend to rise. Consequently the smoke screen tends to rise off the ground relatively quickly and form aerial "pillars" of smoke which are of little use for screening. Tactically this may be counteracted by using WP to get a screen quickly, but then following up with emission type screening agents for a more persistent screen. Some countries have begun using red phosphorus instead. Red phosphorus ("RP") burns cooler than WP and eliminates a few other disadvantages as well, but offers exactly the same weight efficiency. Other approaches include WP soaked felt pads (which also burn more slowly, and pose a reduced risk of incendiarism) and PWP, or plasticised white phosphorus.

Effects on humans
White phosphorus can cause injuries and death in three ways: by burning deep into tissue, by being inhaled as a smoke, and by being ingested. Extensive exposure in any way can be fatal.

Effects of exposure to WP weapons
Incandescent particles of WP cast off by a WP weapon's initial explosion can produce extensive, deep (second and third degree), burns. Phosphorus burns carry a greater risk of mortality than other forms of burns due to the absorption of phosphorus into the body through the burned area, resulting in liver, heart and kidney damage, and in some cases multi-organ failure. These weapons are particularly dangerous to exposed people because white phosphorus continues to burn unless deprived of oxygen or until it is completely consumed. In some cases, burns may be limited to areas of exposed skin because the smaller WP particles do not burn completely through personal clothing before being consumed. According to GlobalSecurity.org, quoted by The Guardian, "White phosphorus results in painful chemical burn injuries".

Exposure and inhalation of smoke
Burning WP produces a hot, dense white smoke. Most forms of smoke are not hazardous in the kinds of concentrations produced by a battlefield smoke shell. Exposure to heavy smoke concentrations of any kind for an extended period (particularly if near the source of emission) does have the potential to cause illness or even death.

WP smoke irritates the eyes and nose in moderate concentrations. With intense exposures, a very explosive cough may occur. However, no recorded casualties from the effects of WP smoke alone have occurred in combat operations and to date there are no confirmed deaths resulting from exposure to phosphorus smoke.

The Agency for Toxic Substances and Disease Registry has set an acute inhalation Minimum Risk Level (MRL) for white phosphorus smoke of 0.02 mg/m³, the same as fuel oil fumes. By contrast, the chemical weapon mustard gas is 30 times more potent: 0.0007 mg/m³ .

Oral ingestion
The accepted lethal dose when white phosphorus is ingested orally is 1 mg per kg of body weight, although the ingestion of as little as 15 mg has resulted in death. It may also cause liver, heart or kidney damage. There are reports of individuals with a history of oral ingestion who have passed phosphorus-laden stool ("smoking stool syndrome")

Arms control status and military regulations
Article 1 of Protocol III of the Convention on Certain Conventional Weapons defines an incendiary weapon as 'any weapon or munition which is primarily designed to set fire to objects or to cause burn injury to persons through the action of flame, heat, or combination thereof, produced by a chemical reaction of a substance delivered on the target'. The same protocol also prohibits the use of incendiary weapons against civilians or in civilian areas.

However, the use against military targets outside civilian areas is not explicitly banned by any treaty. There is a debate on whether white phosphorus should be considered a chemical weapon and thus be outlawed by the Chemical Weapons Convention (CWC) which went into effect in April 1997. The convention is meant to prohibit weapons that are "dependent on the use of the toxic properties of chemicals as a method of warfare" (Article II, Definitions, 9, "Purposes not Prohibited" c.).

The convention defines a "toxic chemical" as a chemical "which through its chemical action on life processes can cause death, temporary incapacitation or permanent harm to humans or animals".(CWC, II). An annex lists chemicals that fall under this definitionm and WP is not listed in the Schedules of chemical weapons or precursors.

In an 2005 interview with RAI, Peter Kaiser, spokesman for the Organisation for the Prohibition of Chemical Weapons (an organization overseeing the CWC and reporting directly to the UN General Assembly), questioned whether the weapon should fall under the convention's provisions:
 * No it's not forbidden by the CWC if it is used within the context of a military application which does not require or does not intend to use the toxic properties of white phosphorus. White phosphorus is normally used to produce smoke, to camouflage movement.
 * If that is the purpose for which the white phosphorus is used, then that is considered under the convention legitimate use.
 * If on the other hand the toxic properties of white phosphorus are specifically intended to be used as a weapon, that of course is prohibited, because the way the convention is structured or the way it is in fact applied, any chemicals used against humans or animals that cause harm or death through the toxic properties of the chemical are considered chemical weapons".

Kaiser was a staff spokesman for the Organisation for the Prohibition of Chemical Weapons. . The OPCW, using member votes, creates Schedules of chemical weapons or dual-use chemicals of concern and white phosphorus is not in any of these schedules.

The Convention on Certain Conventional Weapons, not the Chemical Weapons Convention, goes on, in its Protocol III, to prohibit the use of all air-delivered incendiary weapons against civilian populations, or for indiscriminate incendiary attacks against military forces co-located with civilians. However, that protocol also specifically excludes weapons whose incendiary effects are secondary, such as smoke grenades. This has often been read as excluding white phosphorus munitions from this protocol, as well. Several countries, including the United States and Israel, are not signatories to Protocol III.

The legal position however, is not the only consideration in any war. For instance, concerning the U.S. use of WP in Iraq, the British Liberal Democrat foreign affairs spokesman Sir Menzies Campbell, said
 * "The use of this weapon may technically have been legal, but its effects are such that it will hand a propaganda victory to the insurgency. The denial of use followed by the admission will simply convince the doubters that there was something to hide".

Military regulations


Within the US Army, there appears to be conflicting advice on the use of WP against humans. According to the field manual on the Rule of Land Warfare, "The use of weapons which employ fire, such as tracer ammunition, flamethrowers, napalm and other incendiary agents, against targets requiring their use is not violative of international law." However, the ST 100-3 Battle Book, a student text published by the US Command and General Staff College at Fort Leavenworth states that "It is against the law of land warfare to employ WP against personnel targets." At the same time, other field manuals discuss the use of white phosphorus against personnel.