White phosphorus

**White phosphorus** (Also called yellow phosphorus) (Chemical formula : P4) is a material made from a common allotrope of the chemical element phosphorus that is used in smoke, tracer, illumination, and incendiary munitions. Other common names include **WP** and the slang term "Willie Pete" or "Willie Peter" derived from William Peter, the World War II phonetic alphabet for "WP", which is dated from its use in World War II and Vietnam and is still sometimes used in military jargon. As an incendiary weapon, white phosphorus is pyrophoric (self-igniting), burns fiercely and can ignite cloth, fuel, ammunition, and other combustibles.
In addition to its offensive capabilities, white phosphorus is a highly efficient smoke-producing agent, which burns quickly and produces an immediate blanket of smoke. As a result, smoke-producing white phosphorus munitions are very common, particularly as smoke grenades for infantry, loaded in grenade launchers on tanks and other armored vehicles, or as part of the ammunition allotment for artillery or mortars. These create smoke screens to mask from the enemy movement, position, infrared signatures, or the origin of fire.

## History

White phosphorus is believed to have been first used by Fenian arsonists in the 19th century, in the form of a solution in carbon disulfide. When the carbon disulfide evaporated, the phosphorus would burst into flames. 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 struggle over conscription for the First World War, 12 members of the Industrial Workers of the World, a workers union opposed to 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 framed by the police. Most were released in 1920 after an inquiry.

The British Army introduced the first factory-built WP grenades in late 1916. During World War I, 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. The British military also used white phosphorus bombs against Kurdish villagers and Al-Habbaniyah in Al-Anbar province during the Great Iraqi Revolution of 1920.

In the interwar years, the U.S. Army trained using white phosphorus, by artillery shell and air bombardment.

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 (see also 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 black-powder grenade launcher). These were improvised anti-tank weapons, hastily fielded in 1940 when the British were awaiting a German invasion after losing the bulk of their modern armaments in the Dunkirk evacuation. Instructions on each crate of SIP grenades included the observations, among other things:

Store bombs (preferably in cases) in cool places, under water if possible.
Stringent precautions must be taken to avoid cracking bombs during handling.
At the start of the Normandy campaign, 20% of American 81 mm mortar rounds were white phosphorus. At least five American Medal of Honor citations mention their recipients using white phosphorus grenades to clear enemy positions, and 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 white phosphorus shells in 107-mm (4.2 inch) mortars. White phosphorus 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. US Sherman tanks carried a white phosphorus round intended for artillery spotting, but tank crews found it useful against German tanks. Unable to penetrate German Panther and Tiger tanks at long range, the phosphorus round would adhere to the tank, generate smoke, blind the optics, and often force the crew to abandon the tank or allow US tanks to close to a range where their armor piercing rounds were effective.

When American bombers raided Negros Island in the Philippines in 1945, there was a Japanese artillery use of phosphorus bombs during the air raid.

Incendiary bombs were used extensively by both the Axis and Allied air forces against civilian populations and targets of military significance in civilian areas, including Chongqing, London, Coventry, Hamburg, Dresden, and Tokyo. 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 United States signed Protocols I and II on 24 March 1995 under the Clinton Administration (and the amended article II on 24 May 1999) and later Protocols III, IV, and V, on 21 January 2009 under the Obama Administration.