Israel using white phosphorus in Gaza? 5 things about the controversial weapon

1. What is white phosphorus?

White phosphorus is a pyrophoric that ignites when exposed to oxygen, producing thick, light smoke as well as intense 815-degree Celsius heat. Pyrophoric substances are those which ignite spontaneously or very quickly (under five minutes) when in contact with air.

Under the Globally Harmonized System of Classification and Labeling of Chemicals, the internationally agreed-upon system to standardize chemical hazard classification and communication, white phosphorus falls under “Pyrophoric solids, category 1”, which includes chemicals that catch fire “spontaneously” when exposed to air. It is among the most unstable of pyrophoric substances.

White phosphorus emits a distinct garlic-like odour.

2. What are the military uses of white phosphorus?

White phosphorus is dispersed in artillery shells, bombs, and rockets. It can also be delivered via felt (textile) wedges soaked in the chemical.

Its primary military use is as a smokescreen — used to hide troop movement on the ground. The smoke acts as a visual obscurant. White phosphorus is also known to mess with infrared optics and weapons tracking systems, thus protecting forces from guided missiles.

Munitions can either be ground-burst for more concentrated smoke, or air-burst in order to cover a larger area.

White phosphorus can also be used as an incendiary weapon. According to HRW, US forces used white phosphorus munitions during the second battle of Fallujah in Iraq in 2004, to force concealed combatants to abandon their positions.

3. How harmful is white phosphorus?

Upon exposure, white phosphorus can cause severe burns, often down to the bone. The burns are excruciatingly painful, difficult to heal, and susceptible to infections. Particles of white phosphorus that remain lodged the body can reignite if in contact with air. According to HRW, white phosphorus burns on even 10 per cent of the body can be fatal.

Inhaling white phosphorus particles or smoke can cause respiratory damage and harm to internal organs. Those who survive initial injuries often experience a lifetime of suffering — with impaired mobility and painful, horrific scars.

White phosphorus can also devastate infrastructure and property, damage crops and kill livestock, with raging fires, especially in windy conditions.

4. When were white phosphorus munitions first used?

Irish nationalists in the late 19th century first used white phosphorus munitions, in a formulation that became known as “Fenian fire” (Fenian was an umbrella term for the Irish nationalists). World War I saw extensive use of the chemical by the British and Commonwealth forces in phosphorus grenades, bombs, shells and rockets.

These munitions have since been used in conflicts around the world, from the Normandy invasion in World War II to the US invasion of Iraq in 2004 and the long-drawn Nagorno-Karabakh conflict. Most recently, Russia was accused of using white phosphorus bombs during the invasion of Ukraine last year.

5. What is the legal status of white phosphorus munitions?

White phosphorus munitions are not under a blanket ban, though their use is regulated under the IHL.

It is not considered a chemical weapon because its operational utility is primarily due to heat and smoke, rather than toxicity. Thus, its use is governed by the Convention on Conventional Weapons (CCW), specifically Protocol III, which deals with incendiary weapons. Palestine and Lebanon have joined Protocol III, while Israel has not ratified the protocol.

While Protocol III prohibits the use of airdropped incendiary weapons in “concentrations of civilians”, as per HRW, it has two significant loopholes.

First, it restricts some but not all use of ground-launched incendiary weapons where there are concentrations of civilians. Second, the protocol’s definition of incendiary weapons covers weapons that are “primarily designed” to set fire to and burn people, and thus arguably excludes multipurpose munitions such as those containing white phosphorus, which are considered to primarily be “smoking” agents.

Over the years, there have been multiple proposals to strengthen the CCW to close these loopholes.