War headlines often focus on missiles, drones, or airstrikes. However, some weapons elicit a different kind of reaction. White phosphorus is one of them. It has been used by militaries for decades, but every time a conflict arises, controversy quickly follows.More recently, the substance returned to international debate after human rights groups accused Israel of using white phosphorus in southern Lebanon during escalating regional tensions linked to Iranian-backed forces. Human Rights Watch says it has verified images showing munitions exploding in the air above residential areas. Israel has not confirmed these allegations and says it cannot comment on the photos mentioned in the report.
The accusations revived an old question that often confuses people. Is white phosphorus actually illegal, or is it a legitimate military tool that only becomes controversial in certain cases?
Understanding white phosphorus: Learn about its properties
White phosphorus is a chemical that appears waxy and is pale yellow or white in color. It also has a distinctive smell that many people describe as resembling garlic. An unusual property of white phosphorus is how it interacts with air.
When the chemical is exposed to oxygen, it can ignite almost instantly at temperatures above about 30°C. Once it starts burning, it produces thick white smoke and very intense heat.The burning chemical creates large clouds of smoke that can block visibility on the battlefield. It is sometimes used by armies to conceal troop movements, mark targets, or illuminate areas at night. These uses are technically permitted under international law.
In many cases, white phosphorus is released through artillery shells that explode in the air and scatter burning shrapnel across the area. Those fragments are what makes the weapon controversial.
How and why can white phosphorus be so dangerous?
White phosphorus is extremely dangerous to humans. When the burning chemical comes into contact with the skin, it can cause severe chemical burns that penetrate deeply into the tissue. Medical experts say the burning particles may continue to consume the flesh until the chemical is completely burned or deprived of oxygen.
In some cases, the splinters are said to burn through the muscles and into the bones. Injuries are not only painful, but they are also difficult to treat.
Doctors must carefully remove any remaining phosphorus fragments because they can ignite again when exposed to air during treatment.Smoke from burning phosphorus can also be harmful. Exposure may cause irritation to eyes, lungs and skin. In serious cases, the chemical can be absorbed into the body through inhalation or through wounds.
Researchers say high exposure can damage organs such as the liver and heart, and severe poisoning may lead to shock or even death.
Is white phosphorus illegal under international law?
The legal status of white phosphorus is complex and often misunderstood. The chemical itself is not banned. Many countries own and use white phosphorus munitions for battlefield purposes, particularly for generating smoke and sending signals, according to the World Health Organization.IHL focuses less on the chemical and more on how it is used. Weapons may not be used in ways that indiscriminately harm civilians. When white phosphorus is deployed in densely populated areas, especially through air-burst projectiles that spread burning particles over a wide area, legal experts often say it becomes illegal. Human rights organizations say such use may violate the rules of war because it could lead to uncontrollable fires and casualties among civilians.
Human Rights Watch indicates the suspected use of white phosphorus in Lebanon
Human Rights Watch says it has analyzed several images showing what appear to be white phosphorus artillery shells over the Lebanese town of Yahmar. According to the organization, the clouds of smoke in the footage match the distinctive pattern created by air-explosive phosphorus shells.Civil defense teams were reportedly seen responding to house and vehicle fires in the area shortly after. The Israeli military said it could not confirm these allegations at this stage. Officials say they have not reviewed the specific evidence cited in the report. The Army also noted that the smoke shells it uses may contain small amounts of white phosphorus, which they say is intended for smoke screens and not for starting fires.
According to the Israeli army, these shells are not usually used in densely populated areas.
