The Use of White Phosphorus: A Closer Look

What Is White Phosphorus?

White phosphorus is a solid, waxy chemical that ignites when exposed to oxygen. It is classified as an incendiary agent under the Chemical Weapons Convention—not a chemical weapon. Countries may lawfully use it for smoke screens or marking targets. However, its use in or near civilian areas is prohibited under international law due to the severe and indiscriminate harm it causes.

"It can create cruel injuries—lifelong injuries—or cause death." – Ramzi Kaiss, Human Rights Watch

Health Effects

• Causes severe burns that can penetrate to bone
• Leads to respiratory damage and potential death
• Sticks to skin and clothing, is difficult to extinguish
• Can reignite upon re-exposure to oxygen

Area Impact

One artillery projectile can affect an area 125–250 meters in diameter if burst in the air.

Reported Use in Lebanon

The New York Times reported that Israel used white phosphorus in Nabatieh (population ~40,000) on May 30, verified via social media videos. Footage also indicated use near Tyre and three other towns since March.

Human Rights Watch (HRW) separately verified use over homes in southern Lebanon on March 3.

Previous Incidents

HRW has documented Israeli use of white phosphorus in:

• Lebanon during a 2023 conflict with Hezbollah
• Gaza (2009)

In 2013, Israel pledged to reduce use of the substance.

"It can still burn for several days or weeks later. Our investigators visited places in Gaza days after where white phosphorus was air-dropped, and it was still there." – Budour Hassan, Amnesty International

Israel's Position

Israel denies using white phosphorus in a way that violates international law, stating it uses the substance only for smoke screens.

Background on International Law

White phosphorus use is not banned outright. However, using it in or near populated areas is illegal due to indiscriminate harm. The Chemical Weapons Convention explicitly prohibits incendiary agents in civilian areas.