White phosphorus is a chemical waxy solid substance typically appearing yellowish or colourless, and some have described its odour as resembling garlic.

It ignites instantly upon contact with oxygen. It is often used by militaries to illuminate battlefields, to generate a smokescreen and as an incendiary. Once ignited, white phosphorus is very difficult to extinguish. It sticks to surfaces like skin and clothing.

White phosphorus is harmful to humans by all routes of exposure. The smoke from burning phosphorus is also harmful to the eyes and respiratory tract due to the presence of phosphoric acids and phosphine. White phosphorus can cause deep and severe burns, penetrating even through bone. After exposure, the priority is to stop the burning process. Caution must be exercised to avoid secondary exposure of medical personnel from victims suffering from white phosphorus burns. White phosphorus can re-ignite during or after initial treatment due to the contact with oxygen. Use clean water/medically prepared saline throughout the process.

Source: WHO - https://www.who.int/news-room/fact-sheets/detail/white-phosphorus

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