White phosphorus (Phosphore Blanc) is a colorless, white or yellow, waxy, garlic-smelling combustible solid used in many smoke devices common in military arsenal. White phosphorus (P₄) is an extremely reactive and toxic allotrope of phosphorus, it is a pyrophoric material that ignites spontaneously on contact with air. Combustion stops when all the white phosphorus has been consumed, or when it is no longer in direct contact with oxygen in the air.
Charred pieces of White Phosphorus can retain up to 15% of their white phosphorus content, and may re-ignite if crushed or re-exposed to the open air. Inactive” pieces may reignite several weeks after being deployed.
Military use and regulations
Use
- Create dense smoke screens to mask movements.
- Incendiary agent for destroying structures.
Regulations
- The Convention on Certain Conventional Weapons (CCW) prohibits its use against civilians or in populated areas.
- The 1925 Geneva Protocol, the 1993 Chemical Weapons Convention and international humanitarian law prohibit the use of chemical weapons. As a general rule, white phosphorus munitions are not covered by these prohibitions, as they are not specifically designed or used to cause death or other bodily harm through the toxic properties of white phosphorus smoke. For example, when white phosphorus ammunition is used to produce smoke for camouflage purposes, it is not prohibited as a chemical weapon. However, if a munition containing white phosphorus is specifically designed to cause damage or death through the toxic properties of its smoke, or if white phosphorus is used with this intention (for example, firing a white phosphorus munition into a building to force people out), it would fall within the definition of a chemical weapon. Such use would therefore be prohibited.
Characteristics of white phosphorus
Chemical properties :
- Molecular formula: P₄ (phosphorus tetramer)
- Appearance: Waxy, yellowish-white, odorless solid.
- Flashpoint: Approx. 30°C in open air, ignites spontaneously in contact with atmospheric oxygen.
- Reaction to air :
- In the presence of oxygen, it oxidizes, producing a yellow-white flame and releasing a thick cloud of phosphorus dioxide (P₂O₅).
- Chemical reaction: P4+5O2→P(4) O10
- By-product: Phosphorus pentoxide (P₄O₁₀) is highly hygroscopic, reacting with water to form phosphoric acid (H₃PO₄), a corrosive compound.
Clinical signs and symptoms
Thermochemical burns: White phosphorus burns at around 1300°C, causing thermal and chemical burns. If it comes into contact with the skin, it penetrates rapidly and continues to burn until it is completely consumed or deprived of oxygen. Thermal burns at 2thand 3(th)degrees can cause significant morbidity and prolonged hospitalization.
Asphyxiation: The release of White Phosphorus in an enclosed space may cause asphyxiation due to oxygen depletion. Exposure to smoke produced by burning White Phosphorus from military munitions can cause irritation or damage to the eyes, lungs and throat.
Systemic toxicity: Skin absorption and inhalation of White Phosphorus can lead to tissue necrosis as a result of severe oxidative stress (the lethal dose by ingestion is around 50 mg).
Physiological effects : Whatever the mode of exposure (ingestion, direct contact or inhalation), highly lipid-soluble White Phosphorus eventually accumulates in the liver, heart and kidneys. This can lead to necrosis of the liver (hepatic necrosis) or kidneys (glomerular tubular damage/renal failure). Before kidney and/or liver damage becomes evident, cardiovascular collapse may occur due to hypovolemia caused by chemical burns and cardiotoxicity with heart failure.
White phosphorus can cause serious disorders, such as a rapid drop in calcium (hypocalcemia) and a rise in phosphate (hyperphosphatemia) in the blood, as early as one hour after a burn. These imbalances can lead to cardiac rhythm disorders, with changes in the heart’s electrical activity (e.g., prolongation of the QT interval[1] [1] (with a risk of torsades de pointes), changes in the ST-T wave) and progressive bradycardia.
Death can occur from a relatively small burned area, of the order of 10-15%.
Inhaling white phosphorus for short periods may cause coughing and irritation of the throat and lungs. Inhalation of white phosphorus for long periods may cause a condition known as “phosphorus jaw”, characterized by poor wound healing in the mouth and damage to the jawbone. Ingestion may cause gastrointestinal symptoms (vomiting, abdominal cramps and pain). Ocular exposure may cause irritation, blepharospasm, photophobia, lacrimation and conjunctivitis, and particles may perforate the cornea.
Environmental consequences
Persistence in the environment: White phosphorus can persist in soil and water, posing a long-lasting contamination hazard, and is toxic to aquatic and terrestrial fauna.
Reactions in water: P₄ can react with water to produce weak phosphoric acids, but remains hazardous as it can reform white phosphorus on drying.
Main risks for caregivers
- Secondary chemical and thermal burns: White phosphorus can remain active on patient tissue. In the presence of oxygen, the remaining particles can reignite, causing burns to the caregiver.
- Inhalation of toxic vapours: phosphorus pentoxide (P₂O₅) vapours released during combustion are irritating to the respiratory tract and can cause severe lung damage.
- Skin absorption: Direct contact with skin contaminated with white phosphorus may cause burns and systemic absorption.
- Cross-contamination: Handling contaminated clothing or dressings may spread the substance and prolong exposure.
Patient decontamination and treatment :
Patient decontamination :
During patient decontamination, site safety is the priority. Avoid direct contact with White Phosphorus, and be aware that oxygen may reactivate it. Decontaminate in a well-ventilated area, as absorbed agent may off-gas from clothing and skin.
Skin decontamination: remove all clothing, jewelry, shoes, etc. Wash affected body parts from head to toe with plenty of lukewarm water, protecting the respiratory tract of the patient. Pay particular attention to exposed skin folds, armpits, genitals, feet and eyes*. Then dry the entire body surface with towels to remove desorbed toxic substances and prevent hypothermia. Continuous irrigation can prevent further oxidation and remove particles from the skin surface without the risk of re-inflammation. Phosphorus also fluoresces under ultraviolet light (Wood’s lamp), making it easier to identify encrusted phosphorus.
Wounds: As White Phosphorus spontaneously ignites on contact with air (and can reignite after being extinguished), contaminated wounds should be covered with saline-soaked gauze until the White Phosphorus has completely disappeared. Do not use oily or greasy dressings, as this element is fat-soluble and can penetrate tissues. Careful surgical debridement of any embedded White Phosphorus particles is necessary; wear appropriate gloves and use tools such as forceps or a spoon to remove them. Store any solid particles collected in a water-filled container to prevent re-inflammation.
(*) Eye decontamination: rinse eyes with plenty of water or an isotonic solution. Don’t forget to remove contact lenses!
Patient treatment:
There is no antidote, and treatment is symptomatic. Monitor vital signs, heart rate and 12-lead ECG, and perform blood tests (phosphorus levels, C-reactive protein, glucose, renal and liver function tests and electrolytes). Resuscitate and treat accordingly (respiratory assistance if necessary, treatment of hypotension and arrhythmias, correction of electrolyte abnormalities). Treat burn in accordance with international medical guidelines.
Emergency measures to be taken to limit the risk of White Phosphorus ignition following the treatment of a contaminated victim in a conflict zone
- Personal Protective Equipment (PPE) must be worn by nursing staff: a suitable respirator (FFP3) to reduce inhalation of smoke or White Phosphorus particles, protective goggles and thick work gloves. Gloves should be made of thick leather or similar fire-resistant material. If possible, wear a thick apron and long sleeves in a material similar to that of the gloves. Underneath, wear long garments made of natural materials (cotton, not polyester).
- Have water immediately available in a metal bucket and several towel-sized cloths soaked in water. These can be used to immediately cover any wounds that appear to be smoking.
- Have a pair of surgical scissors ready.
- Make sure the victim is at least 2 m away from any flammable object.
- Immediately extinguish the source of smoke and/or light with a damp cloth or towels, and move away from the smoke or residual fumes.
- If clothing is contaminated and particles cannot be removed, IMMEDIATELY REMOVE CONTAMINATED CLOTHING by cutting with surgical scissors if necessary (DO NOT REMOVE BY THE HEAD) and place in a metal bucket filled with water.
- Decontaminate by brushing away particles with a gloved hand or suitable tool, such as a metal spoon or blunt knife. If particles are stuck to the skin, they should be surgically debrided.
- Check PPE used by healthcare professionals for possible cross-contamination using an ultraviolet lamp (Wood’s lamp).
- In the operating room: debride in a metal bean or similar and cover with water or another liquid to prevent it from igniting inside; a UV lamp can be used to help identify particles remaining in wounds.
- In mortuaries: use running water (if available) to rinse off White Phosphorus particles.
- Contaminated waste management: In an isolated, open area and on a non-flammable surface, empty the contaminated contents of beans and buckets into a metal container and cover with water to prevent ignition of residual White Phosphorus.
Conclusion
The use of White Phosphorus ammunition is reserved for military purposes. However, in practice, civilian personnel involved in conflict zones can suffer collateral damage, including severe toxic burns. Health-care personnel working in war zones are not always aware of the risks associated with this highly flammable chemical, and need to be made aware of prevention and protection measures for their own safety, proper decontamination of victims burned by White Phosphorus, and appropriate symptomatic treatment.
[1] [2] duration of depolarization (contraction) and repolarization (relaxation) of cardiac ventricles