Amorphorous phosphorus (red phosphorus) is a reddish-violet powder that is not considered toxic in its pure form. It is stable under ordinary conditions, however is flammable and can be initiated by excesive shock or friction.

Yellow phosphorus (white phosphorus) is a significantly more hazardous form of the element and may be present as a contaminant in red phosphorus. This allotrope of phosphorus is extremely toxic and the estimated human lethal dose is 50 - 100 mg. This form must be stored under water as it burns rapidly and is spontaneously combustible upon exposure to air.

When working with amorphous phosphorus, it is prudent to consider the potential for yellow phosphorus contamination and related precautions required to handle the material safely.

Emergency Procedures

Skin/Eye Contact:  Red phosphorous is not harmful to skin or mucuous membranes. White phosphorus may cause deep, slow healing burns. Brush off any visible solids.  Rinse with copious amounts of water for at least 15 minutes.  Seek medical attention as needed.  Thoroughly clean contaminated clothing and shoes before reuse.

Ingestion:  Red phosphorous is consider non-toxic in its pure form. However, nausea, vomiting, abdominal pain or garlic odor on breath will indicate poisoning by the yellow allotrope. DO NOT INDUCE VOMITING.  Drink 2-3 glasses of water and seek medical attention immediately.

Inhalation: Red phosphorus is not considered toxic but contamination with yellow phosphorus may cause coughing, bronchitis, possible liver or kidney impairment. Remove to fresh air. If not breathing, give artificial respiration. Seek medical attention immediately.

Fire:  Flood with water and cover with wet sand to keep moist.  Keep wet.

Spill:  Keep spilled material moist.  Wearing personal protective equipment, cover the spill with water and/or wet sand.  Scoop spilled materials with spark-resistant tools and place in a container for disposal.


Wear safety glasses, impervious gloves and a fire-retardant laboratory coat.  Control ignition sources and avoid dust formation.  Avoid heat, shock and friction.  Keep a supply of wet sand available in the work area and ensure there is a water/wet foam extinguisher immediately available.

When large quantities of red or white phosphorus will be used, work in an inert atmosphere, such as a glove box.

Both allotropes of phosphorus are incompatible with halogens, halides, sulfur, oxidizing materials, and will form toxic phosphine gas upon exposure to alkali materials.


Keep red phosphorus in tightly sealed containers in a cool dry place, separate from incompatible materials. Keep yellow phosphorus or contaminated amorphous phosphorus in sealed containers under water to avoid exposure to air.


Store wastes (under a layer of water) in tightly sealed containers.  Dispose as hazardous waste.

For More Information

See safety data sheet for Red Phosphorus from Sigma Aldrich.


Stanley Howell
Program Manager - Chemical Safety

Steve Elwood
Associate Director for Laboratory Safety