PHOSPHORUS

Phosphorus
(White phosphorus, yellow phosphorus)
CAS 7723-14-0

P₄

White to yellow, waxy soft solid
bp 279 °C, mp 44 °C
(Red phosphorus is an amorphous allotropic form that sublimes at 416 °C)
Insoluble in water (0.0003 g/100 mL)

Acrid fumes when exposed to air

4.4 at 279 °C (air = 1.0)

0.03 mmHg at 20 °C

White phosphorus: 30 °C

White phosphorus: 29 °C
Red phosphorus: 260 °C

LD₅₀ oral (rat) 3 mg/kg

PEL (OSHA) 0.1 mg/m ³

TLV-TWA (ACGIH) 0.02 ppm (0.1 mg/m³)

Spontaneously ignites in air; highly toxic by all routes of exposure.

White phosphorus is a highly toxic substance by all routes of exposure. Contact of the solid with the skin produces deep painful burns, and eye contact can cause severe damage. Ingestion of phosphorus leads (after a delay of a few hours) to symptoms including nausea, vomiting, belching, and severe abdominal pain. Apparent recovery may be followed by a recurrence of symptoms. Death may occur after ingestion of 50 to 100 mg due to circulatory, liver, and kidney effects. Phosphorus ignites and burns spontaneously when exposed to air, and the resulting vapors are highly irritating to the eyes and respiratory tract.

Red phosphorus is much less toxic than the white allotrope; however, samples of red phosphorus may contain the white form as an impurity.

Early signs of chronic systemic poisoning by phosphorus are reported to include anemia, loss of appetite, gastrointestinal distress, chronic cough, a garlic-like odor to the breath, and pallor. A common response to severe chronic poisoning is damage of the jaw ("phossy jaw") and other bones. Phosphorus has not been reported to show carcinogenic effects in humans.

White phosphorus ignites spontaneously upon contact with air, producing an irritating, dense white smoke of phosphorus oxides. Use water to extinguish phosphorus fires.

Red phosphorus is a flammable solid but does not ignite spontaneously on exposure to air. At high temperatures (~300 °C), red phosphorus is converted to the white form.

White phosphorus reacts with a number of substances to form explosive mixtures. For example, dangerous explosion hazards are produced upon reaction of phosphorus with many oxidizing agents, including chlorates, bromates, and many nitrates, with chlorine, bromine, peracids, organic peroxides, chromium trioxide, and potassium permanganate, with alkaline metal hydroxides (phosphine gas is liberated), and with sulfur, sulfuric acid, and many metals, including the alkali metals, copper, and iron.

Red phosphorus is much less reactive than the white allotrope but may ignite or react explosively with strong oxidizing agents.

Because of its corrosivity, flammability, and high acute toxicity, white phosphorus should be handled using the "basic prudent practices" of Chapter 5.C, supplemented by the additional precautions for work with compounds of high toxicity (Chapter 5.D) and extremely flammable substances (Chapter 5.F). In particular, work with white phosphorus should be conducted in a fume hood to prevent exposure by inhalation, and splash goggles and impermeable gloves should be worn at all times to prevent eye and skin contact. Phosphorus should be stored under water in secondary containers in areas separate from oxidizing agents and other incompatible substances. The less dangerous red form of phosphorus can be handled using the "basic prudent practices" of Chapter 5.C.

In the event of skin contact, immediately flush with water and remove contaminated clothing. Wet the skin until medical attention is obtained to prevent any remaining phosphorus from igniting. In case of eye contact, promptly wash with copious amounts of water for 15 min (lifting upper and lower lids occasionally) and obtain medical attention. If phosphorus is ingested, give the person (if conscious) large quantities of water to drink and obtain medical attention immediately. If large amounts of phosphorus or smoke and fumes from burning phosphorus are inhaled, move the person to fresh air and seek medical attention at once.

In the event of a spill, douse with water and cover with wet sand or earth; collect material in a suitable container and dispose of properly. Respiratory protection may be necessary in the event of a spill or release in a confined area.

Excess phosphorus and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution's waste disposal guidelines.

The information in this LCSS has been compiled by a committee of the National Research Council from literature sources and Material Safety Data Sheets and is believed to be accurate as of July 1994. This summary is intended for use by trained laboratory personnel in conjunction with the NRC report Prudent Practices in the Laboratory: Handling and Disposal of Chemicals. This LCSS presents a concise summary of safety information that should be adequate for most laboratory uses of the title substance, but in some cases it may be advisable to consult more comprehensive references. This information should not be used as a guide to the nonlaboratory use of this chemical.

Copyright 1995 National Academy of Sciences. All rights reserved.