Substance

Phosphorus

(White phosphorus, yellow phosphorus)

CAS 7723-14-0

Formula

P₄

Physical Properties

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)

Odor

Acrid fumes when exposed to air

Vapor Density

4.4 at 279 °C (air = 1.0)

Vapor Pressure

0.03 mmHg at 20 °C

Flash Point

White phosphorus: 30 °C

Autoignition Temperature

White phosphorus: 29 °C

Red phosphorus: 260 °C

Toxicity Data

LD₅₀ oral (rat)

3 mg/kg

PEL (OSHA)

0.1 mg/m³

TLV-TWA (ACGIH)

0.02 ppm (0.1 mg/m³)

Major Hazards

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

Toxicity

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.