Agent Name
CAS Number
Major Category
Toxic Gases & Vapors
Hydrogen phosphide; Phosphorated hydrogen; Phosphorus hydride; Phosphorus trihydride; [NIOSH]
Colorless gas with a fish- or garlic-like odor. [pesticide] [Note: Shipped as a liquefied compressed gas. Pure compound is odorless.] [NIOSH] Vapor density = 1.17 (heavier than air); [Burke, p. 102]
Phosphine is used as a fumigant and as a dopant in microelectronics manufacturing. Also, law enforcement officers dismantling methamphetamine production labs have died from inhalation of phosphine. Veterinarians were exposed to phosphine gas while treating animals that ingested phosphide salts. [ACGIH] Phosphine is produced by reacting water or acid with metallic phosphides. It may be formed during the production of acetylene gas. "Phosphine is used in the semiconductor industry to introduce phosphorus into silicon crystals as an intentional impurity. It also is used as a fumigant and a polymerization initiator." [ATSDR Medical Management] "If phosphoric acid is used as a catalyst, phosphine can be formed in the strongly reducing atmosphere of the hot emissions. In air, phosphine rapidly oxidizes to phosphorus oxide." [IARC 2012: Iron and steel founding]
“Phosphine is a respiratory tract irritant that attacks primarily the cardiovascular and respiratory systems causing peripheral vascular collapse, cardiac arrest and failure, and pulmonary edema.” [ATSDR Medical Management] “Fumigation workers exposed to phosphine experienced respiratory symptoms of ‘suffocation,’ difficulty breathing, and tightness around the chest lasting up to 3 hours post-exposure and neurological symptoms of headache and giddiness lasting from 10 minutes to 3 hours.” Fatal inhalation exposures to aluminum phosphide fumigation have been reported in ship cargo holds. [ACGIH] Phosphine may be released when the following chemicals are spilled in water: calcium phosphide, aluminum phosphide, sodium phosphide, magnesium aluminum phosphide, magnesium phosphide, potassium phosphide, and strontium phosphide. [ERG 2016] Possible frostbite from contact with liquid; [NIOSH] Phosphides (aluminum, magnesium, and zinc) are used as fumigants and rodenticides. They are major causes of accidental and suicidal poisoning in India and developing countries. The lowest lethal oral doses reported in adults are 500 mg for aluminum phosphide and 4 g for zinc phosphide. Phosphide causes vomiting, diarrhea, and shock after ingestion. Later symptoms are ARDS, acute renal failure, hepatitis, convulsions, and coma. Methemoglobinemia has been reported. [Olson, p. 372-3]
Biomedical References

Exposure Assessment

Skin Designation (ACGIH)
Insufficient data
0.05 ppm
Ceiling (ACGIH)
0.15 ppm
0.3 ppm
0.1 ppm
50 ppm
Excerpts from Documentation for IDLHs
Symptoms such as diarrhea, nausea and vomiting, tightness of the chest, cough, headache, and dizziness have been reported in workers exposed intermittently to concentrations up to 35 ppm [Jones et al. 1964]. It has been stated that 290 to 430 ppm is dangerous to life after 1 hour, and 100 to 200 ppm is the maximum amount for 0.5 to 1 hour [Henderson and Haggard 1943].
Odor Threshold Low
0.01 ppm
Odor Threshold High
5 ppm
Lethal Concentration
LC50 (rat) = 11 ppm/4H
Explanatory Notes
Recognition odor threshold from AIHA (mean = 0.14 ppm); Can ignite spontaneously in cold air; [CHEMINFO] "Odor is not a reliable warning mechanism for phosphine." Ignites spontaneously on contact with air at room temperature; [ACGIH]
Reference Link #2
burn readily
Not appropriate
0.5 ppm
5 ppm

Adverse Effects

Toxic Pneumonitis
MetHgb is secondary toxic effect
Other CNS neurotoxin
Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion
ACGIH Carcinogen
Not Classifiable

Diseases, Processes, and Activities Linked to This Agent


Occupational diseases associated with exposure to this agent: