Title: Phosphine

CAS Registry Number: 7803-51-2

Molecular Formula: H3P

Molecular Weight: 34.00

Percent Composition: H 8.89%, P 91.10%

Line Formula: PH3

Literature References: Formed in small quantity in the putrefaction of organic matter contg phosphorus. Prepd from white phosphorus and aq alkali hydroxide; also by treatment of PH4I with KOH: Klement in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) pp 525-530; by pyrolysis of phosphorous acid: Gokhale, Jolly, Inorg. Synth. 9, 56 (1967); by hydrolysis of a metal phosphide such as calcium phosphide: Klement, loc. cit.; Baudler et al., Z. Anorg. Allg. Chem. 353, 122 (1967). Review of human exposure and toxicity: N. Brautbar, J. Howard, Toxicol. Ind. Health 18, 71-75 (2002).

Properties: Gas. Poisonous! Odor of decaying fish; bp -87.7°. mp -133°. Spontaneously flammable in air if there is a trace of P2H4 present; burns with a luminous flame. Slightly sol in water (0.26 vol. at 20°). Combines violently with oxygen and the halogens. Liberates hydrogen and forms the phosphide when passed over heated metal. Forms phosphonium salts when brought in contact with the halogen acids.

Melting point: mp -133°

Boiling point: bp -87.7°

CAUTION: Potential symptoms of overexposure are nausea, vomiting, abdominal pain, diarrhea; thirst; chest tightness, dyspnea; muscle pain, chills; stupor or syncope; pulmonary edema. Direct contact with liquid may cause frostbite. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 254. See also Clinical Toxicology of Commercial Products, R. E. Gosselin et al., Eds. (Williams & Wilkins, Baltimore, 5th ed., 1984) Section II, p 119.