Phosphorus pentasulfide

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

CAS number: 1314–80–3

NIOSH REL: 1 mg/m3 TWA, 3 mg/m3 STEL

Current OSHA PEL: 1 mg/m3 TWA

1989 OSHA PEL: 1 mg/m3 TWA, 3 mg/m3 STEL

1993-1994 ACGIH TLV: 1 mg/m3 TWA, 3 mg/m3 STEL

Description of substance: Greenish-gray to yellow, crystalline solid with an odor of rotten eggs.

LEL: . . Unknown

Original (SCP) IDLH: 750 mg/m3

Basis for original (SCP) IDLH: No data on acute inhalation toxicity are available on which to base the IDLH for phosphorus pentasulfide (P2S5). MCA [1958] reported that “P2S5 is a compound which by itself possesses little toxicity; P2S5, however, hydrolyses [sic] rapidly on contact with water or even with moisture present in the atmosphere to cause the liberation of hydrogen sulfide (H2S) gas.” For this draft technical standard, therefore, the chosen IDLH has been based on an analogy with H2S assuming complete conversion of P2S5 into H2S gas. [Note: The complete conversion of 750 mg/m3 of P2S5 will result in about 400 ppm H2S.]. Patty [1963] reported that 400 to 700 ppm H2S is dangerous after exposure for 0.5 to 1 hour [Henderson and Haggard 1943]. The chosen IDLH for H2S is 300 ppm.

Short-term exposure guidelines: None developed


Lethal dose data:

Species Reference Route LD50 (mg/kg) LDLo (mg/kg) Adjusted LD Derived value
Rat Marhold 1972 oral 389 ----- 2,723 mg/m3 272 mg/m3

Other data: Phosphorus pentasulfide (P2S5) rapidly hydrolyzes to hydrogen sulfide (H2S) and phosphoric acid on contact with water or with moisture present in the air [ACGIH 1991].

Human data: None relevant for use in determining the revised IDLH.

Revised IDLH: 250 mg/m3

Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for phosphorus pentasulfide (P2S5). Therefore, the revised IDLH for phosphorus pentasulfide is 250 mg/m3 based on acute oral toxicity data in animals [Marhold 1972] and an analogy to hydrogen sulfide [ACGIH 1991] which has a revised IDLH of 150 ppm. [Note: The complete conversion of 270 mg/m3 P2S5 will result in 150 ppm H2S.]


1. ACGIH [1991]. Phosphorus pentasulfide. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 1259-1260.

2. Henderson Y, Haggard HW [1943]. Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, p. 245.

3. Marhold JV [1972]. Sbornik vysledku toxixologiekeho vysetreni latek a pripravku. Prague, Czechoslovakia: Institut Prumyclu, p. 16 (in Czechoslovakian).

4. MCA [1958]. Chemical safety data sheet SD-71: properties and essential information for safe handling and use of phosphorus pentasulfide. Washington, DC: Manufacturing Chemists Association, pp. 1-14.

5. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 899.

Page last reviewed: December 4, 2014