Phosphorus pentasulfide

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

ACUTE TOXICITY DATA:

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.]

REFERENCES:

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.