Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 10026–13–8
NIOSH REL: 1 mg/m3 TWA
Current OSHA PEL: 1 mg/m3 TWA
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 0.85 mg/m3 (0.1 ppm) TWA
Description of substance: White to pale-yellow, crystalline solid with a pungent, unpleasant odor.
LEL: . . Noncombustible Solid
Original (SCP) IDLH: 200 mg/m3
Basis for original (SCP) IDLH: The chosen IDLH is based on an analogy with phosphorus trichloride (PCl3) and statements by Henderson and Haggard  that 2 to 4 ppm Pcl3 is the maximum concentration allowable for short exposures (0.5 to 1 hour) and 50 to 90 ppm is dangerous for short exposures. Therefore, 200 mg/m3 (24 ppm) is chosen as the IDLH for phosphorus pentachloride.
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA:
Lethal concentration data:
|Species||Reference||LC50||LCLo||Time||Adjusted 0.5-hrLC (CF)||Derived value|
|Mouse||Henderson & Haggard 1943||—–||1,020 mg/m3||10 min||704 mg/m3 (1.45)||70 mg/m3|
|Rat||Molodkena 1973||205 mg/m3||—–||?||?||?|
Lethal dose data:
|Species||Reference||Route||LD50(mg/kg)||LDLo(mg/kg)||Adjusted LD||Derived value|
|Rat||Molodkena 1973||oral||660||—–||4,620 mg/m3||462 mg/m3|
Other data: The vapors of phosphorus pentachloride decompose in the presence of moisture with the subsequent liberation of hydrochloric and phosphoric acids [Henderson and Haggard 1943].
Human data: None relevant for use in determining the revised IDLH.
|Revised IDLH: 70 mg/m3Basis for revised IDLH: The revised IDLH for phosphorus pentachloride is 70 mg/m3 based on acute inhalation toxicity data in animals [Henderson and Haggard 1943]. This may be a conservative value due to the lack of relevant acute toxicity data for workers. However, an IDLH of 70 mg/m3 for phosphorus pentachloride (Pcl5) is roughly equivalent on a “chlorine basis” to the revised IDLH of 50 ppm (i.e., 75 mg/m3) for hydrogen chloride (HCl) which may be appropriate since PCl5 decomposes in the presence of moisture to HCl [Henderson and Haggard 1943].|
1. Henderson Y, Haggard HW . Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, p. 134.
2. Molodkena NN . Toxicological comparisons of chlorine phosphate compounds (POCl3, PCl3, PCl5) by single and repeated exposures. Toksikol Nov Prom Khim Vesh 13:104 (in Russian).