Phosphorus trichloride

CAS number: 7719–12–2

NIOSH REL: 0.2 ppm (1.5 mg/m³) TWA, 0.5 ppm (3 mg/m³) STEL

Current OSHA PEL: 0.5 ppm (3 mg/m³) TWA

1989 OSHA PEL: 0.2 ppm (1.5 mg/m³) TWA, 0.5 ppm (3 mg/m³) STEL

1993-1994 ACGIH TLV: 0.2 ppm (1.1 mg/m³) TWA, 0.5 ppm (2.8 mg/m³) STEL

Description of substance: Colorless to yellow, fuming liquid with an odor like hydrochloric acid.

LEL :. . Noncombustible Liquid

Original (SCP) IDLH: 50 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by ACGIH [1971] that serious disturbances in animals resulted from exposure to 50 to 90 ppm for 1 hour [Butjagin 1904].

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal concentration data:

Species	Reference	LC50 (ppm)	LCLo (ppm)	Time	Adjusted 0.5-hr LC (CF)	Derived value
Rat G. pig	Weeks et al. 1964 Weeks et al. 1964	104 50	----- -----	4 hr 4 hr	208 ppm (2.0) 100 ppm (2.0)	21 ppm 10 ppm

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rat	Parent 1990	oral	18	-----	22 ppm	2.2 ppm

Other animal data: Cats and guinea pigs exposed for 6 hours at 0.7 ppm showed only mild signs of intoxication and a 1-hour exposure at 2 to 4 ppm failed to produce severe signs of poisoning; however, a single 1-hour exposure at 50 to 90 ppm resulted in serious disturbances [Butjagin 1904].

Human data: Workers exposed to concentrations ranging from 1.8 to 27 ppm had symptoms that included burning of the eyes and throat, irritation of the pharyngeal mucous membranes, and mild bronchitis within 2 to 6 hours after exposure [Sassi 1952].

Revised IDLH: 25 ppm Basis for revised IDLH: The revised IDLH for phosphorus trichloride is 25 ppm based on acute inhalation toxicity data in humans [Sassi 1952] and animals [Butjagin 1904; Weeks et al. 1964].

REFERENCES:

1. ACGIH [1971]. Phosphorus trichloride. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 211-212.

2. Butjagin PW [1904]. Experimental studies on the effect of technically and hygienically important gases on the organism. Part XII. Studies on phosphorus trichloride. Arch Hyg 49:307-335 (in German). [From ACGIH [1971]. Phosphorus trichloride. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 211-212.]

3. Parent RA, ed. [1990]. Acute toxicity data. J Am Coll Toxicol, Part B 1:71.

4. Sassi C [1952]. Occupational poisoning with phosphorus trichloride. Med Lav 43:298-306 (in Italian).

5. Weeks MH, Musselman NP, Yevich PP, Jacobson KH, Oberst FW [1964]. Acute vapor toxicity of phosphorus oxychloride phosphorus trichloride and methyl phosphoric dichloride. Am Ind Hyg Assoc J 25:470-475.