Perchloromethyl mercaptan

CAS number: 594–42–3

NIOSH REL: 0.1 ppm (0.8 mg/m³) TWA

Current OSHA PEL: 0.1 ppm (0.8 mg/m³) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 0.1 ppm (0.76 mg/m³) TWA

Description of substance: Pale-yellow, oily liquid with an unbearable, acrid odor.

LEL: . . Noncombustible Liquid

Original (SCP) IDLH: 10 ppm

Basis for original (SCP) IDLH: No useful data on acute inhalation toxicity are available on which to base the IDLH for perchloromethyl mercaptan. The chosen IDLH, therefore, has been based on an analogy with hydrogen sulfide. According to ACGIH, perchloromethyl mercaptan is about 20 times more toxic than hydrogen sulfide which has an IDLH of 300 ppm.

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 Rat Mouse Human Mouse Mouse Rat	Althoff 1973 Althoff 1973 Althoff 1973 Flury &Zernik 1931 Izmerov et al. 1982 Marhold 1972 Vernot et al. 1977	11 16 9 ----- 38 ----- 11	----- ----- ----- 388 ----- 46 -----	1 hr 1 hr 3 hr 10 min 2 hr 15 min 1 hr	14 ppm (1.25) 20 ppm (1.25) 16 ppm (1.8) 268 ppm (0.69) 61 ppm (1.6) 36 ppm (0.79) 14 ppm (1.25)	1.4 ppm 2.0 ppm 1.6 ppm 27 ppm 6.1 ppm 3.6 ppm 1.4 ppm

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rat	Marhold 1972	oral	82.6	-----	75 ppm	7.5 ppm

Other human data: It has been stated that perchloromethyl mercaptan is about one-sixth as toxic as phosgene [Prentiss 1937].

Revised IDLH: 10 ppm [Unchanged] Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Flury and Zernik 1931], a value of about 25 ppm would have been appropriate for perchloromethyl mercaptan. However, the original IDLH for perchloromethyl mercaptan (10 ppm) is not being revised at this time based on an analogy to phosgene [Prentiss 1937] which has a revised IDLH of 2 ppm.

REFERENCES:

1. ACGIH [?].

2. Althoff H [1973]. Todliche perchlormethylmercaptan-intoxikation. Arch Toxikol 31:121-134. [From ACGIH [1991]. Perchloromethyl mercaptan. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 1195-1196.]

3. Flury F, Zernik F [1931]. Schädliche gase dämpfe, nebel, rauch- und staubarten. Berlin, Germany: Verlag von Julius Springer, p. 362 (in German).

4. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 97.

5. Marhold JV [1972]. Sbornik vysledku toxixologiekeho vysetreni latek a pripravku. Prague, Czechoslovakia: Institut Prumyclu, p. 13 (in Czechoslovakian).

6. Prentiss AM [1937]. Chemicals in war. A treatise on chemical warfare. New York, NY: McGraw-Hill Book Company, Inc., p. 154.

7. Vernot EH, MacEwen JD, Haun CC, Kinkead ER [1977]. Acute toxicity and skin corrosion data for some organic and inorganic compounds and aqueous solutions. Toxicol Appl Pharmacol 42(2):417-423.