Chlorobenzene

CAS number: 108–90–7

NIOSH REL: The 1989 OSHA PEL may not be protective to workers.

Current OSHA PEL: 75 ppm (350 mg/m³) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 10 ppm (46 mg/m³) TWA

Description of Substance: Colorless liquid with an almond-like odor.

LEL: . . 1.3% (10% LEL, 1,300 ppm)

Original (SCP) IDLH: 2,400 ppm

Basis for original (SCP) IDLH: AIHA [1964] reported that 8,000 ppm was fatal to cats in 30 minutes [Patty 1963; Flury and Zernik 1931]. Patty [1963] reported that the exposure of cats for 1 hour to 2,400 to 2,900 ppm causes unsteadiness, tremor, and twitching [Flury and Zernik 1931]. Based on the data cited above, an IDLH of 2,400 ppm is chosen for this draft technical standard.

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 Cat	Eastman 1978 Eastman 1978 Flury and Zernik 1931	LC67: 22,000 LC67: 9,000	----- ----- 8,000	2.3 hr 3 hr 3 hr	36,520 ppm (1.66) 16,200 ppm (1.8) 8,000 ppm (1.0)	3,652 ppm 1,620 ppm 800 ppm

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rat Rabbit Mouse G. pig	Clayton and Clayton 1981 Clayton and Clayton 1981 Izmerov et al. 1982 Izmerov et al. 1982	oral oral oral oral	2,290 2,250 2,300 2,250	----- ----- ----- -----	3,425 ppm 3,365 ppm 3,440 ppm 3,365 ppm	343 ppm 337 ppm 344 ppm 337 ppm

Other animal data: RD₅₀ (mouse), 1,054 ppm [DeCeaurriz et al. 1981].

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

Revised IDLH: 1,000 ppm Basis for revised IDLH: The revised IDLH for chlorobenzene is 1,000 ppm based on acute inhalation toxicity data in animals [DeCeaurriz et al. 1981; Flury and Zernik 1931].

REFERENCES:

1. AIHA [1964]. Chlorobenzene. In: Hygienic guide series. Am Ind Hyg Assoc J 25:97-99.

2. Clayton GD, Clayton FE, eds. [1981]. Patty's industrial hygiene and toxicology. Vol. 2B. Toxicology. 3rd rev. ed. New York, NY: John Wiley & Sons, Inc., p. 3603.

3. DeCeaurriz JC, Micillino JC, Bonnet P, Guenier JP [1981]. Sensory irritation caused by various industrial airborne chemicals. Toxicol Lett 9:137-143.

4. Eastman Kodak Company [1978]. Toxicity and health hazard summary. Rochester, NY. [From ACGIH [1971]. Chlorobenzene. In: Documentation of threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 48-49.]

5. Flury F, Zernik F [1931]. Schädliche gase dämpfe, nebel, rauch- und staubarten. Berlin, Germany: Verlag von Julius Springer, p. 337 (in German).

6. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 34.

7. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1334.