May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

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


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derivedvalue


Eastman 1978Eastman 1978

Flury and Zernik 1931

LC67: 22,000LC67: 9,000 ———-


2.3 hr3 hr

3 hr

36,520 ppm (1.66)16,200 ppm (1.8)

8,000 ppm (1.0)

3,652 ppm1,620 ppm

800 ppm


Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value


G. pig

Clayton and Clayton 1981Clayton and Clayton 1981

Izmerov et al. 1982

Izmerov et al. 1982










3,425 ppm3,365 ppm

3,440 ppm

3,365 ppm

343 ppm337 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.



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.

Page last reviewed: December 4, 2014