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

CAS number: 532–27–4

NIOSH REL: 0.3 mg/m3 (0.05 ppm) TWA

Current OSHA PEL: 0.3 mg/m3 (0.05 ppm) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 0.32 mg/m3 (0.05 ppm) TWA

Description of Substance: Colorless to gray crystalline solid with a sharp, irritating odor.

LEL: . . Unknown

Original (SCP) IDLH: 100 mg/m3

Basis for original (SCP) IDLH: ACGIH [1971] reported that the effective concentration to produce casualties as estimated from volunteer exposure is greater than 100 mg/m3. Deichmann and Gerarde [1969] reported that a fatality followed an exposure of less than 20 minutes to high concentrations of vapor (5.4 grams in a 34 m3 room, which is roughly equivalent to 160 mg/m3). Based on the data cited above, an IDLH of 100 mg/m3 is chosen.

Short-term exposure guidelines: None developed


Lethal concentration data:

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

G. pig



Ballantyne and Swanston 1978Ballantyne and Swanston 1978

Ballantyne and Swanston 1978

Ballantyne and Swanston 1978

Deichmann and Gerarde 1969

Prentiss 1937






417 mg/m3600 mg/m3

465 mg/m3

490 mg/m3

159 mg/m3

850 mg/m3

15 min15 min

20 min

30 min

20 min

10 min

329 mg/m3 (0.79)474 mg/m3 (0.79)

405 mg/m3 (0.87

490 mg/m3 (1.0)

138 mg/m3 (0.87)

587 mg/m3 (0.69)

33 mg/m347 mg/m3

41 mg/m3

49 mg/m3

14 mg/m3

59 mg/m3


Other animal data: RD50 (mouse), 6.2 mg/m3 [Alarie 1981].

Other human data: It has been reported that 31 mg/m3 is intolerable after 3 minutes [Punte et al. 1962].



1. ACGIH [1971]. alpha-Chloroacetophenone. In: Documentation of threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 48-49.

2. Alarie Y [1981]. Dose-response analysis in animal studies: prediction of human responses. Environ Health Perspect 42:9-13.

3. Ballantyne B, Swanston DW [1978]. The comparative acute mammalian toxicity of 1-chloroacetophenone (CN) and 2-chlorobenzylidene malononitrile (CS). Arch Toxicol 40:75-95.

4. Deichmann WB, Gerarde HW [1969]. Chloroacetophenone. In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., p. 163.

5. Prentiss AM [1937]. Chemicals in war. A treatise on chemical warfare. New York, NY: McGraw-Hill Book Company, Inc., pp. 142-144.

6. Punte CL, Ballard TA, Weimer JT [1962]. Inhalation studies with chloroacetophenone, diphenylaminochloroarsine and pelargonic morpholide. I. Animal exposures. Am Ind Hyg Assoc J 23:194-198.