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

CAS number: 107–20–0

NIOSH REL: 1 ppm (3 mg/m3) CEILING

Current OSHA PEL: 1 ppm (3 mg/m3) CEILING

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 1 ppm (3.2 mg/m3) CEILING

Description of Substance: Colorless liquid with an acrid, penetrating odor.

LEL: . . Unknown

Original (SCP) IDLH: 100 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on an analogy with crotonaldehyde. Rinehart [1967] found 100 ppm crotonaldehyde to be a lethal concentration for rats for a 4-hour exposure; the LC50 for 30 minutes was 600 ppm. Human subjects found 45 ppm crotonaldehyde very disagreeable and conjunctival irritation was observed [Dow 1962 as cited by ACGIH 1971]. Based on the data cited above for crotonaldehyde, an IDLH of 100 ppm is chosen for chloroacetaldehyde.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derivedvalue
Rat EPA 1987 200 —– 1 hr 250 ppm (1.25) 25 ppm


Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value
RatMouse Lawrence et al. 1972Lawrence et al. 1972 oraloral 8982 ———- 191 ppm176 ppm 19 ppm18 ppm


Human data: Volunteers found 45 ppm to be very disagreeable and conjunctival irritation was observed [Dow 1962].



1. ACGIH [1971]. Crotonaldehyde. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 62-63.

2. Dow [1962]. Personal communication to a ACGIH TLV Committee member from the Dow Chemical Company, Biochemical Research Department.

3. EPA [1987]. TSCA section 8e submission and status report on chloroacetone and chloroacetaldehyde. Washington, DC: U.S. Environmental Protection Agency, Office of Toxic Substances, Report No. 8EHQ-0387-0660, April 22, 1987.

4. Lawrence WH, Dillingham EO, Turner JE [1972]. Toxicity profile of chloracetaldehyde. J Pharm Sci 61:19-25.

5. Rinehart WE [1967]. The effect on rats of single exposures to crotonaldehyde vapor. Am Ind Hyg Assoc J 28:561-566.

Page last reviewed: December 4, 2014