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  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
ACUTE TOXICITY DATA
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].
|Revised IDLH: 45 ppmBasis for revised IDLH: The revised IDLH for chloroacetaldehyde is 45 ppm based on acute inhalation toxicity data in humans [Dow 1962]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 45 ppm.|
1. ACGIH . 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 . Personal communication to a ACGIH TLV Committee member from the Dow Chemical Company, Biochemical Research Department.
3. EPA . 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 . Toxicity profile of chloracetaldehyde. J Pharm Sci 61:19-25.
5. Rinehart WE . The effect on rats of single exposures to crotonaldehyde vapor. Am Ind Hyg Assoc J 28:561-566.