Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 75-07-0
NIOSH REL: None established; NIOSH considers acetaldehyde to be a potential occupational carcinogen as defined by the OSHA carcinogen policy [29 CFR 1990].
Current OSHA PEL: 200 ppm (360 mg/m3) TWA
1989 OSHA PEL: 100 ppm (180 mg/m3) TWA, 150 ppm (270 mg/m3) STEL
1993-1994 ACGIH TLV: 25 ppm (45 mg/m3) CEILING, A3
Description of substance: Colorless liquid or gas (above 69øF) with a pungent, fruity odor.
LEL: 4.0% (10% LEL, 4,000 ppm)
Original (SCP) IDLH: 10,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statements by Patty  and ACGIH  that all rats survived a 4-hour exposure to 8,000 ppm, but all rats died from a 16,000 ppm exposure [Smyth 1956].
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||Appelman et al. 1982||13,000||—–||4 hr||26,000 ppm (2.0)||2,600 ppm|
|Hamster||Feron 1979||17,000||—–||4 hr||34,000 ppm (2.0)||3,400 ppm|
|Rat||Skog 1950||20,000||—–||30 min||20,000 ppm (1.0)||2,000 ppm|
|Rat||Skog 1950||20,536||—–||30 min||26,536 ppm (1.0)||2,054 ppm|
Other animal data: RD50 (mouse), 4,946 ppm [Alarie 1981].
Human data: None relevant for use in determining the revised IDLH.
Revised IDLH: 2,000 ppm
Basis for revised IDLH: The revised IDLH for acetaldehyde is 2,000 ppm based on acute inhalation toxicity data in animals [Alarie 1981; Skog 1950]. [Note: NIOSH recommends as part of its carcinogen policy that the “most protective” respirators be worn for acetaldehyde at any detectable concentration.]
- ACGIH . Acetaldehyde. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 1-2.
- Alarie Y . Dose-response analysis in animal studies: prediction of human responses. Environ Health Perspect 42:9-13.
- Appelman LM, Woutersen RA, Feron VJ . Inhalation toxicity of acetaldehyde in rats. I. Acute and subchronic studies. Toxicology 23(4):293-307.
- Feron VS . Effects of exposure to acetaldehyde in Syrian hamsters simultaneously treated with benzo(a)pyrene or diethylnitrosamine. Prog Exp Tumor Res 24:162-176.
- Patty FA, ed. . Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1967.
- Skog E . A toxicological investigation of lower aliphatic aldehydes. I. Toxicity of formaldehyde, acetaldehyde, and butryaldehyde; as well as acrolein and crotonaldehyde. Acta Pharmacol Toxicol 6(4):299-318.
- Smyth HF Jr . Improved communication: hygienic standards for daily inhalation. Am Ind Hyg Assoc Q 17(2):129-185.