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Acetonitrile
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 75-05-8
NIOSH REL: 20 ppm (34 mg/m3) TWA
Current OSHA PEL: 40 ppm (70 mg/m3) TWA
1989 OSHA PEL: 40 ppm (70 mg/m3 TWA), 60 ppm (105 mg/m3) STEL
1993-1994 ACGIH TLV: 40 ppm (67 mg/m3) TWA, 60 ppm (101 mg/m3) STEL
Description of substance: Colorless liquid with an aromatic odor.
LEL: 3.0% (10% LEL, 3,000 ppm)
Original (SCP) IDLH: 4,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the UCC [1965] report that a 4-hour exposure to 4,000 ppm killed 3 of 30 rats, 8,000 ppm killed 10 of 30 rats, and 16,000 ppm killed 17 of 30 rats. It is also based on the statement by AIHA [1960] that some deaths occurred in rats, dogs, and guinea pigs at 4,000 ppm, but no deaths occurred at 1,000 ppm. Pozzani et al. [1959] reported that a 53,000 ppm exposure was lethal to 3 of 6 rats in 30 minutes.
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 |
|---|---|---|---|---|---|---|
| G. pig | Pozzani et al. 1959 | 5,655 | —– | 4 hr | 11,310 ppm (2.0) | 1,131 ppm |
| Dog | Pozzani et al. 1959 | —– | 16,000 | 4 hr | 32,000 ppm (2.0) | 3,200 ppm |
| Rabbit | Pozzani et al. 1959 | 2,828 | —– | 4 hr | 5,656 ppm (2.0) | 566 ppm |
| Rat | Pozzani et al. 1959 | 53,000 | —– | 30 min | 53,000 ppm (1.0) | 5,300 ppm |
| Rat | Pozzani et al. 1959 | 7,500 | —– | 8 hr | 18,750 ppm (2.5) | 1,875 ppm |
| Mouse | Willhite 1981 | 2,693 | —– | 1 hr | 3,366 ppm (1.25) | 337 ppm |
Human data: Exposures to 160 ppm for 4 hours has caused flushing of the face and a feeling of constriction in the chest; exposures to 500 ppm for brief (undefined) time periods has resulted in only irritation to the nose and throat [Deichmann and Gerarde 1969].
| Revised IDLH: 500 ppmBasis for revised IDLH: The revised IDLH for acetonitrile is 500 ppm based on acute inhalation toxicity data in humans [Deichmann and Gerarde 1969]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 500 ppm. |
REFERENCES:
- AIHA [1960]. Acetonitrile. In: Hygienic guide series. Am Ind Hyg Assoc J 21:265-266.
- Deichmann WB, Gerarde HW [1969]. Acetonitrile (methyl cyanide; ethanenitrile). In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., p. 65.
- Pozzani UC, Carpenter CP, Palm PE, Weil CS, Nair JH III [1959]. An investigation of the mammalian toxicity of acetonitrile. J Occup Med 1:634-642.
- UCC [1965]. Toxicology studies: acetonitrile. New York, NY: Union Carbide Corporation.
- Willhite CC [1981]. Inhalation toxicology of acute exposure to aliphatic nitriles. Clin Toxicol 18(8):991-1003.