Acetonitrile

                            
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:


Adjusted LC50 LCLo 0.5-hr Derived Species Reference (ppm) (ppm) Time LC (CF) 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 ppm
Basis 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:

  1. AIHA [1960]. Acetonitrile. In: Hygienic guide series. Am Ind Hyg Assoc J 21:265-266.
  2. Deichmann WB, Gerarde HW [1969]. Acetonitrile (methyl cyanide; ethanenitrile). In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., p. 65.
  3. 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.
  4. UCC [1965]. Toxicology studies: acetonitrile. New York, NY: Union Carbide Corporation.
  5. Willhite CC [1981]. Inhalation toxicology of acute exposure to aliphatic nitriles. Clin Toxicol 18(8):991-1003.

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