Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 67–63–0
NIOSH REL: 400 ppm (980 mg/m3) TWA, 500 ppm (1,225 mg/m3) STEL
Current OSHA PEL: 400 ppm (980 mg/m3) TWA
1989 OSHA PEL: 400 ppm (980 mg/m3) TWA, 500 ppm (1,225 mg/m3) STEL
1993-1994 ACGIH TLV: 400 ppm (983 mg/m3) TWA, 500 ppm (1,230 mg/m3) STEL
Description of substance: Colorless liquid with the odor of rubbing alcohol.
LEL: . 2.0% (10% LEL, 2,000 ppm)
Original (SCP) IDLH: 12,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty  that rats survived when exposed for 4 hours to 12,000 ppm but exposure for 8 hours to 12,000 ppm resulted in death among one half of the group [Smyth 1956].
Existing short-term exposure guidelines: National Research Council [NRC 1984] Emergency Exposure Guidance Levels (EEGLs):
1-hour EEGL: 400 ppm
24-hour EEGL: 200 ppm
ACUTE TOXICITY DATA:
Lethal concentration data:
|Species||Reference||LC50(ppm)||LCLo(ppm)||Time||Adjusted 0.5-hrLC (CF)||Derived value|
|Carpenter et al. 1949NCI 1974
|4 hr3 hr
|32,000 ppm (2.0)23,040 ppm (1.8)
24,000 ppm (2.0)
|3,200 ppm2,304 ppm
Lethal dose data:
|Species||Reference||Route||LD50(mg/kg)||LDLo(mg/kg)||Adjusted LD||Derived value|
|Antonova & Salmina 1978Antonova & Salmina 1978
|14,126 ppm10,080 ppm
|1,413 ppm1,008 ppm
Other animal data: RD50 (mouse), 17,693 ppm [Alarie 1981]. It has been reported that rats survived when exposed to 12,000 ppm for 4 hours [Smyth 1956].
Human data: Ten volunteers exposed for 3 to 5 minutes to 200, 400, or 800 ppm reported mild to moderate irritation of the eyes, nose, and throat at the two higher concentrations [Nelson et al. 1943]. The probable lethal oral dose has been reported to be 190 grams [Gosselin et al. 1984]. [Note: An oral dose of 190 grams is equivalent to a worker being exposed to about 50,700 ppm for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]
|Revised IDLH: 2,000 ppm [LEL]Basis for revised IDLH: Based on health considerations and acute toxicity data in humans [Gosselin et al. 1984; Nelson et al. 1943] and animals [NCI 1974; Smyth 1956], a value of about 2,400 ppm would have been appropriate for isopropyl alcohol. However, the revised IDLH for isopropyl alcohol is 2,000 ppm based strictly on safety considerations (i.e., being 10% of the lower explosive limit of 2%).|
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2. Antonova VI, Salmina ZA . The maximal permissible concentration of isopropyl alcohol in water bodies with due regard for its action on the gonads and the progeny. Gig Sanit 43(1):8-11 (in Russian).
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