Methyl isobutyl carbinol
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 108–11–2
NIOSH REL: 25 ppm (100 mg/m3) TWA, 40 ppm (165 mg/m3) STEL [skin]
Current OSHA PEL: 25 ppm (100 mg/m3) TWA [skin]
1989 OSHA PEL: 25 ppm (100 mg/m3) TWA, 40 ppm (165 mg/m3) STEL [skin]
1993-1994 ACGIH TLV: 25 ppm (104 mg/m3) TWA, 40 ppm (167 mg/m3) STEL
Description of substance: Colorless liquid with a mild odor.
LEL: . . . 1.0% (10% LEL, 1,000 ppm)
Original (SCP) IDLH: 2,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statements by Browning  and Patty  that exposures for 8 hours to 2,000 ppm killed 5 of 6 rats, but no rats died from a 2-hour exposure to the saturated vapor [Smyth et al. 1951].
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA:
Lethal concentration data:
|Species||Reference||LC50 (ppm)||LCLo (ppm)||Time||Adjusted 0.5-hr |
|Rat||Browning 1965||LC83: 2,000||-----||8 hr||5,000 ppm (2.5)||500 ppm|
|Rat||Carpenter et al. 1949||2,000||-----||4 hr||4,000 ppm (2.0)||400 ppm|
|Mouse||McOmie & Anderson 1949||LC60: 4,600||-----||10 hr||12,420 ppm (2.7)||1,242 ppm|
Lethal dose data:
|Species||Reference||Route||LD50 (mg/kg)||LDLo (mg/kg)||Adjusted LD||Derived value|
|McOmie &Anderson 1949 |
Smyth et al. 1951
|1,647 ppm |
|165 ppm |
Other animal data: It has been reported that rats survived a 2-hour exposure to the saturated vapor (about 4,000 ppm at 68°F) [Smyth et al. 1951].
Human data: Eye irritation has occurred after exposures to 50 ppm for 15 minutes [Silverman et al. 1946].
|Revised IDLH: 400 ppm |
Basis for revised IDLH: The revised IDLH for methyl isobutyl carbinol is 400 ppm based on acute inhalation toxicity data in animals [Browning 1965; Carpenter et al. 1949]. This may be a conservative value due to the lack of relevant acute toxicity data for workers exposed to concentrations above 50 ppm.
1. Browning E . Toxicity and Metabolism of Industrial Solvents. New York, NY: Elsevier Publishing Company, p. 369.
2. Carpenter CP, Smyth HF Jr, Pozzani UC . The assay of acute vapor toxicity, and the grading and interpretation of results on 96 chemical compounds. J Ind Hyg Toxicol 31:343-346.
3. McOmie WA, Anderson HH . Comparative toxicologic effects of some isobutyl carbinols and ketones. University of California Publication, Pharmacology 2:217-230.
4. Patty FA, ed. . Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1460.
5. Silverman L, Schulte HF, First MW . Further studies on sensory response to certain industrial solvent vapors. J Ind Hyg Toxicol 28:262-266.
6. Smyth HF Jr, Carpenter CP, Weil CS . Range-finding toxicity data: list IV. AMA Arch Ind Hyg Occup Med 4:119-122.
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