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Isobutyl acetate

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

CAS number: 110–19–0

NIOSH REL: 150 ppm (700 mg/m3) TWA

Current OSHA PEL: 150 ppm (700 mg/m3) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 150 ppm (713 mg/m3) TWA

Description of substance: Colorless liquid with a fruity, floral odor.

LEL: . . 1.3% (10% LEL, 1,300 ppm)

Original (SCP) IDLH: 7,500 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the following statements: a 4-hour exposure to 8,000 ppm killed 4 of 6 rats [UCC 1971; Smyth et al. 1962 as cited by ACGIH 1971] and no deaths resulted from a 4-hour exposure of 6 rats to 4,000 ppm [UCC 1971; Smyth 1964 as cited by ACGIH 1971]. [Note: For “convenience” an IDLH of 7,500 ppm (50 ´ the OSHA PEL of 150 ppm) was chosen rather than 8,000 ppm.]

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal concentration data:

Species Reference LC50 (ppm) LCLo (ppm) Time Adjusted 0.5-hrLC (CF) Derived value
Mammal Clayton & Clayton 1981 LC100: 21,000 —– 2.5 hr 35,700 ppm (1.7) 3,570 ppm
Rat Smyth et al. 1962 LC67: 8,000 —– 4 hr 16,000 ppm (2.0) 1,600 ppm

Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value
Rabbit Munch 1972 oral 4,673 —– 6,772 ppm 677 ppm
Rat NPIRI 1974 oral 13,400 —– 19,420 ppm 1,942 ppm

Other animal data: It was reported that no rats dies following a 4-hour exposure to 4,000 ppm [UCC 1971].

Human data: None relevant for use in determining the revised IDLH.

REFERENCES:

1. ACGIH [1971]. Isobutyl acetate. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 139.

2. Clayton GD, Clayton FE, eds. [1981]. Patty’s industrial hygiene and toxicology. 3rd rev. ed. Vol. 2A. Toxicology. New York, NY: John Wiley & Sons, Inc., p. 2273.

3. Munch JC [1972]. Aliphatic alcohols and alkyl esters: narcotic and lethal potencies to tadpoles and to rabbits. Ind Med 41:31-33.

4. NPIRI [1974]. Raw materials data handbook, physical and chemical properties, fire hazard and health hazard data. Vol. 1. Organic solvents. Bethlehem, PA: National Printing Ink Research Institute, p. 8.

5. Smyth HF Jr [1964]. Private communication. [From ACGIH [1971]. Isobutyl acetate. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 139.]

6. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC, Striegel JA [1962]. Range-finding toxicity data: list VI. Am Ind Hyg Assoc J 23:95-107.6

7. UCC [1971]. Toxicology studies: isobutyl acetate. New York, NY: Union Carbide Corporation.