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Isopropyl acetate

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

CAS number: 108–21–4

NIOSH REL: The 1989 OSHA PEL may not be protective to workers.

Current OSHA PEL: 250 ppm (950 mg/m3) TWA

1989 OSHA PEL: 250 ppm (950 mg/m3) TWA, 310 ppm (1,185 mg/m3) STEL

1993-1994 ACGIH TLV: 250 ppm (1,040 mg/m3) TWA, 310 ppm (1,290 mg/m3) STEL

Description of substance: Colorless liquid with a fruity odor.

LEL(@100°F): 1.8% (10% LEL(@100°F), 1,800 ppm)

Original (SCP) IDLH: 16,000 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the UCC [1970] report that a 4-hour exposure to 16,000 ppm killed 1 of 6 rats.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50




Time Adjusted 0.5-hr


Derived value



Pozzani et al. 1959

Smyth et al. 1954

Smyth et al. 1954


LC83: 32,000

LC17: 16,000




8 hr

4 hr

4 hr

29,795 ppm (2.5)

64,000 ppm (2.0)

32,000 ppm (2.0)

2,980 ppm

6,400 ppm

3,200 ppm

Other animal data: It has been stated that isopropyl acetate is comparable in toxicity to ethyl acetate and n-propyl acetate [ACGIH 1991].

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

Revised IDLH: 1,800 ppm

Basis for revised IDLH: The revised IDLH for isopropyl acetate is 1,800 ppm based on analogies to ethyl acetate and n-propyl acetate [ACGIH 1991]. This value is also 10% of the lower explosive limit of 1.8% (which was determined at 100°F).


1. ACGIH [1991]. Isopropyl acetate. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 826-827.

2. Pozzani UC, Weil CS, Carpenter CP [1959]. The toxicological basis of threshold limit values: 5. The experimental inhalation of vapor mixtures by rats, with notes upon the relationship between single dose inhalation and single dose oral data. Am Ind Hyg Assoc J 20:364-369.

3. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC [1954]. Range-finding toxicity data: list V. AMA Arch Ind Hyg Occup Med 10:61-68.

4. UCC [1970]. Toxicology studies: isopropyl acetate. New York, NY: Union Carbide Corporation.