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

CAS number: 556–52–5

NIOSH REL: 25 ppm (75 mg/m3) TWA

Current OSHA PEL: 50 ppm (150 mg/m3) TWA

1989 OSHA PEL: 25 ppm (75 mg/m3) TWA

1993-1994 ACGIH TLV: 25 ppm (76 mg/m3) TWA

Description of Substance: Colorless liquid.

LEL: . . Unknown

Original (SCP) IDLH: 500 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the mouse 4-hour LC50 of 450 ppm and the rat 8-hour LC50 of 580 ppm [Hine et al. 1956 cited by ACGIH 1971, and Patty 1963].

Short-term exposure guidelines: None developed


Lethal concentration data:






Adjusted 0.5-hr






Hine et al. 1956

Hine et al. 1956





4 hr

8 hr

900 ppm (2.0)

1,450 ppm (2.5)

90 ppm

145 ppm

Other animal data: It has been reported that rats exposed repeatedly to 400 ppm for 7 hours per day, 5 days a week for 10 weeks showed no evidence of cumulative toxicity, only very slight irritation of the eyes, and slight lacrimation and respiratory distress following the first few exposures [Hine et al. 1956].

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

Revised IDLH: 150 ppm

Basis for revised IDLH: The revised IDLH for glycidol is 150 ppm based on acute inhalation toxicity data in animals [Hine et al. 1956].


1. ACGIH [1971]. Glycidol. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 121-122.

2. Hine CH, Kodama JS, Wellington JS, Dunlap MK, Anderson HH [1956]. The toxicology of glycidol and some glycidyl ethers. AMA Arch Ind Health 14:250-264.

3. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1635.

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