OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. This rule was remanded by the U.S. Circuit Court of Appeals and the limits are not currently in force.
CAS: 556-52-5; Chemical Formula: C3H6O2
Previously, OSHA had an 8-hour TWA limit of 50 ppm TWA for glycidol. The ACGIH has a limit of 25 ppm TWA for this colorless liquid. The proposed PEL was an 8-hour TWA of 25 ppm. NIOSH (Ex. 8-47) concurred with this limit, and the final rule promulgates this PEL.
Glycidol causes eye, respiratory, and pulmonary irritation. Hine and associates (1956/Ex. 1-331) conducted a study of animal toxicity caused by glycidol exposure and reported that glycidol is irritating to the lungs, with mice and rats exhibiting pneumonitis and emphysema resulting from vapor inhalation. The LC(50) reported for mice is 450 ppm for a four-hour exposure; the 8-hour LC(50) for rats is 580 ppm (Hine, Kodama, Wellington et al. 1956/Ex. 1-331). A single dermal application was only mildly irritating (Draize score 4.5); however, repeated daily skin applications were severely irritating after four days. One drop of pure glycidol in the rabbit eye caused severe but reversible corneal injury (Hine, Kodama, Wellington et al. 1956/Ex. 1-331). In rats, chronic exposures to 400 ppm (seven hours/day for 50 days) did not cause systemic toxicity, but eye irritation and respiratory distress were observed after the first few exposures (Hine, Kodama, Wellington et al. 1956/Ex. 1-331). A study to determine glycidol’s tumorigenic potential on the skin of mice showed negative results (Van Duuren, Langseth, Goldschmidt, and Orris 1967/Ex. 1-1203). OSHA received no comments, other than that of NIOSH (Ex. 8-47), on this substance.
In the final rule, OSHA is establishing an 8-hour TWA limit of 25 ppm TWA for glycidol. The Agency concludes that this limit will protect workers against the significant risk of eye, respiratory, and pulmonary irritation potentially associated with exposures to this substance. The Agency has determined that this limit will substantially reduce these significant risks.