Previously, OSHA had no limit for propargyl alcohol. The ACGIH has established an 8-hour TWA of 1 ppm, with a skin notation, for this straw-colored liquid, which smells like geraniums. The proposed PEL was an 8-hour TWA of 1 ppm, with a skin notation. NIOSH (Ex. 8-47, Table N1) concurs with this limit, which is established in the final rule.
In rats, guinea pigs, and mice, the oral LD(50)s are 70, 60, and 50 mg/kg, respectively; the 2-hour inhalation LC(50) in both the rat and mouse is reported to be about 850 ppm (NIOSH 1977i/Ex. 1-1182). The dermal LD(50) in rabbits is 88 mg/kg (RTECS).
Propargyl alcohol is a primary skin irritant, but it is not a skin sensitizer (Antara Chemicals 1952, as cited in ACGIH 1986/Ex. 1-3, p. 496). The toxicity of propargyl alcohol is estimated to be equal to that of allyl alcohol (oral LD(50) in rats of 64 mg/kg) (NIOSH 1977i/Ex. 1182). The ACGIH limit is based on the structural and toxicological similarity of propargyl alcohol to allyl alcohol (ACGIH 1986/Ex. 1-3, p. 496). Grace Ziem, an occupational physician, commented (Ex. 46) that the ACGIH Documentation (1986/Ex. 1-3) for propargyl alcohol neglects to mention this substance's ability to cause "degenerative changes in liver and kidneys in [an] 89-day rat study" that is cited by Rowe and McCollister (1982) in (Patty's Industrial Hygiene and Toxicology 1982, Vol. 2C, p. 4673) and also overlooks the fact that propargyl ahcohol is a "moderate CNS depressant." OSHA agrees with Dr. Ziem that this substance has these effects which, in OSHA's opinion, point to the need for the limits being established in this final rule.
OSHA is establishing in the final rule an 8-hour TWA for propargyl alcohol of 1 ppm, with a skin notation. The Agency concludes that these limits will protect workers against the significant risk of skin and mucous membrane irritation, CNS depression, and liver and kidney damage, all of which constitute material impairments of health that are associated with exposure to this substance at levels above the new limit.