Previously, OSHA had no PEL for isooctyl alcohol. The ACGIH has a TLV-TWA of 50 ppm, with a skin notation, for this colorless liquid mixture. The proposed PEL was 50 ppm, with a skin notation, and these limits are established in the final rule. NIOSH (Ex. 8-47, Table N1) concurs with these limits.
The single-dose oral LD(50)s for isooctyl alcohol reported for rats and mice are between 3.2 and 6.4 g/kg; intraperitoneal injection LD(50)s for these species range from less than 0.4 g/kg to 1.6 g/kg (Hodge 1943/Ex. 1-700; Fassett 1951, as cited in ACGIH 1986/Ex. 1-3, p. 332). The dermal LD(50) for the guinea pig is greater than 10 ml/kg (Fassett 1951, as cited in ACGIH 1986/Ex. 1-3, p. 332); in the rabbit, the dermal LD(50) is 2.38 ml/kg (Smyth, Carpenter, Weil et al. 1969/Ex. 1-442). Moderate skin irritation from exposure to isooctyl alcohol has also been reported. Rats and rabbits have shown skin irritation at exposure levels ranging from 1.7 to 3.34 ml/kg (Smyth, Carpenter, Weil, et al. 1969/Ex. 1-442). Fassett (1951, as cited in ACGIH 1986/Ex. 1-3, p. 332) also reported no fatalities in rats after an 8-hour inhalation test at 235 ppm. OSHA received no comments, other than NIOSH's, on this substance.
In the final rule, OSHA is establishing an 8-hour TWA PEL of 50 ppm, with a skin notation, for isooctyl alcohol. The Agency concludes that these limits will reduce the significant risks of skin irritation, a material impairment of health that is associated with exposure to this substance at levels above the new PEL.