1,2,3-TRICHLOROPROPANE

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: 96-18-4; Chemical Formula: CH₂ClCHClCH₂Cl

OSHA’s former PEL for 1,2,3-trichloropropane was 50 ppm as an 8-hour TWA, and the proposed limit was a 10-ppm TWA with a skin notation. NIOSH (Ex. 8-47, Table N6A) concurred with the proposed limit but indicated that it considers this substance to be a potential human carcinogen. The final rule establishes the 10-ppm TWA but does not include a skin notation. 1,2,3-Tri-chloropropane is a colorless to straw-colored, combustible liquid with an odor similar to that of chloroform.

1,2,3-Trichloropropane is not irritating to intact skin; it is also not readily absorbed through the skin. The dermal LD(50) in rabbits is 1770 mg/kg (Dangerous Properties of Industrial Materials, 7th ed., p. 173, Sax and Lewis 1989). However, 1,2,3-trichloropropane is highly irritating to the eyes (Smyth, Carpenter, Weil et al. 1962/Ex. 1-441). Five of six rats exposed to 1000 ppm died after four-hour exposures. Rats and guinea pigs exposed at 800, 2100, or 5000 ppm for 30 minutes showed central nervous system depression, which progressed, at the higher exposure levels, to narcosis and convulsions (Lewis 1979, as cited in ACGIH 1986/Ex. 1-3, p. 601). Several mice exposed for 20 minutes to 5000 ppm died, some as long as several days later, from liver damage. Daily 10-minute exposures at 2500 ppm for 10 days killed 7 of 10 mice (McOmie and Barnes 1949, as cited in ACGIH 1986/Ex. 1-3, p. 601). Animals exposed once for four hours to 1,2,3-trichloropropane at concentrations of 125, 340, 700, or 2150 ppm showed dose-related signs of irritation, which included, at 700 or 2150 ppm, labored respiration, inactivity, and eye and nose irritation; at autopsy, however, no organ or other damage was apparent (McOmie and Barnes 1949, as cited in ACGIH 1986/Ex. 1-3, p. 601).

Drew, Patel, and Lin (1978/Ex. 1-313) noted changes in liver enzymes after a single four-hour exposure to 500 ppm, and Russian studies indicating