Bruckner, Adam

Ferber and Bruckner reduced />-aminobenzoic acid using Adams catalyst (Pt02) at atmospheric pressure, and Schneider and Dillman reduced p-aminobenzoic acid using 10% rhodium on carbon at 140 atm. and 70°. 3-Isoquinuclidone has been prepared, by the previously mentioned investigators, by heating the dry 4-aminocyclohexane carboxylic acid at elevated temperatures. 

The ERA has calculated a subchronic oral reference dose (RfD) of 7x10 mg/kg/day for carblon tetrachloride based on a NOAEL of 1 mg/kg/day (converted to 0.71 mg/kg/day based on intermittent exposure) for rats in a 12-week study (Bruckner et al. 1986 ERA 1989b IRIS 1993). The critical effect was liver toxicity. A chronic oral RfD of 7x10 mg/kg/day was also calculated based on the same NOAEL used for the subchronic RfD. The ATSDR has calculated an acute inhalation MRL of 0.2 ppm based on a LOAEL of 50 ppm for liver effects in an acute 4-day rat inhalation study (David et al. 1981), and an intermediate inhalation MRL of 0.05 ppm based on a NOAEL of 5 ppm for liver effects in an intermediate-duration (187-192 days) inhalation study in rats (Adams et al. 1952). The ATSDR has also calculated an acute oral MRL of 0.02 mg/kg/day based on a LOAEL of 5 mg/kg/day over 10 days for liver effects in the rat (Smialowicz et al. 1991), and an intermediate oral MRL of 0.007 mg/kg/day based on a NOAEL of 1 mg/kg/day over 12 weeks (converted to 0.71 mg/kg/day based on intermittent exposure) for liver effects in the rat (Bruckner et al. 1986). 

Animals studies indicate that exposure to relatively high 1,1,1-trichloroethane concentrations in air (>1,000 ppm) or high oral doses (>1,334 mg/kg) are required to produce liver injury (Adams et al. 1950 Bruckner 1983 Calhoun et al. 1981 McNutt et al. 1975 Torkelson et al. 1958 Tyson et al. 1983). Effects observed in animals include necrosis, fatty change, increased liver weight, and changes in liver and serum enzyme levels. These effects are reversible and subside after termination of exposure (in the case of necrosis, hepatocytes in the proximity of the killed cells proliferate and replace them). 

Department of Chemistry, University of Washington, Seattle, WA 98195 ADAM P. BRUCKNER... 

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