Hexachlorobenzene

Abstract

Sheep were dosed orally for 18 weeks with hexachlorobenzene (HCB) at the rates of 0.1, 1.0, 10.0, and 100.0 mg HCB/sheep/day. Blood and omental fat were sampled from all sheep during the dosing period and the following 42 weeks. Maximum concentrations of HCB attained in the fat were approximately proportional to the dose rates and were 0.9 ppm, 7.5 ppm, 75 ppm, and 650 ppm (group means) respectively. Significant crosscontamination of HCB occurred in the fat of undo sed controls that grazed with dosed sheep, presumably derived from HCB excreted by the dosed animals. Residues of HCB in blood reflected the residues that were present in the fat but at about 1000 times lower concentration. The trial confirmed that HCB-treated cereals, if fed to stock as a supplementary ration, would give rise to excessively high residues of HCB in body fat.