Sub-acute toxicity of hexachlorobenzene in female beagles, including electroencephalographic changes

Adult female beagles were given oral HCB for 21 days. Subdividing the dose resulted in greater accumulation of HCB in fat and seemed to enhance toxic effects. Subjecting the animals to a 10-day period of food restriction immediately following 21 days of dosing further increased residues, but obscured any differences due to dosing regimen. Liver and hepatocyte enlargement, as well as physiologic changes in the central nervous system, were HCB-induced. Weight loss and various hematological changes were equivocal, with dietary stress and HCB probably contributing to the changes to varying degrees. A dose of 50 mg/kg/day of HCB for 21 days must be considered at least minimally toxic to female beagles.