Hepatocellular Tumorigenicity of Butylated Hydroxytoluene Administered Orally to B6C3F1 Mice

Butylated hydroxytoluene (BHT), a preservative widely found in food as a food additive, was orally administered at concentrations of 1% and 2% of the diet to B6C3F1 mice for 104 consecutive weeks. Treated animals underwent a 16-week recovery period prior to pathological examination. In male mice administered BHT, the incidence of mice with either a hepatocellular adenoma or a focus of cellular alteration in the liver was increased in a clear dose-response relationship. The incidences of male mice with other tumors and the incidences of female mice with any tumor were not significantly increased as a consequence of BHT administration. The results of this study indicate BHT to be tumorigenic to the liver of the B6C3F1 male mouse.