Tumorigenicity study of butyl and isobutyl p-hydroxybenzoates administered orally to mice

Butyl p-hydroxybenzoate (n-BHB) and isobutyl p-hydroxybenzoate (i-BHB) were administered orally to ICR/Jcl mice at concentrations of 0.6 (maximum tolerated dose), 0.3 or 0.15% in the diet for up to 102 wk. Tumours were observed at various sites including the haematopoietic system, the lung and the soft tissue. However, at none of the sites did the tumour incidence or the time to death with tumours differ significantly from that in the untreated control group.