FINAL REPORT ON THE SAFETY ASSESSMENT OF BUTYL BENZYL PHTHALATE

Butyl Benzyl Phthalate (BBP) is an aromatic ester that is used as a plasticizer at concentrations below 1.0%. After oral and intravenous (iv) administration, BBP was rapidly excreted. The oral LD50 was: 2.3 g/kg for F344/N rats, and 4.2 - 6.2 g/kg for B6C3F1 mice. Rats and mice exposed to high concentrations of BBP lost weight, had testicular atrophy, hemorrhages, and hepatomegaly. No toxicity was reported in an oral subchronic toxicity study using dogs. BBP was not a reproductive toxin to CD-1 and B6C3F1 mice; however, BBP caused dose-dependent microscopic degenerative changes in the testes of male F344 rats. BBP was nonmutagenic in the Ames Test, L5178Y TK mouse lymphoma mutagenesis assay, dominant lethal mutagenicity assay, and BALB/3T3 cell transformation assay. An increase in the incidence of mononuclear cell leukemia in female F344/N rats was not considered to be related to the exposure to high doses of BBP. BBP was not carcinogenic in studies using B6C3F1 and A/St mice. Slight transient dermal and ocular irritation was produced by undiluted BBP in rabbits. In human dermal studies, BBP was not a significant irritant nor sensitizer. On the basis of data presented in this report, it is concluded that butyl benzyl phthalate is a safe cosmetic ingredient in the present practices of use and concentration.