Benzene and the genotoxicity of its metabolites. II. The effect of the route of administration on the micronuclei and bone marrow depression in mouse bone marrow cells.

Benzene (880 mg/kg) and 4 of its metabolites, i.e., phenol (265 mg/kg), hydroquinone (80 mg/kg), catechol (40 mg/kg), and p-benzoquinone (5-20 mg/kg) have been tested for their capability to induce micronuclei in bone marrow cells of male mice after oral administration or intraperitoneal injection. Oral administration of benzene shows more activity than intraperitoneal injection, whereas the metabolites show more activity if administered by the latter method. The respective genotoxic strengths of the benzene metabolites are the following: hydroquinone much greater than phenol greater than catechol = p-benzoquinone. This last is active when administered orally.