Chloroform inhalation exposure conditions necessary to initiate liver toxicity in female B6C3F1 mice.

Chloroform is a nongenotoxic-cytotoxic carcinogen in rodent liver and kidney, including the female B6C3F1 mouse liver. Because tumors are secondary to events associated with cytolethality and regenerative cell proliferation, these end points are valid surrogates for tumor formation in cancer risk assessments. The purpose of the experiments presented here was to more clearly define the combinations of atmospheric concentration and duration of exposure necessary to induce cytolethality and regenerative cell proliferation in the sensitive female B6C3F1 mouse liver.