To date, a number of in vivo cytogenetic assays have studied the clastogenicity (chromosome aberrations, micronuclei formacion) in bone marrow of rodents exposed to styrene by various routes. NMRI mice were exposed by whole body inhalation to styrene concentrations of 750 mg/m3 and 1,500 mg/ m3 for 1, 3, 7, 14 and 21consecutive days (6 h/day).
Animals were killed directly after exposure and bone marrow was sampled for analysis of micronucleus induction. Under the experimental conditions used in the present investigation, there was no evidence of clastogenicity at any concentration or exposure interval.