Alpha and beta isomers of tetrabromoethylcyclohexane (TBECH) flame retardant: depletion and metabolite formation in vitro using a model rat microsomal assay.

The metabolism of α- and β-isomers of the flame retardant chemical tetrabromoethylcyclohexane (TBECH) was investigated using a model in vitro enzyme-mediated biotransformation assay based on rat liver microsomes. In enzymatically active assays, concentrations of both α- and β-TBECH isomers were equally depleted by about 40% and in a time-dependent fashion over a 60-min assay incubation period, and determined by GC-MS(ECNI) analysis. No such depletion was observed in nonenzymatically active control assays.