This study was conducted to determine species differences in the metabolism of ethylbenzene (EB) in liver and lung. EB (0.22-7.0mM) was incubated with mouse, rat and human liver and lung microsomes and the formation of 1-phenylethanol (1PE), acetophenone (AcPh), 2-ethylphenol (2EP), 4-ethylphenol