Impact of bioavailability on the correlation between in vitro cytotoxic and in vivo acute fish toxic concentrations of chemicals

It is concluded that the frequently observed low sensitivity of in vitro cytotoxicity test systems, compared to fish acute toxicity assays, at least in part, can be explained by differences in the availability of chemicals in vitro and in vivo. Moreover, neglecting these differences systematically causes a bias of the correlation between in vivo and in vitro toxic potencies of chemicals. Taking them into account, however, increases the predictivity of the in vitro assays.