Toxicokinetics as a key to the integrated toxicity risk assessment based primarily on non-animal approaches

► Toxicokinetics (TK) is a key element to integrate the results from in silico, in vitro and in vivo studies. ► TK is needed to estimate target organ doses expected from realistic human external exposure scenarios. ► TK is necessary for quantitative in vitro-in vivo extrapolation (IVIVE). ► Physiologically based toxicokinetic modelling (PBTK) is the most adequate approach to simulate human TK. ► PBTK models are mechanism-based, but high-quality in vitro and in silico data is necessary for their success.