Bioaccumulation potential of chemicals is frequently assessed from bioconcentration, conventionally measured according to OECD 305 (Bioaccumulation: Flow-through Fish Test) (OECD,1996) and expressed as Bioconcentration Factor (BCF). These studies deliberately reduce the manifold uptake and elimination mechanisms in aquatic organisms to respiratory absorption via gills and diffusion through the skin (e.g. Arnot and Gobas, 2003; Sijm et al. 2007). Despite the simplifications, testing costs are high and a minimum of 108 fish are consumed in each OECD 305 bioconcentration guideline study (ILSI HESI, 2006).