Das Projekt "Literatur- und Datenbankrecherche zum Einfluss der Molekülgröße und Oktanollöslichkeit auf das Bioakkumulationspotential" wird vom Umweltbundesamt gefördert und von Fraunhofer-Institut für Molekularbiologie und Angewandte Oekologie durchgeführt. The study has addressed five major issues to rationalize the effects of molecular size and lipid solubility on the bioaccumulation potential of environmental contaminants: - Do studies on biological membranes support limits of permeability related to size or lipid solubility of the chemicals? - Do studies on bioconcentration support limits of uptake and accumulation po tential related to size or lipid solubility of the chemicals? - How relevant are active transport mechanisms for the uptake of large organi c chemicals? - Do compound properties related to size or lipid solubility provide guidance in assessment schemes of bioaccumulative chemicals? Which parameters are potentially useful? Can cut-off triggers be defined? - Do high quality-data for superhydrophobic substances provide new insights to relationships between BCF and log KOW? New insights to relationships between BCF and log KOW cannot be provided. The currently available database is insufficient to conclusively substantiate the effects of molecular size and lipid solubility on the bioaccumulation potential of environmental contaminants. Once the CEFIC LRI gold standard database on BCF is available, the findings of this study should be re-examined and adjusted as necessary. This study confirms again the importance to exclude experimental artefacts from analysis of bioaccumulation of superhydrophobic substances. As size-related criteria for limited bioaccumulation appear not to be a clear cut-off trigger, a combination of multiple properties appears a viable option. Evidence-driven assessments on a case-by-case basis should also consider information on aquatic toxicities upon long-term exposure, i.e. absorption potential. The extent to which uptake in mammalian/terrestrial species may be used, still requires validation.