Bioavailability-based toxicity endpoints of bifenthrin for Hyalella azteca and Chironomus dilutus

► Bioavailability-based benchmarks were developed for Hyalella and Chironomus. ► Median lethal and effect concentrations could be developed using SPMEs and Tenax. ► Bioavailable concentrations were related to organic carbon normalized concentrations. ► A relationship exists between SPME fiber and Tenax extractable concentrations. ► Extrapolations could be made between SPME fiber and Tenax concentrations.