AbstractCoal liquefaction compounds could, through accidental release, enter aquatic environments. Experiments were conducted to determine the kinetics, degree of bioconcentration and stability of two of these compounds at the first level of the aquatic food web. We exposed the freshwater phytoplankterScenedesmus quadricaudato sublethal concentrations of14C‐labeled phenol and aniline. Both accumulation and elimination occurred within a few hours and followed hyperbolic kinetics. Results indicate that substantial quantities of accumulated compounds remain as the parent compound (22% for phenol and 52% for aniline) for up to 24 h and could be available to animals higher in the food web. Bioconcentration factors [(nm parent compound/cm3phytoplankton) ÷ (nm parent compound/cm3water)] were 3.5 for phenol and 91 for anili