acute toxicity test on D. magna using the solvent spiking and passive dosing approaches of BACs are compared in Figure . Neither mortality nor immobilization of D. magna was observed in the blank controls, solvent controls or controls with clean PES membrane. The experimental median effective concentration (EC50) values, which were calculated using the arithmetic mean of measured Cw at adding daphnids and at the end of the experiment for each beaker, of the studied BACs are listed in Table . Notably, there was no significant difference between the arithmetic mean and the geometric mean here. D. magna 48 h-EC50