Where:
EC50The effective concentration of a wastewater sample that causes an inhibition of test organism by 50 %.
Samples were classified according to ACE 89/BE 2/D3 Final Report Commission EC (TUa < 0.4—non toxic (I class); 0.4 ≤ TUa < 1.0—low toxicity (II class); 1.0 ≤ TUa < 10—toxic (III class); 10 ≤ TUa ≤ 100—high toxicity (IV class); TUa > 100—extremely toxic (V class)).