Statistical uncertainty of predicted and observed effect concentrations for mixtures (ESCREEN).

CA – Concentration Addition, IA – Independent Action, CI – Confidence Interval; All predictions statistically significant to the observed ECs are shown in bold; *Effect mixture concentration for effect levels higher than the lowest estimated compound maximal model asymptote are extrapolated either (i) by assuming no contribution of this compound to the overall mixture effect (toxic unit equals zero), or (ii) by setting the compounds’ toxic unit to a fixed level equalling the value at the mixture concentration producing an effect of 0.7*θmax (see Table 3). The right side of the interval corresponds to (i) and the left side to (ii), defining the range of possible CA predictions.