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Adsorption was determined by using EPIWIN QSAR-model (SRC KOCWIN v 2.00). As the determination of a mixture Koc-value was impossible, Koc-values for the pure homologues contained in the mixture were calculated. Therefore smiles-codes of the unethoxylated alcohols as well as smiles-codes of the alcohol ethoxylates containing 1 EO and 3 EO of each of the homologues contained in the mixture were entered in EPIWIN. The result is given as range of the calculated values representing the variation of carbon chain length and the degree of ethoxylation according to substance specifications. The log Koc values from EPIWIN calculation for alcohol ethoxylate ((Z)-9-Octadecen-1-ol ethoxylated, < 2.5 EO, CAS 9004-98-2) range from 3.92 to 4.19 (MCI method) and 3.94 to 4.66 (log Kow method). 

Additionally the Koc was determined according to a specific QSAR method, developed for alcohol ethoxylates from measured sorption data by van Compernolle et al. (2006). The work by these authors has investigated the adsorption of several radio-labelled specific alcohol ethoxylate homologues onto activated sludge and river water solids. These results, together with results from validated published and unpublished work, were used to derive a Koc based sorption QSAR. It can be expected that the work carried out by van Compernolle et al. (2006) describes the adsorption properties of alcohol ethoxylates more specific than the EPIWIN model. Hence the Koc-values determined according to the method of van Compernolle et al. (2006) are used for further assessment. In case of alcohol ethoxylate ((Z)-9-Octadecen-1-ol ethoxylated , < 2.5 EO, CAS 9004-98 -2) the log Koc values estimated according to the method of van Compernolle et al. (2006) ranged from 5.6 to 5.74. Based on the composition of the mixture the weighted average of the Koc values was calculated to be 457467 L/kg. This value is used for the determination of PNECsediment with the equilibrium partitioning method.