Water imputation

If water has been selected as an additional source of exposure, but concentration data is missing, then, fixed concentration values can be assigned to water for the five most toxic active substances, with the toxicity ranking being based on the relative potency factors. For all other substances, zero concentrations are imputed. The default imputation value is 0.05 µg/L, but this value can be chosen as a setting. If specified, substance authorisations may be used to restrict to the set of active substances for which water concentrations are imputed to only those for which concentrations may be expected from authorised use.