Besides developing HA-QSARs for new endpoints, the KREATiS team is working hard to expand the applicability domain of its existing QSARs. The iSafeRat ecotox models were revisited recently to include further non-MoA 1 models. Building on esters, we have now validated a QSAR for aldehyde ecotoxicity. The reliability of these updated models was assessed using a high quality validation set and ensuring that the models can predict aldehydes following a strict validation procedure based on the five OECD principles for QSAR validation.