AbstractEight chemical model systems were developed for a multivariate physicochemical characterization of halogenated aliphatics. The chemical model systems were developed to obtain descriptors which contained information related to lipophilicity and chemical reactivity of the studied compounds. A selected set of 15 halogenated aliphatic compounds were characterized by the chemical model systems. The information content in eight new descriptors combined with eight old physico‐chemical descriptors were validated in a QSAR. The used biological responses were acute oral toxicity to rat, highest non‐lethal dose to mouse and in vitro genotoxicity from a DNA precipitation assay. This model was compared with a QSAR based on eight old‐physico‐chemical descriptors. It was found that the addition of the new descriptors improved t