Phenols and especially halogenated phenols represent a substantial part of the chemicals produced worldwide and are known as aquatic pollutants. Quantitative structure–toxicity relationship (QSTR) models are useful for understanding how chemical structure relates to the toxicity of chemicals. In the present study, the acute toxicities of 45 halogenated phenols to Tetrahymena Pyriformis were estimated using no cost semi-empirical AM1, PM3, and PM6 quantum chemistry methods. QSTR models were established using the multiple linear regression technique and the predictive ability of the models was evaluated by the internal cross-validation, the Y-randomization and the external validation. Their structural chemical domain has been defined by the leverage approach. The results show that that the best QSTR model is obtained with the AM1 method (R2= 0.91, R2CV= 0.90, SD= 0.20 for the training set and R2= 0.96, SD= 0.11 for the test set). Moreover, all the Tropsha’ criteria for a predictive QSTR model are checked. The obtained QSTR models were developed with a few number of meaningful descriptors and put in evidence the importance of the transport factor expressed by the hydrophobicity parameter and the electronic effect expressed by the Parr’s electrophilicity index in the interpretation and the prediction of the toxicity of halogenated phenols.
