Application of the OECD QSAR Toolbox software for calculating the parameters of acute aquatic toxicity of chemicals

Introduction. The Organization for Economic Cooperation and Development (OECD) has developed the QSAR Toolbox software, which allows predicting the properties of chemicals including (eco)toxic based on the structure of the substance using mathematical statistics methods. The purpose of this work was to study the applicability of the OECD QSAR Toolbox software for calculating the acute aquatic toxicity parameters (LC₅₀ and EC₅₀) of chemicals necessary, for example, to determine the hazard class of chemical products according to GOST 32419-2013 “Classification of chemical products. General requirements” or to prepare a safety data sheet for products.

Materials and methods. The OECD QSAR Toolbox software version 4.4.1 (current for August 2021), documents, manuals and webinars of the OECD, the European Chemical Agency (ECHA), the Laboratory of Mathematical Chemistry of the University of Burgas, Bulgaria (the main software developer), articles.

Discussion of the results. The OECD QSAR Toolbox software version 4.4.1 allows calculating the acute aquatic toxicity parameters (LC₅₀, EC₅₀) of chemicals using trend analysis and read across, as well as automated and standardized workflows. About 50 chemicals with experimental data of LC₅₀ and EC₅₀ belonging to different hazard classes according to GOST 32419-2013, with different functional groups in the structure of the molecule, were selected for testing. Calculated values of LC₅₀ and EC₅₀ of chemicals were compared with the experimental data.

Conclusion. The OECD QSAR Toolbox software version 4.1.1 can be successfully used to calculate the acute toxicity parameters LC₅₀, Pimephales promelas, 96 h; LC₅₀ (EC₅₀), Actinopterygii, 96 h and LC₅₀, Daphnia magna, 48 h for a wide range of organic compounds, but is not applicable for inorganic substances, organometallic compounds, polymer molecules, chemicals containing metal ions.