Open Chemical database and Modelling environment (OCHEM) and its recent open source release -openOCHEM () were used to develop and disseminate models. OCHEM contains numerous descriptors and machine learning methods, which include both commercial and publicly available tools. openOCHEM contains only open source code (GPL, LGPL, AGPL) or binary codes, which were released under permissive licenses and can be used without restrictions for academic, educational, recreational or evaluation purposes. All models were validated using 5-fold cross-validation (5CV). The statistical coefficients calculated using 5CV protocol were also used to evaluate model performances and select models for the challenge as described below.