To assess whether a chemical is well represented by the model training set, we performed the applicability domain (AD) assessment. The AD assessment was done by calculating the leverage of each chemical compared to the training set. The leverage was calculated using Eq.1, where X is the matrix of the training set (including the descriptors), x i is the vector of descriptors for an individual chemical, and the h ii is the calculated leverage. The leverage calculations are typically done only using the model variables, in other words only the descriptors used for the optimized model. In this study we performed both the full descriptor space (i.e. assuming the model using all the descriptors) and the model specific descriptors (i.e. conventional approach). This strategy enabled us to systematically assess which chemicals are well represented by the training set.