All data was gathered from Therapeutic Data Commons (TDC) (version 0.4.0) which provided standardized output for the ChEMBL database (version 29) and the Ames dataset including standardized splitting. Both datasets were cleaned using RDKit (version 22.9.3) . Datasets were processed to remove stereochemistry and salts; to correct invalid hybridization, conjugation, chirality, and valency; and to set correct chirality, aromaticity and chemical property flags. Corresponding canonical SMILES were then generated and duplicates were removed. SMILES were tokenized based on the character representations of the string format and given both a beginning-of-sequence (BOS) and end-of-sequence (EOS) token together with optional padding (PAD) tokens to make sequences of equal length, according to the original paper from Karpov et al. . Structural alerts were gathered from Kazius et al. and generated using RDKit SMARTS (SMILES arbitrary target specification) representations. Identification of alerts in molecules was performed using RDKit substructure search.