More specific substructure queries were used to interrogate these results further according to the PMT/vPvM criteria, shown in the remaining rows of Table and Figure , using the structures of melamine, benzotriazole and benzidine as well as the "larger PFAS parts" definition (contains -CF2CF2-) from the PubChem PFAS tree . The search was then progressively restricted to exclude the searched substructures from being part of larger ring systems and substances with molecular weights greater than 300 g/mol. The results of this search were also used to perform persistence and toxicity prediction as discussed above. The top two rows of Figure show these substructure query results. Like their less specific triazine counterpart, they seem too broad to capture only PMT/vPvM substances. However, when restricting the search to only compounds below 300 g/mol, between 87 and 99% of the compounds would meet the CLP definition of mobility. The most restricted PubChem search results were also used for biodegradability and LC50 predictions using the ReadyBiodegradable model from OPERA and MS2Tox (compounds which fell outside the applicability domain of the ReadyBiodegradable model were excluded in the biodegradability results; this information is not given by MS2Tox). As can be seen in Figure , almost all compounds inside the applicability domain were classified as non-biodegradable.