The results of the normalized structures classified as PFAS are shown in The overlaps between the lists extracted here and the existing PFAS lists were much lower than expected. Likewise more entries were missing from PubChem than originally expected, especially for the CORE database. The results were reality checked -here documented with an example for the CORE set using the stringent definition C (915 compounds not in PubChem). One of these 915 compounds includes OCID190080091261 (InChIKey LZICQIXBOVBGMV-UHFFFAOYSA-N), shown in To enhance the discovery of these PFAS in environmental samples, both datasets have been made available as CSV files for use in mass spectrometry-based screening approaches, such as MetFrag 53 and patRoon