The suspect list section was entitled "PFAS and fluorinated compound collections" rather than "PFAS suspect lists" since the content of various suspect lists were not always PFAS and extremely large lists such as the OntoChem Patent collection (> 1 million entries) are too big for suspect screening. Fluorinated compounds that are not necessarily PFAS are also gaining attention as potentially harmful. For instance, there is great interest in fluorine containing pesticides and pharmaceuticals, but not all entries in the published lists (e.g., lists S92 and S94 of the NORMAN-SLE, containing fluorinated pharmaceuticals and pesticides 49 respectively) are PFAS. By sending these nodes to PubChem Search and subsequently Entrez, it is possible to subset the entire PubChem PFAS Tree by a given suspect list (or combination thereof) and determine which entries are PFAS, organofluorine, etc., as shown in Figure . The steps required to perform this query are explained in greater detail elsewhere . The OntoChem lists, which are too big for efficient suspect screening, are already available elsewhere as database files . Note that the numbers in the suspect lists in the PubChem PFAS Tree may deviate from the original lists, since only discrete chemicals are included, such that polymers and/or UVCBs will be missing (and the numbers consequently smaller) for lists containing polymer/UVCB entries in addition to discrete chemicals. Only one CompTox PFAS list (PFASMARKUSH) contained exclusively polymer/UVCB entries by design and is not displayed. While the OntoChem lists contained only discrete chemicals, these numbers also differ slightly from the published article due to edge cases encountered during PubChem deposition. As discussed in Barnabas et al. , different cheminformatics toolkits perceive the structures differently: PubChem use internal code as well as the OEChem and CACTVS 52 toolkits for standardization and deposition to create chemical records, while OntoChem used OpenChemLib 54 to produce their final lists. This "PFAS and fluorinated compound collections" section is also designed to enable the addition of new PFAS or fluorinated content into PubChem as they are documented, to fill gaps in the database and ensure rapid discovery of new and relevant entries by the community. The necessity for a rapid discovery of new PFAS of concern is one motivation for the regular updates of the entire PubChem PFAS Tree. As mentioned above, the integration of these collections has resulted in the addition of >200,000 new PFAS entries to PubChem, including >200,000 from OntoChem, 1,232 from the NIST PFAS Suspect List and several entries from both the CompTox and NORMAN-SLE contributions, which have been deposited progressively over several years. Almost 25% of the NIST PFAS list was new content to PubChem, showing the importance of hand curated expert knowledge from researchers to fill knowledge and database gaps. The NORMAN-SLE 6,7 hosts several lists, developed using templates designed together with PubChem , which can be used to add new PFAS or other compounds as soon as a reference information is available, thus providing a channel for the scientific community to add new data to the public domain. Contact details are given in the documentation . Several examples of community contributions were provided in the webinar . The information should be available under an appropriate license (e.g., CC-BY ) to enable inclusion.