Past efforts to identify and collect chemical structures of existing PFAS have resulted in several so-called "suspect" lists. The Organisation for Economic Co-operation and Development (OECD) released a PFAS list containing 4,729 PFAS entities in 2017 (hereafter "OECDPFAS"). The United States Environmental Protection Agency (EPA) "PFASMASTER" list currently (December 2021) contains 12,048 PFAS entries , merged from several PFAS lists on the EPA CompTox Chemicals Dashboard . Of these two lists, PFASMASTER contains 10,785 entries that can be represented by an International Chemical Identifier (InChI), while the OECDPFAS list contains 3,741 entries with an InChI, using versions downloaded from the EPA website on 2021-12-11 and available in the supplementary material . The other entities in the lists are substances without a clear composition, or with known composition that cannot be represented fully with an InChI. Of the 3,741 OECD compounds with an InChI, 3,731 are also contained in the PFASMASTER list (by matching InChI).