There have been several attempts to classify and group PFAS to help answer different questions. The comprehensive OECD efforts 9,10 contained detailed classifications. The "splitPFAS" method for automated classification was developed and tested on five of these categories . Recently, overviews of PFAS uses have emerged , while others have looked at strategies for grouping PFAS for the protection of human and environmental health , or narrowed the OECD PFAS list down to those of commercial relevance, estimated to be ~6 % of the total list . Most, if not all, of these approaches are still largely manual.