For example, the term "sting" could be annotated as a known musician, a species, a disease or a protein. OC|processor disambiguates based on the term environment and the presence of related concepts, assigning the annotation / knowledge domain with the highest confidence value. The precision and recall of OC|processor has been detailed elsewhere . For this study, the growing bodies of open access document repository CORE (COnnecting REpositories) and patent full text documents in Google Patents were selected to demonstrate the automated capability of identifying and analyzing scientific entities, applied to the case study of potential PFAS in documents. OC|processor 18 was used to automatically identify and extract mentions of chemical compounds from patents and other open access scientific documents such as scientific articles and university documents in CORE. The resulting collection of diverse chemical compounds was subsequently filtered for small molecule compounds for which a unique InChI 24 could be generated, thus removing incompletely-defined structures such as substances, polymers as well as mentions of chemical class terms and Markush-like 17 structures. Of the three definitions presented above, Definition B was used for most of the detailed investigations in this study. The final PFAS lists are available for all 3 definition versions described above and have been made public, together with additional results, in various formats (see also data availability) for general assessment and as input for future studies.