Figure shows a patent network analysis of the S111 PMTPFAS list, with nodes represented by their degree centrality for China (A) and Europe (B), and their PageRank centrality for China (C) and Europe (D), each featuring the top 25 nodes. This analysis highlights differences in regional patent activity related to key PFAS compounds. In plots A, B, and C, the top candidate is tetrafluoroborate (CID 26255, see Figure , top left, "+" symbol), which is used for electroplating and as an electrolyte additive for batteries. In the EU PageRank Centrality plot, it ranks only 5 th , indicating a relatively lower number of patent applications involving this compound or within this sector compared to other regions or compounds. In plot D, the top compound is trifluoroacetic anhydride (TFAA, CID 9845, "*" in Figure ), which is second highest in A and B, third in C. TFAA serves as a recommended desiccant for trifluoroacetic acid (CID 6422, "^"), which is fourth in A and second in C, but is less prominent in Europe (B) and absent in D. Trifluoroethanol (CID 6409, "°"), a solvent used in organic chemistry, ranks third in A and B, second in D, and seventh in C. Fluometuron (CID 16562, sideways " §"), a herbicide, is second in D, tenth in C, and lower in both A and B. Lactofen (CID 62276, "-"), another herbicide, appears consistently across A, C and D, but is missing in B. PFOA (CID 9554, "X"), a well-known PFAS compound restricted by the Stockholm Convention since 2019, is present in all four plots, highest in Figure (4 th place). The differences between the plots underscore how regulatory environments, industrial needs, and research priorities shape the patenting activities related to PFAS compounds in the EU and China (and US -see Figure ). The presence of compounds like PFOA in both regions highlights ongoing attention to regulated substances, but the specific applications and frequency of patent filings reveal divergent technological focuses and market demands between the two regions. A similar analysis for agrochemicals is included in the SI, Figure . Both examples show how investigating the patent data on various lists of chemicals could help isolate "stand-out" trends in chemical activity and act as (or help support) a potential early warning system for up and coming action.