- Type
- Per- and polyfluoroalkyl substance
- How serious
- High severity
- Evidence
- Strong evidence
Why it is flagged
Listed for global elimination under the Stockholm Convention in 2022, and one of the four PFAS behind EFSA's tolerable intake, which rests on a weaker vaccine response in children. Human studies also link it to altered thyroid hormones. For PCOS the evidence is emerging: higher blood PFHxS went with higher odds of PCOS in a US fertility-clinic cohort, and PCOS was diagnosed about twice as often among women in a Swedish town whose drinking water carried PFOS and PFHxS.
Health topics it bears on
Sources
- State of Per- and Polyfluoroalkyl Substances (PFAS) Report Environment and Climate Change Canada and Health Canada, 2025
- Objective for Canadian drinking water quality – per- and polyfluoroalkyl substances Health Canada, 2024
- The new POPs under the Stockholm Convention Secretariat of the Stockholm Convention on Persistent Organic Pollutants, 2025
- Per- and polyfluoroalkyl substances exposure is associated with polycystic ovary syndrome risk among women attending a fertility clinic Science of the Total Environment (Zhang et al.), 2024
- Perfluoroalkyl substances (PFAS) in drinking water and risk for polycystic ovarian syndrome, uterine leiomyoma, and endometriosis: A Swedish cohort study Environment International (Hammarstrand et al.), 2021
- Risk to human health related to the presence of perfluoroalkyl substances in food European Food Safety Authority, 2020
Also listed as
pfhxs, perfluorohexanesulfonic acid, perfluorohexane sulfonate, perfluorohexanesulfonate