Conventional water treatment systems in India cannot remove polyfluoroalkyl substances, and the country currently lacks a specific drinking-water limit under standard IS 10500:2012.
An IIT-Madras study found that PFAS concentrations in treated water at a Chennai plant were 5% to 103% higher than in raw water due to potential unidentified precursors.
The International Agency for Research on Cancer classified perfluorooctanoic acid as carcinogenic to humans and perfluorooctanesulfonic as possibly carcinogenic in its 2025 monograph.