When Treatment Adds the Toxin: Why India's PFAS Safeguard Must Be a Standard, Not a Plant

The Treatment Plant Is Not the Safeguard

• the Standard Is India's drinking-water specification, IS 10500:2012, is the country's formal promise about what is safe to drink. For per- and polyfluoroalkyl substances - PFAS - that promise does not yet exist. The standard sets no PFAS limit. The data now show why that silence matters more than it seems.

The target was nothing; the data show something PFAS are held together by carbon-fluorine bonds that need about 105.4 kcal/mol to break.

Nature rarely supplies that, so they persist almost indefinitely. Indian studies are now finding them across the water cycle:

• A 2024 IIT-Madras study analysed 14 samples from Chennai. The highest PFAS levels were in groundwater from wells near garbage dumps.
• A GITAM University study published in July 2026 tested seawater and sewage around Visakhapatnam for 77 PFAS and detected 38.
• A 2025 review examined monitoring and regulation in Gujarat, Maharashtra, Tamil Nadu and West Bengal. Its lead author, Rajneesh Kumar Gautam, said the national extent of contamination is poorly defined, partly because research groups test differently.

The finding that changes the argument The most important result came from inside a Chennai treatment plant.

All eight target PFAS were 5 to 103 percent higher in treated water than in raw water. IIT-Madras professor Indumathi M. Nambi suggested, as reported, that unmeasured precursor chemicals may convert into more stable PFAS during treatment.

The study did not quantify these precursors. Abhradeep Majumder of BITS Pilani-Hyderabad said conventional biological wastewater treatment cannot remove PFAS and that low-cost adsorbent materials are yet to be developed.

The consequence is direct. India's usual answer to water contamination is to build or upgrade a treatment plant. For PFAS, that answer can make exposure worse. The safeguard has to move upstream, to what is allowed into water in the first place.

Where exactly the chain breaks The failure is not a single gap.

It sits at three specific links:

1. Standard-setting: IS 10500 has no PFAS limit. A BIS Working Group on Emerging Contaminants and Forever Chemicals is examining limits and methods, but its scope is not final.
2. Source control: The Environment Ministry has said there is no specific rule banning PFAS manufacture. Researchers say India does not yet map which PFAS are made, imported and used.
3. Enforcement: Former CSIR-CIMFR scientist Girija K. Bharat said there is no clear route to penalise a source of contamination. The health case is no longer speculative. In IARC Monograph Volume 135 (2025), the WHO's cancer agency classified PFOA as carcinogenic to humans and PFOS as possibly carcinogenic. The US has set enforceable limits of 4 parts per trillion for PFOA and PFOS and the EU caps the sum of 20 PFAS at 0.1 µg/L from January 2026.

What is

working There is genuine progress. CSIR-IITR, Lucknow, part of a UNEP-funded national implementation plan, can now detect 50 PFAS molecules, as its scientist reported. Indian research groups are producing the first serious baseline data and BIS has a dedicated working group.