6:2FTS
1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2 FTS)
- EPA federal limit
- No federal limit
- Detected in
- 10,289 systems
- Regulatory status
- Unregulated (UCMR 5)
What is 6:2FTS?
1H,1H,2H,2H-perfluorooctanesulfonic acid, known as 6:2FTS, is a man-made chemical that belongs to the PFAS family, a group of substances often called "forever chemicals" because they break down very slowly in the environment and can build up in the human body over time. 6:2FTS is a fluorotelomer compound, meaning it was designed using a process that bonds fluorine atoms to a carbon chain, making it extremely resistant to heat, water, and oil. Like other PFAS, it does not easily go away once it enters soil, water, or living things.
Where does it come from?
6:2FTS is used in industrial settings and shows up in a variety of consumer products. It has been found in firefighting foams, water-resistant clothing, stain-resistant fabrics, and some food packaging materials. It can enter the environment through industrial discharge, the use of firefighting foam at airports or military bases, and the breakdown of other fluorotelomer-based chemicals.
Health concerns
Research on 6:2FTS is still limited compared to more studied PFAS like PFOA or PFOS. Animal studies have associated 6:2FTS with liver effects and changes in hormone levels, but strong human data is not yet available. Because the evidence is early-stage, scientists have not drawn firm conclusions about its risks to people. If you have specific health concerns, consult a healthcare provider.
EPA standard
No federal maximum contaminant level (MCL) — the legal limit for a chemical in drinking water — has been established for 6:2FTS by the EPA. This means public water systems are not currently required to test for or limit this chemical. The absence of a legal limit does not mean the chemical is considered safe.
What you can do
If 6:2FTS is detected in your water, consider using a certified reverse osmosis filter or a granular activated carbon filter, both of which research studies suggest can reduce PFAS levels in drinking water. Remember that boiling water does not remove PFAS — it can actually concentrate them. Contact your local water utility for testing information.
About this summary: Narrative text on this page was drafted by an AI model (claude-sonnet-4-6) from EPA UCMR 5 data and reviewed before publication. The numeric data above is reported by water utilities directly to the EPA. If you spot an error, email data@checkyourwater.org.