EPA legal limit
No federal limit
Maximum Contaminant Level
EWG health guideline
No guideline
Science-based, stricter target
Health effects
NEtFOSAA is a precursor to PFOS: it transforms to PFOS via environmental degradation and metabolism in the body, meaning its health concerns substantially mirror those of PFOS. PFOS is associated with cancer, immune suppression, thyroid disruption, and developmental harm. NEtFOSAA exposure should be considered additive to PFOS body burden.
Where it comes from
Legacy use in 3M Scotchgard fabric and upholstery protection products, paper coatings, and related fluorochemical applications. Phased out in 2002 by 3M but persists in environments with legacy contamination. Found in water impacted by historical PFAS manufacturing and product use.
How it's regulated
No federal EPA MCL. Not individually regulated under the 2024 PFAS NPDWR. Monitored under UCMR5 as a PFOS precursor. No EWG health guideline established. PFOS itself is regulated at 4 ppt under the 2024 NPDWR.
How to filter netfosaa
Not all filters address netfosaa. Look for independently certified filters—NSF International certification means the removal claim has been independently verified.
Frequently asked questions
What is netfosaa?
NEtFOSAA is a PFOS precursor compound — an eight-carbon sulfonamido acetic acid used historically in Scotchgard and other 3M fluorochemical products. It degrades to PFOS in the environment and in the body. Included in UCMR5 because its presence in drinking water indicates ongoing PFOS-precursor contamination from legacy products.
What are the health effects of netfosaa?
NEtFOSAA is a precursor to PFOS: it transforms to PFOS via environmental degradation and metabolism in the body, meaning its health concerns substantially mirror those of PFOS. PFOS is associated with cancer, immune suppression, thyroid disruption, and developmental harm. NEtFOSAA exposure should be considered additive to PFOS body burden.
Is netfosaa regulated in drinking water?
No federal EPA MCL. Not individually regulated under the 2024 PFAS NPDWR. Monitored under UCMR5 as a PFOS precursor. No EWG health guideline established. PFOS itself is regulated at 4 ppt under the 2024 NPDWR.
Where does netfosaa come from?
Legacy use in 3M Scotchgard fabric and upholstery protection products, paper coatings, and related fluorochemical applications. Phased out in 2002 by 3M but persists in environments with legacy contamination. Found in water impacted by historical PFAS manufacturing and product use.
How do I remove netfosaa from tap water?
The most effective methods for removing netfosaa are: Reverse osmosis (RO), NSF 58 certified RO system, Activated carbon block filter. Look for NSF-certified systems—independent certification confirms removal claims have been verified.
Is netfosaa in your water?
Enter your ZIP code to see the measured level in your specific utility.