EPA legal limit
No federal limit
Maximum Contaminant Level
EWG health guideline
0.5 ppt
Science-based, stricter target
Health effects
PFUnA is highly bioaccumulative — it concentrates in blood, liver, and kidney tissue. Animal studies show reproductive toxicity, developmental effects, and immune suppression. Due to its length, it has a longer biological half-life than PFOA (estimated 10+ years). It is found in human blood samples at low but measurable levels in the general population.
Where it comes from
Industrial use as a surfactant and processing aid in fluoropolymer manufacturing. Found near manufacturing sites and in water impacted by PFAS-containing industrial waste. Less prevalent than PFOA in drinking water but detected at meaningful levels near contamination sources.
How it's regulated
No federal EPA MCL. Not individually regulated under the 2024 PFAS NPDWR. Monitored under UCMR5. EWG health guideline: 0.5 ppt, reflecting the high bioaccumulation potential of very long-chain PFAS compounds.
How to filter pfuna
Not all filters address pfuna. Look for independently certified filters—NSF International certification means the removal claim has been independently verified.
Frequently asked questions
What is pfuna?
PFUnA is an eleven-carbon long-chain carboxylic acid PFAS. It is among the longer perfluoroalkyl acids monitored in UCMR5 and is detected in water serving 4.3 million people across 17 states. Its long carbon chain makes it among the most bioaccumulative of the UCMR5-monitored PFAS compounds.
What are the health effects of pfuna?
PFUnA is highly bioaccumulative — it concentrates in blood, liver, and kidney tissue. Animal studies show reproductive toxicity, developmental effects, and immune suppression. Due to its length, it has a longer biological half-life than PFOA (estimated 10+ years). It is found in human blood samples at low but measurable levels in the general population.
Is pfuna regulated in drinking water?
No federal EPA MCL. Not individually regulated under the 2024 PFAS NPDWR. Monitored under UCMR5. EWG health guideline: 0.5 ppt, reflecting the high bioaccumulation potential of very long-chain PFAS compounds.
Where does pfuna come from?
Industrial use as a surfactant and processing aid in fluoropolymer manufacturing. Found near manufacturing sites and in water impacted by PFAS-containing industrial waste. Less prevalent than PFOA in drinking water but detected at meaningful levels near contamination sources.
How do I remove pfuna from tap water?
The most effective methods for removing pfuna are: Reverse osmosis (RO), NSF 58 certified RO system. Look for NSF-certified systems—independent certification confirms removal claims have been verified.
Is pfuna in your water?
Enter your ZIP code to see the measured level in your specific utility.