PFNA in drinking water
Also called perfluorononanoic acid.
A PFAS used in making fluoropolymers, notably near some New Jersey plants.
Health: Linked to developmental, liver and immune effects. Also part of the Hazard Index.
EPA proposed in May 2026 to rescind this limit. The proposal is not final. The April 2024 limit stays on the books until a final rule says otherwise.
Across the US
Those 9 systems serve about 163,771 people.
From EPA's UCMR 5 testing, 2023–2025: every community system serving 3,300+ people and a sample of smaller ones.
Highest results
States with the most detections
- Pennsylvania: 21
- New York: 13
- New Jersey: 9
- Florida: 7
- California: 7
- Texas: 3
- Ohio: 3
- Idaho: 2
- Delaware: 2
- Rhode Island: 1
- Louisiana: 1
- West Virginia: 1
Sources
The limits, health goals and health effects on this page come from these EPA sources. The results come from EPA's monitoring data for each water system.
- EPA: Per- and polyfluoroalkyl substances (PFAS) drinking water rule
- EPA: Fifth Unregulated Contaminant Monitoring Rule (UCMR 5)
- EPA: UCMR occurrence data (the test results)
This page summarizes public regulatory information. It is not medical advice. How we source and check this site.
Questions
What is the safe level of PFNA in drinking water?
The federal legal limit (MCL) is 10 ppt. EPA's health goal (MCLG), the level with no known risk, is 10 ppt. EPA proposed in May 2026 to rescind this limit. The proposal is not final. The April 2024 limit stays on the books until a final rule says otherwise.
How do I remove PFNA from tap water?
See the filter guidance on this page: look for a product certified for PFNA specifically, and check the claim in NSF's certified product listings.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.