PFHxA in drinking water
A short-chain PFAS used as a replacement in coatings. No federal limit.
Health: USGS screening level 3,000 ppt, based on EPA's 2023 IRIS assessment.
Across the US
From EPA's UCMR 5 testing, 2023–2025: every community system serving 3,300+ people and a sample of smaller ones.
Highest results
| Water system | People | Highest result |
|---|---|---|
| PRASA – Experimental | 6,445 | 260 ppt |
| Widefield Water & Sanitation District | 27,640 | 141 ppt |
| Commonwealth Utilities Corp (Saipan) | 48,524 | 122 ppt |
| Emerald Coast Utilities Authority (ECUA) | 242,172 | 111 ppt |
| Telford Borough Authority | 7,700 | 94.6 ppt |
| Caernarvon Township Authority | 4,245 | 92 ppt |
| Artesian Water Company | 231,114 | 72.2 ppt |
| City of Great Bend | 14,580 | 69 ppt |
| Yeshiva Farm Settlement Water System | 300 | 69 ppt |
| Georgetown Water Department | 7,259 | 68 ppt |
| Hatfield Water Dept | 3,164 | 60.8 ppt |
| Raynham Center Water District | 10,964 | 58.8 ppt |
| MDWASA – Main System | 2.4 million | 58 ppt |
| Bayleaf Master Water System | 16,715 | 57.3 ppt |
| Bluffton Village Water System | 4,082 | 55 ppt |
| City of North Bay Village | 8,317 | 52.9 ppt |
| Valley Utilities Water Company Glendale | 6,003 | 52 ppt |
| Ottawa Village Water System | 4,393 | 51.8 ppt |
| City of Fountain | 25,130 | 50.8 ppt |
| Southwood Water System | 64,155 | 48 ppt |
| Suffolk County Water Authority | 1.1 million | 43.5 ppt |
| Stratmoor Hills Water & Sanitation District | 6,500 | 42 ppt |
| Emmaus Borough Public Water | 14,000 | 41.5 ppt |
| Yarmouth Water Department | 38,900 | 40.6 ppt |
| Pewaukee City Water and Sewer Utility | 8,671 | 40 ppt |
States with the most detections
- Texas: 369
- California: 131
- New Jersey: 128
- Florida: 112
- Pennsylvania: 110
- Massachusetts: 102
- North Carolina: 92
- South Carolina: 70
- Alabama: 69
- Georgia: 48
- Ohio: 42
- Illinois: 42
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 PFHxA in drinking water?
There is no federal legal limit. USGS health-based screening level: 3,000 ppt.
How do I remove PFHxA from tap water?
See the filter guidance on this page: look for a product certified for PFHxA 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.