PFAS
PFAS explained: what they are, EPA limits (4 PPT for PFOA/PFOS), health risks, how to test, and which water filters actually remove forever chemicals.
PFAS are synthetic chemicals found in the drinking water of an estimated 110 million Americans. The EPA set a legal limit of 4 parts per trillion for PFOA and PFOS in April 2024. PFAS are linked to cancer, thyroid disease, and immune suppression. Reverse osmosis and certified carbon filters are the most effective home treatments.
What is PFAS?
PFAS (per- and polyfluoroalkyl substances) are a group of over 14,000 synthetic chemicals characterized by strong carbon-fluorine bonds that do not break down in the environment. They are called forever chemicals because they persist in water, soil, and living organisms indefinitely. PFOA and PFOS are the two most studied and regulated compounds in the group.
Is PFAS Dangerous?
Epidemiological research associates PFAS exposure with increased cholesterol levels, thyroid disease, immune system suppression (including reduced vaccine effectiveness), kidney and testicular cancer, reproductive effects including reduced fertility and increased risk of preeclampsia, and developmental effects in children. Health risks increase with concentration and duration of exposure.
4 PPT for PFOA and PFOS individually (finalized April 2024, compliance by 2031).
How to Identify PFAS in Your Water
PFAS cannot be detected by sight, taste, or smell. Laboratory testing is required. Home test kits for PFAS are not widely available. Certified lab tests ($150 to $350) analyze for 30 or more PFAS compounds. Check your utility's Consumer Confidence Report for system-level data.
How PFAS Is Regulated
The EPA finalized national PFAS limits in April 2024: 4 PPT for PFOA individually, 4 PPT for PFOS individually, and a hazard index of 1.0 for mixtures of PFHxS, PFNA, HFPO-DA (GenX), and PFBS. Initial monitoring must be completed by 2027; compliance with treatment requirements by 2031. Before this rule, there were no enforceable federal limits.
| Standard | Limit | Notes |
|---|---|---|
| EPA MCL (2024) | 4 PPT | 4 PPT for PFOA and PFOS individually (finalized April 2024, compliance by 2031). |
| EPA Health Advisory | 4 PPT | Health-based advisory; enforceable MCL is 4 PPT |
How to Remove PFAS
- Reverse Osmosis Recommended — 90% to 99% removal of PFOA, PFOS, and most short-chain PFAS · Single tap
- Activated Carbon (Block) — 70% to 95% for PFOA and PFOS, less effective on short-chain PFAS · Single tap or whole house
- Whole-House Carbon Filter — Varies by media type and contact time · Whole house
- Pitcher Filter (NSF P473) — Varies by model, requires NSF P473 certification · Drinking water only
PFAS Levels in US Cities
| City | State | Level | Rating |
|---|---|---|---|
| Sugar Land | TX | 828.5 PPT | Significantly Elevated |
| Woodbury | MN | 280.5 PPT | Significantly Elevated |
| Miami | FL | 230.9 PPT | Significantly Elevated |
| Doral | FL | 230.9 PPT | Significantly Elevated |
| Pensacola | FL | 210.4 PPT | Significantly Elevated |
| Hialeah | FL | 193.1 PPT | Significantly Elevated |
| Pembroke Pines | FL | 146.7 PPT | Significantly Elevated |
| Pembroke Pines West | FL | 146.7 PPT | Significantly Elevated |
| Ocala | FL | 138.1 PPT | Significantly Elevated |
| Casa Grande | AZ | 128.0 PPT | Significantly Elevated |
| Riverton | WY | 125.6 PPT | Significantly Elevated |
| Abilene | TX | 124.6 PPT | Significantly Elevated |
| Sioux City | IA | 122.2 PPT | Significantly Elevated |
| Oxford | MS | 119.7 PPT | Significantly Elevated |
| Tempe | AZ | 116.3 PPT | Significantly Elevated |
| Augusta | GA | 101.5 PPT | Significantly Elevated |
| Lauderhill | FL | 88.4 PPT | Significantly Elevated |
| Pflugerville | TX | 85.4 PPT | Significantly Elevated |
| Downey | CA | 85.2 PPT | Significantly Elevated |
| Prattville | AL | 83.6 PPT | Significantly Elevated |
Top 20 of 453 cities above 4 PPT in our database of 1000 cities. Look up your city.
Frequently Asked Questions
Does boiling water remove PFAS?
Do Brita filters remove PFAS?
Are PFAS only a problem in certain areas?
Sources
- EPA PFAS Health Effects Summary — Health effects
- EPA Final PFAS NPDWR Rule (April 2024) — Regulation
- USGS PFAS Tap Water Study (2023) — Prevalence
Related
Guides: Best PFAS Water Filters · EPA PFAS Regulation Timeline
Problems: Pfas
Other Contaminants: Trihalomethanes
Treatment: Reverse Osmosis · Activated Carbon (Block) · Whole-House Carbon Filter · Pitcher Filter (NSF P473)