PFAS
PFOS in your water
Health effects
PFOS is another "forever chemical" from older firefighting foams and consumer coatings. Like PFOA it accumulates in the body and is linked to immune, thyroid, liver, and developmental effects. EPA set an enforceable limit for it in 2024.
The guideline vs. the legal limit
The federal legal limit is the maximum allowed by law. The EWG health guideline is what independent scientists consider safe — it is often far stricter.
Health guideline (EWG)
0.004 ppt
Federal legal limit (MCL)
4 ppt
Source: EWG Tap Water Database & EPA MCLs · 2026
What removes PFOS
Waterdrop · Reverse Osmosis Systems
Waterdrop G3P800 Tankless RO (800 GPD)
- gpd
- 800
- stages
- 7
- tankless
- true
GE Appliances (Haier) · Reverse Osmosis Systems
GE GXRV40TBN 5-Stage Reverse Osmosis
- gpd
- 14.76
- stages
- 5
- antimicrobial
- true
Aquasana · Reverse Osmosis Systems
Aquasana OptimH2O Reverse Osmosis + Claryum
- gpd
- 35
- stages
- 3
- fluoride pct
- 95
Aquasana · Reverse Osmosis Systems
Aquasana SmartFlow Reverse Osmosis
- stages
- multi
- tankless
- true
- efficiency
- high-recovery
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Is PFOS in your water?
Check your city's public record, then book a free 30-minute test to confirm what's in your home.