PFAS
PFOS in your water
Is PFOS in drinking water dangerous?
It depends on the level and how long you're exposed. The EPA legal limit (MCL) for PFOS is 4 ppt. The EPA also sets a non-enforceable health goal (MCLG) of 0 ppt. Meeting the legal limit isn't the same as zero risk — test your water to know your level.
How do you remove PFOS from water?
PFOS is treated by Reverse Osmosis and Whole-House Carbon Filter. Choose a system independently certified to NSF/ANSI standards to reduce PFOS, and test your water first to confirm the level.
Source: EPA MCL / MCLG; WHO guidelines; NSF/ANSI · 2026
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 health-based goal vs. the legal limit
The federal legal limit (MCL) is the maximum allowed by law. The EPA health goal (MCLG) is the level below which no health risk is expected — it is non-enforceable and often stricter than the legal limit.
EPA health goal (MCLG)
0 ppt
Federal legal limit (MCL)
4 ppt
Source: EPA National Primary Drinking Water Regulations (MCL / MCLG) · 2026
What removes PFOS
Semipermeable membrane filtration
Reverse Osmosis
Pushes water through a fine membrane that removes the dissolved solids most filters miss.
Look for: NSF/ANSI 58 certification
How it works→Activated carbon adsorption
Whole-House Carbon Filter
A point-of-entry carbon bed that strips chlorine, chloramine, and chemical taste from every tap.
Look for: NSF/ANSI 42 certification
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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.