PFOS (Perfluorooctane Sulfonic Acid)
Category: pfas
EPA MCL
4 ppt
Status
EPA Regulated
NSF Standard
NSF/ANSI 53, NSF/ANSI 58 (formerly P473)
Health Effects
Associated with increased risk of certain cancers, immune system effects, thyroid disease, elevated cholesterol, and developmental effects in fetuses and infants. EPA set the MCLG at zero.
Where It Comes From
Synthetic chemical used historically in stain-resistant treatments (Scotchgard), firefighting foams (AFFF), and industrial processes. One of the most persistent PFAS compounds - extremely long environmental half-life.
Where It's Commonly Found
Communities near military bases and airports (AFFF use), industrial sites, and wastewater treatment plants. Often found alongside PFOA.
Detected in approximately 3,500+ public water systems under UCMR 5. An estimated 176 million Americans have detectable PFAS in their drinking water.
How to Remove It
Effective Technologies
- activated carbon
- carbon block
- reverse osmosis
- ion exchange
- nanofiltration
Does NOT Remove It
- UV
- water softener
- mechanical filtration
Filters That Address PFOS (Perfluorooctane Sulfonic Acid)
11 filters in our database list PFOS (Perfluorooctane Sulfonic Acid) reduction.
Clearly Filtered Pitcher
pitcher
$90
$165/yr filters
Price checked Apr 2026
Epic Water Filters Pure Pitcher
pitcher
$70
$212/yr filters
Price checked Apr 2026
ZeroWater 10-Cup
pitcher
$34.99
$107.94/yr filters
Price checked Apr 2026
Epic Water Filters Nano
pitcher
$82
$138/yr filters
Price checked Apr 2026
Berkey Big Berkey
gravity
$367
$10/yr filters
Price checked Apr 2026
ProOne Big+
gravity
$183.96
$126.32/yr filters
Price checked Apr 2026
Aquasana AQ-5200
under sink
$249.99
$147.98/yr filters
Price checked Apr 2026
Aquasana AQ-5300
under sink
$349.99
$167.98/yr filters
Price checked Apr 2026
Official Sources
Related Contaminants
Learn More
Check if PFOS (Perfluorooctane Sulfonic Acid) is in your water
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Enter Your ZIP Code →Informational guidance based on EPA data and NSF standards - not medical advice.