Contaminant Reduction Claims
At NSF, we certify various water treatment systems, from filtration to reverse osmosis, which are designed to reduce contaminants. We have listed certified products based on the pollutants we regularly ask about to help you find the best water filter for your home or office. Remember that no systems may be certified to reduce that specific contaminant if a filter type is not listed. Contact us with your questions.
Lead
View all filters and systems certified by NSF to reduce lead.
- Water Pitchers With Filters
- Faucet Filters
- Under-Sink Filters
- Reverse Osmosis Filters
- Counter-Top (Manual-Fill) Filters
- Counter-Top Filters Connected to a Sink Faucet
- Refrigerator Filters
- Aftermarket Refrigerator Filters
- Integrated Refrigerator Filters
Arsenic (Pentavalent) for Treating Incoming Levels of <=50 ppb
View all filters and systems certified by NSF to reduce arsenic less than 50 ppb.
Bacteria/Coliform/Cyst/Virus
Chlorine
View all filters and systems certified by NSF to reduce chlorine.
- Whole House Systems
- Faucet Filters
- Water Pitchers With Filters
- Counter-Top Filters Connected to a Sink Faucet
- Counter-Top (Manual Fill) Filters
- Under-Sink Filters
- Reverse Osmosis Systems
- Refrigerator Filters
- Integrated Refrigerator Filters
- Aftermarket Refrigerator Filters
Chloramine
View all filters and systems certified by NSF to reduce chloramine.
- Faucet Filters
- Counter-Top Filters Connected to a Sink Faucet
- Counter-Top (Manual-Fill) Filters
- Under-Sink Filters
- Reverse Osmosis Systems
Chromium (Hexavalent)
View all filters and systems certified by NSF to reduce hexavalent chromium.
Fluoride
Nitrate/Nitrite
PFOA/PFOS
View all filters and systems certified by NSF to reduce PFOA/PFOS.
- Counter-Top Filters Connected to a Sink Faucet
- Under-Sink Filters
- Reverse Osmosis Systems
- Refrigerator Filters
- Aftermarket Refrigerator Filters
- Refrigerator Filters (Integrated)
- Water Pitchers With Filters
- Whole-House Filters
Total Trihalomethanes (TTHM) and Volatile Organic Compounds (VOCs)
View all filters and systems certified by NSF to reduce VOCs including TTHM.
How NSF Can Help You
What’s New with NSF
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June 19, 2026Third-party certification plays a key role in independently verifying the sustainability of seafood operations.
iNADO Partners with NSF to Support Members and Athletes
May 27, 2026iNADO is pleased to welcome NSF’s expertise and experience in support of its members and the athletes they serve
NSF Ends UK’s Three-Year Testing Gap with REG 31 Testing Designation
May 20, 2026NSF’s Oakdale laboratory becomes the UK’s sole facility offering comprehensive BS 6920 and REG 31 testing, closing a critical drinking water safety gap.