NSF/ANSI 42, 53 and 401: Filtration Systems Standards
NSF/ANSI 42, 53 and 401 are the leading industry standards for filtration products and systems. Read more about the scope, testing and claims under each.
The most common certifications for filtration systems are NSF/ANSI 42, 53, and 401, which certify that a product effectively reduces specific contaminants from drinking water.
NSF/ANSI 42: Drinking Water Treatment Units – Aesthetic Effects
This standard establishes minimum requirements for systems designed to reduce non-health-related contaminants.
- Scope: Point-of-use and point-of-entry systems.
- Claims: Chlorine, taste and odor, chloramine, particulate, iron, manganese, zinc, and total dissolved solids (TDS).
- Testing: Material safety (including content in accordance with NSF/ANSI/CAN 372), structural integrity, and specific aesthetic-related contaminant reduction claims (claims vary by product).
NSF/ANSI 53: Drinking Water Treatment Units – Health Effects
This standard establishes minimum requirements for systems designed to reduce specific health-related contaminants.
- Scope: Point-of-use and point-of-entry systems.
- Claims: This standard offers over 50 contaminant reduction claims. Some of the most popular include lead, Cryptosporidium, VOCs, and chromium.
- Testing: Material safety (including content in accordance with NSF/ANSI/CAN 372), structural integrity, and specific health-related contaminant reduction claims (claims vary by product).
NSF/ANSI 401: Emerging Compounds/Incidental Contaminants
This standard addresses the ability of a water treatment device to remove up to 15 individual contaminants identified in published studies as occurring in drinking water. The pollutants covered in NSF/ANSI 401 have been detected in drinking water supplies at trace levels and can affect some consumers’ perception of drinking water quality.
- Scope: Point-of-use and point-of-entry systems.
- Claims: This standard offers up to 15 specific contaminant reduction claims. The most popular categories include prescription drugs, over-the-counter medications, herbicides, pesticides, and chemical compounds.
- Testing: Material safety (including content in accordance with NSF/ANSI/CAN 372), structural integrity, and specific emerging compounds/incidental contaminants outlined in the standard.
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