Standards
What water treatment certifications mean
| Standard | Covers |
|---|---|
| NSF/ANSI 42 | Taste and odor: chlorine, chloramine, particulates |
| NSF/ANSI 44 | Water softeners |
| NSF/ANSI 53 | Health contaminants such as lead and cysts |
| NSF/ANSI 58 | Reverse osmosis |
Manufacturers choose which claims to certify. A filter certified for chlorine is not automatically certified for chloramine. Look the model up in NSF’s public listings.
Sources: NSF standards overview, NSF 42, 53 and 401.
Quick answers
What does NSF/ANSI 44 cover?
Water softeners that reduce hardness from calcium and magnesium by exchanging them for sodium or potassium.
Is an NSF certification for the whole product?
Not necessarily. Certification is claim by claim, so check that the specific claim you care about is listed.