FILTER CERTIFICATIONS
The number on the box tells you what it removes.
A filter claim means little without a certification. These are the standards to look for.
THE STANDARDS
Five to know.
| Standard | Covers |
|---|---|
| NSF/ANSI 42 | Taste, odor and chlorine |
| NSF/ANSI 53 | Health-related contaminants such as lead and certain chemicals |
| NSF/ANSI 58 | Reverse osmosis systems |
| NSF/ANSI 401 | Some emerging compounds found at low levels |
| NSF/ANSI 177 | Shower filters, for free chlorine |
CHECK IT
How to verify.
- Look up the exact model in NSF’s certified product listings
- Check which contaminants it is certified for, not just the standard
- Replace cartridges on the schedule it was certified for
SHOWERS
A separate standard.
Shower filters are covered by NSF/ANSI 177. The EESystem store sells a 15-stage shower filter for $80. As with any filter, ask which certification it holds.
SOURCES
Where these facts come from.
QUESTIONS
Straight answers.
Which filter certification matters for lead?
NSF/ANSI 53, and the listing should name lead specifically.