NSF Standards for Refrigerator Water Filters - What to Look for in Certification

The standards applicable to refrigerator water filters are set by NSF International (which itself is recognized by the American National Standards Institute (ANSI)), which has developed three standards: NSF/ANSI 42, 53, and 401.

4 to find the certification of the W10295370A water filter you are considering, then it would be a piece of cake. But that's not the case.

Three large testing organizations can certify filters based on these standards and allow their manufacturers to put certification badges on their filters and packaging. These organizations include the Water Quality Association (WQA), the International Association of Plumbing and Mechanical Officials (IAPMO), and NSF itself.

Just because a filter has a badge (for example, marked with a blue circle NSF) does not mean that it fully meets the certification. Problematic aftermarket filter suppliers can put badges on their products while meeting some basic requirements and skipping the ones you may really care about. Counterfeit filters will have very realistic fake badges.