How to read an NSF listing for a fridge filter
Last checked October 28, 2026
Search the model number at info.nsf.org, then check three things: that the exact model number appears in the listing, which standards it sits under (42, 53, 401), and which claims are named next to it.
The columns, using a real listing
Example: Whirlpool's listing for everydrop Filter 4 (EDR4RXD1), NSF listing, read October 28, 2026.
- Brand Name / Trade Name / Model: the maker's internal model (here W11256135 and W11311161).
- Replacement Element: the numbers sold in stores (here EDR4RXD1, EDR4RXD1B, EDR4RXD1R, KAD4XD1, WHR4RXD1, Kenmore 9084 and W10790818). This is where your box's number should appear.
- Service Cycle (gallons): the rated capacity. Whirlpool's two listed versions are rated 100 and 200 gallons.
- Flow Rate (gpm): the rated flow, here 0.7 gallons per minute.
- Claim: what the filter is listed to reduce.
The section headings are the standards
The same model can appear under several headings. NSF titles them: NSF/ANSI 42 “Drinking Water Treatment Units, Aesthetic Effects”; NSF/ANSI 53 “Health Effects”; NSF/ANSI 401 “Emerging Compounds/Incidental Contaminants”. For EDR4RXD1 the 53 claims include 2,4-D, Asbestos, Atrazine, Benzene, Carbofuran, Chlorobenzene, Cyst, Endrin and more; the 401 claims include Atenolol, Bisphenol A, Carbamazepine, DEET, Estrone, Ibuprofen, Linuron, Meprobamate.
Three traps
- Close is not the same. AQF-LT1000P and AQF-LT1000P-D are different listings. Match every character.
- A brand in the database is not your model. Only the exact model counts.
- Not found is not proof of anything. A maker may use IAPMO R&T or WQA instead; check those too (how).
Sources
- NSF listing for EDR4RXD1: https://info.nsf.org/Certified/DWTU/Listings.asp?TradeName=EDR4RXD1&submit3=Search (read October 28, 2026)
- NSF drinking water treatment search and standard names: info.nsf.org/certified/dwtu (read October 28, 2026)