Standard
NSF/ANSI 401: incidental and emerging compounds
A separate list of incidental contaminants. Its own number for a reason.
Named on the listing: NSF/ANSI 401. Not named: 42, 53.The third cell. In this catalog it is never filled alone: every listing naming 401 also names 42 and 53. That is a fact about these four listings, not a property of the standard.
What it covers
A defined list of incidental contaminants and emerging compounds, the group that includes certain pharmaceutical and pesticide residues found at trace levels in some supplies.
What NSF/ANSI 401 actually is
NSF/ANSI 401 exists because a set of compounds started showing up in trace amounts in treated supplies that the older standards were not written around. Rather than stretch 53, the answer was a separate standard with its own defined list, its own test protocols and its own number.
The list is defined by the standard. That is the important structural fact: a compound is either on it or not, and a certification covers the claims a manufacturer tested for. "Removes emerging contaminants" as a phrase on a listing is not the same as a claim under 401, even when the same listing also names 401 somewhere else.
Why it is a third number rather than an extension
People reasonably assume the numbers are tiers, as though 401 were a stronger 53 and 53 a stronger 42. They are not tiers. They are three scopes, and a product can hold any combination of them.
This catalog contains every interesting combination. Across the twelve refrigerator cartridges here, four name all three numbers, two name only 42, two name NSF/ANSI without any number at all, and four name no certification whatsoever. Reading those states as a ladder is the mistake the three-cell chip on this site was designed to prevent.
The microplastics line
Three listings in this catalog state a reduction of 99% microplastics. That figure is not a claim under 401, or under any of the three standards named here. It is a seller statement that appears alongside the certification, and this site records it as one.
Which is worth being plain about: a listing can name three genuine standard numbers and, in the next clause, publish a percentage that belongs to none of them. Both parts of the sentence are on the box. Only one of them has a certifier behind it.
What it does not cover
- Anything on the 42 aesthetic list or the 53 health effects list
- Compounds outside the standard's own defined list, however similar they sound
- Every compound on the list automatically; certification is per claim here too
- Microbiological safety of the incoming water
- Any statement about what trace levels of anything mean for a person
How to read a claim
A listing naming 401 has said the product carries at least one claim from that list. It has not said which, and it has said nothing about 42 or 53. Where a listing names all three numbers it has made three separate statements, and each one is still claim by claim underneath.
Listings that name it
The same four listings that name 53. No listing in this catalog names 401 without also naming the other two numbers.
The first of them is everydrop Filter 1, EDR1RXD1. The listing names all three standard numbers, which is why all three cells are filled. It sits in Refrigerator Water Filters.
4 listings shown, which is all of them
Only listing here naming coconut shell carbonCoconut shell carbon appears on one filter listing in this category. The others name carbon block or name no medium at all.
everydrop Filter 1, EDR1RXD1
6 month life statedThe listing states NSF 42, 53 and 401 certification, reduction of 70 contaminants including 99% microplastics, coconut shell carbon, 6-month life.
Named on the listing: NSF/ANSI 42, 53, 401.The listing names all three standard numbers, which is why all three cells are filled.
View the listing on AmazonA genuine cartridge whose listing names all three standard numbers, which almost nothing else in this category does. The 70 contaminants and 99% microplastics figures are separate seller claims that sit beside the certification rather than inside it.
Suits A Whirlpool-family fridge that takes the EDR1RXD1 cartridge.
everydrop Filter 2, EDR2RXD1
6 month life statedThe listing states NSF 42, 53 and 401 certification, reduction of 70 contaminants including 99% microplastics, 6-month life.
Named on the listing: NSF/ANSI 42, 53, 401.The listing names all three standard numbers, which is why all three cells are filled.
View the listing on AmazonThe Filter 2 cartridge, with the same three standard numbers named and the same six month stated interval. The cartridge shape is the difference from Filter 1, not the certification.
Suits A Whirlpool-family fridge that takes the EDR2RXD1 cartridge.
everydrop Filter 4, EDR4RXD1
The listing states NSF 42, 53 and 401 certification and reduction of 32 contaminants including 99% microplastics.
Named on the listing: NSF/ANSI 42, 53, 401.The listing names all three standard numbers, which is why all three cells are filled.
View the listing on AmazonThe Filter 4 cartridge names the same three standard numbers as Filters 1 and 2 but states 32 contaminants rather than 70. That is the clearest example on this site of two numbers moving independently: the certification is identical, the seller's contaminant count is not.
Suits A Whirlpool-family fridge that takes the EDR4RXD1 cartridge.
Only listing here stating a gallon figure200 gallons, and it is the one fridge filter listing in this category that states gallons rather than months alone.
LG LT1000P Refrigerator Filter
200 gallon rating statedThe listing states NSF 42, 53 and 401 certification, a 6-month or 200-gallon capacity.
Named on the listing: NSF/ANSI 42, 53, 401.The listing names all three standard numbers, which is why all three cells are filled.
View the listing on AmazonA genuine LG cartridge that names all three standard numbers and states both a six month interval and a 200-gallon capacity. Stating both is the correct way to rate a filter, and it is why this listing is the one the filter life tool has the most to work with.
Suits An LG fridge that takes the LT1000P cartridge.