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Quick answer from a licensed plumber: “NSF certified” only means something once you read the listing. NSF/ANSI 42 covers taste, odor and chlorine; 53 covers health contaminants such as lead; 58 covers reverse osmosis; 401 covers emerging compounds such as microplastics. P473’s PFOA and PFOS rules were folded into 53 and 58, and PFAS claims now sit under those two. Check any claim on NSF’s, WQA’s or IAPMO’s public listings by model number. Our listed picks: the 3M Aqua-Pure 3MDW301-F under the sink, the PUR Plus FM2500V on the faucet, the Brita Everyday Elite pitcher, the iSpring RCC7AK-BN for RO, the A. O. Smith AO-WH-FILTER for the whole house and the EcoPure EPINL30 for a fridge line.
Widest NSF claim list of our picks: the 3M Aqua-Pure 3MDW301-F under-sink system, listed under 42, 53 and 401. Check the 3M Aqua-Pure 3MDW301-F on Amazon
“NSF certified” on a filter box tells you less than it seems. The number after it, 42, 53, 58 or 401, tells you the kind of test. The certifier’s listing tells you what the filter actually passed, at what flow and for how many gallons. This guide explains each standard in plain terms, shows how to check a claim in a few minutes, and gives one listed pick for each filter type. Every certification below was read on the certifier’s public listing on September 29, 2026. The picks link to our full guide for each type, where you will find more options.
What Each NSF/ANSI Standard Certifies
| Standard | What it certifies | Claims you will see on a listing |
|---|---|---|
| NSF/ANSI 42 | Aesthetic effects | Chlorine, chloramine, taste and odor, particulate by class |
| NSF/ANSI 53 | Health effects | Lead, cysts, VOC, mercury, asbestos, MTBE; PFOA, PFOS and Total PFAS where listed |
| NSF/ANSI 58 | Reverse osmosis systems | TDS plus named claims such as lead, fluoride, barium, arsenic |
| NSF/ANSI 401 | Emerging compounds, incidental contaminants | Microplastics, BPA, ibuprofen, DEET, estrone and similar |
| NSF P473 (folded into 53 and 58) | PFOA and PFOS (older protocol) | Now claimed under 53 or 58; NSF lists no products under P473 |
| NSF/ANSI 55 | Ultraviolet (UV) systems | Class A disinfection or Class B supplemental treatment |
| NSF/ANSI 177 | Shower filters | Free available chlorine |
| NSF/ANSI/CAN 372 | Lead content of the product’s materials | A “lead free” parts listing, not lead removal |
Titles and claim names come from the NSF and WQA listings; the P473 history comes from NSF’s 2019 announcement.
NSF/ANSI 42: taste, odor and chlorine
NSF titles 42 “Aesthetic Effects.” It covers what you can taste, smell or see: chlorine, chloramine, taste and odor, and particulate. Particulate claims come in classes. Class I covers particles of 0.5 to 1.0 microns, per Solventum’s 3MDW301 page, and EPA suggests a Class I claim on lead filters because some particles can contain lead. A 42-only filter makes your water taste better. It makes no health claim.
NSF/ANSI 53: health contaminants
NSF titles 53 “Health Effects.” This is the one for lead, cysts, VOC, mercury and similar. NSF says certification to 53 requires the maker to state the filter’s capacity, the gallons before it must be changed. NSF also says certified lead filters were tested up to 150 ppb of lead and should not be relied on above that. A 53 listing never covers everything. It names each contaminant, and those names are the claim.
NSF/ANSI 58: reverse osmosis
NSF/ANSI 58 is the standard for reverse osmosis systems. NSF describes RO as a system that connects under the sink and uses a membrane to reduce lead, and that can also reduce minerals and total dissolved solids (TDS). Every 58 listing we read names TDS reduction. Some add lead, fluoride, arsenic, barium and more. The listing also shows a daily production rate in gallons per day, which may be lower than the number in the product name.
NSF/ANSI 401: emerging compounds
WQA’s directory calls 401 “Emerging Compounds/Incidental Contaminants.” On the listings we read, it covers compounds such as microplastics, BPA, ibuprofen, naproxen, DEET, estrone and a few prescription drugs. Each model lists its own set. One pitcher we checked has microplastics as its only 401 claim. A faucet filter we checked has 15.
NSF P473 and PFAS
P473 was NSF’s protocol for PFOA and PFOS, two PFAS chemicals. In 2019 NSF announced that 53 and 58 now include those criteria, and that the requirements were previously in P473. Searching NSF’s listings for P473 today returns no products. Trade press reports that the 2022 versions of 53 and 58 added five more PFAS and a “Total PFAS” claim. So a box that says “P473” is old wording. Look for PFOA, PFOS or Total PFAS on a current 53 or 58 listing.
NSF/ANSI 55 and 177, and the 372 trap
NSF/ANSI 55 covers UV systems in two classes, and 177 covers shower filters. Both are covered below. NSF/ANSI/CAN 372 is different: it certifies the lead content of the product’s own materials, the “lead free” plumbing rule. A 372 mark does not mean the filter removes lead from your water. Only a 53 or 58 listing with a lead claim means that.
How to Check a Certification Claim
EPA notes there is no federal requirement for point-of-use filters to be certified, so checking is on you. It takes about five minutes.
- Find the certifier’s mark on the box or listing. EPA names NSF, IAPMO, WQA, UL and CSA as ANSI-accredited certifiers for lead-reduction filters. Each has its own public directory.
- Search that certifier’s directory. NSF’s is at info.nsf.org/Certified/DWTU. Pick the standard, then search by company or trade name. WQA’s is at find.wqa.org, and IAPMO’s is at pld.iapmo.org.
- Search the company on the listing, not the brand on the box. PUR is listed under Kaz USA, the 3M under-sink system under Solventum Purification, and the EcoPure inline filter under Water Channel Partners. If the brand search comes up empty, try the maker’s parent company or the model number.
- Match the exact model and replacement cartridge. Suffixes matter. NSF lists the iSpring RCC7AK-BN for nine claims and a plain RCC7AK, from another factory, for TDS only. WQA notes that replacement components “may or may not reduce all reduction claims that system makes.”
- Read the claim column, then the gallons and flow. The claim names are what is certified. The rated gallons and flow on the listing are the conditions it passed at.
What we found when we checked our picks
Four of the six products had a gap between the listing and what the maker or seller says:
- EcoPure’s box calls its NSF/ANSI 42 certification “material and structural requirements only,” while NSF’s listing shows chlorine and taste and odor reduction.
- A. O. Smith’s product page says the whole-house filter reduces chloramine and fits city or well water. The NSF listing names chlorine, not chloramine, and the manual says municipally treated water only.
- iSpring sells the RCC7AK-BN as 75 GPD. The NSF listing shows 25.41 gallons per day. The Amazon listing claims PFAS reduction that the NSF listing does not name.
- Brita’s data sheet lists 30 substances. WQA certifies 9 claims for the Everyday pitcher (our count).
None of this makes these bad products. It is why you read the listing. For how our faucet filter guide handles “tested to” versus “certified to” wording, see our faucet filter comparison.
NSF-Certified Picks by Filter Type
| Filter type | Pick | Listed by | Standards | Key listed claims | Full guide |
|---|---|---|---|---|---|
| Pitcher | Brita Everyday Elite | WQA | 42, 53, 401 | Lead, mercury, cadmium, benzene, asbestos; microplastics | Pitchers |
| Faucet mount | PUR Plus FM2500V | NSF, WQA, IAPMO | 42, 53, 401 | Lead, mercury, VOC; Total PFAS (IAPMO) | Faucet filters |
| Under-sink | 3M Aqua-Pure 3MDW301-F | NSF | 42, 53, 401 | Lead, cysts, VOC, TTHM, MTBE; chloramine | Under-sink |
| Reverse osmosis | iSpring RCC7AK-BN | NSF | 58 | Lead, fluoride, TDS and 6 more | RO systems |
| Whole house | A. O. Smith AO-WH-FILTER | NSF | 42 | Chlorine, taste and odor | Whole house |
| Fridge inline | EcoPure EPINL30 | NSF | 42 | Chlorine, taste and odor | Inline fridge |
Certifications from the NSF, WQA and IAPMO R&T listings, read on September 29, 2026. Five linked listings were sold by Amazon.com, and the A. O. Smith listing by the maker’s Amazon storefront.
Brita Large 10-Cup Everyday Pitcher with Elite Filter
Pitcher OB46 with Elite filter OB06 (Amazon listing model OB46/OB06) · certifier: WQA · NSF/ANSI 42: chlorine, Class I particulate, taste and odor · 53: asbestos, benzene, cadmium, lead, mercury · 401: microplastics · 120 gallons per filter, about 6 months (Brita)
This pitcher’s certification is held by WQA. NSF’s own listings name the Elite filter only with a few other Brita pitchers, so for this one you check WQA’s directory. WQA’s listing for the Elite filter (OB06) in the OB46 Everyday pitcher shows three standards. Under NSF/ANSI 42 it lists chlorine, Class I particulate, and taste and odor. Under 53 it lists asbestos, benzene, cadmium, lead and mercury. Under 401 it lists microplastics for this pitcher model. Brita rates the filter at 120 gallons, which it puts at about 6 months for the average family.
Brita’s data sheet lists 30 substances, but WQA’s listings certify 9 claims for this pitcher and filter pair (our count). Eight of those 30 are on WQA’s listings for this pitcher, and 22 are not. The sheet marks two of the eight, benzene and cadmium, as valid only for other pitcher models, but WQA lists both under 53 for this one. The ninth WQA claim, taste and odor, is not on the sheet. This is the plainest example of why you read the listing for your exact model. For the full pitcher comparison, including a ZeroWater and a Clearly Filtered option, see our water filter pitcher picks and how often to change a pitcher filter.
- WQA lists lead, mercury, cadmium, benzene and asbestos under NSF/ANSI 53
- Chlorine, Class I particulate, and taste and odor under 42
- 120 gallons per filter, about 6 months (Brita)
- No plumbing work at all
- WQA certifies 9 claims for this model, fewer than the 30 on Brita’s sheet
- Only microplastics under 401 for this pitcher model
- This model’s listing is on WQA’s directory, not NSF’s
Verdict: The pitcher to buy when you want certified lead reduction with no install, and you check WQA’s listing rather than the box.
PUR Plus FM2500V Vertical Faucet Filter
Model FM2500V with RF-9999 filter · certifier: NSF (also WQA and IAPMO R&T) · NSF/ANSI 42: chlorine, Class I particulate, taste and odor · 53: asbestos, chlordane, lead, mercury, toxaphene, VOC · 401: 15 compounds incl. microplastics (our count) · 100 gallons, 0.52 gpm (NSF listing) · 100 gallons or up to 3 months (PUR)
NSF lists the FM2500V under Kaz USA, Inc., the company name on PUR’s listings. Its NSF/ANSI 53 row names asbestos, chlordane, lead, mercury, toxaphene and VOC. Its 401 row names 15 compounds, from atenolol to microplastics (our count). IAPMO R&T also lists it under NSF/ANSI 53 for lead, mercury, Total PFAS and VOC. NSF’s own rows for this model do not name PFAS, so the PFAS claim rests on the IAPMO listing. Both listings give 100 gallons at 0.52 gpm for the filter.
PUR says the filter lasts 100 gallons or up to 3 months, and that this vertical unit is not designed for pull-out or hand-held faucets. It suits a plain faucet with a threaded aerator. The certified flow is about half a gallon a minute, so filling a stock pot is slow. Our faucet water filter picks compare it with the horizontal PFM410F, the Brita faucet system and a Culligan unit.
- Three certifiers list it under 42, 53 and 401
- IAPMO’s 53 listing names Total PFAS
- Lead, mercury and VOC on NSF’s 53 row
- Installs on the faucet with no tools, per PUR
- Short life: 100 gallons or 3 months (PUR)
- Not for pull-out or hand-held faucets (PUR)
- Certified flow is 0.52 gpm
Verdict: The faucet mount to buy when you want lead, VOC and a Total PFAS claim on current listings, for a kitchen with a standard threaded faucet.
3M Aqua-Pure 3MDW301-F Under-Sink System
NSF lists model 3MDW301 with cartridge 3MDW311 (the -F version adds a faucet) · certifier: NSF, listed under Solventum Purification Inc. · NSF/ANSI 42: chlorine, chloramine, Class I particulate, taste and odor · 53: 1,2,3-TCP, asbestos, cysts, lead, MTBE, TTHM, VOC · 401: 14 compounds incl. microplastics (our count) · 1,000 gallons, 0.75 gpm (NSF listing) · replace every 12 months (Solventum)
Of the six picks here, this one carries the most NSF claims: 25 across three standards, against 24 for the PUR (our count). Its 42 row adds chloramine. Its 53 row covers cysts, lead, MTBE, trihalomethanes (TTHM), VOC, asbestos and 1,2,3-TCP. Its 401 row names 14 compounds, including microplastics (our count). One tip for checking it: search NSF’s database for Solventum, not 3M. That is the company name on the listing.
Solventum rates the cartridge at 1,000 gallons at 0.75 gpm and says to change it every 12 months, or sooner if the gallons run out first. The head has a built-in shut-off valve, so you change the cartridge without closing the stop. The 3MDW301-F comes with a stainless faucet. You mount it in an existing countertop hole or drill a new one. Plumber’s note: on stone tops, have the hole cut by the fabricator or with a proper core bit. For more under-sink options, see our under-sink water filter picks.
- Sold and shipped by Amazon
- Chloramine on the NSF 42 row, useful on chloraminated city water
- Cysts, lead, MTBE, TTHM and VOC on the NSF 53 row
- Built-in shut-off for cartridge changes (Solventum)
- Needs a countertop hole for the dedicated faucet
- 0.75 gpm certified flow, fine for drinking water, slow for filling pots
- No PFAS claim on the listing
- Listed under Solventum, which confuses a search for 3M
Verdict: The pick for a city-water kitchen that wants one certified drinking-water tap covering lead, cysts, VOC and chloramine.
iSpring RCC7AK-BN Reverse Osmosis System
Model RCC7AK-BN · certifier: NSF · NSF/ANSI 58: asbestos, barium, cadmium, trivalent chromium, copper, fluoride, lead, selenium, TDS · listed daily production 25.41 gpd (marketed as 75 GPD) · listed cartridges FP15, FC15, FG15, MC7 membrane, FT15, FA15 · 3.2 gal tank (iSpring)
NSF lists the RCC7AK-BN as a full system under NSF/ANSI 58, the reverse osmosis standard. The row names asbestos, barium, cadmium, trivalent chromium, copper, fluoride, lead, selenium and TDS. iSpring’s page quotes the same nine with percentages. Two details are worth reading. First, the listed daily production rate is 25.41 gallons per day, while iSpring sells it as a 75 GPD system. Plumber’s note: size for the listed number, not the name on the box. Second, NSF also lists a plain RCC7AK from a different factory for TDS reduction only. The suffix on the model you buy matters.
The Amazon listing also claims PFAS reduction of 96 to 99 percent. That claim is not on NSF’s listing for this model, so we treat it as iSpring’s own figure. RO sends part of the water it treats to the drain, and it needs a drain connection, a tank spot and a faucet hole. Our under-sink reverse osmosis picks cover a tankless option, and our RO install cost guide covers the job.
- Sold and shipped by Amazon
- Whole system listed under NSF/ANSI 58, not just parts
- Fluoride, lead and TDS among nine listed claims
- Listed cartridge set is named, so replacements are easy to match
- Listed production 25.41 gpd, well under the marketed 75 GPD
- PFAS claim on Amazon is not on the NSF listing
- Chromium on the listing is trivalent only
- Needs a drain connection and a faucet hole
Verdict: The RO pick when you want a full-system NSF/ANSI 58 listing with fluoride and lead on it, and you size it by the listed gallons.
A. O. Smith AO-WH-FILTER Whole House Filter
Model AO-WH-FILTER, replacement AO-WH-FILTER-R · certifier: NSF · NSF/ANSI 42: chlorine, taste and odor · 600,000 gallons, 7 gpm (NSF listing) · 20 to 100 psi, 40 to 90°F (A. O. Smith) · 6 years or 600,000 gallons (A. O. Smith) · 3/4 in. shut-off valve in the box (manual)
NSF lists the AO-WH-FILTER as a point-of-entry unit under NSF/ANSI 42 for chlorine, and for taste and odor, at 600,000 gallons and 7 gpm. That is the whole claim. It is an aesthetic listing, not a health-effects one. It does not cover lead, PFAS or anything under 53. A. O. Smith’s data sheet shows about 2 mg/L of free chlorine going in and no more than 0.18 mg/L coming out at every sample point up to 600,000 gallons.
A. O. Smith’s product page lists “City or Well” and says it reduces chloramine. Its manual and data sheet say the filter is “for use with municipally treated water only.” Chloramine is not on the NSF listing. Go by the listing and the manual: city water, chlorine. The manual says to install it where the main enters the house, before the water heater, upright and on cold water only. It recommends a sediment pre-filter. The Amazon listing is sold by A. O. Smith’s own storefront. For other whole-house options, see our whole house water filter picks and under-sink vs whole-house filters.
- Sold by the maker’s Amazon storefront
- NSF-listed as a point-of-entry (whole-house) unit
- 600,000 gallons at 7 gpm on the listing
- Maker data sheet shows chlorine held low to the end of rated life
- Listed for chlorine, taste and odor only
- Manual says municipally treated water only, despite “City or Well” on the product page
- Chloramine claim on the product page is not on the NSF listing
- Sediment pre-filter recommended, bought separately
Verdict: The whole-house pick for city water with a chlorine taste or smell, when you want a certified listing behind the claim.
EcoPure EPINL30 Inline Refrigerator Filter
Model EPINL30 · certifier: NSF, listed under Water Channel Partners · NSF/ANSI 42: chlorine, taste and odor · 2,500 gallons, 0.5 gpm (NSF listing) · 5-year filter (EcoPure) · 1/4 in. compression and push-to-connect fittings in the box (EcoPure)
This splices into the 1/4 in. line feeding a fridge or ice maker that has no filter of its own. NSF’s current listing names chlorine reduction and taste and odor reduction under NSF/ANSI 42, at 2,500 gallons and 0.5 gpm. It is listed under Water Channel Partners, not EcoPure, so search that name. EcoPure’s installation guide says the filter is certified to NSF/ANSI 42 “for material and structural requirements only.” The listing shows performance claims too, so the listing is the more current word. This is a good reason to check the database instead of the box.
EcoPure sells it as a 5-year filter and puts both 1/4 in. compression and push-to-connect fittings in the box. It is a taste and odor filter. It carries no lead or cyst claim. If your fridge already takes a built-in cartridge, buy that model’s certified cartridge instead. See our inline refrigerator water filter picks for a second option, the Aqua-Pure AP717.
- Sold and shipped by Amazon
- NSF lists chlorine, taste and odor at 2,500 gallons
- Both fitting types in the box (EcoPure)
- Long 5-year rating (EcoPure)
- Taste and odor only: no lead or cyst claim
- Box wording and NSF listing disagree on what is certified
- Listed under a different company name than the brand
Verdict: The inline pick for a fridge or ice maker line on city water when the goal is chlorine taste, not health contaminants.
I send an occasional note when a new guide goes up — repairs worth doing yourself, and the parts that actually last. No spam, no course funnel; written by a licensed Georgia plumber.
Shower Filters and UV Systems
Shower filters: NSF/ANSI 177
NSF/ANSI 177 is the shower filter standard. The claim on the listings is “Free Available Chlorine Reduction.” Very few shower filters hold it. NSF’s 177 listing showed 7 manufacturers and 11 products on September 29, 2026, none of them the brands in our shower filter guide. WQA lists Rainshower’s CQ-1000 for free available chlorine. We found none of the three filters in our shower head filter picks on NSF’s or WQA’s 177 listings. The Rainshower Amazon listing we found was sold by a third-party seller, so we did not link it. If a shower filter says “NSF certified,” look for 177 and a chlorine claim on the listing. A 42 or 372 mark on a shower filter does not tell you it was tested as a shower filter.
UV systems: NSF/ANSI 55 Class A and Class B
UV lamps kill or inactivate microorganisms. They do not remove chemicals. NSF’s standards page and an article by NSF’s Rick Andrew explain the two classes. Class A systems are meant to inactivate bacteria, viruses, Cryptosporidium and Giardia in contaminated water, and they must have a UV sensor and alarm. Class B systems are for supplemental treatment of water that is already disinfected, or has been tested and deemed acceptable. He writes that Class B systems “are not intended for disinfection of microbiologically unsafe water.”
The class is on the NSF listing. NSF lists Viqua’s PRO10, PRO20 and PRO30 as Class A. It lists Viqua’s VH410M-V as Class B at 14 gpm, while an Amazon listing we found sells the VH410M as an 18 gpm unit. Plumber’s note: on a private well with a bacteria problem, only a Class A system sized to your flow belongs on the line, after sediment filtration. See our well water filter picks for the rest of a well setup.
Before You Buy
- Know what is in your water. Pick the claim first, then the filter. On city water, start with your utility’s annual water quality report. On a private well, get a lab test.
- Match the standard to the problem. Taste and smell: 42. Lead, cysts, VOC: 53 with those claims. Fluoride, arsenic or TDS: usually a 58 RO system. Bacteria on a well: 55 Class A.
- Check the listing for your exact model and cartridge. Use the five steps above.
- Plan for the certified gallons, not the months. The certification was tested to the listed gallons. Past that, you are outside what was tested. Cartridges run from 100 gallons on a faucet mount to 600,000 gallons on the whole-house unit here.
- Count the install. Pitchers and faucet mounts need no tools. An under-sink system with its own faucet, like the 3M here, needs a faucet hole. RO needs a faucet hole and a drain connection. Whole-house filters go on the main line before the water heater. Our sediment micron guide covers pre-filters.
FAQ
What does NSF certified mean on a water filter?
It means a certifier tested that exact model against an NSF/ANSI standard and lists it with the specific contaminants it passed. The certifier can be NSF, WQA, IAPMO R&T or another ANSI-accredited body; EPA names NSF, IAPMO, WQA, UL and CSA. The standard number alone tells you little. The claims on the listing, such as lead reduction under NSF/ANSI 53, are what count.
Is NSF 53 better than NSF 42?
They cover different things. NSF/ANSI 42 is for aesthetic effects such as chlorine, taste, odor and particulate. NSF/ANSI 53 is for health effects such as lead, cysts and VOC. For lead, EPA suggests a filter certified to 53 for lead and to 42 for Class I particulate. Many filters carry both.
What does NSF 401 cover?
NSF/ANSI 401 covers emerging compounds and incidental contaminants. On the listings we read it names things like microplastics, BPA, ibuprofen, DEET and a few pharmaceuticals. Each model lists its own set, so check which ones yours covers.
Does NSF 53 cover PFAS?
It can. NSF first set PFOA and PFOS requirements in a separate protocol, P473, then moved them into NSF/ANSI 53 and 58, as NSF announced in 2019. The 2022 versions added more PFAS and a Total PFAS claim. A filter only has a PFAS claim if its listing names PFAS. None of the NSF or WQA rows for our picks do, though IAPMO lists the PUR FM2500V for Total PFAS under 53.
Is WQA or IAPMO certification as good as NSF?
They certify to the same NSF/ANSI standards. EPA lists NSF, IAPMO, WQA, UL and CSA as ANSI-accredited certifiers for lead-reduction filters. What matters is that the model is on a current listing with the claim you need, whichever certifier holds it.
Why Trust Plumbing Picks
Plumbing Picks is written by a licensed Georgia journeyman plumber. Every certification on this page comes from the certifiers’ public listings, and every spec from the maker documents listed below or the Amazon listings we link. Nothing here comes from hands-on testing. On September 29, 2026, the Brita, PUR, 3M, iSpring and EcoPure listings were sold by Amazon.com and in stock, and the A. O. Smith listing was sold by A. O. Smith’s own Amazon storefront and in stock. Listings and certifications change, so check both before you buy. If you buy through a link we may earn a commission at no extra cost to you. Nobody pays to be included here. More on who writes this and how we pick.
Sources
- NSF: Drinking Water Treatment Units listings (NSF/ANSI 42, 53, 55, 58, 177, 401), searched by company on September 29, 2026, NSF: certified product listings for lead reduction (explains NSF/ANSI 53 and 58)
- WQA: Find Gold Seal certified products (Brita OB06 under 42, 53, 401; Rainshower under 177)
- IAPMO R&T: certificate W-29904, NSF/ANSI 53 (PUR FM2500V), IAPMO product listing directory
- US EPA: A Consumer Tool for Identifying POU Drinking Water Filters Certified to Reduce Lead (EPA/600/F-18/335)
- NSF International: PFOA/PFOS reduction claims added to NSF/ANSI 53 and 58 (May 21, 2019), WaterWorld: NSF adds PFAS compounds to NSF/ANSI 53 and 58 (2023)
- NSF: Standards for water treatment systems (NSF/ANSI 55 Class A and B, 177), WC&P: NSF/ANSI 55 Class A versus Class B UV systems, by NSF’s Rick Andrew (2015)
- Brita: Elite filter (OB06) performance data sheet, Jan 2026
- PUR: PUR Plus vertical faucet system (FM2500V) product page
- Solventum (3M): Under Sink Dedicated Faucet Water Filtration System 3MDW301 / 3MDW301-F
- iSpring: RCC7AK product page
- A. O. Smith: AO-WH-FILTER product page, owner’s manual, performance data sheet
- EcoPure: EPINL30 product page and the EPINL30 installation guide and specification sheet
- Amazon listings for the six linked products (checked September 29, 2026)
Bottom Line
Read the claim, not the number. NSF/ANSI 42 is taste and chlorine, 53 is health contaminants, 58 is reverse osmosis and 401 is emerging compounds; PFAS claims now sit under 53 or 58. Before you buy, find the model on NSF’s, WQA’s or IAPMO’s listing and check that it names what is in your water. For a certified drinking-water tap, the 3M Aqua-Pure 3MDW301-F has the widest NSF list of our picks. For no install at all, the PUR Plus FM2500V and the Brita Everyday Elite pitcher are both listed for lead.