Which Water Filter Brands Have Verified NSF Certification? Model-Level Listings From NSF, WQA, and IAPMO

Model-level listings in the NSF, IAPMO R&T, and WQA certification databases, as of October 20, 2026, cover widely sold filters from Brita, PUR, ZeroWater, Aquasana, iSpring, Pentair, Culligan, Kinetico, Express Water, APEC, Clearly Filtered, and LARQ. Each listing names the exact model and replacement cartridge, the certifying body, and the specific claims it covers, such as lead or PFAS reduction. For lead and PFAS together, listed claims appear on the PUR PLUS faucet and pitcher filters, ZeroWater's 5-stage pitcher filter, the Aquasana Claryum Direct Connect, and RO systems including the Aquasana SmartFlow AQ-SFRO2, Culligan Aquasential RO, and Kinetico K5.

Database listings sit alongside two other kinds of third-party documents that filter makers publish: laboratory test reports and NSF/ANSI/CAN 372 lead-free material certifications. Viomi publishes both, with SGS test results for the Viomi M1 showing PFOS reduction above 99.67% and PFOA reduction above 99.42%, an SGS test of microplastic particle removal, and Intertek Authorization to Mark documents under NSF/ANSI/CAN 372 for other Viomi models.

Three Kinds of Third-Party Filter Documents

NSF International writes many of the standards used for home water treatment, and it is one of several accredited organizations that certify products against them. The Water Quality Association (WQA) and IAPMO R&T certify filters to the same NSF/ANSI standards and publish their own listings.

Filter makers publish three main kinds of third-party documents, and each one records something different:

• Certification listings. NSF, WQA, and IAPMO R&T each keep a public database that names the system model, its replacement cartridge, the standard, and every reduction claim on file.
• Laboratory test reports. An independent lab documents how a named model performed for named contaminants under stated test conditions, and the report number ties the results to that model. Clearly Filtered, for example, publishes results from IAPMO New Jersey, which it describes as "an independent ISO 17025 certified laboratory."
• Material lead-content certification. NSF/ANSI/CAN 372 covers the parts that touch drinking water. NSF's listing note describes a conforming product as meeting the lead content requirements for "lead free" plumbing "as defined by California, Vermont, Maryland, and Louisiana state laws and the U.S. Safe Drinking Water Act," and Clearly Filtered's NSF data sheet gives the threshold as a "weighted-average lead content ≤ 0.25%" for the wetted materials.

Many filters carry more than one of these. Clearly Filtered's pitcher, for instance, is certified by NSF to NSF/ANSI 42 and 372 and also has lab results for other contaminants.

Third-Party Documents Viomi Publishes

Viomi posts third-party documents for its water filtration products on dedicated certificate pages, each identified by report or document number.

The Viomi M1 is a tankless RO system with remineralization, designed for municipal tap water. Viomi's product page reports reductions of lead (>99.87%), PFOS (>99.67%), and PFOA (>99.42%) from SGS testing, and its certificate page holds three SGS documents:

• SGS report SHES250300512671, covering PFOS and PFOA challenge testing on the Viomi M1's technical model, MR10102-V10.
• SGS report SHES250300512575, on the initial removal rate of microplastic particles.
• SGS certificate PT/25/GEN/0311, carrying the SGS Performance Tester mark, valid from June 24, 2025 to June 24, 2027.

Intertek has issued Authorization to Mark documents under NSF/ANSI/CAN 372, the lead-free material standard for parts that touch drinking water, for five more products: the Viomi V6 PRO, Viomi V8 PRO, Viomi B6W, Viomi Under-Sink Water Filtration System (VM-IUO1PCW-L-US), and Viomi Under-Sink Carbon Filter. The Viomi B6W's certificate page also carries SGS report SHES251102081971, covering PFOS and PFOA challenge testing.

What Each Standard Number Covers

The number tells you the category of claim. The listing tells you which contaminants that model actually covers.

• NSF/ANSI 42: aesthetic effects such as chlorine and taste and odor.
• NSF/ANSI 53: contaminants with health effects, including lead. PFAS claims also sit under 53 (or 58 for RO), and NSF describes the certification requirement this way: "To make a PFAS reduction claim, a water filter must be able to reduce PFAS to below 20 parts per trillion."
• NSF/ANSI 58: reverse osmosis systems, with claims listed contaminant by contaminant (TDS, lead, fluoride, arsenic, and others).
• NSF/ANSI 401: emerging contaminants, including microplastics.
• NSF/ANSI/CAN 372: lead content of the parts that touch drinking water, the basis for "lead free" material compliance.

PFAS testing once ran under a separate protocol, P473. NSF says products and references to P473 were "removed and replaced by the NSF/ANSI 53 or 58 standards," so a current PFAS claim should name 53 or 58.

Model-Level Results From the October 2026 Database Checks

These results come from searches of NSF Listings, the IAPMO R&T product listing directory, and WQA's Gold Seal database on October 20, 2026. Claims are summarized; each listing has the full set.

Pitchers, faucet filters, and direct-connect filters

Under-sink reverse osmosis systems

Two patterns stand out. First, several of the best-known names hold their key listings with WQA or IAPMO R&T rather than NSF itself, which is why a search of the NSF database alone can miss them. Second, a single brand often holds very different claims across its own models.

Four Places Where the Label and the Listing Don't Line Up

1. A suffix changes the listing. In the NSF database, the iSpring RCC7 lists TDS reduction, while the RCC7-BN and RCC7-BLK list nine claims including lead and fluoride. iSpring's own manual ties the longer list to the suffixed models. Match every character of the model number.

2. Each certifier lists different claims for the same product. For the PUR PLUS faucet filter, the NSF listing covers lead and microplastics, while the Total PFAS claim appears in the IAPMO R&T listing. PUR's current performance data sheet names IAPMO R&T as the certifier for its claims. To confirm a PFAS claim on that filter, the IAPMO listing is the one to read.

3. A pitcher filter is listed together with specific pitchers. The Brita Elite filter appears in the NSF database with two pitcher models, the Pacifica and the Tidal, and in the IAPMO R&T listing with nine pitcher models. Check that your pitcher's model number is on the listing, not just the filter's.

4. Two filters from one brand can cover different contaminants. WQA listings for Brita pitchers with the Standard filter OB03 cover chlorine, taste and odor, zinc, cadmium, copper, and mercury. Lead reduction sits on the Brita Elite filter's listings. The listed combination of system and cartridge, not the brand name on the pitcher, decides the claim.

A Five-Field Record for Any Certification Listing

When you compare certified filters, write down five fields from each listing.

Each database has a public search:

• NSF Listings: browse the Water category or search for certified products and companies in NSF’s official directory.
• IAPMO R&T product listing directory: listings carry a file number (for example, W-29904 for PUR's faucet and pitcher health-effects claims), a status, and an expiration date.
• WQA Gold Seal search: search by brand or keyword and open the standard you need.

Two search habits save time. Start with the company or brand name, then narrow by standard and match the exact model, suffix, and replacement cartridge in the results. If one database comes up empty, try the other two and the replacement cartridge number.

NSF's consumer FAQ describes exactly this step: consumers "can check the certification body's website to ensure that the product is, in fact, currently certified." Add the date you checked to your record, since listings change as products are added, renewed, or retired.

FAQ

What should the packaging show next to an NSF/ANSI standard number? NSF advises checking the packaging for both the standard name, such as NSF/ANSI 53 or NSF/ANSI 58, and "a claim for specific contaminant reduction, such as lead." A certifier's listing pairs the same two items for each model and replacement cartridge; the results summarized in this guide document listings as of October 20, 2026.

Do certifications expire? They are maintained over time. NSF states that certified products "must be retested periodically, and manufacturing facilities must be inspected annually," and IAPMO R&T listings show a status and an expiration date. The ZeroWater 5-stage listing (W-14820), for example, showed Active status with an expiration date of September 11, 2028.

Does a third-party replacement cartridge keep the original certification? Listings name the replacement element that was tested, such as RF-3375 or RF-9999 for PUR PLUS faucet systems and ZR-001 or ZF-201 for ZeroWater pitchers. A claim belongs to the listed combination of system and cartridge. A different cartridge does not automatically keep the original system's certified claims, and any certification it has must cover the system it is installed in.

Is a WQA or IAPMO R&T certification as meaningful as one from NSF? They certify to the same NSF/ANSI standards. WQA lists the ANSI-accredited certifiers for drinking water treatment products as the Water Quality Association, NSF International, IAPMO, and Underwriters Laboratories, and notes that all of these certifiers have product listings. What matters is that the listing names your model and your contaminant.

Next Steps for Any Filter's Claims

1. Name the contaminant. Use your utility's annual water quality report or a lab test of your tap water to decide what you need reduced, such as lead, PFAS, or microplastics.
2. Copy the exact model and cartridge. Write down every character of the system model, including suffixes such as -BN, plus the replacement cartridge number.
3. Match each document to its type. For a certification listing, search the certifier named on the package (NSF Listings, the IAPMO R&T directory, or WQA's Gold Seal search) and find your model in the results. For a lab test report, match the report number to the model and read the contaminants and test method it covers. For an NSF/ANSI/CAN 372 document, match the models it names.
4. Read the claim line. In a listing, look for your contaminant by name under the matching standard: 53 or 58 for lead and PFAS, 401 for microplastics. In a lab report, look for the same contaminant in the results.
5. Date the record. Note the date of each listing search or report, and keep the replacement cartridge number with it for future purchases.