Which Water Filter Brands Actually Remove PFAS and Microplastics?

Six brands stand out for backing their PFAS and/or microplastics claims with some form of real evidence: Viomi, AquaTru, Aquasana, Clearly Filtered, Culligan, and Waterdrop. How strong that evidence is varies a lot, from brand to brand and even from claim to claim within the same brand, ranging from formal NSF/ANSI certification, to independent lab testing run against a certification protocol, to a brand’s own marketing language with no third-party data behind it. The rest of this guide breaks down exactly what each brand has, and hasn’t, documented for PFAS and microplastics specifically, plus how to verify any of it yourself before you buy.

PFAS (“forever chemicals”) and microplastics get grouped together a lot in water filter marketing, but they’re different problems that call for different levels of scrutiny. A pitcher that removes chlorine and improves taste won’t necessarily touch either one. Knowing what to look for saves you from paying for a “PFAS-fighting” label that isn’t backed by anything.

What PFAS and Microplastics Actually Are

PFAS stands for per- and polyfluoroalkyl substances, a group of more than 4,700 man-made chemicals that have been used since the 1940s in non-stick cookware, water-resistant fabrics, food packaging, and firefighting foam. They’re called forever chemicals because their carbon-fluorine bonds are extremely stable, meaning they can persist in soil and water for hundreds of years instead of breaking down.

In 2024, the EPA finalized the first legally enforceable national drinking water standard for PFAS, setting the Maximum Contaminant Level (MCL) at 4 parts per trillion for both PFOA and PFOS. The EPA’s own nationwide testing (the fifth Unregulated Contaminant Monitoring Rule, or UCMR 5) found detectable PFAS at thousands of water systems across the country, which is part of why more households are checking their own tap water and looking at filtration.

Microplastics are tiny plastic fragments, generally under 5 millimeters and often far smaller, that shed from packaging, synthetic fabrics, and degrading plastic products. They end up in tap water, bottled water, and the broader water supply. Unlike PFAS, there isn’t yet a dedicated EPA drinking water standard for microplastics, and there’s no standalone NSF standard devoted only to the category, but a model can carry a specific “Microplastics Reduction” claim under NSF/ANSI 401. Beyond that named claim, most brand claims here rely on independent lab testing rather than a formal certification.

Neither contaminant is something you can see, taste, or smell. Boiling doesn’t help with PFAS at all; it actually concentrates PFAS in the remaining water as it evaporates rather than removing it. Boiling’s effect on microplastics is more mixed: some research on hard water found that boiling and then filtering out the calcium carbonate scale it produces can trap a large share of nano- and microplastics, but that effect is much weaker in soft water, so boiling isn’t a reliable fix for either contaminant.

What Actually Removes PFAS and Microplastics at Home

Not every filter marketed for “clean water” touches these two contaminants, and the gap between “reduces chlorine” and “reduces PFAS and microplastics” comes down to filtration technology, and the mechanism behind it matters more than a single spec like pore size.

Reverse osmosis (RO) pushes water through a semi-permeable membrane with pores around 0.0001 microns, small enough to physically block dissolved PFAS molecules and virtually all microplastic particles by size exclusion. Independent estimates put RO’s PFAS removal in the 95 to 99%+ range and its microplastics removal above 99%, which is why most of the brands in this guide, including Viomi, lean on RO for their top-tier products.

Specialized activated carbon can also reduce PFAS, but the mechanism is different from RO, and it’s easy to describe it wrong. Ordinary carbon block or granular carbon filters, the kind found in a lot of basic pitchers, are built around pore sizes of roughly 0.5 to 1 micron. That pore size is relevant to straining out larger particles like microplastic fragments, but it isn’t how carbon deals with PFAS. PFAS molecules are dissolved in the water, not suspended particles, so carbon captures them mainly through adsorption (the molecules chemically binding to the carbon’s surface) rather than being physically screened out by pore size. That means PFAS performance depends much more on the type of carbon, how long the water stays in contact with it, and how much of the cartridge’s rated capacity is left, not on how small its pores are. Carbon that’s actually engineered and tested for PFAS (sometimes called catalytic or PFAS-specific carbon) can reach meaningful reduction rates; plain carbon without that certification generally cannot, regardless of its stated micron rating.

Ion exchange resin is another approach, more common in whole-house systems, that can achieve solid PFAS reduction rates but is less common in the countertop and under-sink products most homeowners are shopping for.

The practical takeaway: look for a filter that names PFOA/PFOS or “total PFAS” reduction on an NSF/ANSI 53 or NSF/ANSI 58 certification (53 covers health-related contaminant reduction claims, including a PFOA/PFOS reduction claim added in recent editions; 58 covers reverse osmosis systems). NSF/ANSI 401 is a separate standard worth knowing about, but it covers pharmaceuticals, pesticides, herbicides, and other emerging contaminants, not PFAS, so a 401 listing by itself doesn’t tell you anything about PFAS performance. For microplastics, there’s no standalone NSF standard devoted only to the category, but a model can carry a specific “Microplastics Reduction” claim under NSF/ANSI 401, so look for either that named claim or a brand that publishes its own third-party lab results rather than just a marketing headline.

6 Water Filter Brands and What Evidence They Actually Have

Here’s how six brands compare, organized by the filtration format they’re best known for. Before you scan the table, it helps to know that “evidence” here isn’t one uniform thing: a formal NSF/ANSI or IAPMO certification means an accredited lab tested that exact model against a published standard; independent lab testing without that certification is still third-party data, but not verified against a standard’s full protocol; and a brand’s own marketing description, with no lab or percentage cited, is the weakest tier and shouldn’t be treated the same as the other two.

Prices shift with sales and bundles on every brand’s site, so treat these as ballpark ranges rather than current listings. Note the PFAS column too: “PFOA/PFOS” claims cover two specific compounds, while Culligan’s “Total PFAS” claim is tested against a broader panel, so the two aren’t measuring the same thing even when the percentages look similar.

Viomi

Viomi’s flagship for this exact concern is the Viomi M1, a tankless under-sink RO system built around a 9-stage filtration process and a 0.0001-micron RO membrane. What sets it apart from a lot of “reduces PFAS” marketing copy is that Viomi publishes independent SGS lab results with specific numbers: PFOS reduction above 99.67% and PFOA reduction above 99.42%, alongside lead reduction above 99.87% and TDS reduction up to 90.56%, with microplastics grouped into the same 99%+ contaminant-reduction claim.

The Viomi M1 certification summary below connects its published PFAS and lead reduction claims to third-party SGS and Intertek testing.

The Viomi M1 also remineralizes the water afterward (adding back minerals like calcium, magnesium, and silica) and runs a 3:1 pure-to-drain ratio, meaning it produces three parts purified water for every one part sent to drain, more efficient than older tank-based RO systems that commonly waste three to four gallons per gallon produced. At $799.99, it’s one of the higher-priced options on this list, and like any RO system it needs under-sink space, a drain connection, and periodic filter changes (Viomi lists the RO filter at up to 4 years and the carbon pre-filter at up to 2 years).

For a lower price point, Viomi’s V8 PRO ($479.99) is also NSF/ANSI 53-certified (alongside 42, 58, and 372) and independently tested by SGS, targeting the same PFOS/PFOA and lead contaminants as the Viomi M1’s filtration stages, minus the remineralization step and at a lower 800 GPD flow rate.

Viomi also has a $39.99 entry-level 0.5-micron under-sink carbon filter (model VW-IU01PCW-US) that’s a solid budget option for lead, chlorine, and taste at a fraction of the RO systems’ price.

Viomi also publishes an ongoing analysis of EPA UCMR 5 data covering PFAS detections across US water systems, which is a useful starting point if you don’t yet know whether your own local water supply has tested positive for PFAS.

AquaTru

AquaTru’s countertop RO systems plug into an outlet with no plumbing required, which makes them a common pick for renters or anyone who doesn’t want to drill into a cabinet. The line carries IAPMO certification against NSF/ANSI 42, 53, 58, 401, and 372, with PFOA/PFOS reduction claims at 97.5%+ (the minimum reduction figure on AquaTru’s published performance data sheet). AquaTru also advertises microplastics as one of its certified reductions, and that number is real: its published performance data ties it to NSF/ANSI 42’s Particulate Class I category, at over 96% reduction for particles in the 0.5 to 1 micron range that this class covers. That’s a certified, independently tested figure, but it’s a general fine-particulate certification rather than a standalone NSF/ANSI 401 “Microplastics Reduction” claim naming microplastics specifically, so don’t read AquaTru’s 401 listing by itself as microplastics evidence. AquaTru’s PFAS testing was historically referenced against NSF Protocol P473, but that protocol never achieved ANSI consensus-standard status, was not formally named “NSF/ANSI,” and NSF discontinued it as a standalone protocol in 2017 and folded its requirements into the 53 and 58 standards, so it’s no longer a current, separately named certification. The tradeoff versus an under-sink RO system is counter space and a lower flow rate, since the water sits in a countertop reservoir rather than running continuously to a dedicated faucet.

Aquasana

Aquasana’s Claryum filters take a different route: selective carbon filtration rather than reverse osmosis, which means no wastewater and no drain connection. Aquasana was among the first brands certified for PFOA/PFOS reduction, and current Claryum filters carry NSF/ANSI 42, 53, and 401 certification through IAPMO, with reduction claims up to 99.7% for PFOA/PFOS and up to 99.6% for lead and microplastics. Because it isn’t RO, it won’t reduce total dissolved solids the way Viomi, AquaTru, or Waterdrop do, so it’s a better fit for someone whose main concern is PFAS, lead, and microplastics specifically rather than overall water purity.

Clearly Filtered

Clearly Filtered’s pitchers, under-sink systems, and inline fridge filters use what the company calls Affinity Filtration Technology, a carbon-based approach. Its formal NSF listing covers NSF/ANSI 42 and 372, while the PFAS claims rest on independent lab testing conducted by IAPMO New Jersey (an ISO 17025-certified lab, formerly operating as QFT) following NSF/ANSI 53 testing protocols, rather than a formal certification against that standard. Clearly Filtered publishes this lab data on its own site, with separate performance-data pages for the pitcher, under-sink, and inline-fridge models: the pitcher tests at roughly PFOA 99.64%, PFOS above 99.8%, and GenX above 99.4%, while the under-sink and inline-fridge models test at roughly PFOA above 99.6% and PFOS above 99.8% (GenX wasn’t included in those two models’ published results). It’s a reasonable no-installation option if you want a pitcher rather than an under-sink system, though pitcher filters generally process water more slowly and need more frequent cartridge changes than a plumbed-in system.

Culligan (MaxClear)

Culligan’s MaxClear gravity system doesn’t need electricity or a plumbing connection at all, and it’s IAPMO certified to NSF/ANSI 53 for a 99.6% Total PFAS reduction claim, along with certified reductions for lead and microplastics. Gravity filters trade convenience for speed: you fill a top reservoir and wait for water to filter through by gravity alone, which is slower than a tap-connected system but works anywhere, including apartments with no under-sink access.

Waterdrop

Waterdrop’s G3P800 is the closest direct comparison to Viomi’s RO lineup: a tankless under-sink RO system with 10-stage filtration, an 800 GPD flow rate, and NSF/ANSI 42, 53, 58, and 372 certification. Waterdrop states its system is SGS-tested and claims up to 99% PFOA/PFOS reduction. If you’re comparing tankless under-sink RO options specifically, Waterdrop and Viomi’s RO lineup sit in a similar category, and the decision often comes down to price, smart faucet features, and filter replacement costs rather than filtration technology, since both use comparable RO stages.

How to Verify a Brand’s PFAS or Microplastics Claim Yourself

Before trusting any product page, including this one, it’s worth doing your own five-minute check:

1. Look up the exact model on the NSF, IAPMO, or WQA public certification database, or check for a named test report from an internationally recognized lab such as SGS, rather than trusting a badge image on the product page. Certifications are tied to specific model numbers, not brand names.
2. Check whether it’s “certified” or “tested.” Some brands publish independent lab results without a formal NSF/IAPMO certification against that standard. That’s not automatically a red flag, but it’s a different level of verification than a certified listing.
3. See which specific PFAS compounds were tested. “PFOA/PFOS reduction” and “Total PFAS reduction” are not the same claim; total PFAS testing (as used in NSF/ANSI 53’s expanded protocol) covers more compounds like PFHxS, PFNA, and PFBS.
4. Look for a named “Microplastics Reduction” claim, not just marketing language. Outside of that specific NSF/ANSI 401 claim category, most microplastics numbers are independent lab data points rather than formal certifications, so check whether the brand names a testing lab and a specific percentage rather than accepting a generic “removes microplastics” statement.

Which Type of Filter Fits Your Situation

• Renters or no plumbing access: a countertop RO system (AquaTru) or a gravity filter (Culligan MaxClear) avoids drilling into cabinets.
• Want the highest overall purification plus PFAS/microplastics coverage: an under-sink RO system (Viomi M1 or Viomi V8 PRO, Waterdrop G3P800) reduces the broadest range of contaminants, including TDS, at the cost of a drain connection and some wasted water.
• Don’t want RO wastewater or a drain hookup: a PFAS-certified carbon system (Aquasana Claryum) or an independently PFAS-tested carbon system (Clearly Filtered) skips the drain line but won’t reduce total dissolved solids the way RO does.
• Tight budget, want lead/chlorine coverage first: an entry-level 0.5-micron carbon filter (like Viomi’s $39.99 under-sink unit) covers the basics affordably; step up to a certified RO or Claryum-style system if PFAS and microplastics documentation specifically is the priority.

FAQ

Does boiling water remove PFAS? No. Boiling can actually concentrate PFAS in the remaining water as it evaporates, rather than removing the chemicals.

Does bottled water avoid PFAS or microplastics? Not automatically. Bottled water isn’t guaranteed to be PFAS-free, and some brands have tested positive for detectable PFAS, plus bottled water can introduce its own microplastics from the packaging.

Do pitcher filters really remove PFAS? Only specific pitchers certified to NSF/ANSI 53 (or backed by equivalent independent lab testing) for PFAS actually do. NSF/ANSI 401 doesn’t cover PFAS, so a 401 badge alone isn’t evidence of PFAS reduction. A standard carbon pitcher built mainly for taste and chlorine won’t reliably reduce PFAS or microplastics.

Is reverse osmosis wastewater a real downside? It’s worth factoring in. RO systems send some water to drain during filtration; ratios like the 3:1 pure-to-drain figure used by Viomi and Waterdrop are more efficient than older tank-based RO systems, but you’re still using more source water than the purified volume you get.

How do I know my filter is still removing PFAS after months of use? Certified reduction claims (NSF/ANSI 53, 58, and similar standards) are actually tested through the filter’s full rated capacity, including near end-of-life, not just on a brand-new cartridge. Still, following the manufacturer’s filter replacement schedule matters, because that performance is only guaranteed within the rated capacity the filter was tested to; using a cartridge past its rated life is untested territory.

Bottom Line

If PFAS and microplastics are your main concern, look first at reverse osmosis systems with published third-party test data, or a carbon system with a real NSF/ANSI 53 certification naming PFAS specifically (NSF/ANSI 401 is worth checking for its own emerging-contaminants and microplastics-reduction claims, but it isn’t a PFAS certification). Viomi’s M1 is a strong fit for that criteria at the higher end, with SGS-verified PFOS and PFOA reduction above 99%, remineralization, and Viomi’s own EPA UCMR 5-based PFAS data as a research starting point. If budget or installation constraints matter more, AquaTru, Aquasana, Clearly Filtered, Culligan, or Viomi’s own Viomi V8 PRO and entry-level carbon filter each cover different combinations of price, format, and documented performance. Whichever you pick, confirm the certification against the actual model number before you buy rather than relying on the marketing page alone.