Best Water Filter for Microplastics 2026: Only 6 of 13 Are Certified

The certification that matters

Filters are certified against NSF/ANSI standards by one of three bodies: NSF, the Water Quality Association (WQA) or IAPMO R&T. They certify to the same standards, so any of the three counts. What matters is the claim on the listing:

• NSF/ANSI 401 is the only standard with a microplastics claim, tested on particles 0.5 to 1 µm with at least 85% reduction required. It also covers some pharmaceuticals and other emerging contaminants.
• NSF/ANSI 42 covers taste, odour and chlorine, and has a separate fine-particulate claim that is not a microplastics claim.
• NSF/ANSI 53 covers health contaminants such as lead, PFOA/PFOS and cysts. NSF/ANSI 58 is the reverse-osmosis standard, for dissolved solids and a listed set of contaminants. Neither has a microplastics claim.

So a filter can be “NSF certified” and still have no certified microplastic result. Look for “microplastics” on the 401 listing itself, on the certifier's database or the maker's performance data sheet.

13 filters compared

Certifications change. Check the model number on the NSF, WQA or IAPMO database, or the maker's performance data sheet, before you buy.

Brand by brand: Brita, AquaTru, Clearly Filtered and Berkey. Pitchers only: water filter pitchers ranked. Reverse osmosis only: best reverse osmosis systems.

How each type works

• Dense carbon media (Brita Elite, Clearly Filtered, Epic, Multipure, Aquasana, each under its own brand name): activated carbon, often layered with other media, fine enough to trap small particles as well as adsorb chemicals such as chlorine.
• Granular carbon (standard Brita Classic, many fridge filters): loose carbon granules made for taste and chlorine, not for trapping fine particles. That is why the Classic is not certified for microplastics and the Elite, in the same pitcher, is.
• Membrane (LifeStraw): a microfilter membrane that blocks particles and bacteria, paired with carbon for taste and chemicals.
• Reverse osmosis (AquaTru, Waterdrop, APEC, iSpring): water is pushed through a membrane that rejects dissolved salts and metals. RO is the strongest option for dissolved contaminants, but only AquaTru here has a certified microplastic result, and it is lower than the best pitchers. AquaTru is rated 75% efficient; Waterdrop says 3:1 pure to drain.
• Berkey: gravity-fed Black Berkey elements, which Berkey describes as “a proprietary blend of media” (not ceramic). Berkey publishes no pore size and says it has not tested them for microplastics.

What about nanoplastics?

A 2024 study in PNAS counted about 240,000 plastic particles per litre of bottled water, around 90% of them nanoplastics smaller than 1 µm. No filter certification tests below 0.5 µm, so no filter can show certified nanoplastic removal. Claims that reverse osmosis removes “everything, including nanoplastics” are not backed by any certification, and the same PNAS team suggested that RO used in bottling may remove larger particles while leaving mostly nanoplastics behind. What you can buy with evidence is certified reduction of 0.5–1 µm particles.

What else each filter is certified to remove

• AquaTru: the broadest list here, including lead (99.1%), fluoride (93.5%), pentavalent arsenic (98.0%), nitrate/nitrite (89.9%), PFOA/PFOS and several pharmaceuticals.
• Waterdrop G3P800: PFOA/PFOS, lead, fluoride, cadmium, barium, radium and dissolved solids. Arsenic, nitrate and pharmaceuticals are tested by the brand, not certified.
• APEC ROES-50 and iSpring RCC7AK: dissolved solids (TDS). Other claims are not certified for these models.
• PUR PLUS: lead and total PFAS under NSF 53. Aquasana Clean Water Machine: PFOA/PFOS under NSF 53.
• Berkey: Berkey publishes its own test reports for PFOA, heavy metals and more; none is a certification.
• Brita Classic: chlorine and taste, plus cadmium, copper and mercury.

Cost per litre

For two people drinking 2 litres a day (about 1,460 litres or 386 gallons a year), at each brand's own prices and filter ratings on 21 September 2026:

Pitcher costs depend on how many cartridges you get through: Clearly Filtered and Epic cartridges are rated for 100 gallons, which is three to four months for two people. Countertop units with long-life filters work out cheapest after the first year.

Maintenance

• Pitchers: no installation. Change the cartridge at its rated capacity; performance is only certified up to it.
• AquaTru: pre/carbon filter every 6 months or 600 gallons, VOC filter every 12 months, RO membrane every 24 months or 1,200 gallons.
• Under-sink RO (Waterdrop G3P800): carbon pre-filter every 6 months, carbon block every 12, RO membrane every 24. Needs space under the sink and a drain connection.
• Berkey: scrub the Black Berkey elements with a stiff brush or Scotch-Brite pad when the flow slows; Berkey rates a pair at 6,000 gallons.
• Whole-house systems usually run sediment and carbon stages that are not certified for microplastics. Check the listing, or add a certified filter at the kitchen tap.

What about just boiling it?

In hard water, boiling helps. A 2024 study in Environmental Science & Technology Letters found that boiling water harder than 120 mg/L of calcium carbonate removed at least 80% of added polystyrene, polyethylene and polypropylene particles from 0.1 to 150 µm: the particles get trapped in the limescale that forms, which you then filter out. Soft water has little calcium to form scale, so the effect is much weaker there. More in does boiling water remove microplastics.

Best filter by situation

Cheapest certified option

PUR PLUS, or the Brita Elite cartridge if you already own a Brita pitcher. Both are certified under NSF 401 for microplastics (99.8% and 99.6%), with no installation. The LifeStraw Home glass pitcher is the certified option in glass.

More water, no plumbing

Aquasana Clean Water Machine: a powered countertop dispenser certified to NSF 401 for microplastics (99.6%) and to NSF 53 for PFOA/PFOS. AquaTru Classic ($475) if you also want reverse osmosis for lead, fluoride, arsenic and nitrate: it has the broadest certified list here, including microplastics at 96.48%.

Under the sink

None of the under-sink RO systems we checked is certified for microplastics. For a certified under-sink option, look at carbon block systems certified to NSF 401, such as the Multipure Aquaversa. Choose under-sink RO like the Waterdrop G3P800 for its certified PFOA/PFOS, lead and fluoride reduction, not for microplastics.

Off-grid or no power

A certified pitcher (PUR PLUS, Brita Elite, LifeStraw Home glass) is gravity-fed and needs no power. We can't recommend Berkey for microplastics: Berkey says it has not tested its elements for them, and EPA ordered Black Berkey sales stopped in 2022 and 2023 because the elements were sold with antimicrobial claims without pesticide registration.

Only chlorine and taste

A standard Brita Classic does that job, but it is not a microplastic filter.

See also: microplastics in tap water.