The short answer
Microplastics in drinking water are plastic particles smaller than 5 millimeters, found in tap and bottled water. In 2019 the World Health Organization said they don’t appear to pose a health risk at current levels, while stressing that data are limited, and in April 2026 the EPA named them a priority group for possible regulation. There’s no federal limit yet. To reduce them, use a filter whose NSF/ANSI 401 certification lists microplastics. Our picks are in the best water filters for microplastics.
What are microplastics?
Plastic pieces less than five millimeters long, about the size of a pencil eraser, are called microplastics (NOAA). The EPA defines them as particles from 5 millimeters down to the nanometer scale, and California’s drinking water definition reaches down to 1 nanometer (State Water Board). The smallest are often called nanoplastics.
Are microplastics in water harmful?
The honest answer is that it isn’t known yet. In 2019 the WHO said microplastics in drinking water don’t appear to pose a health risk at current levels, that particles larger than 150 micrometers are not likely to be absorbed, and that data on very small particles are extremely limited. Its 2022 report set out further research needs. The EPA says there are data gaps that require more research before it can understand the health risks.
Does bottled water have more microplastics?
Bottled water isn’t a way around them. A 2024 study in PNAS counted more than 100,000 particles in each liter of bottled water it tested, most of them nanoplastics.
Are microplastics in water regulated?
- EPA: no limit. In April 2026 the EPA’s draft Contaminant Candidate List designated microplastics a priority contaminant group for the first time (EPA). That’s a step toward possible regulation, not a rule.
- California: adopted the first definition of microplastics in drinking water on June 16, 2020 (State Water Board) and a four-year testing plan: source water testing by large systems from fall 2023 to fall 2025, with treated drinking water testing planned from fall 2026 (Resolution 2022-0032).
How do you know a filter removes microplastics?
Look for microplastics on the filter’s NSF/ANSI 401 listing. NSF/ANSI 401 covers many emerging contaminants, and a filter can be certified to it without a microplastics claim. NSF notes the microplastics claim is bracketed by NSF/ANSI 42 Class I particulate testing (NSF listings), which covers particles 0.5 to under 1 micron.
| # | Filter | Score | Certified by | Lead | PFAS | Fluoride | Running cost | Price |
|---|---|---|---|---|---|---|---|---|
| 01 | AquaTru CarafeBest overallCountertop RO | 4.6 | IAPMO R&T | Certified | Certified | Certified | $0.33/gal | See priceon Amazon › |
| 02 | Aquasana Claryum Max FlowBest under the sinkUnder-sink carbon | 4.3 | WQA | Certified | Certified | No | $0.11/gal | $449.99on Amazon › |
| 03 | Aquasana Clean Water MachineBest countertop, no wastewaterCountertop carbon | 4.3 | WQA | Certified | Certified | No | $0.12/gal | $199.99on Amazon › |
| 04 | PUR PLUS PitcherBest pitcherPitcher | 4.0 | IAPMO, WQA, NSF | Certified | Certified | No | About $0.25/gal | $28.12on Amazon › |
| 05 | Culligan MaxClear VentureBest without powerGravity | 3.6 | IAPMO R&T | Certified | Certified | No | $1.58/gal | See priceat Culligan › |
Certified: Certified by an independent body (named in each pick). Lab test: Tested by a named independent lab, not certified. Claim: The maker's claim, not certified. No: No claim. PFAS means PFOA/PFOS, or Total PFAS where the pick says so.
Common questions
Does tap water have microplastics?
Studies have found them in tap and bottled water, though monitoring data are limited (WHO). California is testing drinking water supplies under its 2022 plan (State Water Board).
Does a Brita filter remove microplastics?
The Brita Elite filter (OB06) does in most Brita pitchers: WQA certifies it for microplastics under NSF/ANSI 401, though not in the Tahoe. We found no microplastics listing for the standard Brita filter. The PUR PLUS pitcher filter is also certified for microplastics, by IAPMO R&T. See our microplastics filter picks.
Does reverse osmosis remove microplastics?
Certified systems do: the AquaTru Carafe is certified by IAPMO R&T for microplastics under NSF/ANSI 401. Check the listing for any system you consider.
Is there a legal limit for microplastics in water?
Not in the US. The EPA added microplastics to its draft priority list in April 2026 (EPA), a step toward possible future regulation.
Does boiling water remove microplastics?
Boiling isn’t a certified way to reduce microplastics. Use a filter whose NSF/ANSI 401 listing includes them.
Sources
Prices as of October 19, 2026. Product prices and availability are accurate as of the date/time indicated and are subject to change. As an Amazon Associate we earn from qualifying purchases.