Reverse osmosis systems remove the large majority of microplastics by pushing water through a membrane with roughly 0.0001-micron pores. Activated carbon blocks capture particles down to about 0.5 microns. Ultrafiltration works for larger fragments. Not every filter removes microplastics; ceramic and basic pitcher filters often miss them.
These steps work in any kitchen. Start with #1 and build from there.
Not all filters are the same. Here's what the research shows.
| Filter Type | Pore Size | Microplastic Removal | Cost | Best For | |-----------------|---------------|--------------------------|----------|-------------| | Reverse Osmosis | 0.0001 micron | 95-99% (includes nanoplastics) | $200-600 | Households serious about removing all contaminants, including PFAS | | Activated Carbon Block | 0.5-1 micron | 80-95% (NSF test data; particles >1 micron) | $30-150 | Budget-conscious users; removes chlorine and improves taste | | Ultrafiltration | 0.01-0.1 micron | 85-98% (Water Research Foundation 2024; microplastics, not all nanoplastics) | $150-400 | Faster flow rate than RO; good middle ground | | Ceramic Filter | 0.2-0.9 micron | 60-80% (not certified for microplastics; varies by quality) | $40-120 | Not our top pick for microplastics | | Pitcher/Faucet Filter (GAC) | 5-50 microns | Low for most loose-carbon models; few are certified for microplastics | $15-50 | Convenience only; won't solve microplastics |
Our take: reverse osmosis is overkill for some households, but if you're filtering microplastics in tap water and PFAS at the same time, it's the only technology that handles both reliably. Carbon block is the budget pick.
Microplastics range from 5 millimeters down to 1 nanometer. That's a huge range. A standard pitcher filter uses granular activated carbon (GAC) with pore sizes around 20-50 microns–way too large to catch microplastics, which are typically 1-10 microns.
According to the Orb Media study (2018), which tested tap water from 14 countries, 83% of samples contained plastic fibers. The U.S. had the highest contamination rate at 94%. Most of those fibers were between 5-10 microns. A filter needs pores smaller than 1 micron to catch them.
The problem: most manufacturers don't specify pore size. They'll say "removes 99% of contaminants" without defining what that means. We're not sure this kind of vague marketing should even be legal.
The microplastics reduction claim sits in NSF/ANSI 401, the standard for emerging contaminants. To earn it, a filter must reduce particles in the 0.5 to 1 micron range by at least 85%. It does not test nanoplastics, and it is an optional claim, so a filter certified to 401 for other contaminants may not carry it.
If a filter's listing shows microplastics reduction, it passed that test. Adoption is still limited, so check the NSF database for the exact model.
PFAS reduction is certified separately, under NSF/ANSI 53 (or 58 for reverse osmosis). Some filters are certified for both. If you're dealing with PFAS contamination–check your ZIP code here–look for dual certification.
Bottled water is not the safer option. In fact, it's worse.
The 2024 Columbia University study analyzed three popular bottled water brands and found an average of 240,000 detectable plastic particles per liter. About 90% of those were nanoplastics (smaller than 1 micron), which come from the bottle itself as it degrades.
Municipal tap water generally contains far fewer plastic particles than bottled water, though counts vary widely by location and most utilities don't yet test for them.
Reverse osmosis removes the large majority of those particles, which is why filtered tap water is the lowest-microplastic option.
So the order is simple: bottled water is the worst, unfiltered tap is better, and RO-filtered tap is best. Switch to filtered tap.
Three factors matter: your water source, your contamination profile, and your budget.
If you're on city water: Start by checking your utility's water quality report. Most cities publish annual reports that list detected contaminants. If microplastics aren't listed (most don't test for them yet), assume they're present. A carbon block or RO system will handle them. An RO system that also filters PFAS and heavy metals covers both in one step.
If you're on well water: You're dealing with unknowns. Well water can have microplastics from agricultural runoff, degraded irrigation pipes, or nearby landfills. But you won't know without testing. Send a sample to SimpleLab or Tap Score before buying a filter. If the test shows high plastic particle counts, go with RO.
If you're renting or can't install an under-sink system: Look for a countertop RO unit or a high-quality carbon block pitcher. The Clearly Filtered pitcher is one of the few that specifies sub-micron filtration. Cost is around $70 plus $50 per replacement filter.
If you're filtering for a family of four or more: Flow rate matters. According to NSF performance data, RO systems are slow–typically 50-75 gallons per day. That's enough for drinking and cooking but not for filling large pots quickly. Ultrafiltration has faster flow rates (100-200 gallons/day) and still removes most microplastics. It's a good middle ground.
And budget matters. If you can't afford a $400 RO system right now, a $60 carbon block filter is better than nothing. Just replace the cartridge every 3-6 months or it stops working.
The research on microplastics is early. We don't know the long-term health effects of ingesting 100,000+ particles per year – for the full picture of what's proven versus still unknown, see are microplastics in drinking water dangerous. A 2021 Environmental Science & Technology review noted potential links between microplastic exposure and inflammation markers, but the researchers cautioned that human health impacts remain uncertain. The EPA hasn't set a maximum contaminant level (MCL) for microplastics yet–probably because there's no consensus on what a safe threshold looks like.
We also don't know how much microplastic exposure comes from water vs. food vs. air. A 2019 University of Victoria meta-analysis estimated that Americans ingest 39,000-52,000 microplastic particles per year from food and water alone, with bottled water drinkers adding another 90,000 annually. But those numbers are based on limited sampling.
The precautionary principle applies here: we're not sure how bad this is, so reducing exposure makes sense until we know more.
Filters lose effectiveness over time. Microplastics clog the pores. Carbon gets saturated. Membranes degrade.
RO membranes: Replace every 2-3 years. Pre-filters and post-filters (usually carbon) need replacement every 6-12 months.
Carbon block cartridges: Replace every 6 months or after 500-1,000 gallons, whichever comes first. If the flow rate drops noticeably, replace it early.
Ceramic filters: Clean them every 1-2 months by scrubbing the outer surface with a brush. Replace the cartridge every 12 months.
Most people forget to replace filters on schedule. Set a phone reminder. A clogged filter doesn't just stop working–it can release captured contaminants back into the water.
Do Brita filters remove microplastics?
No. Standard Brita filters use granular activated carbon with pore sizes too large to capture microplastics. They improve taste and remove chlorine but aren't certified to reduce plastic particles. Brita's "Elite" model is a different, tighter carbon block filter; check its current performance data sheet for an NSF/ANSI 401 microplastics claim before relying on it.
What's the difference between microplastics and nanoplastics?
Microplastics are plastic particles between 1 micron and 5 millimeters. Nanoplastics are smaller than 1 micron (down to 1 nanometer). Both are in drinking water. Nanoplastics are harder to remove because they pass through larger filter pores. According to NSF testing standards, only reverse osmosis with membranes rated at 0.0001 microns reliably captures nanoplastics.
Can boiling water remove microplastics?
No. Boiling kills bacteria and viruses but doesn't reliably remove plastic particles, and heating water in a plastic kettle can add microplastics shed from the container. Use filtration, not boiling.
Is tap water safer than bottled water for microplastics?
Yes. The 2024 Columbia study found bottled water contains far more plastic particles than typical municipal tap water, and many of those particles come from the bottle itself. Check your local tap water quality and filter it instead of buying bottled.
How do I know if my filter is working?
Send a water sample to a lab before and after filtration. SimpleLab and Tap Score both offer microplastic testing for around $200 per sample. According to their testing protocols, if you see a 90%+ reduction in particle count, your filter is working.
Reverse osmosis removes the large majority (roughly 95-99%) of microplastics from drinking water. Carbon block filters work for particles larger than 1 micron. Pitcher filters don't work. Bottled water is worse than tap water. Install an RO or carbon block system under your sink, replace the filters every 6-12 months, and test your water once to confirm it's working. That's it.