The short version
Microplastics are tiny plastic fragments now found in most tap and bottled water. There’s no federal limit and no easy home test, so the practical response is filtration. Reverse osmosis and sub-micron filters remove them reliably; ordinary pitchers and switching to bottled water do not. One counterintuitive point: bottled water usually contains far more microplastics than filtered tap.
Skip to the filters we recommend ›What are microplastics?
Microplastics are plastic particles smaller than 5 millimeters, roughly the size of a sesame seed and down to specks invisible to the eye. The smallest, under one micron, are called nanoplastics, and they’re the ones that can pass through biological barriers. They form as larger plastics break down in the environment, and they shed from synthetic clothing, tire wear, packaging, plastic pipes, and the plastic bottles that water itself is sold in.
They are, at this point, effectively everywhere. Studies have detected microplastics in rain, soil, seafood, table salt, and the tap water of cities on every continent. Because they don’t readily break down and can’t be removed at the source, the only thing within your control is filtering them out of the water you drink.
The health concerns
The science here is young and moving fast, so honesty means saying clearly what is known and what isn’t. What’s established is that microplastics get into the human body: researchers have now found them in blood, lungs, the placenta, and breast milk. What’s still being worked out is exactly what they do once there.
The early signals are enough that scientists are paying close attention. A 2024 study published in the New England Journal of Medicine found micro- and nanoplastics in the artery plaque of heart-surgery patients, and those patients had a higher risk of heart attack, stroke, and death over the following years. That’s an association, not proof of cause, but it’s a serious one. Researchers are also concerned that plastic particles act as carriers, adsorbing other contaminants like PFAS and heavy metals and ferrying them into the body.
The honest read: we don’t yet have proof that microplastics in drinking water cause specific diseases. But they’re accumulating in our bodies, the early findings are concerning, and removing them is cheap and easy. That’s a reasonable case for filtering, without the fear-mongering.
Where they come from, and why bottled isn’t the answer
Microplastics reach your tap from environmental contamination, aging plastic infrastructure, and the treatment process itself. The instinctive fix, buying bottled water, usually makes the problem worse, not better. A widely-reported 2024 study using new detection methods found that the average liter of bottled water contained around 240,000 plastic particles, most of them nanoplastics shed from the bottle and cap. That’s far more than typical filtered tap water.
Don’t switch to bottled to avoid microplastics. You’d likely be drinking more of them, at a far higher cost. Filtering your tap water and storing it in glass or stainless steel is both cheaper and cleaner.
Where the rules stand
There is currently no enforceable federal limit on microplastics in US drinking water, and the EPA has not set one. The clear leader is California, which in 2020 became the first place in the world to legally define microplastics in drinking water, then adopted standardized testing methods and now requires large water systems to monitor and publicly report microplastic levels over a multi-year period.
That’s monitoring, not a safety limit, and it applies to California utilities rather than your home. The takeaway for a household is the same as with most emerging contaminants: the rules are years behind the science, so if you want microplastics out of your water now, filtration is the reliable route.
How to know if they’re in your water
Realistically, you can’t test at home. Detecting and counting microplastics requires laboratory spectroscopy (the same Raman and infrared methods California standardized), which isn’t available in a consumer test kit. So the practical approach is different from other contaminants:
- Assume some presence. Microplastics have been found in nearly every water supply tested, so treat them as a “when,” not an “if.”
- Check California reporting if you’re in-state, as utilities begin publishing monitoring data.
- Filter as a precaution. Because a good filter removes them cheaply, the cost-benefit favors filtering rather than testing.
How to know a filter actually removes them
Because microplastics span a huge size range, the thing that matters is how small a particle the filter blocks. Two signals prove it:
- A sub-micron rating. A filter rated to 0.5 micron or finer physically blocks the vast majority of microplastic particles. Reverse osmosis, at 0.0001 micron, removes essentially all of them.
- An NSF/ANSI 401 or microplastics listing. NSF’s protocol verifies reduction of particles in the 0.5 to 1 micron range. Few consumer filters carry the specific claim yet, so a sub-micron rating or RO is often your best proof.
An ordinary pitcher or fridge filter with no sub-micron rating may catch some larger fragments, but you shouldn’t count on it for the nanoplastics that matter most.
Which filters actually remove microplastics
The good news: microplastics are physically larger than dissolved contaminants like PFAS or fluoride, so any filter fine enough to block particles handles them well. Here’s how the options compare.
| Technology | Microplastic removal | Why |
|---|---|---|
| Reverse osmosis | Excellent | 0.0001-micron membrane blocks all |
| Sub-micron carbon block | Reliable | 0.5-micron pores trap particles |
| Certified pitcher (NSF 401) | Good | Tested for the 0.5–1 micron range |
| Standard carbon pitcher | Partial | Catches larger bits, not nanoplastics |
| Standard fridge filter | Limited | Not rated sub-micron |
Good news for your wallet: unlike PFAS or fluoride, you don’t necessarily need reverse osmosis. A certified sub-micron carbon filter or an NSF/ANSI 401 pitcher removes microplastics well for less money.
Filters we recommend for microplastics
Each of these is certified or verified to remove microplastics, and earned its place in our rankings. Reverse osmosis is the most thorough; the certified pitcher is the budget entry point.
When you buy through the links below we may earn a commission, at no extra cost to you. It never affects our rankings, see our affiliate disclosure.
AquaTru Carafe
PUR PLUS Pitcher
iSpring RCC7AK
Any of our reverse-osmosis picks removes microplastics as a matter of course: the no-install AquaTru Carafe, the under-sink Waterdrop G3P800, and the value iSpring RCC7AK. On a budget, a microplastics-certified pitcher like the PUR PLUS is the cheapest reliable option. Because microplastics often travel with other contaminants, it’s worth reading our PFAS guide too.
Frequently asked questions about microplastics
Does bottled water have fewer microplastics than tap?
Usually the opposite. A 2024 study found the average liter of bottled water held around 240,000 plastic particles, mostly nanoplastics shed from the bottle, far more than typical filtered tap water. Filtering your tap and storing it in glass or steel is cheaper and cleaner than buying bottled.
Does boiling water remove microplastics?
Only partially, and only for hard water. A 2024 study found that boiling calcium-rich water can trap some nanoplastics in the limescale that forms, but you’d then have to filter out that scale, and it does nothing for soft water. A sub-micron filter or reverse osmosis is the dependable route.
Do standard Brita or fridge filters remove microplastics?
Not reliably. A basic carbon pitcher or refrigerator filter may catch larger fragments, but without a sub-micron rating it won’t stop the nanoplastics that matter most. Look for a filter rated to 0.5 micron or finer, an NSF/ANSI 401 listing, or reverse osmosis.
Do I need reverse osmosis, or is a filter enough?
Unlike PFAS or fluoride, microplastics are large enough that you don’t strictly need RO. A certified sub-micron carbon filter or an NSF/ANSI 401 pitcher removes them well for less money. RO is the most thorough and also handles dissolved contaminants at the same time.
Can I test my water for microplastics at home?
No. Counting microplastics requires laboratory spectroscopy, which isn’t available in a home kit. Since they’re found in nearly every supply and a good filter removes them cheaply, the sensible move is to filter rather than test.