Are there microplastics in tap water?

Yes, microplastics have been detected in tap water in most places studied, though usually at far lower levels than in bottled water. A widely cited 2018 study in PLOS ONE (Kosuth, Mason, and Wattenberg) sampled tap water from several continents and found microplastic particles in the large majority of samples, mostly fibres. The World Health Organization reviewed the available evidence in its 2019 report on microplastics in drinking-water and concluded that microplastics are present in drinking water but that, based on current knowledge, they do not appear to pose a health risk at the levels typically found, while noting the data were limited and more research was needed. So the honest picture is that tap water is not plastic-free, but for most public supplies the counts are modest, and treated tap water generally carries fewer particles than bottled water. If your goal is to lower the number you drink, a filter matters more than switching to bottles.

Does bottled water contain more microplastics than tap water?

In the studies done so far, yes, and often by a striking margin, which surprises people who buy bottled water to feel safer. A 2024 study in PNAS (Qian et al.) used a new laser-imaging method sensitive to the smallest nanoplastics and estimated that a litre of bottled water contained on the order of 240,000 plastic particles, far more than earlier methods had detected and far more than typical tap water. Much of that plastic appears to come from the bottle and cap themselves, shedding into the water during manufacturing, storage, and every time the cap is opened and closed. Earlier work had already found bottled water tended to carry more microplastics than tap, and the 2024 study pushed the gap wider by counting the tiny particles previous techniques missed. The practical implication is clear: buying bottled water to avoid microplastics generally does the opposite, and filtered tap water in a glass or steel bottle is the lower-plastic choice.

Where do the microplastics in water come from?

From several sources that join the water at different points, which is why no single fix removes all of them. Some enter at the source: rivers and groundwater already carry microplastics from synthetic-textile fibres shed in laundry, tyre-wear particles washed off roads, and the breakdown of larger plastic litter, and not all of these are fully removed by conventional treatment. Some are added closer to the tap, from plastic pipes and fittings in distribution and plumbing. And in bottled water, a large share comes from the packaging itself, the plastic bottle and cap shedding particles into the water they hold, which is why bottled counts run so high. The mix is why the same glass of water can contain fibres, fragments, and film-like particles of different plastics at once. Because packaging is such a big contributor for bottled water specifically, the single most effective step for many people is simply not drinking from single-use plastic bottles.

Is it harmful to drink microplastics in water?

The honest answer is that clear harm has not been established at the levels found in drinking water, but the science is still developing and cannot yet rule it out. The World Health Organization's 2019 assessment concluded that, on current evidence, microplastics in drinking water do not appear to present a health risk at typical concentrations, while stressing that the available studies were few and of limited quality and that more research was needed, particularly on the smallest nanoplastic particles and on the chemicals plastics can carry. That is a measured position rather than an all-clear: it means the best evidence we have does not show harm, not that harm has been disproven. Given that, the reasonable response is neither panic nor dismissal. Reducing how many particles you drink is cheap and easy through filtration, so it is a sensible precaution to take even while the health question stays genuinely open, rather than something to lose sleep over.

How do you remove microplastics from drinking water?

A good filter is the effective route, and the type of filter matters more than the brand. Reverse osmosis systems are the most thorough, because their membrane has pores small enough to block even nanoplastics along with a wide range of dissolved contaminants, which is why they consistently top the list for microplastic reduction. High-quality activated-carbon block filters, including many countertop and under-sink units and the better pitcher filters, also capture a large share of microplastic particles, since the particles are far larger than the pore structure the carbon relies on. What does not help is boiling alone, which kills microbes but leaves particles behind, or buying bottled water, which as the research shows tends to add plastic rather than remove it. We compare the options in detail in our guide to the best filter to remove microplastics and, for a whole-home approach, our reverse osmosis water filter guide.

Is tap or bottled water the better choice for avoiding microplastics?

Filtered tap water is the clear winner for most people, and that runs against the instinct that bottled must be purer. The research points the same way each time: bottled water generally carries more microplastics than tap, and the 2024 PNAS study found dramatically more once the smallest particles were counted, with much of it coming from the bottle itself. Unfiltered tap water does contain some particles, but usually far fewer, and running it through a decent carbon or reverse-osmosis filter brings the count lower still while costing a fraction of bottled water over time. Carrying filtered tap water in a glass or stainless-steel bottle avoids the single-use plastic entirely and sidesteps the leaching that happens when bottled water sits warm in storage. So the lower-plastic, lower-cost, and lower-waste choice is the same one: filter your tap water and skip the bottles. Our best water filters guide covers where to start.

The Explainer· Microplastics

Microplastics in water: what is in your tap and bottled water, and what removes it

A glass of water beside a countertop water filter on a pale stone kitchen counter in soft natural daylight.

By The PlasticFreeLab TeamUpdated July 18, 20269 min read

Microplastics have been measured in tap water, and in far higher numbers in bottled water, but the amounts and what they mean for health are easy to misread. Here is what the research shows about how much plastic is in the water people drink, where it comes from, whether it is worth worrying about, and the filters that actually reduce it.

The FAQ

What people ask us next.

Are there microplastics in tap water?: Yes, microplastics have been detected in tap water in most places studied, though usually at far lower levels than in bottled water. A widely cited 2018 study in PLOS ONE (Kosuth, Mason, and Wattenberg) sampled tap water from several continents and found microplastic particles in the large majority of samples, mostly fibres. The World Health Organization reviewed the available evidence in its 2019 report on microplastics in drinking-water and concluded that microplastics are present in drinking water but that, based on current knowledge, they do not appear to pose a health risk at the levels typically found, while noting the data were limited and more research was needed. So the honest picture is that tap water is not plastic-free, but for most public supplies the counts are modest, and treated tap water generally carries fewer particles than bottled water. If your goal is to lower the number you drink, a filter matters more than switching to bottles.
Does bottled water contain more microplastics than tap water?: In the studies done so far, yes, and often by a striking margin, which surprises people who buy bottled water to feel safer. A 2024 study in PNAS (Qian et al.) used a new laser-imaging method sensitive to the smallest nanoplastics and estimated that a litre of bottled water contained on the order of 240,000 plastic particles, far more than earlier methods had detected and far more than typical tap water. Much of that plastic appears to come from the bottle and cap themselves, shedding into the water during manufacturing, storage, and every time the cap is opened and closed. Earlier work had already found bottled water tended to carry more microplastics than tap, and the 2024 study pushed the gap wider by counting the tiny particles previous techniques missed. The practical implication is clear: buying bottled water to avoid microplastics generally does the opposite, and filtered tap water in a glass or steel bottle is the lower-plastic choice.
Where do the microplastics in water come from?: From several sources that join the water at different points, which is why no single fix removes all of them. Some enter at the source: rivers and groundwater already carry microplastics from synthetic-textile fibres shed in laundry, tyre-wear particles washed off roads, and the breakdown of larger plastic litter, and not all of these are fully removed by conventional treatment. Some are added closer to the tap, from plastic pipes and fittings in distribution and plumbing. And in bottled water, a large share comes from the packaging itself, the plastic bottle and cap shedding particles into the water they hold, which is why bottled counts run so high. The mix is why the same glass of water can contain fibres, fragments, and film-like particles of different plastics at once. Because packaging is such a big contributor for bottled water specifically, the single most effective step for many people is simply not drinking from single-use plastic bottles.
Is it harmful to drink microplastics in water?: The honest answer is that clear harm has not been established at the levels found in drinking water, but the science is still developing and cannot yet rule it out. The World Health Organization's 2019 assessment concluded that, on current evidence, microplastics in drinking water do not appear to present a health risk at typical concentrations, while stressing that the available studies were few and of limited quality and that more research was needed, particularly on the smallest nanoplastic particles and on the chemicals plastics can carry. That is a measured position rather than an all-clear: it means the best evidence we have does not show harm, not that harm has been disproven. Given that, the reasonable response is neither panic nor dismissal. Reducing how many particles you drink is cheap and easy through filtration, so it is a sensible precaution to take even while the health question stays genuinely open, rather than something to lose sleep over.
How do you remove microplastics from drinking water?: A good filter is the effective route, and the type of filter matters more than the brand. Reverse osmosis systems are the most thorough, because their membrane has pores small enough to block even nanoplastics along with a wide range of dissolved contaminants, which is why they consistently top the list for microplastic reduction. High-quality activated-carbon block filters, including many countertop and under-sink units and the better pitcher filters, also capture a large share of microplastic particles, since the particles are far larger than the pore structure the carbon relies on. What does not help is boiling alone, which kills microbes but leaves particles behind, or buying bottled water, which as the research shows tends to add plastic rather than remove it. We compare the options in detail in our guide to the best filter to remove microplastics and, for a whole-home approach, our reverse osmosis water filter guide.
Is tap or bottled water the better choice for avoiding microplastics?: Filtered tap water is the clear winner for most people, and that runs against the instinct that bottled must be purer. The research points the same way each time: bottled water generally carries more microplastics than tap, and the 2024 PNAS study found dramatically more once the smallest particles were counted, with much of it coming from the bottle itself. Unfiltered tap water does contain some particles, but usually far fewer, and running it through a decent carbon or reverse-osmosis filter brings the count lower still while costing a fraction of bottled water over time. Carrying filtered tap water in a glass or stainless-steel bottle avoids the single-use plastic entirely and sidesteps the leaching that happens when bottled water sits warm in storage. So the lower-plastic, lower-cost, and lower-waste choice is the same one: filter your tap water and skip the bottles. Our best water filters guide covers where to start.

References

Sources we cited on this page.

About the byline

The PlasticFreeLab Team

A small group of researchers and writers cutting through the noise around non-toxic living. We read the studies, read the labels, test the products. We update our recommendations as the science evolves. We do not accept payment for product placement, we disclose every affiliate relationship, and we name the brands we reject.

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Microplastics in water: what is in your tap and bottled water, and what removes it

What people ask us next.

Sources we cited on this page.

The PlasticFreeLab Team

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