Microplastics have been detected in tap water, bottled water, food, air, and the environment. That naturally raises two questions: should you be concerned about the water you drink, and can you do anything about it?
The short answer is that exposure is real, but scientists are still determining what typical everyday exposure means for long-term human health. Meanwhile, there are practical ways to reduce unnecessary exposure without eliminating plastic from your life entirely.
Last reviewed: October 17, 2026.
Microplastics in Drinking Water: The Quick Answer
Are they in drinking water?
Yes. Researchers have detected microplastics in both municipal tap water and bottled water.
Are they dangerous?
We don't have a complete answer yet. Exposure is well established, but the health effects of typical everyday exposure are still being investigated.
Does bottled water solve the problem?
No. Bottled water can also contain microplastics and nanoplastics, and packaging may contribute particles under some conditions.
Can water treatment help?
Yes, depending on the particle and treatment technology. Municipal and home treatment processes can capture particles, but performance varies considerably by particle size and system design.
What Are Microplastics?
Microplastics are small plastic particles generally measuring less than 5 millimeters in at least one dimension. That's roughly the size of a sesame seed at the upper end, although many of the particles studied in drinking water are far smaller and cannot be seen with the naked eye.
Microplastics aren't one particular chemical. They can be fragments, fibers, films, beads, or other shapes made from many different types of plastic.
Primary vs. secondary microplastics
Primary microplastics are manufactured at a small size, such as certain plastic raw materials used in manufacturing.
Secondary microplastics form when larger plastic products gradually break down. Sunlight, heat, friction, weathering, washing, and ordinary use can cause plastics to fragment into progressively smaller particles.
Common environmental sources include:
- Breakdown of plastic packaging and other discarded products
- Synthetic fibers released from clothing
- Tire and road wear
- Paints and coatings
- Plastic manufacturing and industrial materials
- Household plastic products as they wear
What about nanoplastics?
Nanoplastics are even smaller plastic particles. Definitions are still evolving, but they are commonly described as particles smaller than approximately one micrometer.
For comparison, a human hair is roughly 70 micrometers wide.
This distinction matters. Smaller particles are harder to detect, harder to study, and potentially behave differently from larger microplastics. Advances in laboratory technology are also one reason newer studies sometimes report dramatically more particles than older studies: researchers can now detect particles that earlier methods missed.
How Do Microplastics Get Into Drinking Water?
Microplastics can move through the environment by air, stormwater runoff, wastewater, rivers, lakes, soil, and groundwater.
For example, rain can wash particles from roads and urban surfaces into streams and reservoirs. Synthetic fibers released during laundry can enter wastewater. Lightweight fibers can also travel through the air before settling onto land or water.
That means drinking water is one part of a much larger environmental cycle.
What happens at a municipal water treatment plant?
Conventional drinking-water treatment wasn't originally designed specifically for microplastics. Nevertheless, treatment processes that remove suspended material can also capture many plastic particles.
Processes such as coagulation, sedimentation, and filtration may reduce microplastics before treated water enters the distribution system.
The WHO’s 2019 drinking-water review discusses treatment and important evidence gaps. There is no meaningful universal removal percentage, however. Performance can depend on:
- Particle size
- Particle shape
- Plastic type
- Treatment technology
- Water chemistry
- Plant operating conditions
This is particularly important for very small particles and nanoplastics, which present greater measurement and treatment challenges.
Tap Water vs. Bottled Water: Which Has More Microplastics?
If your goal is to avoid microplastics, switching automatically from tap water to bottled water isn't a guaranteed solution.
| Comparison | Tap Water | Bottled Water |
|---|---|---|
| Microplastics detected? | Yes | Yes |
| Possible sources | Source water, treatment and distribution environment | Source water, processing, packaging and handling |
| Plastic packaging? | No, when consumed directly from the tap | Usually yes |
| Always lower in microplastics? | No | No |
Studies have detected plastic particles in both.
A 2018 bottled-water study reported synthetic polymer contamination. A 2024 study using sensitive chemical imaging examined three bottled-water brands and detected many smaller particles that earlier methods could miss.
These studies cannot rank every tap supply against every bottled-water brand. Differences in detection size, sampled brands, handling, and analytical methods prevent a simple comparison. A higher count from a more sensitive method does not, by itself, establish a greater health risk.
Are Microplastics in Drinking Water Harmful?
This is the most important question—and currently the one science cannot answer with a simple yes or no.
Scientists have established that humans are exposed to microplastics and nanoplastics through food, beverages, air, and the broader environment. Researchers have also reported plastic-associated material in human samples and tissues.
What has not yet been established is exactly what typical long-term exposure means for human health.
What laboratory studies have found
Experiments involving cells and animals have reported biological responses under certain conditions, including inflammation, oxidative stress, altered immune signaling, and other effects.
These studies help researchers identify possible biological mechanisms. They do not automatically demonstrate that the same effects occur in humans at typical environmental exposure levels.
What about studies in humans?
A 2024 study published in the New England Journal of Medicine examined patients undergoing surgery for carotid artery disease. Researchers reported an association between detectable micro- and nanoplastics in arterial plaque and a higher rate of subsequent cardiovascular events.
The study attracted considerable attention because it combined tissue analysis with patient outcomes.
However, it was an observational study. It did not establish that the detected particles caused heart attacks, strokes, or deaths. It also did not identify drinking water as the source of those particles or establish the risk for the general population.
What does the FDA currently say?
The FDA acknowledges that microplastics and nanoplastics can enter the food supply through environmental pathways. Its current evidence summary says the overall evidence does not demonstrate that levels found in foods pose a human health risk.
The FDA also emphasizes a major limitation of the research: scientists still lack fully standardized methods for detecting, measuring, and characterizing microplastics and nanoplastics.
In other words, the appropriate conclusion isn't that microplastics have been proven harmless—or that they have been proven to cause widespread disease. Important scientific uncertainties remain.
Can Water Filters Remove Microplastics?
Some water treatment and filtration technologies can reduce particles within specific size ranges. But "microplastics" encompasses such a broad range of sizes that there isn't a single removal percentage that applies to every filter and every plastic particle.
Different filtration technologies work differently:
Reverse Osmosis
RO systems use a semipermeable membrane and can reject many extremely small substances and particles. Many under-sink models require plumbing and water pressure, while some countertop models use a reservoir and pump. Membranes and cartridges require maintenance; a general RO claim is not proof of removal of every nanoplastic.
Membrane & Ceramic Filtration
These technologies physically restrict particles based largely on the characteristics and pore size of the filtration medium. Performance depends heavily on the individual filter.
Activated Carbon Systems
Activated carbon is widely used for taste, odor, chlorine, and various chemical contaminants. Particle reduction depends on the overall filter design and should not be inferred solely from the presence of activated carbon.
Gravity Water Filters
Gravity systems move water through filtration elements without electricity or a permanent plumbing connection. Performance depends on the element design and should be evaluated using contaminant-specific testing where available.
Look for the specific certification claim
NSF lists products with an explicit Microplastics Reduction claim under NSF/ANSI 401. Check the exact model, replacement cartridge, rated service life, and performance data. Certification to Standard 401 for a different substance does not automatically include microplastics. Consult the NSF microplastics-reduction directory.
A certified claim applies to the specified testing requirements. It does not establish elimination of every plastic type or particle size, and it should not be extended to all nanoplastics.
Why particle size matters
A claim that a filter "removes microplastics" can sound more definitive than it really is.
A 1-millimeter plastic fragment and a submicron particle can both fall under the category of microplastics, yet they present completely different filtration challenges.
When comparing filtration products, look beyond the headline percentage and ask:
- What particle size was actually tested?
- Was the testing performed by an independent laboratory?
- What test method was used?
- Was performance evaluated over the element's service life?
- Can you review the actual performance information?
These questions tell you considerably more than a broad "microplastic removal" claim.
Choosing a Home Water Filter for Everyday Drinking Water
Microplastics may be one concern, but they probably aren't the only reason you're considering a water filter.
Your household may also care about chlorine taste and odor, lead, PFAS, VOCs, disinfection byproducts, or other substances associated with the local water supply.
That's why choosing a filter solely for its broad microplastics claim can be misleading.
A better approach is to:
- Understand your water source. Review your local utility's water-quality report if you use municipal water.
- Identify the contaminants you actually want to address.
- Compare filtration technologies.
- Review contaminant-specific testing and certification information.
- Consider capacity, maintenance, installation, and operating cost.
For a broader starting point, see our Drinking Water Contaminants Reference Guide.
For Berkey® Owners
A gravity-fed housing describes how water moves through a system, not which particles it captures. For Black Berkey® or Phoenix Gravity elements, require evidence for the specific element and particle sizes of interest. Chlorine reduction, lead-content certification, or a report mentioning an NSF test method does not establish certified microplastics reduction.
Use the Berkey® filter test-results library to examine available reports. Do not interpret the use of a stainless-steel housing as proof that the finished water is free of microplastics or nanoplastics.
Practical Ways to Reduce Unnecessary Plastic Use
These are optional steps for reducing disposable packaging and avoiding unnecessary wear or heating. Research has not established how much each step changes a person’s total microplastic exposure or long-term health risk.
- Choose reusable containers when practical. Clean glass or stainless-steel bottles can reduce single-use plastic packaging. Lids and seals may still contain plastic, and no container guarantees particle-free water.
- Follow storage and temperature instructions. Use food-contact containers as intended. Choose a heat-safe glass or ceramic container when you prefer to avoid heating food in plastic.
- Replace damaged items. Follow manufacturer guidance when bottles, containers, or kitchenware become badly worn.
- Maintain any water filter. Replace cartridges on schedule and check the evidence for the specific claim you need.
- Prioritize established water hazards. Follow advice about germs, lead, arsenic, and other known local contaminants. Continue drinking enough safe water.
Do not treat these choices as a detox program or a guarantee of improved health. The FDA’s evidence overview explains why health conclusions remain limited.
Can You Test Your Water for Microplastics?
Specialized laboratories can analyze selected particle sizes and polymers, but a routine home strip or TDS meter cannot identify microplastics. Before paying for a test, ask about the smallest size detected, which plastics are identified, collection instructions, and controls for contamination from air, bottles, and laboratory materials.
Check whether results are expressed as particle counts or plastic mass; they answer different questions. A result covering larger particles cannot rule out nanoplastics, and a particle count alone does not translate into an individual health-risk estimate.
California has adopted methods for microplastics analysis in drinking water, illustrating the importance of a defined sampling and analytical protocol. See the California Water Board’s microplastics program.
Does the EPA Regulate Microplastics in Drinking Water?
There is currently no federal Maximum Contaminant Level (MCL) specifically for microplastics in U.S. drinking water.
However, the regulatory picture is changing.
On April 2, 2026, the U.S. Environmental Protection Agency announced its draft Sixth Contaminant Candidate List (CCL 6). For the first time, the draft includes microplastics as a contaminant group.
That is significant, but it does not mean EPA has established a microplastics drinking-water limit.
The EPA’s draft CCL 6 materials say important data gaps remain before the agency can fully understand the health risks associated with microplastics in drinking water.
CCL inclusion therefore represents an important step in federal evaluation—not an enforceable limit on public water systems.
Why Do Microplastics Studies Report Such Different Numbers?
You may see one headline reporting hundreds of particles per liter and another reporting hundreds of thousands. That doesn't necessarily mean one study is wrong.
Imagine two people searching the same beach for shells. One counts only shells larger than a coin. The other counts everything down to grains of sand. Their totals will be dramatically different even though they searched the same beach.
Microplastics research has a similar problem.
Results can vary because laboratories use different:
- Minimum particle sizes
- Sample volumes
- Collection procedures
- Identification techniques
- Contamination controls
- Reporting methods
Methods such as FTIR spectroscopy, Raman spectroscopy, and pyrolysis-GC/MS can answer different analytical questions and have different capabilities.
The important question isn't simply "How many particles did the study find?" It is also "What sizes and types of particles was the study capable of detecting?"
Frequently Asked Questions
Are there microplastics in tap water?
Yes. Studies have detected microplastics in municipal drinking-water supplies. Reported concentrations vary substantially depending on location, source water, treatment, distribution conditions, particle size, and analytical method.
Does bottled water contain microplastics?
Yes. Microplastics and nanoplastics have been detected in bottled water as well as tap water. Bottled water therefore shouldn't automatically be assumed to be microplastic-free.
Can you see microplastics in drinking water?
Usually not. Although the broad definition of microplastics includes some particles large enough to see, many particles studied in drinking water are microscopic and require specialized laboratory equipment for detection and identification.
Are microplastics harmful to humans?
Scientists are actively investigating this question. Human exposure is well established, and laboratory research has identified biological mechanisms that deserve further study. However, the health effects associated with typical everyday human exposure have not been fully established.
Does boiling water remove microplastics?
Boiling should not be treated as a universal microplastics-removal method. Research has investigated boiling under particular water-chemistry conditions followed by separation or filtration, but the results shouldn't be generalized to all household water.
Can a home water filter reduce microplastics?
Some filtration technologies can reduce particles within particular size ranges. Performance depends on the filter design, particle size, water conditions, and test method. Look for clear performance information rather than assuming every filter removes every microplastic or nanoplastic.
Does reverse osmosis remove microplastics?
Reverse osmosis uses a semipermeable membrane capable of rejecting many extremely small substances and particles. Actual performance depends on the RO membrane, system condition, installation, and the particle being evaluated.
Does the EPA have a limit for microplastics in drinking water?
No federal Maximum Contaminant Level specifically for microplastics currently exists. EPA included microplastics as a group in its draft Sixth Contaminant Candidate List announced in April 2026, which supports further evaluation but does not itself impose a drinking-water requirement.
Can I completely avoid microplastics?
Probably not. Microplastics have become widespread in the environment, food, water, and air. Practical exposure reduction is a more realistic objective than trying to eliminate exposure completely.
Making a Practical Water Decision
Microplastics are present in both tap and bottled water, but their presence alone doesn't tell us the level of health risk.
Scientists have become much better at finding extremely small plastic particles, including nanoplastics. The harder question is determining what different particles do in the human body and what typical lifetime exposure means for health.
You don't need to wait for every scientific question to be answered to make reasonable choices. Reducing disposable packaging and choosing a filter with a specific, verifiable claim are practical options. Neither establishes a measured improvement in health.
At the same time, avoid treating every alarming particle count as proof of danger. In microplastics research, particle size, detection method, exposure level, and study design all matter.