The simplest way to reduce microplastics in your drinking water is to filter it, boil it, or both. No regulatory limit for microplastics in drinking water exists yet in the United States, so protecting yourself comes down to the choices you make at home: what you drink from, how you treat your water, and what you store it in.
Bottled Water Is Part of the Problem
If your instinct is to reach for bottled water as the “clean” option, the research points in the opposite direction. A study from Ohio State University found that bottled water contained three times as many nanoplastic particles as treated tap water. A 2024 analysis published by the National Institutes of Health went further, finding that a single liter of bottled water contained roughly 240,000 tiny plastic fragments on average. About 90% of those were nanoplastics, particles so small they can pass through cell membranes. That count was 10 to 100 times higher than earlier estimates, which had only measured larger particles.
The plastic bottles themselves are the main source. Most bottled water is sold in PET containers, and the manufacturing process uses antimony trioxide as a catalyst. Research has confirmed that both antimony and lead can leach from PET bottles into the water inside, especially in warm conditions. Switching away from single-use plastic bottles is one of the highest-impact changes you can make.
Boil Your Tap Water
Boiling is surprisingly effective and costs nothing. A 2024 study published in the journal Environmental Science & Technology Letters found that boiling hard tap water removes at least 80% of common microplastics, including polystyrene, polyethylene, and polypropylene particles ranging from 0.1 to 150 micrometers.
The mechanism is straightforward. Hard water contains dissolved calcium carbonate. When you heat the water, that calcium carbonate crystallizes and physically wraps around plastic particles, trapping them in chalky clumps. This encapsulation process begins around 50°C (122°F) and becomes effective at 70°C (158°F), well below a full boil. Once the water cools, you simply pour it through a basic coffee filter or fine mesh strainer to catch the visible mineral deposits, and the trapped plastic particles come out with them.
This works best with hard water (above 120 mg/L of calcium carbonate), which is common in much of the U.S., particularly the Midwest and Southwest. If you have soft water, boiling still helps, but the removal rate will be lower because there’s less calcium carbonate available to encapsulate the particles. You can check your water hardness on your utility’s annual water quality report, which is usually available online.
Use an Effective Filter
Not all water filters are equal when it comes to microplastics. The particle size matters: microplastics range from 1 micrometer to 5 millimeters, while nanoplastics are smaller than 1 micrometer. Your filter needs pores small enough to physically block them.
Reverse osmosis (RO) systems are the gold standard for home use. They force water through a membrane with pores tight enough to block the vast majority of plastic particles. Coagulation-based treatment processes paired with reverse osmosis have achieved removal rates above 90% in controlled studies. Countertop and under-sink RO units are widely available and typically cost between $150 and $500, with replacement filters needed once or twice a year.
If a full RO system isn’t practical, look for filters rated to remove particles down to at least 1 micrometer. Many solid carbon block filters meet this threshold. Standard pitcher filters with loose activated carbon granules are better than nothing, but their larger pore sizes let smaller microplastics through. When shopping, check for NSF/ANSI certification, which verifies the filter performs as claimed.
Choose the Right Container
What you store and drink your water from matters as much as how you filter it. Research comparing different bottle materials found that coated stainless steel and aluminum bottles are essentially harmless with respect to leaching trace metals into drinking water. Glass is similarly inert. Both are far better options than PET plastic for daily use.
One caveat: not all metal containers are safe. Testing found that pewter flasks released substantial amounts of antimony and thallium, exceeding international safety guidelines by 5- and 11-fold respectively. Stick with food-grade stainless steel (look for 18/8 or 304 grade) or plain glass. Avoid decorative or novelty metal containers that may use different alloys.
At home, the same principle applies. Store filtered or boiled water in glass pitchers or stainless steel containers rather than plastic ones. If you use a plastic pitcher filter, transfer the filtered water to a non-plastic vessel for storage, especially if it will sit for hours.
Reduce Exposure Beyond Your Glass
Your drinking water is a major source of microplastic exposure, but it’s not the only one. A few additional habits help reduce your overall intake:
- Don’t microwave food in plastic. Heat accelerates the release of micro and nanoplastics from containers. Use glass or ceramic instead.
- Avoid plastic tea bags. Nylon and PET mesh tea bags release billions of nanoplastic particles per cup when steeped in hot water. Paper or loose-leaf tea sidesteps the problem entirely.
- Skip the plastic cutting boards for hot foods. Cutting and chopping on plastic surfaces generates fine particles that transfer to your food. Wood or bamboo boards don’t carry this risk.
- Run the tap briefly before filling your glass. Water that’s been sitting in household pipes picks up more particles from any plastic plumbing components. A 10- to 15-second flush helps.
Where Regulations Stand
There is currently no enforceable limit on microplastics in U.S. drinking water. The EPA announced in 2024 that it would, for the first time, include microplastics as a priority contaminant group in its draft Sixth Contaminant Candidate List under the Safe Drinking Water Act. This signals that the agency considers microplastics a serious concern, but inclusion on the list does not create any regulation. It opens the door for research funding and potential future standards, which could take years to develop and implement.
Until binding limits exist, municipal water treatment plants aren’t required to test for or remove microplastics specifically. Many treatment processes do reduce them incidentally, which is why tap water tends to contain fewer particles than bottled water. But the final step of protection falls to you at home. A combination of boiling, filtering through a reverse osmosis or fine carbon block system, and storing water in glass or stainless steel covers the most ground with the least complexity.