TL;DR: Neither the FDA nor the EPA currently sets a legal limit for microplastics in bottled or tap water in the US. The FDA regulates bottled water as a packaged food, the EPA regulates tap water — and both are still studying microplastics, not enforcing limits.
Short answer: In the United States, no federal agency has set an enforceable limit for microplastics in drinking water. The FDA oversees bottled water as a packaged food. The EPA oversees public tap water under the Safe Drinking Water Act. Both have acknowledged microplastics as an emerging concern — but neither has issued binding standards as of 2025.
If you've been searching for a clear answer on what the US government does about microplastics in the water you drink, this page lays it out without spin. For the bigger picture on why this matters, see our pillar guide on microplastics in bottled water.
Who regulates what: FDA vs. EPA
Drinking water in the US is split between two agencies, and the split matters for how microplastics are handled.
- FDA (Food and Drug Administration): Regulates bottled water because it is sold as a packaged food product. Rules sit in 21 CFR Part 165.
- EPA (Environmental Protection Agency): Regulates public tap water through the Safe Drinking Water Act (SDWA), passed in 1974 and amended in 1996.
That means a sealed bottle of spring water on a gas station shelf falls under the FDA. The water from your kitchen tap falls under the EPA. Two different agencies, two different rulebooks, and — for microplastics — two different stages of catching up.
Quick comparison
| Topic | FDA (Bottled Water) | EPA (Tap Water) |
|---|---|---|
| Legal authority | Federal Food, Drug, and Cosmetic Act | Safe Drinking Water Act |
| Microplastic limit | None set | None set federally |
| Required testing for microplastics | Not required | Not required (federal) |
| Status | Monitoring research | Studying, not yet regulating |
What the FDA says about microplastics in bottled water
The FDA's public position, restated several times in recent years, is that the current science does not show that microplastics in food or bottled water present a risk to human health at the levels typically detected. The agency continues to review studies and does not, as of 2025, require bottlers to test for microplastics or report results.
Bottled water producers must still meet existing FDA rules, which cover things like:
- Source water quality and approved treatment processes
- Good Manufacturing Practices (GMP) under 21 CFR Part 129
- Labeling standards ("spring water," "purified water," "mineral water" each have legal definitions)
- Limits on specific contaminants like lead, arsenic, and coliform bacteria
Microplastics are not on that contaminant list. So a bottled water brand can comply fully with FDA rules and still contain hundreds or thousands of microplastic particles per liter — a finding documented in multiple peer-reviewed studies. We cover the actual numbers in how many microplastics are in a bottle of water.
What the EPA says about microplastics in tap water
The EPA has been more publicly active on microplastics, mainly because of its broader water-quality mandate. The agency has funded research, contributed to international reviews, and acknowledged microplastics as a "contaminant of emerging concern." That label is important — and limited. It means the EPA is studying a substance, not regulating it.
Under the Safe Drinking Water Act, the EPA can add a contaminant to the National Primary Drinking Water Regulations only after a multi-step process: occurrence data, health-effects review, a determination that regulation would meaningfully reduce risk, and a formal rulemaking. Microplastics are not currently in that pipeline at the federal level.
The EPA has, however, supported standardized methods for measuring microplastics in water, partly so that future regulation — federal or state — has a defensible scientific baseline.
The WHO and international context
The World Health Organization issued a 2019 report concluding that microplastics in drinking water do not appear to pose a health risk at current levels, but flagged significant data gaps and called for more research. US agencies have generally cited that report as consistent with their own stance. You can read the WHO summary on the official WHO website.
Since 2019, peer-reviewed studies — including a widely cited 2024 paper in Proceedings of the National Academy of Sciences that found roughly 240,000 plastic fragments per liter in average bottled water — have pushed the conversation forward, but not yet the regulations.
State-level action: California is ahead
While the federal picture is static, California has moved. The State Water Resources Control Board adopted the world's first definition of "microplastics in drinking water" in 2020 and approved standardized testing methods in 2022. A four-year monitoring program for large public water systems began rolling out, with results intended to inform future health-based thresholds.
California's approach is monitoring-first, not limit-first — the state is building data before setting numbers. Other states, including New York and New Jersey, have introduced or considered related bills, but none have enforceable consumer-facing standards yet.
The regulatory gap is a fact to plan around, not panic about. Until rules catch up, the practical option is to filter at the point of drinking.
What this means for you as a consumer
The honest summary:
- No US agency tells bottled water companies how few microplastics their product can contain.
- No US agency tells your local water utility to test or treat for microplastics.
- Independent research consistently finds microplastics in both bottled and tap water, with bottled water typically higher per liter.
- You don't need to wait for regulation to do something about your own intake.
If you're curious how bottled compares to what comes out of your sink, see bottled water vs tap water microplastics. If you want to know whether the particles matter for your body, our overview on are microplastics in water bad for you walks through the current evidence.
Where Clear Flow fits in
Clear Flow is not a regulator, a lab, or a public-health agency. It's a simple cap-style filter that screws onto a standard plastic bottle and removes microplastics from the water you're already drinking. It does one thing — and that one thing is exactly what the FDA and EPA do not currently require bottlers or utilities to do.
Until federal rules catch up with the science, the practical option is to filter at the point of drinking. To see how the cap works, visit our guide to on-the-go microplastic filters.
The bottom line
The FDA and EPA both acknowledge microplastics in drinking water. Neither regulates them. Bottled water in the US can legally contain microplastics, and tap water is not federally tested for them. State-level action — led by California — is the closest thing to real movement, and it's still in the data-gathering phase. For a consumer, the regulatory gap is a fact to plan around, not panic about.
Don't wait for regulation. Filter at the cap.
Federal rules haven't caught up — but you can act now. ClearFlow screws onto a standard bottle cap and removes microplastics before they reach your mouth.
- Fits standard PET bottles — no new equipment required
- Fully portable — gym, travel, office, car
- Effective filtration of microplastic particles
- Sustainable: also reduces single-use plastic consumption
- USPTO patent pending (MPF™)
Frequently Asked Questions
Does the FDA regulate microplastics in bottled water?
The FDA regulates bottled water as a packaged food but has not set a specific limit for microplastics. Bottlers are not required to test for or report microplastic content as of 2025.
Does the EPA test tap water for microplastics?
No federal EPA rule requires public water utilities to test tap water for microplastics. The EPA classifies microplastics as a contaminant of emerging concern and is funding research, but has not issued an enforceable standard.
Is there any US state with microplastic drinking water rules?
California is the most advanced. It adopted a formal definition of microplastics in drinking water in 2020 and approved standardized testing methods in 2022, with a multi-year monitoring program underway for large public water systems.
Is bottled water safer than tap water for microplastics?
Independent research generally finds higher microplastic concentrations in bottled water than in tap water, largely because the plastic bottle and cap themselves shed particles. Neither source is currently regulated for microplastics.
Why hasn't the FDA set a microplastic limit yet?
The FDA states that current evidence does not establish a clear human health risk at typical exposure levels. Setting a federal limit also requires standardized testing methods and occurrence data, both of which are still being developed.
Disclaimer: This article is for general informational purposes only and does not constitute legal, medical, or product safety advice. Regulatory status reflects publicly available information as of 2025 and may change.
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