Short Answer
Yes for PFAS and fluoride. A 2026 study of 20 refill kiosks in the US found that reverse osmosis removed both. For microplastics, we found no study that has tested refill machines yet. A reverse osmosis membrane is built to hold back dissolved chemicals, which are far smaller than a microplastic, so our inference is that it holds back most of them too.
Our pick: if PFAS is on your mind, refill with reverse osmosis. It's the most common water type in our directory: more than 7,000 stations list it. Bring a clean glass or stainless jug, and give the machine a quick check before you fill.
PFAS: yes
PFAS are the "forever chemicals" used in things like nonstick cookware and stain-resistant furniture. The EPA says exposure to PFAS may lead to health problems. In 2024 it set national drinking water limits for six PFAS, with water systems given until 2029 to meet them. In 2026 it proposed keeping the limits for PFOA and PFOS, letting systems ask for two more years, and dropping the limits for the other four.
At home, the EPA's home filter guide lists reverse osmosis as one of three filter types that can be effective at reducing PFAS, alongside activated carbon and ion exchange.
The better news for refillers comes from the field. A University of Iowa-led study of US water kiosks, published in Environmental Science & Technology in 2026, tested 20 refill kiosks from four manufacturers in six states. Most of them used reverse osmosis, and it removed PFAS. It's the first study we know of that checked real refill machines rather than home systems.
Fluoride: yes
The same kiosk study found that reverse osmosis removed fluoride, along with leftover disinfectant. If you'd rather skip fluoride, RO refill water is one simple option. If you want fluoride for your teeth, ask your dentist.
Microplastics: likely, but untested at refill machines
Here we have to be straight with you: we found no study that counts microplastics in refill machine water. What we do know is that microplastics run from 5 millimeters down to 1 micrometer, according to the NIH. The EPA describes reverse osmosis as forcing water through an extremely thin barrier that separates chemicals from the water. Dissolved chemicals are far smaller than any microplastic.
Our inference, not a test result: a working RO membrane should hold back most microplastics. Nanoplastics, which are smaller than 1 micrometer, are harder to study, and nobody has checked how refill machines handle them. The NIH also notes that polyamide, a plastic often used to help filter and purify water, was the most common plastic found in bottled water, so no filtered water should be called plastic-free.
For more on this, read microplastics in bottled water.
The catch: the machine matters
The kiosk study had a warning too. Lead turned up in water from 15 of the 20 kiosks, and 5 were above the 1 µg/L level the American Academy of Pediatrics recommends. The researchers linked it to corrosion of plumbing parts placed after the reverse osmosis step, parts that met the legal definition of "lead-free." Reverse osmosis can make water low in alkalinity and pH, which is more corrosive. The researchers called kiosks "poorly regulated and sparingly monitored for quality."
RO does its job, but what happens to the water after the membrane matters too. That's why we built a 30-second refill safety checklist.
How to get RO water near you
- Nearly every chain listing in our directory lists reverse osmosis, including every Publix, Walmart, Whole Foods, Sprouts and Natural Grocers listing. See our grocery store refill roundup.
- Search your city: Denver, Austin, Tampa, or all cities.
FAQ
Does a pitcher filter remove PFAS?
It depends on the filter. The EPA says to check the packaging for NSF/ANSI 53 or NSF/ANSI 58 certification for PFAS reduction. RO refill water is a simpler route if you'd rather not shop for a filter.
Does RO remove everything?
No. The kiosk study shows water can pick up lead from parts after the membrane. The EPA also notes that filters only work when they're maintained, and that current PFAS filter certifications don't yet show removal down to its new drinking water limits.
Is RO water safe to drink every day?
RO water is low in minerals. Germany's Federal Institute for Risk Assessment (BfR) reviewed very low-mineral bottled water in 2020 and concluded it isn't expected to cause long-term health problems for people with a balanced diet who drink normal amounts. It said some groups, like pregnant or breastfeeding women and people on restricted diets, should keep an eye on their total mineral intake. If you have a health condition, talk to your doctor.