Does Path water have microplastics?
Yes. We bought Path at a grocery store in Los Angeles and it tested positive for particles consistent with microplastics, with a PET fluorescence signature.
So did the other six brands we tested. Not one came back clean. What follows is the reading, how it was produced, and — the part that matters most — what a fluorescent dye can and cannot prove.
Path returned the lowest reading of the seven. It is still a clear PET signal, and the gap between Path and Dasani is narrower than the gap between either of them and a clean filter. Lowest of the batch is not the same as clean.
What the reading is — and isn’t
The number above is a fluorescence signal strength, not a particle count. It comes from staining the sample with undiluted Nile Red, pushing it through a PCTE membrane, and measuring how brightly the retained material glows across three wavelengths. A brand with a higher reading produced a stronger signal from material consistent with plastic. Nobody counted 143 of anything.
The scored brands span a narrow range, from Path at 106 to Dasani at 143. Three brands were not assigned a number in this round. We are not going to rank those three against each other to fill out a list, because we do not have the data to do it honestly.
Nile Red binds hydrophobic material. Plastic is hydrophobic — and so are lipids, oils, and some organic debris. That is why every result here is phrased as particles consistent with microplastics rather than as confirmed plastic. Definitive polymer identification requires spectroscopy, not a dye. Our full error budget, including the contamination sources we know about and the ones we suspect, is published at thewatertest.com/limitations. Read it before you treat any number on this page as gospel.
These are results from an ongoing study, not a peer-reviewed paper. Our method is adapted from published work (Meyers et al. 2022; Leonard et al. 2022); those authors have not reviewed or validated it.
The other six brands
Path was one of seven bought together and run the same way. Reading any single brand in isolation is a mistake — the finding of the study is not that Path is bad, it is that the container is the common thread and every brand tested positive.
Read the full comparison, including how we identified the plastic type and why the aluminum cans scored the same as the plastic bottles, in We Tested 7 Bottled Water Brands for Microplastics.
Path is a registered trademark of its owner. The Water Map is not affiliated with, endorsed by, or sponsored by that company. The brand name is used here only to identify the specific product tested. We purchased the product at retail, at our own expense, and received nothing from anyone in connection with this test.
Every test we run is published, including the ones that make our own method look bad. All of our data is open — see the license.