Tap water vs bottled water
Is bottled water actually cleaner than the tap?
The verdict
Tap, by a wide margin, and this is the most consequential swap on the site. Bottled water is the most-measured microplastic exposure there is — around 240,000 particles per litre in the 2024 PNAS work. Tap water has no bottle, no cap and no shelf life, which is where almost all of that comes from.
These carry different evidence grades. Aquafina is grade A and Tap water is grade B. One component of our score is measured release, which only earns points where a laboratory has actually counted particles — so a product nobody has tested scores lower than an identical one that has been. Part of the gap you are looking at is a difference in how much anyone has looked. Why we do it this way →
Where they actually differ
| Aquafina | Tap water | |
|---|---|---|
| The container | A PET wall and cap in contact for months | None. The polymer contact is plumbing, in the seconds before you drink it |
| Measured | ~240,000 particles/L; 93% of bottles contaminated | Synthetic particles in 81% of samples worldwide, at far lower counts |
| Evidence grade | A — the brand was in a tested cohort | B — measured globally, but your supply is not your neighbour's |
| Cost per litre | Roughly a thousand times tap | Fractions of a penny |
Where this comparison stops being reliable
Tap water varies far more between municipalities and between houses than bottled water varies between brands — old plumbing, lead service lines and local treatment all matter, and none of that is a microplastics question. The global tap study was also fibre-dominated, which is the weakest kind of detection. If you have a specific reason to distrust your supply, filter it rather than bottling it.
The full picture on each
Does Aquafina have microplastics?
Yes, and this one has actually been measured. Aquafina was one of the eleven brands in the 2018 Mason study, which found microplastic in 93% of the 259 bottles it tested across those brands, averaging 325 particles per litre.
Full score breakdown and sources →
Does Tap water have microplastics?
Yes, and far less than bottled. Synthetic particles were detected in 81% of tap samples worldwide — but tap water has no bottle, no cap and no shelf life, which is where most of bottled water's far larger count comes from.
Full score breakdown and sources →
Neither of these is what you own
A comparison is between two product types. The item in your cupboard has its own packaging, its own age and its own condition. Scan it and get the same five-component score for the actual object.
Scan what I actually have