Microplastics in bottled water (plastic bottles)
A 2024 U.S. study (PNAS) found about 240,000 particles in 1 L of bottled water, about 90% of them nanoplastics. On the other hand, critics say the experiment’s “blank” (a control that runs the same procedure on water with nothing added) was about as contaminated as the water itself. The ranking by container type flips from study to study.
Amounts found in studies
| Study | What was tested | Size range and method | Results |
|---|---|---|---|
| Qian et al. (2024, PNAS) | 3 brands in the U.S. | SRS microscopy (down to the nano scale) | About 240,000 particles per L, about 90% nanoplastics. By number, nylon (PA) was the main one; by weight, PET. Only about 10% of the particles could be identified |
| Mason et al. (2018) | 259 bottles of 11 brands | Nile Red staining, about half of the particles over 0.1 mm confirmed by FTIR | 10.4 particles per L over 0.1 mm (54% of the confirmed particles were polypropylene, the material of the cap). The 325 particles that included smaller ones were not confirmed by spectroscopy |
| Schymanski et al. (2018) | By container type in Germany | Micro-Raman | Per L: returnable PET 118 particles, single-use PET 14, carton 11, glass bottle 50. The blank was 14, and only returnable PET was higher than the blank |
| Oßmann et al. (2018) | By container type in Germany | Micro-Raman (down to 0.001 mm) | Per L: single-use PET 2,649 particles, glass bottle 6,292. Over 90% were under 0.005 mm |
Results can differ by orders of magnitude depending on the smallest particle size counted and whether particles are counted or weighed. Numbers from different studies cannot be compared directly (→ Why numbers differ).
Good to know
- Materić et al. (2024, letter to PNAS) pointed out that a blank run through the whole procedure with ultrapure water, which was as contaminated as the bottled water, was not used, and that against this baseline every sample would fall below the blank. Qian et al. replied that “the ultrapure water itself was contaminated and unsuitable as a blank” and that “the polymer makeup differs by brand and cannot be explained by laboratory contamination.”
- As for why nylon was prominent, the authors suggest it may have come from the reverse osmosis membranes (a nylon-based material) in the water purification process.
- Mason 2018 was a project of the news organization Orb Media. A 2018 review by Germany’s Fraunhofer Institute says the reported amounts do not raise a safety concern.
Data from Japan
We found no study that measured bottled water in Japan.
Types of plastic found
Related explainers
Sources
- Qian N, et al. PNAS 2024;121(3):e2300582121 (PMID 38190543)
- Materić D, et al. PNAS 2024 (letter) (PMID 39546557)
- Qian N, et al. PNAS 2024 (reply) (PMID 39546558)
- Mason SA, et al. Front Chem 2018;6:407 (PMID 30255015)
- Schymanski D, et al. Water Res 2018;129:154 (PMID 29145085)
- Oßmann BE, et al. Water Res 2018;141:307 (PMID 29803096)
- Welle F, Franz R. 2018 (PMID 30451587)
Last checked 2026-10-01. “Confirmed in the abstract” means we report only what the paper's abstract says. This page is a translation of our Japanese page; if they differ, the Japanese page is the reference.