PET plastic bottle
High releasePolyethylene terephthalate, PET (#1)
The short answer
The single largest packaging source of microplastic exposure. Earth Action attributes roughly a third of all packaging-related exposure to PET bottles, and a 2024 PNAS study counted ~240,000 particles per litre in bottled water.
What actually drives release
- Particle shedding from the bottle wall into the contents over shelf life
- Cap abrasion each time the closure is twisted, which grinds the neck thread
- UV degradation, which Earth Action found can raise release up to 100x
- Mechanical stress from squeezing, dropping and pressure changes
When it gets worse
- Stored warm — a car, garage, sunny shelf or warehouse
- Opened and resealed repeatedly rather than drunk in one go
- Carbonated, since dissolved CO2 keeps the wall under constant pressure
- Refilled and reused, which it was never designed for
Better options
- Glass bottle
- Aluminium can
- Filtered tap water in stainless steel
Where you'll find it
Bottled waterSoft drinksJuiceSports drinksCondiments
Scan what you actually buy
Packaging changes the answer more than the brand does. Scan your product with MicroPlastics for a 0–100 exposure score and a lower-plastic version of the same thing.
Scan my productFrequently Asked Questions
Do pet bottles leach microplastics?
The single largest packaging source of microplastic exposure. Earth Action attributes roughly a third of all packaging-related exposure to PET bottles, and a 2024 PNAS study counted ~240,000 particles per litre in bottled water.
What makes pet plastic bottle worse?
Stored warm — a car, garage, sunny shelf or warehouse. Opened and resealed repeatedly rather than drunk in one go. Carbonated, since dissolved CO2 keeps the wall under constant pressure. Refilled and reused, which it was never designed for.
What should I use instead of pet plastic bottle?
In order of preference: Glass bottle, Aluminium can, Filtered tap water in stainless steel. Packaging is usually the cheapest variable to change in any product decision.
Sources
- Earth Action with rePurpose Global (2026). Microplastic migration from food and beverage packaging (reported May 2026). Forbes.
- Qian N, Gao X, Lang X, et al. (2024). Rapid single-particle chemical imaging of nanoplastics by SRS microscopy. Proceedings of the National Academy of Sciences (PNAS).
- Winkler A, Santo N, Ortenzi MA, et al. (2022). Does mechanical stress cause microplastic release from plastic water bottles?. Water Research.
- Hernandez LM, Xu EG, Larsson HCE, et al. (2019). Plastic teabags release billions of microparticles and nanoparticles into tea. Environmental Science & Technology.