Synthetic Tea Bags Can Release Billions of Microplastic and Nanoplastic Particles Into Your Tea

Billions of microplastics released from tea bags into your cup. Illustration by the author.

Our comforting daily cups of tea may not be as healthy as we think. They release billions of tiny plastics when steeped in hot water .

A study in 2019 from McGill University found that a single tea bag could release around 11,6 billion microplastics and 3.1 billion nanoplastics. These bags, nylon and PET, interestingly, are more common in premium tea.

The Autonomous University of Barcelona in 2024 found that polypropylene nylon and even some cellulose tea bags release millions to billions of tiny plastic particles and some of these particles can easily enter intestinal cells which raises concerns about long term health effects

The 2025 study by the University of Birmingham looked at 155 drinks from UK brands; they found microplastics in every sample. Hot tea had the most with roughly 60 particles per litre. Disposable cups and lids contribute to the factor. They tested a wide range of drinks, and Microplastics were found in every sample, with hot beverages showing the highest levels. The researcher estimated that UK adults ingest roughly 1.6 to 1.7 microplastics per kilogram of body weight daily from beverages alone.

Although the scientists aren't sure what the long-term risk, the microplastics could disrupt natural gut bacteria and can worsen infections; they could also carry chemicals that affect hormones. So, cutting our exposure by using loose-leaf tea with a metal or glass infuser, avoiding plastic cups or lids, and picking plastic-free tea bags when possible can make our daily cup safer .

References:

Hernandez, L. M., Yousefi, N., & Tufenkji, N. (2019) . Plastic tea bags release billions of microparticles and nanoparticles into tea. Environmental Science & Technology, 53(21, 12300–12310.
https://doi.org/10.1021/acs.est.9b02540

Fard, A. Gómez , M. & Barceló, D. (2024). Teabag-derived micro/nanoplastics as human intestinal cell contaminants. Chemosphere , 335, 140810. https://pubmed.ncbi.nlm.nih.gov/39542373/

University of Birmingham. (2025). Synthetic microplastics in hot and cold beverages from the UK market . Science of the Total Environment, 943, 162972. https://research.birmingham.ac.uk/en/publications/synthetic-microplastics-in-hot-and-cold-beverages-from-the-uk-mar