Laura M. Hernandez · Environmental Science & Technology 2019 · laboratory experimental study · n=?

Plastic Teabags Release Billions of Microparticles and Nanoparticles into Tea

Cited 1119 times in the scientific literature.

Level 5 - mechanism / opinion, no new human data

Benchtop physical and chemical analysis with non-human invertebrate toxicity testing.

OpenAlex W2975218902 · doi:10.1021/acs.est.9b02540 · record verified 2026-08-28

What was done

Researchers evaluated whether plastic teabags release microplastics and nanoplastics during standard brewing. Teabags were steeped at 95 °C, and the released particles were quantified and characterized using Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) to verify composition against the original nylon and polyethylene terephthalate packaging. An initial acute invertebrate toxicity assay was performed to measure developmental and behavioral outcomes.

What was found

Steeping a single plastic teabag at 95 °C released approximately 11.6 billion microplastics and 3.1 billion nanoplastics into a single cup. The released particles matched the nylon and polyethylene terephthalate composition of the teabags at levels several orders of magnitude higher than previously reported in other food products. Invertebrate exposure to the extracted particles produced dose-dependent behavioral and developmental effects.

Why it matters

This work demonstrates that steeping plastic teabags generates billions of microplastic and nanoplastic particles per cup, identifying a substantial source of dietary particle exposure.

Limits

Toxicity was assessed only acutely in an invertebrate model, leaving human absorption, tissue distribution, and clinical health impacts unmeasured. The abstract does not report the number of teabag brands or replicates tested, particle size distributions, or whether tea leaves altered particle shedding.

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