A hot cup of tea still starts with leaves and water, but some research suggests the bag itself can become part of the brew. Recent studies and food safety statements show that certain tea bag materials can release microplastic particles during steeping, while health agencies say the evidence on human harm remains incomplete.
What researchers found in brewed tea
Newer studies have kept the question in the spotlight. A 2026 paper indexed by PubMed reported that nylon tea bags steeped in hot water for five minutes released measurable large and small microplastics into simulated brewed tea, and the authors said hot brewing produced more release than colder conditions. That adds to a growing body of research looking at what happens when plastic based food contact materials meet very hot water.
The numbers in this field can vary sharply from study to study. A 2024 Food Chemistry paper found microplastics released from filter bags in tea infusions ranged from 80 to 1,288 micron sized pieces per bag, plus measured submicron material by mass. A 2026 open access study in npj Science of Food also reported microplastic release from plastic tea bags and compared bagged tea with bulk tea.
At the...