A study published October 13, 2026, in the peer-reviewed journal npj Science of Food found that plastic mesh tea bags shed between 555 and 2,498 microplastic particles per cup of tea under normal brewing conditions. Every cup tested also contained detectable levels of bisphenol A (BPA) and phthalate plasticizers. The findings add a new household source to the growing body of evidence on plastic exposure through food and drink.
The research
The study, "Microplastic release from plastic tea bags versus bulk tea and migration of bisphenol A and plasticizer esters" by Necla Pehlivan and Kenan Gedik, examined four plastic bag brands alongside bulk-leaf tea. Bags were steeped at 95°C for three minutes, matching standard household brewing. Infusions were then analyzed for particles larger than 100 micrometers and dissolved chemical migrants.
What the numbers mean
All particles captured were polyamide fibers, confirming the bag mesh as the source. The count of up to 2,498 particles per cup covers only particles above 100 micrometers. Smaller particles would push the total higher.
For BPA, the modeled daily intake reached between 4.55% and 21.70% of the European Food Safety Authority's tolerable daily intake benchmark. That figure applies to a single cup. The authors flagged the upper end as a particular concern for pregnant women and children.
Bulk leaf tea contained 146 to 1,178 microplastic particles per kilogram, which translates to roughly 0.3 to 2.4 particles per two-gram serving. That is roughly a thousand times fewer particles than the bagged alternatives tested.
In the kitchen
Plastic tea bags are the standard format for most mass-market tea. The mesh is typically polyamide (nylon), the same polymer identified in the particle counts here. Brewed in near-boiling water, the bag sheds fibers and leaches plasticizers simultaneously.
The study measured phthalate esters (PAEs) alongside BPA in all four brands. Phthalates are added as plasticizers to improve bag flexibility during manufacturing; BPA serves as a structural stabilizer and thermal-resistance agent. The researchers expressed particular concern about BPA concentrations for pregnant women and children.
What to do
Switching to loose-leaf tea brewed in a ceramic or metal infuser removes the plastic contact point entirely. The study's authors also recommend a cold-water wash of bulk leaves before brewing to reduce ambient particle contamination. If you're shopping right now, the product directory is filtered against the criteria this study calls out.
Cover image: Seven Colors via Unsplash (Unsplash License). Source.
