Researchers found that plastic tea bags released hundreds to thousands of microplastic particles, along with bisphenol A and plasticizer chemicals, into hot water during brewing, raising questions about long-term exposure from a widely consumed beverage.
By yourNEWS Media Newsroom
Plastic tea bags can release thousands of microscopic plastic particles and potentially harmful chemicals into hot water during brewing, according to a newly published scientific study that examined contamination associated with commercially available tea products.
The research, published Oct. 13 in the journal npj Science of Food, found that plastic tea bags released between 555 and 2,498 microplastic particles per cup under controlled brewing conditions. Researchers also detected bisphenol A (BPA) and phthalate plasticizers in the resulting infusions, identifying another potential source of exposure to chemicals associated with plastic manufacturing.
The study, conducted by researchers Necla Pehlivan and Kenan Gedik, compared plastic tea bags with loose-leaf tea to examine how packaging materials contribute to microplastic contamination and the migration of chemical compounds into beverages.
The findings suggest that the materials used to manufacture certain tea bags can introduce additional contaminants during normal preparation, even when the tea itself contains relatively low amounts of plastic particles.
Researchers examined samples representing 14 bagged-tea and 14 bulk-tea brands, with four plastic tea bag brands selected for detailed brewing experiments.
The plastic tea bags were steeped in water heated to approximately 95 degrees Celsius, or 203 degrees Fahrenheit, for three minutes, simulating common tea preparation conditions.
Scientists then analyzed the resulting infusions using microscopy, infrared spectroscopy and chemical testing to identify plastic particles and measure the presence of BPA and plasticizer compounds.
The plastic tea bags released between 555 and 2,498 microplastic particles per cup, with considerable differences between brands.
The particles identified in the bagged-tea samples were primarily polyamide fibers, consistent with the plastic material used to manufacture the tea bags.
Polyamide, commonly associated with nylon, is used in certain mesh-style tea bags because it can withstand relatively high temperatures and maintain its structure during brewing.
However, the researchers found that exposure to hot water could cause the material to shed microscopic fibers into the beverage.
The study identified particles larger than 100 micrometers, meaning smaller microplastics and nanoplastics were not included in the reported counts. Consequently, the total number of plastic particles present in the beverages could be greater than the figures measured.
The researchers also examined bulk tea leaves, finding between 146 and 1,178 microplastic particles per kilogram of dry tea.
That amounted to an estimated 0.3 to 2.4 particles per typical two-gram serving, substantially lower than the concentrations measured in tea brewed with plastic bags.
However, the bulk tea samples were analyzed directly rather than brewed under identical conditions, limiting how precisely the two results can be compared.
Unlike the plastic tea bags, which primarily released polyamide fibers, the bulk tea contained a mixture of plastic materials, including polyethylene, polypropylene, polyethylene terephthalate and polyamide.
Researchers suggested that contamination of loose tea could originate from agricultural packaging, manufacturing equipment, airborne particles and processing operations.
Tea leaves can encounter plastic materials during harvesting, transportation, drying and packaging, creating multiple opportunities for microscopic particles to accumulate before reaching consumers.
In addition to the plastic particles, researchers detected BPA and phthalate esters in all four plastic tea bag infusions analyzed.
BPA is an industrial chemical used in the production of certain plastics and resins. Phthalates are a group of chemicals commonly used to modify the flexibility and other physical properties of plastic products.
Both chemical groups have attracted attention from public health researchers because certain compounds can interfere with hormonal activity.
The Oct. 27 report by Medical Xpress noted that the researchers also modeled potential health risks associated with consuming the detected contaminants.
Their assessment found that estimated BPA intake from the plastic tea bag samples represented between 4.55% and 21.7% of the European Food Safety Authority’s tolerable daily intake benchmark.
The authors expressed concern that tea consumption could contribute to total daily BPA exposure when combined with other potential sources, including food packaging and household products.
“Our study found that BPA intake could reach 21.7% of the EFSA TDI value, a finding that serves as a critical warning, particularly for vulnerable groups such as pregnant women and children,” the researchers wrote.
The study’s modeled cumulative hazard index remained below the threshold used in its assessment, suggesting that the estimated exposures did not exceed that particular risk benchmark.
However, the authors emphasized that their findings did not account for every possible source of chemical exposure or the potential effects of long-term consumption.
The study did not directly examine health outcomes in people who drink tea from plastic bags, and the detection of microplastics or chemical compounds does not establish that consuming the tested beverages causes disease.
The findings nevertheless contribute to growing scientific interest in how plastic food-contact materials behave when exposed to heat.
Previous research has also identified substantial microplastic release from certain tea bags.
A 2019 study published in Environmental Science & Technology reported that steeping a single plastic tea bag at approximately 95 degrees Celsius could release billions of microscopic plastic particles, including nanoplastics.
Particle estimates vary considerably between studies because researchers use different measurement techniques, examine different materials and count different particle sizes.
A separate 2026 investigation published in Environmental Science: Processes & Impacts also identified extensive particle shedding from nylon tea bags exposed to hot water.
That research found that brewing conditions, including temperature and steeping duration, could affect the release of plastic particles.
The newly published Pehlivan and Gedik study used a standardized brewing temperature and duration, so it did not independently establish how changing steeping times or temperatures would affect chemical release across the tested products.
Questions about the potential health consequences of consuming microplastics remain unresolved.
Microplastics have been detected in drinking water, food, soil, air and human biological samples, but scientists are still investigating how different particle sizes, concentrations and chemical compositions may affect health.
Germany’s Federal Institute for Risk Assessment previously examined research involving plastic tea bags and concluded that, based on available evidence, adverse health effects from the reported levels of microplastic exposure were not expected.
In its August 2025 assessment, the institute also questioned the reliability of some earlier particle estimates and emphasized the need for improved scientific measurement methods.
Researchers continue studying whether microplastics can accumulate in human tissues, contribute to inflammation or transport chemical substances into the body.
Regulatory agencies have also examined potential risks associated with BPA and certain phthalates in food-contact materials.
The European Food Safety Authority has adopted a substantially more restrictive assessment of BPA exposure than earlier evaluations, citing concerns about potential immune system effects.
Food-contact regulations differ among countries, and the chemicals permitted in one type of packaging material may be restricted or prohibited in another.
Tea bag manufacturers generally must comply with applicable food-contact safety requirements, although consumers may not always be able to determine which plastics or additives are present in a particular product from its packaging.
Some tea bags are manufactured primarily from paper or cellulose, while others contain plastic mesh, coatings or heat-sealing materials. Products marketed as plant-based or biodegradable may also incorporate polymer components.
The authors of the October study recommended reducing exposure by choosing loose-leaf tea prepared with reusable metal or ceramic infusers rather than plastic tea bags.
They also suggested that manufacturers and regulators examine the release of plastic particles and chemicals from packaging under realistic food preparation conditions.
Further research is needed to determine how different tea bag materials compare, whether alternative packaging substantially reduces exposure and what levels of long-term consumption may present meaningful health risks.
The study did not prompt an immediate product recall or a new regulatory restriction specifically targeting plastic tea bags.
Its findings identify a measurable source of microplastic and chemical exposure during ordinary tea preparation, while leaving open the question of how those exposures may affect human health over time.
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