Tea Bags Leach Thousands of Microplastic Particles and Toxic Chemicals into Brew, Study Finds
Researchers warn that plastic tea bags release significant amounts of microplastics and chemicals like BPA and plasticisers, recommending a switch to loose-leaf tea.
A single tea bag can release up to 2,500 microplastic particles into a hot cup of tea, according to a study by researchers at Recep Tayyip Erdogan University. These particles are larger than 100 micrometres, and the total number could be significantly higher as smaller particles were not captured by the study's methods.
The research also found that plastic tea bags leach toxic chemicals, including Bisphenol A (BPA) and plasticisers such as phthalate esters (PAEs), into the beverage. BPA is an endocrine disruptor that can interfere with normal development and has been linked to a weakened immune system, obesity, diabetes, low sperm count, infertility, and cardiovascular disease. Studies also suggest it may impair brain development, increasing the risk of ADHD and autism spectrum disorder.
The study, published in the journal npj Science of Food, analyzed four popular Turkish bagged tea brands and 14 types of loose-leaf tea. When brewed in 95°C (203°F) water for three minutes, the plastic tea bags released a substantial number of microplastic particles.
In contrast, a two-gram serving of loose-leaf tea contained only 0.3-2.4 particles, with these contaminants likely originating from plastic packaging used during farming or atmospheric dust. This suggests that the microplastics found in tea bags are primarily from the bag material itself, often made of plastic mesh.
One of the most concerning findings was the presence of di(2-ethylhexyl) phthalate (DEHP), a type of PAE plasticiser. Studies in animals have shown that DEHP exposure is linked to an increased rate of cancer over long periods, though its effect on humans is not fully understood. The researchers noted that the concentration of DEHP in the brewed tea, while below official limits, could pose a public health concern with long-term or high-volume consumption.
Drinking just 500ml of tea from plastic bags means consuming 4.55 to 21.7 percent of the safe daily limit for BPA, a level the researchers described as a "critical warning," especially for vulnerable groups like pregnant women and children.
Previous studies have indicated even higher levels of microplastic release. One study from the Universitat Autònoma de Barcelona suggested that some tea bags could release billions of microplastic particles, particularly those made from polypropylene.
Other research has highlighted microplastic contamination throughout the tea-making process. For instance, the initial boil in a new kettle can release approximately 12 million nanoparticles per millilitre, which can equate to nearly three billion particles in an average 250ml cup of tea. Takeaway cups have also been found to release millions of microplastic and nanoplastic particles when exposed to hot liquids.
Given these findings, the study authors recommend consumers reduce their microplastic exposure by opting for loose-leaf tea over plastic-bagged varieties. They also suggest washing tea bags under cold water before brewing as an additional measure to limit contamination.