Teabags Might Leak Plastic Into Your Cup

Microplastics are tiny plastic pieces between 1 micrometer and 5 millimeters. Even smaller ones are called nanoplastics, and both are now found in many foods and drinks.

“Tea is an interesting and complex case because plastic can enter at many points, from farm to cup,” says lead author Neamatollah Jaafarzadeh Haghighi Fard. The review looked at loose-leaf tea, hot tea made with bags, bottled cold tea and bubble tea.

The review found several possible sources of plastic in tea. Some come from the environment, and some come from the way tea is processed and packed.

• Production water: Water used to wash or process tea leaves can already contain microplastics.

• Tea leaves themselves: Leaves can pick up plastic from soil, air and dust during growing and drying.

• Packaging: Plastic bottles, inner linings of cartons and take-out cups can all shed particles.

• Teabags: Many modern bags use plastic fibers, mesh or glue that touch boiling water directly.

Across all these, teabags stood out as the biggest single source of microplastics in hot tea. “Teabags steeped in boiling water can generate concentrations higher than most other foods and drinks that have been tested,” says co-author Andrew Turner.

Not every study used the same methods, so the numbers vary a lot. Still, the pattern is clear: plastic-heavy bags can release huge amounts of particles when you pour on near-boiling water.

By comparison, bottled cold teas in plastic bottles usually contained around 1 to about 7 microplastic pieces per liter. Bubble tea samples ranged from fewer than 10 to a few hundred particles per liter, often as fibers or small fragments from cups, lids or straws.

Loose-leaf tea did contain microplastics, but in much lower amounts than plastic teabags. One Chinese study found around 220,000 to 330,000 particles per kilogram of dry leaves, which means only a tiny fraction ends up in a single brewed cup.

You might think “biodegradable” or paper-like bags are a safe bet. The review shows it is not that simple.

Some bags sold as compostable or cellulose-based still contained up to about 35% plastic such as polyethylene, polypropylene or PET when scientists tested them. “Labels like ‘biodegradable’ do not always mean plastic-free,” says Fard.

Other work on polylactic acid (PLA) biodegradable bags found millions of nanoplastic particles released per bag in hot water. Composite bags that mix paper fibers with plastic glue or threads can also shed plastic, especially at the heat used for brewing.

Traditional paper-style bags without plastic mesh or visible plastic often performed better, but some still had plastic sealing fibers. This means the safest choice is a bag that is clearly labeled plastic-free and has been tested by independent groups, which can be hard to confirm.

Right now, scientists do not know exactly what these levels of microplastics in tea mean for your health. No human studies have tested long-term tea drinking and microplastic exposure directly.

Lab and animal studies on microplastics in general suggest possible problems, like inflammation, stress on cells and effects on gut bacteria. But the doses and types of plastic in those tests often do not match what you would get from a cup of tea.

Some studies also found that plastic additives and leftover chemicals can leach out when teabags are steeped. It is not always clear whether these come from the bag surface or from the tiny plastic particles themselves.

“The potential risks for people and the environment are a concern, but the evidence is still incomplete,” says Turner. That means there is no need to panic or quit tea, but it makes sense to lower avoidable exposure where you can.

You do not have to give up your daily mug to reduce microplastics. Small switches in how you brew and buy tea can make a real difference.

• Choose loose-leaf tea: Brew in a stainless-steel or glass infuser instead of a plastic mesh ball or plastic-lined pod.

• Skip plastic mesh pyramid bags: These are often nylon or PET and have released some of the highest particle counts in tests.

• Look for clearly plastic-free bags: Some brands now advertise unbleached paper bags without plastic sealing fibers.

• Limit very hot contact with plastic: Avoid boiling water in plastic kettles and try not to steep tea in plastic travel mugs.

• Cut back on bottled tea: When you can, brew at home and carry it in stainless steel or glass instead of buying plastic bottles.

• Ask for paper or metal straws when available.

• Choose shops that use paper cups or certified compostable cups with less plastic.

• Limit how often you drink large, plastic-heavy take-out drinks.

Microplastics and nanoplastics are now showing up in many foods and drinks, and tea is no exception. Plastic-rich teabags, especially nylon or PET mesh and some “biodegradable” designs, can release very high numbers of particles into a single cup.

Health risks are not fully known yet, but experts agree that lowering avoidable plastic exposure is a smart move. By choosing loose-leaf tea, plastic-free bags and fewer very hot drinks in plastic containers, you can keep enjoying your tea ritual while cutting down on microplastics in your cup.