Are Tea Bags Harmful or Safe? The Microplastics Question Answered

Are Tea Bags Harmful? The Short Answer

Are tea bags harmful? No harm has been proven. Most tea bags are paper. Some silky pyramid bags are made of nylon or PET plastic. In one lab test, one plastic tea bag in 95 °C water shed about 11.6 billion tiny plastic bits into a cup (McGill University, 2019). Whether that harms people is not known.

Germany's food safety institute (BfR) found far fewer particles in its own tests, and it says there is no evidence that microplastics harm human health (BfR, 2025). "Safe" and "ideal" are still different things.

The honest answer has a few parts. Not all tea bags contain plastic. Scientists are still studying how microplastics affect health. The amount matters too. If you want no plastic in your tea at all, the fix is simple. Brew loose-leaf tea in a glass or stainless steel infuser.

I run InstaCuppa, and we sell a glass tea infuser bottle. That is my bias. I will be open about it and show the research fairly.

What Are Tea Bags Made Of? Three Types and Their Plastic

Tea bags come in three main types. Silky pyramid bags can be nylon or PET plastic. Paper bags may have a small plastic heat-seal. Plant-based bags use PLA, a plastic made from plants.

Some silky, premium-looking pyramid bags are made of nylon or PET. These are the kind of bags the McGill study tested. A plain paper tea bag can still have plastic in its seal, but much less. A 2025 review found that paper-plastic and biodegradable bags also release particles when steeped (Fard et al., 2025).

More brands now sell plant-based bags. Tea maker Clipper says it moved its heat-seal bags from polypropylene to plant-based PLA in 2018. Clipper also says PLA is a "bio-plastic", so it now calls the bags "plant-based" rather than "plastic-free" (Clipper Teas FAQ). Check the pack for the bag material.

What Did the Research Actually Find?

The best-known study came from McGill University in Canada in 2019. Researchers steeped empty plastic tea bags (nylon and PET) in water at 95 °C. Then they counted the particles that came off. The result was about 11.6 billion microplastics and 3.1 billion nanoplastics per cup (Hernandez et al., 2019).

Important context that often gets lost in headlines:

• The bags were cut open, the tea was taken out and the bags were rinsed before the test. So a normal cup with leaves inside was not tested.
• Germany's BfR ran its own tests. It found 5,800 to 20,400 microplastic particles larger than 1 micrometre per tea bag. That is 100 to 1,000 times fewer than McGill reported for particles of that size.
• The BfR says most of what McGill counted were probably not plastic bits. They were short-chain by-products of the plastic that formed when the samples were dried.
• The study tested nylon and PET bags only, not paper bags with polypropylene seals. Other labs, using other methods, have counted from a few hundred particles per bag to billions (Kashfi et al., 2023; Fard et al., 2025).

A separate 2011 lab study tested 455 plastic food products. Most of them leached chemicals with estrogen-like activity, including some sold as BPA-free (Yang et al., 2011). Tea bags were not part of that test. The paper also discloses that several authors worked for or owned shares in plastic-testing companies.

Are Microplastics in Tea a Health Risk?

Here, honesty means admitting what we do not know. Scientists have not settled this question yet.

As of 2026, no study has shown that microplastics from tea bags cause any disease in people. In 2019, the World Health Organization reviewed microplastics in drinking water. Dr Maria Neira of WHO said: "Based on the limited information we have, microplastics in drinking water don't appear to pose a health risk at current levels. But we need to find out more." (WHO, 2019). In 2025, the BfR said there is no evidence that microplastics harm human health.

What we do know:

• Microplastics have been found in human blood, lung tissue and the placenta (Leslie et al., 2022; Jenner et al., 2022; Ragusa et al., 2021). Finding them does not prove they cause harm.
• In a lab dish, tiny particles from tea bags were taken up by human gut cells (Banaei et al., 2024). A dish is not a human body, so what this means for people is not known.
• Chemicals with estrogen-like activity are reported to cause health effects in animals, mostly at low doses in young animals (Yang et al., 2011).
• Exposure adds up. If you drink three or four cups of tea a day for years, it is fair to want less plastic in each cup.

No proof of harm is not the same as proof of safety. If you drink tea many times a day, cutting plastic contact is a sensible step, even without firm evidence.

Are Green Tea Bags Safe?

Yes. Green tea bags are as safe as any other tea bag. The tea inside is the same green tea you would brew loose. The US National Center for Complementary and Integrative Health says: "No safety concerns have been reported for green tea consumed as a beverage by adults." (NCCIH). The only open question is the bag, not the tea.

So check what the green tea bag is made of. A paper or plant-based bag has little or no oil-based plastic. A silky pyramid bag may be nylon or PET. NCCIH also notes that green tea contains caffeine, so drink it in sensible amounts.

Green tea is usually brewed with water below boiling. The guide for our gooseneck kettle suggests 80 °C for green tea. For times and temperatures, see how to brew green tea perfectly.

What Can You Do About It?

You have a few simple options. Here they are, from easiest to most effective.

1. Choose paper or plant-based tea bags. Clipper, for example, now seals its bags with plant-based PLA instead of polypropylene. Check the pack for the bag material.
2. Avoid silky nylon or PET pyramid bags. These gave the highest particle counts in lab tests. Stick to paper bags if you use bags.
3. Do not boil the tea bag. The highest counts came from bags steeped in very hot water (95 °C). Whether cooler water lowers the count has not been well tested. But letting the water cool a little is easy, and green tea is usually brewed below boiling anyway.
4. Switch to loose-leaf tea. This is the most effective step. Loose-leaf tea brewed in a glass or stainless steel infuser has no bag at all. You also choose how strong your tea is.

Is Loose-Leaf Tea Better Than Tea Bags?

For avoiding plastic, yes. Loose-leaf tea has no bag, so there is no bag plastic in your cup. It has a few other plus points too, and some claims about it are not proven.

• Flavour. Many tea bags hold small, broken bits of leaf called fannings and dust. Loose-leaf tea keeps larger leaf pieces, which many tea drinkers prefer.
• Antioxidants. Some say loose leaf keeps more antioxidants than bagged tea. We could not find a reliable figure for this, so treat it as unproven.
• Cost per cup. Loose-leaf tea can cost less per cup than premium tea bags. Prices vary a lot by brand, so compare the price per gram.
• Less waste. No staples, tags, strings or bag. Used tea leaves can go into compost.
• You control the strength. You choose the amount of leaf, the water temperature and the steep time. With a tea bag, the brand decides for you.

The main problem with loose-leaf tea has always been ease of use. You need a strainer and a pot, and it is hard to take on the go. A portable glass infuser bottle solves this. Add leaves, pour water, steep, lift out the infuser and carry your tea. It is about as easy as a tea bag, with no bag in the cup. For more, read loose-leaf tea vs tea bags in India.

The InstaCuppa Glass Tea Infuser Bottle is made of double-wall borosilicate glass with a removable stainless steel infuser. You lift the infuser out when the tea is ready, so the tea does not turn bitter. For a step-by-step guide: How to Brew Loose-Leaf Tea On the Go.

Which Kettle Helps You Brew Loose-Leaf Tea?

A kettle with temperature control helps most. Water temperature changes how tea tastes, and each tea has its own best heat. The InstaCuppa Electric Gooseneck Kettle holds 1 litre and lets you set the temperature from 40 to 100 °C, so you can pick the right heat for each tea. Check availability.