What toxins are in teabags? An In-Depth Look at Hidden Chemicals

November 4, 2025 •

4 min read

A 2019 study from McGill University found that steeping a single plastic tea bag can release billions of microplastic and nanoplastic particles into a cup of hot water. This discovery has brought the question of what toxins are in teabags? to the forefront of discussions on nutrition and consumer health.

Quick Summary

Many teabags can leach microplastics, harmful chemicals like epichlorohydrin, and residues from bleaching into hot water. Poor-quality tea leaves inside bags may also contain pesticides and heavy metals, posing health risks that consumers should be aware of.

Key Points

Microplastics are a major concern: Studies show that plastic-based teabags can release billions of micro- and nanoplastic particles into hot water during brewing.
Chemicals like epichlorohydrin add wet strength: Some paper teabags are treated with epichlorohydrin, a potential carcinogen, to prevent them from tearing.
Bleaching agents can leave residues: Chlorine-bleached paper teabags can introduce harmful chemicals, including dioxins, into your cup.
Low-quality tea leaves may contain toxins: The 'dust' and fannings often used in teabags are more susceptible to containing pesticide residues and heavy metals absorbed from soil.
Loose-leaf tea is the safest alternative: Switching to high-quality loose-leaf tea with a reusable infuser completely avoids the issue of teabag toxins and often provides a better flavor.
Look for certified plastic-free teabags: For convenience, choose brands that use plant-based, compostable materials like cornstarch-based PLA or abaca fiber, and verify that they are unbleached.

For many, a cup of tea represents a moment of peace and a health-conscious ritual. The warmth and purported health benefits have made it a daily staple for millions globally. However, growing scientific scrutiny reveals that the convenient teabag itself may be a source of unwanted and potentially harmful chemicals, tainting what is meant to be a clean beverage. This article delves into the various toxins that can be found in teabags and offers actionable steps for a safer and more nutritious brew.

The hidden microplastic problem

In recent years, the spotlight has fallen on the issue of microplastics leaching from teabags, particularly those made from synthetic materials. Many teabags, especially premium-looking pyramid or silky sachets, are made from nylon, polyethylene terephthalate (PET), or polypropylene to maintain their shape and durability in hot water. The problem arises when these plastics are exposed to boiling water, as research indicates they can shed billions of micro- and even smaller nanoplastic particles into your tea. The long-term health effects of ingesting microplastics are still under investigation, but studies on human cells show potential for absorption by intestinal cells. Some microplastics are also known to carry toxic chemicals like phthalates, which are suspected endocrine disruptors.

Carcinogens and chemical additives

Beyond plastics, conventional paper teabags are not without their own set of chemical concerns. To prevent the paper from disintegrating in hot water, some manufacturers treat it with epichlorohydrin, a chemical used to add wet strength. This chemical is classified as a potential carcinogen and can hydrolyze into harmful compounds when exposed to high temperatures. Additionally, many paper teabags are bleached to achieve a bright white appearance. This bleaching process, often using chlorine-based agents, can leave behind residues such as dioxins, which are potent and persistent cancer-causing chemicals. While the levels are often low, chronic exposure is a concern for regular tea drinkers.

Pesticide residues and heavy metals

The contamination isn't always from the bag itself. The quality of the tea leaves inside the bags is also a factor. Mass-produced teabags often contain 'tea dust' or fannings, which are the remnants of broken tea leaves. Lower-quality tea may come from farms where synthetic pesticides are standard practice. Unwashed tea leaves carry these pesticide residues, which can then leach into your tea when brewed. Studies have detected various pesticide residues in teabags, even in some organic brands. Another issue is the presence of heavy metals. Tea plants are known to be efficient accumulators of certain elements from the soil, such as aluminum, lead, and cadmium, especially when grown in acidic soil conditions. The leaves of lower-grade teas, often found in teabags, can contain higher concentrations of these toxic heavy metals.

How to choose a safer, healthier cup

The best way to avoid these toxins is to be an informed consumer. Choosing the right products can significantly minimize your exposure to harmful chemicals and microplastics. Making a simple switch can have a big impact on your nutrition diet and overall health.

Practical steps for a cleaner brew

Embrace loose-leaf tea: This is the most effective solution, as it eliminates the need for a teabag altogether. Use a reusable stainless steel mesh infuser or a glass teapot. High-quality loose-leaf tea also tends to have a more complex and satisfying flavor profile.
Opt for plastic-free teabags: If convenience is key, look for brands that explicitly advertise plastic-free, compostable teabags. These are typically made from plant-based materials like cornstarch-based PLA, sugarcane fibers, or abaca fiber.
Choose organic: Selecting certified organic tea reduces the risk of consuming pesticide residues. However, be mindful that some biodegradable teabags may still contain bio-plastics derived from genetically engineered crops, so verify the packaging if this is a concern.
Look for bleached-free options: Search for teabags that are unbleached or processed with oxygen rather than chlorine to avoid potential dioxin contamination.
Be aware of water quality: Since heavy metals are absorbed from soil, the source of the tea leaves matters. Research brands known for sourcing from less contaminated regions. The article mentioned in the citations offers more insight on this: The Benefits and Risks of Consuming Brewed Tea: Beware of Toxic Element Contamination.

Comparison: Loose-leaf tea vs. Conventional teabags


Feature	Loose-Leaf Tea	Conventional Teabags
Material Toxicity	Low to non-existent; no packaging to leach chemicals.	High; potential for microplastics, epichlorohydrin, and bleaching residues.
Environmental Impact	Very low; leaves are compostable. Minimal packaging.	High; non-biodegradable plastics in many bags contribute to waste.
Flavor & Quality	Superior; whole leaves expand fully, releasing complex flavors and aromas.	Inferior; often contains lower-quality fannings and dust, resulting in less nuanced flavor.
Cost	Can be cheaper in the long run as leaves can be steeped multiple times.	Generally cheaper upfront per serving due to mass production.
Convenience	Slightly more involved; requires an infuser or strainer.	Maximum convenience; single-use and mess-free.
Antioxidant Levels	Higher; whole leaves are less processed and retain more antioxidants.	Lower; broken leaves have less surface area for beneficial compounds.

Conclusion

While the ritual of enjoying a cup of tea is deeply ingrained in many cultures and diets, the hidden toxins within conventional teabags present a legitimate health concern. The presence of microplastics, chemical additives, and potential heavy metal contamination warrants a closer look at our daily brew. By making informed choices, such as switching to high-quality loose-leaf tea or seeking out certified plastic-free, unbleached teabags, consumers can continue to enjoy the nutritional benefits of tea without compromising their health. Prioritizing loose-leaf tea with a reusable infuser is the most surefire way to avoid potential contaminants and ensure a truly clean cup. This small shift in routine can make a significant difference in a nutrition diet focused on wellness and avoiding unwanted toxins.

Frequently Asked Questions

Many teabags, especially the pyramid-shaped ones, are made from synthetic materials like nylon, polyethylene terephthalate (PET), or polypropylene. These are used for their durability and heat resistance, but can release microplastics when brewed in hot water.

You can often tell by looking at and feeling the bag. If it has a silky or mesh-like feel and holds its shape perfectly when wet, it likely contains plastic. Paper teabags that contain plastic sealant are harder to identify, but reading the packaging for terms like 'compostable' and 'plastic-free' is the best approach.

Epichlorohydrin is a chemical sometimes used to add wet strength to paper teabags. It is considered a potential carcinogen and can form harmful compounds when it comes into contact with hot water.

Not necessarily. While organic certification covers the tea leaves and ensures they are free from synthetic pesticides, it does not always mean the teabag material itself is free of harmful components. Some biodegradable or organic-branded teabags might still use plant-based bioplastics (PLA) that can release nanoplastics or sealant glues that are not fully compostable.

Tea plants are naturally capable of absorbing heavy metals from the soil, such as lead, aluminum, and cadmium. These can be present in higher concentrations in lower-quality teas often found in teabags, especially if grown in contaminated areas.

Yes, using loose-leaf tea with a reusable infuser made of stainless steel or another non-toxic material is the most reliable way to avoid the plastics and chemicals associated with teabags. It also allows for a fuller flavor experience from the whole leaves.

The use of plastic in teabags contributes to the global plastic pollution problem, as they do not fully biodegrade. Compostable or biodegradable teabags offer a more eco-friendly alternative by breaking down safely over time.