Microplastics in Tea Bags: Which Tea Bags Are Plastic and What to Buy Instead

MicroPlastics Research DeskEditorial team

February 5, 2026

10 min read

Last reviewed: May 25, 2026 by the MicroPlastics Research Desk. Submit a correction or see our editorial standards.

Quick Answer

Pyramid mesh tea bags are often plastic (nylon or PET). Paper tea bags often contain plastic too , usually a polypropylene heat-seal. A 2019 McGill study found a single plastic pyramid bag at brewing temperature released ~11.6 billion microplastic particles plus 3.1 billion nanoplastic particles per cup. Germany's BfR later challenged the counts as likely overstated, but did not dispute that the bags are plastic and release particles. The fix is simple: loose-leaf tea + stainless infuser, or paper-only bags from brands that disclose (Numi, Pukka, Clipper, Traditional Medicinals).

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A single tea bag steeping in a clear glass cup of amber tea beside loose tea leaves

Most people don't realize they may be steeping plastic in their morning tea. Pyramid mesh bags are often nylon or PET. Even traditional paper bags frequently use a polypropylene sealant or heat-seal fibres. Hot water released billions of microplastic particles per cup from nylon and PET bags in a 2019 McGill study. German regulators later raised methodology concerns, but the polymer composition of those bags hasn't been disputed.

Tea bag materials, what to look for
Bag type	Typical material	Plastic risk	Verdict
Pyramid / silken mesh	Nylon-6 or PET	High, confirmed by 2019 McGill study	Avoid
Traditional paper bag (heat-sealed)	Paper + polypropylene seal	Moderate, seal is plastic; bag mostly paper	Acceptable; certified plastic-free preferred
Stapled paper bag (no seal)	Paper + cotton thread + staple	Low / none	Best paper option
Fold-and-tag (Lipton-style)	Often heat-sealed paper	Moderate	Check brand for “plastic-free” claim
PLA bioplastic mesh	Plant-derived bioplastic	Still polymer, releases particles	Better than nylon; not plastic-free
Loose leaf + infuser	Tea + stainless / glass infuser	None	Best option

Key Takeaways

Pyramid / mesh tea bags are usually nylon or PET, both shed at brewing temperature.
Most traditional paper bags use a polypropylene heat-seal, even if the bag itself is paper.
The 2019 McGill study found billions of particles per cup from nylon/PET pyramid bags.
Germany's BfR critique focused on method limitations, not the fact that the bags are plastic.
Loose leaf + stainless infuser is the cleanest brewing setup, and usually cheaper per cup.
Brands that explicitly market “plastic-free tea bags”: Numi, Pukka, Clipper, Traditional Medicinals, Yogi (most lines), Tetley (UK plastic-free since 2021).

Why tea bags are a microplastic source

Three real mechanisms:

Polymer mesh. Pyramid and silken bags use nylon-6 or polyethylene terephthalate (PET). Both polymers hydrolyze and shed at 95°C brewing temperature.
Heat-seal on paper bags. Even traditional paper bags need to be sealed, and the most common method is a thin polypropylene melt seal. The paper portion isn't the issue; the seal is.
Plastic outer packaging. Individual foil-wrap sachets are usually plastic-lined; the box overwrap is often PET film.

Stat card: a single plastic tea bag can shed billions of micro and nanoplastic particles at brewing temperature. Source: McGill University, 2019.

What the 2019 McGill study found, and what the BfR said

Hernandez et al. (Environmental Science & Technology, 2019) emptied four pyramid-mesh tea bags, washed them, then steeped the empty bags in 95°C water. They counted released particles using electron microscopy. The result: ~11.6 billion microplastic particles and ~3.1 billion nanoplastic particles per cup.

Germany's Federal Institute for Risk Assessment (BfR) later critiqued the methodology, arguing that the particle counting approach likely overestimated the true particle release. The BfR did not dispute that pyramid mesh bags are made of plastic, that they release particles, or that switching to loose-leaf tea reduces this exposure.

The honest takeaway: the precise number is contested. The existence of the exposure is not. If you brew nylon or PET tea bags daily, you are ingesting plastic particles. The amount is somewhere on a spectrum, and the spectrum starts above zero.

Brand-by-brand cheat sheet

Common tea brands, packaging at a glance (verify current product)
Brand	Bag material	Verdict
Numi	Plant-based, unbleached, no plastic	Plastic-free
Pukka	Plant-fibre stitched bag, no plastic	Plastic-free
Clipper	Unbleached paper, plant-based seal	Plastic-free
Traditional Medicinals	Paper with no plastic sealant	Plastic-free
Yogi (most lines)	Unbleached paper with starch seal	Plastic-free
Tetley (UK)	Plastic-free since 2021	Plastic-free in UK
Lipton Pyramid	Polyethylene terephthalate (PET) mesh	Plastic, avoid
PG Tips (older)	Polypropylene seal (now claiming biodegradable)	Verify current packaging
Twinings (string & tag)	Heat-sealed paper (contains polypropylene	Mixed) verify line
Bigelow	Heat-sealed paper (typically polypropylene	Mixed) verify line
Tazo (mesh)	Nylon mesh	Plastic, avoid
TWG / Mariage Frères (pyramid)	Cotton, no plastic in many lines	Verify line, best premium options

What to buy instead

Loose-leaf tea + stainless infuser. The cleanest setup. OXO Brewing Basket (~$15), FORLIFE infuser (~$10), or a basic stainless tea ball ($5). Tea is usually fresher and cheaper per cup too.
Paper-only certified tea bags. Numi, Pukka, Clipper, Traditional Medicinals, Yogi, Tetley (UK) all explicitly market plastic-free bags.
Stapled paper bag (no heat-seal). Traditional stapled bags (some Salada and older Lipton lines) avoid the plastic seal issue, though they use a metal staple.
Brew in a glass or ceramic teapot, not a plastic kettle. The boiling step matters less than the steeping vessel; both add up.

Why “plant-based” bags are not the fix

Several brands have moved from nylon to PLA(polylactic acid), a polymer made from corn starch or sugarcane, and market the result as plant-based, biodegradable or compostable. Those claims are all about end of life — specifically that the bag will break down in an industrial composting facility. They say nothing about what the bag does in your mug.

PLA is still a plastic in the sense that matters here: a synthetic polymer mesh sitting in near-boiling water, shedding particles under exactly the conditions that drive release. A compostable pyramid is a real environmental improvement and a marginal personal-exposure one. If you are reading this for exposure reasons, PLA is a step down from nylon rather than a solution.

What about plastic kettles?

Many electric kettles have plastic interiors, heating element housing, water line, lid mechanism. Hot water in contact with PP / PA / silicone parts can release particles. Glass or fully stainless kettles eliminate this exposure. See our microplastics in electric kettles guide.

What the MicroPlastics app checks

Tea bag material when declared, paper-only, polypropylene seal, nylon mesh, PET mesh, PLA mesh.
Brand and product line, “plastic-free” claims and certifications.
Packaging, outer wrap, sachet liner, box materials.
Brewing context you log, boiling water vs cooler brew vs cold brew.
Linked published studies for each scan, including the McGill 2019 and BfR responses.

Use the App

Scan your tea before you brew it

Snap a photo of the box. The app pulls brand + bag type and gives a 0–100 risk score, plus loose-leaf or paper-only alternatives if your current brand contains plastic.

Scan tea packaging

Frequently Asked Questions

Are tea bags made of plastic?

Many are. Pyramid mesh tea bags are commonly nylon or PET. Most traditional paper tea bags use a polypropylene heat-seal even though the bag itself is paper. Stapled paper bags and explicitly "plastic-free" certified bags (Numi, Pukka, Clipper, Traditional Medicinals, Yogi, Tetley UK) avoid both.

How many microplastics are in a tea bag?

A 2019 McGill study (Hernandez et al., Environmental Science & Technology) found that a single nylon or PET pyramid tea bag released approximately 11.6 billion microplastic particles and 3.1 billion nanoplastic particles per cup at brewing temperature. Germany's BfR later challenged those counts as likely overstated, but did not dispute that the bags are plastic and release particles.

Which tea brands are plastic-free?

Numi, Pukka, Clipper, Traditional Medicinals, Yogi (most lines), and Tetley UK all explicitly market plastic-free tea bags. Many premium loose-leaf brands (Harney & Sons, Adagio, Vahdam) sell loose tea that requires no bag at all.

Is it safer to use loose-leaf tea?

Yes. A stainless or glass infuser with loose leaves is the cleanest brewing setup, no polymer in contact with hot water. It's also typically cheaper per cup and produces fresher tea. The startup cost is one infuser ($10–15).

Are PLA / bioplastic tea bags safer than nylon?

Somewhat. PLA (polylactic acid) is derived from plant sugars and is generally less harmful than nylon or PET, but it's still a polymer that releases particles at brewing temperature. "Compostable" doesn't mean it doesn't shed in your cup. Paper-only or loose-leaf remains the cleanest option.

What about traditional Lipton or Bigelow paper bags?

Most heat-sealed paper bags from major brands contain a polypropylene seal. Verify the current packaging, many brands have switched to plastic-free seals in some markets and not others. If the box doesn't explicitly say "plastic-free," assume the seal is plastic.

Does steeping at lower temperature reduce particle release?

Yes, somewhat. Particle release scales with temperature, green tea at ~80°C and cold brew at room temperature release fewer particles than black tea brewed at 95°C+. Cold brew of loose-leaf tea is the lowest-particle method.

Should I throw out the tea bags I already bought?

Drink what you have, but use the box as a transition. Switch to loose-leaf with an infuser, or to a verified plastic-free brand on your next purchase. The biggest gain is changing the daily habit, not discarding inventory.

Sources

Hernandez LM, Xu EG, Larsson HCE, et al. (2019). Plastic Teabags Release Billions of Microparticles and Nanoparticles into Tea. Environmental Science & Technology.
Bundesinstitut für Risikobewertung (BfR) (2019). Releases from teabags: Scientific evaluation of the Hernandez et al. study. BfR.
Khan A, Jia Z (2023). Recent insights into uptake, toxicity, and molecular targets of microplastics and nanoplastics relevant to human health impacts. iScience.
WHO (2022). Dietary and inhalation exposure to nano- and microplastic particles. World Health Organization.
European Food Safety Authority (2016). Presence of microplastics and nanoplastics in food, with particular focus on seafood. EFSA Journal.

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