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From PFAS to Microplastics, What Might Be Leaking Out of Your Teabag?

A mug of tea.
Credit: Toa Heftiba/Unsplash
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Read time: 3 minutes

What’s inside your teabag? Tea leaves, obviously. But is there anything else? Anything smaller that may be leaking out into your mug? Quite possibly.

Depending on the brand, your favorite cup of tea could be contaminated with billions of microplastics and/or traces of per-and polyfluoroalkyl substances (PFAS).

What damage are these compounds wreaking? The research is still in its infancy, but here’s what we know so far.

Microplastics and tea

Although teabags are typically made from paper, some companies have opted to use nylon and polyethylene terephthalate (PET), both of which can degrade in contact with hot water.

One paper published in 2019 found that, when brewed with boiling water, a single plastic teabag can release approximately 11.6 billion microplastics and 3.1 billion nano-plastics into a single cup of tea.

The researchers concluded that the levels of nylon and PET particles released from the teabag packaging were “several orders of magnitude higher” than plastic loads previously reported in other foods.

Another study published in 2021 found that this kind of particle release is further amplified by microwaving the mug of tea.

Many brands have recently scrapped these types of plastic bags in response to this research and the larger consumerism trend away from plastics. Some of the new paper bags, however, reportedly still contain plastic fibers in their sealant.

So, how unhealthy is it to ingest millions of microplastics? Science doesn’t know yet. Microplastics research is an expanding field and while some plastics are known to be toxic to humans and linked to lung irritation, headaches, asthma and even cancers, it’s yet to be determined if the average level of microplastics in a typical person is past the threshold for such harm. 

What is known is that tea is far from the sole dietary source of minuscule plastics. Seafood, fruit, vegetables and drinking water have all been linked to microplastic contamination. Even the air you’re breathing now may be contaminated with tiny polymers that have shed from some nearby plastic product.

PFAS and tea

Microplastics have had their fair share of bad press at this point, so many tea drinkers will try (as challenging as that is) to avoid them if they can. PFAS, on the other hand, are less well-known. Many tea drinkers will be unaware they risk slurping them down. So, what are PFAS?

PFAS are a group of surfactants used to waterproof consumer products like pans, paints and packaging – including teabags. They’re known as the “forever chemicals” because they have an almost-unbreakable highly-fluorinated alkyl chain backbone that makes them extremely chemically stable and difficult to degrade naturally.

This robustness is all the more troubling considering the recent wave of research linking the chemicals to some cancer types and low birth weights.

How much of a health risk does PFAS in teabags carry? It’s hard to say; only a few studies have been conducted so far.

One recent paper revealed that young people who drank more tea were more likely to have high PFAS levels in their blood than those who drank more sugary drinks. The researchers didn’t test the teabags to ascertain whether the PFAS was indeed leeching from the bags, but that was their suspicion. 

“In our study, the findings showed that PFAS levels were higher in people who reported drinking more tea,” Hailey Hampson, a PhD candidate at the University of Southern California, told Technology Networks. “Because of this, our study does not tell us which component of tea may be contaminated with PFAS.”

“PFAS in tea could potentially come from one or more sources, but more research is needed to determine which part of tea may be a source of PFAS.”

“With this in mind, we can still hypothesize about how PFAS may contaminate teas, based on previous scientific studies,” Hampson continued. “Our primary hypothesis is currently based on a study published last year, which found that some tea bags have PFAS in them. This study, which was conducted in India, tested 108 tea bag samples that were collected from the Indian market and found that 90% of them contained detectable concentrations of PFAS.”

“Independent of the findings from our study, this study shows that tea bags can be a source of PFAS contamination. However, we need more research on commercially available tea bags in the USA to determine the degree to which PFAS contamination in tea bags is an issue in the USA. Based on our findings and the findings from other researchers, we are currently performing a study to test for PFAS contamination in tea bags from the US market.”

What to drink?

Microplastics and PFAS are impossible to avoid in the modern world; both contaminants have been found as far afield as the Arctic.

But for those regular tea drinkers concerned about their daily dose of the forever chemicals, the best option would appear to be ditching the bag all together and straining your tea the old fashioned way.