How Clean is Your Tea?

How Clean is Your Tea?

Author: Millennia TEA’s Official Science Steeper - Allison Tannis, MSc RHN


7 Facts about Tea That’ll Make You Wonder How Dirty is Your Tea?

Eating clean is a hot trend that’s reaching a boiling point and has many of you steeping away, wondering, how clean is your tea? From which teas are really dirty to teas one would include in a clean eating lifestyle, here are 7 facts about tea that’ll make you wonder how dirty is your tea. You bet that if you enjoy a good cuppa every now and then, this blog is definitely going to be your cup of tea.


7 Facts About Tea: Dirty Drink or Clean Eating Approved?

  • Bagged tea contains plastic
  • Tea plants are commonly sprayed with pesticides
  • Most teas are not washed
  • Some tea plants can be grown organically
  • Some teas include added “natural flavours”
  • Additives are added to improve the shelf life of dried teas
  • Broken tea leaves are often used

What’s in Your Cup of Tea?

Cradled between your hands, that steeping hot mug of tea you brewed using your favourite dried tea bag contains some well-known healthy compounds, such as flavonoids, but it may also contain harmful compounds, like microplastics, pesticides, and chemicals. STEEPING in the upcoming science on tea bags, tea farming, and results from laboratory analysis of brewed cups of tea using dried tea bags, may LEAF you wondering, how clean is your tea? Yet, this tale is good to the last drop: tea can be part of clean eating. Here’s how…


Does My Tea Bag Contain Plastic?

Yes, many tea bags are made with plastics. The plastics in tea bags may shed billions of microplastics per cup, according to a study from McGill University in Montreal. In hot water, the tea bags released microplastics and even smaller nanoplastic particles at a shocking amount: billions per cup of tea. One cup of tea brewed using a single tea bag contained 11.6 billion microplastic and 3.1 billion nanoplastic particles. Microplastics are pieces of plastic that are smaller than a sesame seed that forms when plastic degrades. The tea bags contained PET (polyethylene terephthalate) and nylon. In the study, the researchers noted gourmet, pyramid-shaped tea bags, called silken bags, from a variety of different brands contain plastics. Other tea bags may also contain plastics, or other chemicals used to create a bag that won’t degrade in hot water.  If you’re going to choose to brew your tea in a teabag, look for plastic-free bags. Better yet, brew your tea leaves right in the cup – a TEArrific part of a clean eating lifestyle.


Should I Rinse My Tea?

Yes, you want to drink washed tea! Camellia sinensis plants, where all tea leaves come from, are commonly sprayed with pesticides to preserve the plants from destruction from bugs. (But, it’s not convenient to rinse your dried tea in that teabag your holding.) Let’s say you did rinse your dried tea leaves. Researchers did a laboratory study on this and found the most you could eliminate was 24% of the 8 common insecticides sprayed on Camellia sinensis plants if you rinsed your dried tea leaves for up to 30 seconds. Of note, rinsing dried tea leaves before brewing causes the loss of up to 11% of the valuable antioxidant, epigallocatechin gallate (EGCG). There’s a better way to brew! You can buy tea leaves that have been washed.


Millennia Tea is fresh tea leaves that are washed before they are flash-frozen to preserve their nutritious value.

Are Pesticides in Tea Harmful?

Tea leaves used to create the common dried tea bag contain pesticides. According to a 2014 Canadian Broadcasting Corporation (CBC) Marketplace report, some teas on the Canadian market contained pesticide levels that exceed the allowable limits. In a study published in the Journal of Agricultural Food Chemistry, laboratory examination found the pesticides on dried tea leaves do make their way into brewed tea, therefore poses a risk to consumers. Pesticides found in dried tea bags in the Canadian market analysis included bifenthrin, imidacloprid, acetamiprid, chlorfenapyr, pyridaben, acephate, dicofol, and monocrotophos. With tea being the world’s most popular beverage and Canadian adults consuming 83 liters per person each year, it’s important to consider the potential harm of pesticides in your teacup.


Do Organic Teas have Pesticides?

Yes, most organic teas contain pesticides. These same tea leaves are left un-washed before they are dried and processed to create the traditional dried tea you find on your local store shelf.


Benefit of Washed Tea Leaves

Washing tea leaves helps remove any unwanted pesticide residues on tea leaves. In a 2020 study, washing the fresh tea leaves with water reduced the presence of pesticides by 45-72%.

Millennia Tea Leaves are washed twice to remove any environmental residues.

Are Heavy Metals in Tea?

A study published in the Journal of Toxicology, found high levels of lead in over 70% of traditional teas tested, and 20% had aluminium and other metals. Traditional teas in this study included off-the-shelf dried black, green, white, and oolong teas sold in tea bags. Lead levels were detectable in the teas studied, with the highest amounts observed in Chinese oolong tea. (Coal plants in China have increased the presence of lead and mercury in the area, one of the largest producers of Camellia sinensis leaves). Of note, mercury was not found in the brewed tea in the study. The toxic elements tested only aluminum and lead had levels that were unacceptable. Factors to consider when trying to brew a cup of tea that is worthy of a clean eating lifestyle include the water you brew with (distilled water contains fewer heavy metals than tap water), and the vessel you steep in (some older china cups can leach lead into hot water). Also, look at where your tea was grown.


Millennia Tea is grown in Sri Lanka, by a ‘Fairest Fair Trader Award’ Winner.


What are natural flavours in teas?

If you haven’t noticed the term natural flavours on the list of ingredients on your traditional tea bag packaging, you may after reading this. It’s misleading – a study by Consumer Reports found people prefer to buy food labelled natural. But, is it natural? Health Canada allows the use of the term natural flavours without requiring transparency as to what exactly that means. According to the Code of Federal Regulations in the United States, ‘natural flavours’ could be extracts derived from botanical sources, such as fruits or spices, or an essence, essential oil, protein hydrolysate, edible yeast, fermentation product, meat, seafood, or a whole variety of other things. Some teas include artificial flavours.


Are There Additives in Tea?

Additives may be added to improve the shelf life of dried teas. Citric acid, a naturally-occurring acid found in citric fruits, can be found as an additive in traditional dried teabags. Of note, some teas include other additives, such as colour and sweeteners.


The Quality of the Leaf

Since all tea comes from the Camellia sinensis plant, how the leaves are picked can have a big impact on the quality of your cup of tea. Traditional dried teas are picked farther down the stem of the plant, resulting in more stem than leaf in the final tea product. Selectively picking the higher quality bud and top two tender leaves of the plant, Millennia Tea Leaves contain a higher catechin content.



How dirty is your tea? It might be time to start brewing a cleaner cuppa tea.






Pesticide residue transfer rates (percent) from dried tea leaves to brewed tea. Journal of Agricultural and Food Chemistry 2013, Dec; 62(4).


Rinsing tea before brewing decreases pesticide residues in tea infusion. Journal of Agricultural Food Chemistry 2019 May 15;67(19):5384-5393.


The benefits and risks of consuming brewed tea: beware of toxic element contamination. Journal of Toxicology 2013 Oct (1): 370460.


Washing fresh tea leaves before picking decreases pesticide residues in tea. Journal of the Science of Food and Agriculture 2020 May; 100(13):4921-4929.