Pesticides, natural plant toxins, microplastics and PFAS – what does the research say?
A cup of tea is often associated with calm, warmth, and something natural. For many, it's a regular part of daily life and a symbol of well-being.
Yet, tea has already embarked on a long journey before it reaches your cup. Climate, soil, cultivation methods, harvesting, processing, packaging, and transportation can all affect the final product.
In recent years, research has been examining which substances may be present in tea or in the materials that come into contact with it. Simultaneously, the Norwegian Food Safety Authority has published guidance for importers on relevant chemical hazards when importing tea.
The aim is not to create concern.
The goal is to understand how tea is produced, what quality requirements apply, and how consumers can make informed choices.
Brief summary
- Pesticides are one of the most important chemical issues highlighted by the Norwegian Food Safety Authority when importing tea.
- Natural plant toxins (pyrrolizidine alkaloids) can occur in certain herbal teas if weeds are harvested along with the tea plants.
- Some plastic-based tea bags can release micro- and nanoplastics during brewing, but the health implications are still being investigated.
- PFAS are primarily an issue related to packaging and food contact materials – not to tea in general.
How is tea grown?
Tea is primarily grown in China, India, Japan, Sri Lanka, Kenya, and several other countries with warm and humid climates.
Like other agricultural crops, tea plants can be attacked by fungi, insects, and plant diseases. Many producers therefore use pesticides, while others cultivate tea organically or use biological pest control methods.
Usage varies significantly between countries, producers, and certification schemes. Therefore, it is difficult to refer to "tea" as a single, uniform category.
Two products can both be green tea, yet be grown under completely different conditions and with different production methods.
For consumers, origin, quality, and traceability have therefore become increasingly important when choosing tea.
Pesticides – a central chemical issue
According to the Norwegian Food Safety Authority's guide on tea imports, pesticide residues are one of the chemical hazards importers should be aware of.
Several scientific publications have documented pesticide residues in commercial tea products. In most studies, levels are within current limits, but the content can vary between products, countries of origin, and cultivation methods.
How much is actually transferred to the finished tea depends, among other things, on the chemical properties of the substances, water temperature, brewing time, and the type of tea being brewed.
The collective research therefore paints a more nuanced picture than what often emerges in public debate.
For most tea drinkers, this is not a question of stopping drinking tea, but of understanding how the raw material is produced and what quality requirements apply throughout the entire value chain. 
(Various pests that can attack agricultural plants.)
Natural plant toxins – a lesser-known challenge
Not all substances that may occur in tea are due to pesticides or industrial pollution.
One example is pyrrolizidine alkaloids (PA) – natural plant toxins produced by certain weed species. If such plants are harvested along with the tea, these substances can end up particularly in herbal teas and herbal blends.
The Norwegian Food Safety Authority therefore refers to pyrrolizidine alkaloids as a known chemical hazard when importing tea and herbs. Within the EU and EEA, there are maximum limits for such substances, and importers are responsible for ensuring that products comply with regulations.
This shows that not all food safety challenges are caused by man-made substances. Some occur naturally in plants and are part of the quality control work that producers and authorities follow up through analysis and inspection.
Microplastics from certain tea bags
Microplastics have become an increasingly studied topic by researchers in recent years.
Recent research shows that some plastic-based tea bags can release micro- and nanoplastics when brewed in boiling water.
This does not apply to all tea bags. Tea bags are produced from various materials, and information on material composition varies between manufacturers. Several manufacturers have also reduced the use of plastic in tea bags in recent years.
The health significance of such exposure is still under research, and there is currently no basis for drawing firm conclusions about its impact on humans.
In the next section, we will look more closely at PFAS, how you can choose tea consciously, and what the combined research actually says about tea and health.
(Tea bag next to loose tea leaves.)
PFAS – primarily a question of food contact materials
PFAS (per- and polyfluoroalkyl substances) are a large group of synthetic chemicals that have been used in products with water, grease, and dirt-repellent properties. These substances are found in certain textiles, industrial products, and food contact materials, among other things.
When it comes to tea, it is important to distinguish between the raw material itself and the materials that come into contact with the tea.
Surveys by the Norwegian Food Safety Authority show that PFAS can occur in certain paper and cardboard food contact materials, and that small amounts can sometimes migrate to food. At the same time, recent studies show lower levels than before, which indicates a positive development and increased awareness regarding material selection.
The available research does not provide a basis for stating that tea generally contains PFAS. Research primarily focuses on packaging and other materials that come into contact with food and beverages.
This illustrates how modern food research not only investigates the raw material itself but the entire production chain – from cultivation to packaging.
How can you choose tea thoughtfully?
For most people, there is no need to avoid tea.
But if you want to make conscious choices, the following might be helpful to look for:
- tea with a clear origin
- organically certified tea if this is important to you
- loose leaf tea or plastic-free tea bags if you want to reduce contact with certain plastic materials
- producers who are open about quality, traceability, and analyses
Such choices are primarily about quality, transparency, and personal preferences.
No two products are exactly alike, and no single factor alone determines quality. Origin, cultivation methods, processing, and the producer's quality control all play a role.
Conclusion
Tea remains one of the world's most popular beverages and can, for most people, be part of a varied and balanced diet.
At the same time, both research and the Norwegian Food Safety Authority's guidance indicate that production methods, raw material quality, and packaging are relevant topics when assessing food safety.
Knowledge about pesticides, natural plant toxins, microplastics, and PFAS does not mean that tea should be avoided.
It provides a better basis for understanding how tea is produced – and for making informed choices when standing in front of the tea shelf.
The goal is not to create concern.
The goal is to contribute to greater insight into how the food and drink we consume are produced.
An option for those who want local herbal tea
Locally sourced herbal teas produced with a focus on traceability, raw material quality, and transparency can be an option for those who want greater insight into where their tea comes from and how it is produced.
Frequently Asked Questions (FAQ)
Can tea contain pesticides?
Yes. Several scientific publications have detected pesticide residues in some commercial tea products. In many cases, the levels are within current limits, but the content can vary between products, countries of origin, and cultivation methods.
Do all tea bags contain microplastics?
No. The research mainly concerns certain plastic-based tea bags. Tea bags are produced from various materials, and several manufacturers have reduced the use of plastic in recent years.
Are PFAS found in tea?
The available research does not provide a basis for stating that tea generally contains PFAS. Research primarily focuses on packaging and food contact materials that come into contact with food and beverages.
What are pyrrolizidine alkaloids (PA)?
Pyrrolizidine alkaloids are natural plant toxins produced by certain weed species. If such plants are harvested along with the tea, these substances can occur in certain herbal teas, among others. Therefore, there are maximum limits in EU/EEA regulations, and the Norwegian Food Safety Authority refers to them as a relevant chemical hazard when importing tea and herbs.
Is organic tea a better choice?
Organic tea is produced according to stricter rules for the use of synthetic pesticides. Many therefore choose organic tea, but no farming method can guarantee that a product is completely free of all trace substances. For many, the choice is primarily about quality, traceability, and personal preferences.
Sources and further reading
Public sources
- The Norwegian Food Safety Authority – Chemical hazards when importing tea
- The Norwegian Food Safety Authority – PFAS in food contact materials made of cardboard and paper
- The Norwegian Food Safety Authority – PFAS in food, drinking water, and feed
Scientific publications
- National Library of Medicine (PubMed) – Study on pesticide residues in tea and herbal tea
- National Library of Medicine (PubMed) – Review article on micro- and nanoplastics in tea
- National Library of Medicine (PubMed) – Review article on PFAS, environment, and health
This article is based on publicly available information from the Norwegian Food Safety Authority and peer-reviewed scientific publications. It is intended as general information and does not replace advice from health authorities or individual risk assessments of single products.