Fluoride exposure from tap water and tea brands like Tetley – An Explanation

Various water-based beverages, such as tea, are popular globally. However, we notice a lot of misleading information being spread on social media regarding these.

Social Media Posts 

A viral social media post raises alarm over fluoride exposure from tap water and tea, calling it a “poison” and suggesting it poses serious health risks, particularly for children, fetuses, and vulnerable adults. The post claims that tea, especially decaffeinated brands like Tetley, contains high levels of fluoride and implies that consumers are unknowingly ingesting harmful doses. It further questions the safety and regulation of fluoridated water provided by public utilities. The UK Teesside University`s  Fluoride database is used in social media posts as an evidence of fluoride in tea.

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We decided to do a fact check on this. 

Fact Check 

This fact-check will explore the scientific accuracy and context behind the following claims:

Claim 1. Is there a known safe or recommended daily dose of fluoride for fetuses, infants, children, and adults—including those with health conditions?

Health agencies set recommended and upper fluoride limits by age. For example, The European Food Safety Authority (EFSA) defines an adequate intake  of 0.05 mg/kg body weight/day (≈3.5 mg/day for a 70-kg adult) for all ages, including pregnancy and lactation .More details can be read here.  The National Institute of Health in USA also mentioned recommended amounts of Flouride for various age groups in their web.The web fact sheet can be referred here.

Claim 2. Is fluoride in tea, particularly decaffeinated tea (like Tetley), present at levels as high as 4–8 mg/litre or 1–2 mg per cup?

Tea plants naturally absorb fluoride from the soil, and studies show that brewed tea can contain anywhere from 0.3 mg/L to over 8 mg/L depending on the brand, type, and steeping time.

For example, a 2022 study by Krishnankutty et al. found fluoride levels in tea bags ranging from ~0.3 to 2.7 mg/L, while loose-leaf black teas reached ~0.7 to 4.5 mg/L. The study can be read here.  

A UK survey also reported that common black tea bags could release 3–6 mg/L after 2–3 minutes of brewing, and even higher levels if steeped longer. The survey can be read here.  

According to Teesside University’s Fluoride in Tea Database (2015), Tetley Decaffeinated contained about 5.0 mg/L after 1 minute, and up to 8.66 mg/L after 60 minutes. Other brands showed similar results:

• PG Tips Decaf: ~6.8 mg/L at 1 min
• Yorkshire Tea Decaf: ~9.0 mg/L at 60 min
• Twinings Green Tea: ~4.4 mg/L (2 min)
• Tetley Green Tea: ~2.7 mg/L (2 min)

These values are at the higher end, but not uncommon—especially with longer steeping. In a typical cup (200–250 mL), this translates to roughly 1–2 mg of fluoride in strong tea. The university database can be reached here.

So, while high levels are possible, they depend heavily on how the tea is prepared.

Claim 3. Is Tetley the only tea brand with a relatively high concentration of fluoride??

No. While Tetley Decaffeinated tea has been shown to contain relatively high levels of fluoride in some tests, it is not unique in this regard. Several other common tea brands have demonstrated similar or even higher fluoride concentrations depending on the brew time and leaf quality (Source). The variation reflects natural fluoride accumulation in tea leaves, not a Tetley-specific issue. Therefore, singling out Tetley as exceptionally high is misleading without broader context. 

Claim 4. Does the tea plant (Camellia sinensis) absorb and retain fluoride in dangerous amounts?

Tea plants naturally accumulate fluoride far more than many crops. Fluoride in soil, water or air is absorbed via roots and leaves and concentrates in the mature leaves. Studies report tea-leaf fluoride from a few mg/kg up to >300 mg/kg dry weight. For example, one Chinese study found leaf F ranging 5– 306 mg/kg (mean ~82 mg/kg) across varieties and seasons. The study can be read here. 

Claim 5. Can drinking tea made with non-fluoridated water still lead to fluoride overexposure?

Much of the fluoride in leaves can leach into brew: WHO notes that 100 mg/kg in dried tea would yield roughly 0.4–0.8 mg per 2–3 cups. In short, the tea plant is a “fluoride accumulator” – a normal part of Camellia biology. This means that even with fluoride-free water, brewed tea can still contribute significantly to total fluoride intake due to the natural fluoride content in tea leaves. More details can be found here. 

Claim 6. Is fluoride a proven neurotoxin at levels typically found in fluoridated tap water or tea?

Claims that normal fluoride exposure is neurotoxic are controversial. An EU risk assessment (2024 draft) acknowledged potential developmental effects but only at higher exposures. It found that adverse effects “start to occur at or above” ~1.5 mg/L in water (the current EU legal limit) . Below that, the evidence is “inconsistent and insufficient” to draw firm conclusions . Likewise, a major toxicology review (2020) concluded that available data do not support classifying fluoride as a developmental neurotoxicant at exposure levels typical in Europe . In other words, while any toxin can harm at some dose, no authoritative body regards fluoride at ~0.7–1.5 mg/L (or equivalent intakes) as a proven neurotoxin. Major health organizations (CDC, ADA, WHO, etc.) note that fluoridation of water at ~0.7 mg/L is safe and one of public health’s successes . (For context, acute toxicity would require ingestion of many grams of fluoride.) In summary, fluoride at the levels found in tea and municipal water has not been reliably shown to cause neurological damage; research continues, but current consensus treats optimal fluoridation as beneficial for teeth and without proven neurotoxic risk.The stance of American Dental Association(ADA) can be read here.

Claim 7. Is it misleading to refer to fluoride in water and tea as “poison,” especially in the context of regulated public health measures?

Some critics use alarmist terms like “poison” for fluoride. Scientifically, whether a substance is a poison depends on dose. Fluoride at high doses (grams) can cause acute toxicity, but at common exposure levels it is viewed as a dental preventive, not a deadly toxin. Public health messaging emphasizes “the dose makes the poison.” For example, US agencies note that adjusting water to 0.7 mg/L is designed to prevent cavities , and adverse effects (like hormone changes) have been observed only at 2–3 mg/L and higher. More details can be read here. 

 Experts reject equating fluoridated water or tea with actual poisons. As the National Kidney Foundation put it, “fluoride will not harm a dialysis patient if it is ingested in normal amounts in water” . Regulatory limits reflect this: the US EPA’s enforceable medical contaminant level is 4.0 mg/L (to prevent skeletal fluorosis) , and the secondary level is 2.0 mg/L (to limit dental fluorosis) . Water and food laws are based on these risk thresholds, not on blanket “poison” language. Thus, calling fluoride in tea or water a poison is not scientifically justified within accepted public health standards. 

Claim 8. Does the UK Teesside University Fluoride Database support the claim that commonly

available teas have toxic fluoride levels?

For context, tea infusions are not regulated for fluoride in most countries (unlike drinking water). The relevant limits are for water and medical-use products. The WHO guideline for drinking water is 1.5 mg/L (to avoid dental fluorosis), and the EU legal limit is also 1.5 mg/L . By those measures, strong tea infusions exceed the water standard – but tea is not consumed by the liter like water, and its fluoride contribution is counted on top of water intake. Many health experts would advise caution (especially for children and pregnant women) if consuming very large quantities of high-fluoride tea. However, moderate consumption of Tetley or similar teas has not been shown to cause harm when total fluoride intake remains within guidelines

Conclusion

The claims exaggerates the risks and lacks important context, making it misleading. While Tetley teas, especially decaffeinated types, can contain relatively high levels of fluoride, they are not unusual compared to other popular tea brands. Scientific evidence does not support the claim that such teas are “poisonous” at typical consumption levels. Health authorities consider moderate tea drinking safe for most people, as long as total fluoride intake from all sources remains within recommended limits.