Do Tea Leaves Carry the Risk of Benzo[a]pyrene (BaP) or Other Polycyclic Aromatic Hydrocarbons (PAHs)?

Hello everyone:

I'm Andy, a tea enthusiast.

Benzo[a]pyrene (BaP) has become one of the most closely watched food safety topics recently.

Tea leaves may also be affected - but please don't worry.

Research shows that even when BaP is detected in tea leaves, very little of it actually dissolves into the brewed tea.

This time, I'd like to share: do tea leaves carry the risk of benzo[a]pyrene (BaP) or other polycyclic aromatic hydrocarbons (PAHs)?

What are benzo[a]pyrene (BaP) and polycyclic aromatic hydrocarbons (PAHs)?

You may have come across the name "benzo[a]pyrene" in the news.

Its full name is benzo[a]pyrene (BaP), and it belongs to a family of substances called polycyclic aromatic hydrocarbons (PAHs).

PAHs are formed from multiple fused benzene ring structures, with hundreds of known varieties, found widely in air, soil, and food.

Their formation is straightforward: whenever organic matter undergoes incomplete combustion at high temperatures, PAHs can be produced.

Grilling, smoking, vehicle exhaust, and high-heat charring during cooking are all common sources.

Tea is not a grilled food, but if the production process involves charcoal roasting, smoke-drying, or poorly controlled temperatures, PAHs in the tea can still increase.

BaP is the most carcinogenically significant member of the PAHs family,

classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen - meaning there is sufficient scientific evidence of carcinogenicity in humans.

It has therefore become the primary indicator compound monitored by food safety regulations worldwide.

(Source: SGS Knowledge Platform, https://msn.sgs.com/Knowledge/FOOD/6381)

Are there regulations governing BaP or PAHs in tea?

In most regions, regulatory controls on BaP or PAHs in tea remain advisory in nature,

without the specific legal limits that exist for edible oils or smoked meats.

Here is a breakdown by region.

Taiwan

Taiwan's Standards for Contaminants and Toxins in Food Products sets BaP limits for specific categories including edible oils,

smoked chili peppers, and pepper products.

No dedicated BaP or PAHs limit has been set specifically for tea.

The authorities tend to manage this through sampling inspections, risk assessments, and targeted audits.

European Union

The EU takes a relatively strict approach to PAHs regulation, with clear limits for oils,

smoked foods, spices, and dried herbs. For dried herbs,

limits of BaP not exceeding 10 μg/kg and PAH4 totals not exceeding 50 μg/kg have been established.

Whether tea should be regulated in the same way is still under research and discussion,

and no mandatory dedicated limit equivalent to that for oils has been set to date.

Mainland China

Systematic food contaminant standards exist,

but no single clear legal limit specifically for BaP or PAHs in tea has yet been established - management remains based on risk assessment and monitoring programs.

Why is there still no clear limit for tea?

Several reasons emerge from the literature. First, transfer rates are uncertain:

PAHs in dry tea do not necessarily dissolve into the brewed liquid in large quantities,

making it difficult to estimate actual exposure from dry-leaf data alone.

Second, research data is still accumulating: the wide variation across tea types and brewing methods means regulators need more comprehensive data before setting limits.

Third, compared to high-exposure categories like edible oils and smoked meats,

the overall risk from tea is considered lower, so regulatory priority has been lower accordingly.

For quality control and export professionals,

it is advisable to treat PAHs/BaP in tea as items that, while lacking a legal limit,

are subject to international monitoring and client requirements - using EU limits for dried herbs as an internal management benchmark alongside regular testing.

Under what conditions do tea leaves produce BaP or PAHs, and how can this be avoided?

Tea leaves do not produce PAHs on their own - the appearance of these compounds is almost always tied to production processes.

The three most common scenarios are as follows.

The first is when roasting temperatures are too high or roasting times too long, causing localized charring of the tea.

The second is when charcoal, wood fire, or smoke comes into direct contact with the tea leaves - smoke itself may already carry PAHs.

The third is when tea gardens or processing facilities are near combustion pollution sources,

and the tea leaves absorb externally introduced PAHs from the surrounding environment.

How can risk be reduced at the process level?

The core principle can be summed up in three phrases:

less smoke, less char, less direct fire. Specific steps include using temperature-controlled indirect heating methods where possible,

avoiding extreme temperatures or excessively long roasting times,

ensuring proper smoke barriers and ventilation in processing environments,

and including PAHs or BaP in regular testing programs for roasted, charcoal-fired, or heavily fired teas.

Does brewed tea carry the risk of BaP or PAHs?

This is the question most consumers care about most.

Based on current literature, the overall answer is: the risk is relatively limited.

The reason is that PAHs have strong hydrophobicity - their solubility in water is low.

Even when these substances are detected in dry tea, the proportion actually released into brewed tea during steeping is typically quite small.

Multiple studies consistently conclude that detection in dry tea leaves does not equate to the same level of exposure when drinking.

The overall assessment in most research is that the health risk from ordinary tea drinking is low, particularly with moderate consumption.

That said, if you regularly drink heavily roasted or charcoal-fired teas, or teas from suppliers with non-transparent production processes,

it is still advisable to choose brands with good quality control records and regular testing results.

The point is not to stop drinking tea because of risk - it is to understand which types of processing deserve more attention,

so you can drink with greater confidence.

References: tea and BaP / PAHs

1. 2018 - Determination and risk characterization of polycyclic aromatic hydrocarbons of tea by using the Margin of Exposure (MOE) approach

This study found that PAHs can be detected in tea samples,

with some showing higher concentrations - particularly maté tea. After applying the Margin of Exposure (MOE) method for risk assessment,

the authors concluded that the overall public health risk from everyday tea consumption is low,

while recommending continued monitoring of high-risk tea types and their processing conditions.

2. 2017 - Contamination of Tea and Tea Infusion with Polycyclic Aromatic Hydrocarbons

This study confirmed the presence of BaP and other PAHs in dry tea, but found the proportion that transferred into brewed tea to be limited.

The results indicate that contamination in dry leaves does not equal actual consumption exposure, and that overall exposure risk is relatively limited.

3. 2023 - Polycyclic aromatic hydrocarbons in commercial tea from China and implications for human exposure

The study found detectable PAHs in commercially available Chinese tea, with varying degrees of contamination across tea types.

Black tea, oolong, and green tea all showed signs of contamination, but exposure assessment results indicated overall health risks remained low.

Processing methods and heat treatment were identified as important contributing factors.

4. 2023 - Occurrence and Exposure Evaluation of Polycyclic Aromatic Hydrocarbons in Tea Samples Consumed in Beijing-Tianjin-Hebei Regions of China

Analysis of 129 tea samples found that PAH distribution varied by tea type, and the proportion released into brewed tea was low.

Risk assessment indicated that exposure levels for ordinary tea drinkers were within acceptable ranges, though fully fermented teas warranted somewhat greater attention.

5. 2018 - Polycyclic aromatic hydrocarbons as a potential source of esophageal cancer risk in mate tea drinkers

The study suggested that maté tea may have elevated PAH levels due to processing or drying methods, potentially increasing esophageal cancer risk.

The authors noted that high-temperature consumption and PAH exposure may together heighten health concerns, making maté a tea type that merits particular attention.

6. Review Literature - PAHs in Tea and Processing-Related Risk Research

Related reviews indicate that PAHs in tea originate primarily from incomplete combustion, smoking, drying, and high-temperature roasting.

Overall, if production processes are well controlled, the risk from ordinary tea consumption is low.

However, for heavily roasted, charcoal-fired, or smoked products, monitoring and management should be strengthened.

Hope this article has been helpful.

See you next time.


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