Plain language summary

PLS: Update of the risk assessment of dioxins and dioxin-like PCBs in feed and food

Background

• Polychlorinated dibenzo-p-dioxins and dibenzofurans (referred to as 'dioxins' in this summary) and dioxin-like polychlorinated biphenyls (DL-PCBs) persist in the environment.
• Dioxins are by-products of certain industrial processes and may be formed during incineration of waste; DL-PCBs were part of PCB oils used for various applications in the past.
• Levels in humans have decreased substantially thanks to regulatory measures put in place to reduce emissions.
• However, dioxins and DL-PCBs still enter the food chain and accumulate in fatty foods such as meat, fish, eggs and dairy products, and over time can accumulate in the human body.
• Exposure to dioxins and DL-PCBs before birth and at young age may cause reproductive issues, such as lower sperm concentrations in later life.
• Reducing exposure of women of childbearing age helps to reduce the risk of such effects to unborn and young children.
• In 2018, EFSA published an assessment of the health risks from dioxins and DL-PCBs in food and feed; the main conclusions were:
  • early-life exposure may harm male reproductive health;
  • a tolerable weekly intake (TWI) below 2 picograms toxic equivalents (pg TEQ)/kg body weight per week, expressed using the 2005 World Health Organization toxic equivalency factors (WHO-TEFs), would protect consumers.
• In 2022, WHO updated its TEF values, which for some dioxins and DL-PCBs were decreased, for others increased.

What was EFSA asked to do?

• The European Commission requested EFSA to update their previous assessment from 2018 using the new 2022 WHO-TEFs.

How did EFSA carry out this work (and what data were used)?

• EFSA assessed:
  • the exposure levels of humans and food-producing animals to dioxins and DL-PCBs through food and feed, respectively, using the new 2022 WHO-TEFs;
  • whether applying the new 2022 WHO-TEFs changed the TWI established in 2018;
  • how dioxins and DL-PCBs transfer from feed to food of animal origin.
• EFSA considered new, extensive data and systematically reviewed new, published evidence including:
  • food and feed monitoring data from EU Member States, Norway and Iceland;
  • EFSA's Comprehensive European Food Consumption Database;
  • data on occurrence levels in human milk in Europe.
• EFSA:
  • used evidence from studies in both humans and experimental animals;
  • identified the exposure level linked to a decrease in sperm production;
  • estimated how dioxins and DL-PCBs accumulate in body fat over time;
  • evaluated the need to apply default uncertainty factors to accommodate gaps in knowledge (notably on differences between people, especially mothers and infants) and to provide a confidence measure in the conclusions;
  • considered comments from a public consultation.

What were the outcomes and their implications?

Outcomes

• The updated assessment confirmed the link between dioxin exposure and developmental reproductive effects, such as lower sperm count, observed both in animals and humans.
• EFSA calculated a new, lower TWI of 0.6 pg TEQ/kg body weight per week, expressed using the 2022 WHO-TEFs, derived from a study of rats exposed during development to the most toxic dioxin, TCDD.
• Based on the overall weight of evidence from animal and human studies, an uncertainty factor (of 3.16) for variation in kinetics between humans was applied to derive the TWI.
• EFSA found that the updated 2022 WHO-TEFs change how much each dioxin and DL-PCB contributes to the overall dietary exposure.
• Use of the 2022 WHO-TEFs reduced the estimated dietary exposure to dioxins and DL-PCBs by about 27-35% compared with those based on the 2005 WHO-TEFs.
• Even so, the estimated dietary exposure for all age groups in Europe still exceeds the new TWI in all age groups.
• Levels of dioxins and DL-PCBs in human milk confirmed the exceedance of the new TWI.

Implications

• Although estimated dietary exposure levels are lower using the 2022 WHO-TEFs, EFSA concluded that exposure levels in European women of childbearing age may still harm the reproductive health of future sons.

What were the limitations/uncertainties?

• EFSA identified several uncertainties linked to the research methods and the accuracy of data on dioxin and DL-PCB occurrence, exposure and effects.
• EFSA concluded:
  • with about 95% certainty that the TWI is equal to or higher than 0.6 pg TEQ/kg body weight per week, expressed using the 2022 WHO-TEFs;
  • with 99-100% certainty that current average adult exposure exceeds the TWI.

What are the key recommendations?

EFSA made several recommendations to reduce the uncertainties in the risk assessment of dioxins and DL-PCBs to human health via food:

• further development of approaches to compare animal- and human-based data to derive TEFs that are more relevant for humans;
• more data to confirm that dietary exposure from plant-based foods is low;
• improved toxicokinetic models that include differences in the behaviour of the various dioxins and DL-PCBs in the body;
• expanded biomonitoring in human milk and blood across more European populations;
• improved analytical methods to reduce the amount of biological samples needed for analysis;
• further investigation on the contribution of soil eaten by food-producing animals to the levels in animal-derived food;
• improved understanding of how dioxins and DL-PCBs affect sperm production.

Glossary

Toxic equivalency factor (TEF): A measure to compare the toxicity of a dioxin or DL-PCB with that of the most toxic dioxin, TCDD.

Toxic equivalents (TEQ): The combined toxicity of a mixture of dioxins and DL-PCBs based on the TEFs of the individual compounds. The TEQ concept assumes that the relevant dioxins and DL-PCBs cause the same type of biochemical and adverse effects. Another important requirement of the TEQ concept is the persistence and accumulation of the compounds in the body.

Tolerable weekly intake (TWI): The maximum weekly intake of contaminants present in food that can be ingested over a lifetime without presenting an appreciable risk to health. In the case of dioxins and DL-PCBs, it is expressed as pg TEQ/kg body weight per week, using the WHO-TEFs.

Uncertainty factors: factors used in risk assessment to address potential differences between animals and humans, differences between individuals, and gaps in the scientific data.

Disclaimer

• This plain language summary (PLS) is a simplified communication of EFSA's EFSA's Update of the risk assessment of dioxins and dioxin-like PCBs in feed and food. The full EFSA opinion can be found here.
• The purpose of the PLS is to enhance transparency and inform interested parties on EFSA's work on the topic using simplified language to present a summary of the main findings.
• The PLS was produced with the assistance of artificial intelligence, using the licensed version of Microsoft Copilot. Copilot was used to summarise EFSA's scientific output, using a standardised prompt. The generated text was reviewed by EFSA scientific staff for accuracy and completeness, and additional editing was provided by EFSA Journal staff. EFSA holds editorial responsibility for the final PLS.

Reference

Update of the risk assessment of dioxins and dioxin-like PCBs in feed and food

DOI: https://doi.org/10.2903/j.efsa.2026.10103

ISSN: 1831-4732

© European Food Safety Authority, 2026

Reproduction is authorised provided the source is acknowledged.

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