Dioxins and PCBs

Introduction

Dioxins and polychlorinated biphenyls (PCBs) are toxic chemicals that persist in the environment and accumulate in the food chain. Their presence in the environment in Europe has declined since the 1970s, following concerted efforts by public authorities and industry.

In the context of EFSA’s work, ‘dioxins’ refers to two groups of compounds: Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Dioxins have no technological or other use, but are generated in a number of thermal and industrial processes as unwanted and often unavoidable by-products. PCBs had widespread use in numerous industrial applications, and were produced in large quantities for several decades with an estimated total world production of 1.2-1.5 million tonnes, until they were banned in most countries by the 1980s.

Dioxins and PCBs are found at low levels in many foods. Longer-term exposure to these substances has been shown to cause a range of adverse effects on the nervous, immune and endocrine systems, and impair reproductive function. They may also cause cancer. Their persistence and the fact that they accumulate in the food chain, notably in animal fat, therefore continues to cause some safety concerns.

Dioxins and some PCBs referred to as dioxin-like PCBs (due to their similar toxicological properties) are often considered together within the context of public health. Other PCBs referred to as ‘non dioxin-like PCBs’ have a different mechanism of toxicity but can also cause adverse effects on health.

The Panel on Contaminants in the Food Chain (CONTAM) completed EFSA’s first comprehensive review of the risks to human and animal health from dioxins and dioxin-like PCBs in food and feed. The experts reduced the tolerable weekly intake seven-fold based on new data and methods. They concluded that dietary exposure to dioxins and dioxin-like PCBs is a health concern as data from European countries indicate an exceedance of the new tolerable intake level across all age groups.

While these exceedances are a health concern, the toxicity of the most harmful dioxin-like PCB may have been overestimated due to use of internationally-agreed values known as ‘toxicity equivalency factors’ (TEFs). The CONTAM Panel would support a review of the TEFs for both dioxins and dioxin-like PCBs in light of new scientific data. If confirmed to be less toxic, this would reduce the concern for consumers.

2018 – EFSA publishes its first comprehensive risk assessment of dioxins and dioxin-like PCBs in food and feed, reducing the tolerable weekly intakes seven-fold based on new data and methods and indicating a health concern due to exceedance of the new TWI across the EU population.

2018 – EFSA holds an info session with national authorities in EU Member States to discuss the scientific approach, including the use of human data, of its new risk assessment

2018 – Two scientific opinions assess decontamination processes for dioxins and PCBs from fish meal by extraction and/or replacement of fish oil

2015 – EFSA reviews different tolerable intakes of dioxins and dioxin-like PCBs in food and feed, and accepts a request from the European Commission for a comprehensive risk assessment for animal and human health

2012 – A scientific opinion looks at dioxins and dioxin-like PCBs in commercially available foods for infants and young children following a request from Germany’s Federal Institute for Risk Assessment (BfR)

2012 – Recent monitoring data for dioxins and PCBs report show drop in dietary exposure over the preceding decade

2011 – A scientific opinion looks at the human health risks related to the presence of high levels of dioxins and dioxin-like PCBs in liver from sheep and deer

2010 – EFSA publishes European overview of dioxin levels in food and feed

2008 - EFSA responds to Commission’s urgent request on dioxins in Irish pork

EFSA’s Panel on Contaminants in the Food Chain (CONTAM) provides scientific advice and risk assessments on dioxins and PCBs to EU risk managers to help them assess the need for regulatory measures such as the setting of maximum levels of dioxins and PCBs in contaminated food and feed. In particular, the CONTAM Panel is required to:

  • Assess human and animal exposure using occurrence data, in particular, from monitoring by EU Member States
  • Consider the exposure for specific population groups, e.g. infants and children and/or people following specific diets
  • Consider the exposure of farm and domestic animals and the level of carryover from feed to foods of animal origin
  • Make recommendations for the collection of data on dioxins and PCBs that enable the refinement of risk assessments.

EFSA also collects and analyses occurrence data on dioxins and PCBs in food and feed. EU-wide data on the presence of dioxins and PCBs in the food chain can be used with food consumption data to evaluate the progress made in EU Member States in reducing the dietary exposure of the population to these contaminants. Risk managers may also use these data to revise maximum levels found in food and feed.

n 2001, the European Union adopted a strategy on dioxins and PCBs aimed at reducing contamination levels of these substances in the environment, in feed and in foodstuffs to ensure a high level of public health protection. The European Commission website summarises the key milestones and provides details on the policy developments and regulatory measures taken since then.

In 2001, the European Commission set for the first time maximum levels for dioxins, which were extended to dioxin-like PCBs in 2006. Regulation EU 1259/2011 and Regulation EU 277/2012 recently updated them and set maximum levels for non dioxin-like PCBs in food and feed respectively. These regulations took account of more recent data on dioxins and PCBs in food and feed published in two EFSA scientific monitoring reports, and an EFSA scientific opinion on non dioxin-like PCBs.

Member States are responsible for the monitoring of the levels of dioxins and PCBs in food. Previously, EFSA has been asked by the European Commission to collect, analyse and publish these data.