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Questions and Answers on Dioxins and PCBs

Commission Européenne - MEMO/06/54   03/02/2006

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MEMO/06/54

Brussels, 03 February 2006

Questions and Answers on Dioxins and PCBs

What are dioxins?

Dioxins are a group of chemicals. They are polychlorinated aromatic compounds with similar structures, chemical and physical properties. They are not produced intentionally or deliberately, but are formed as a by-product of chemical processes. These range from natural events such as volcano eruptions and forest fires to manmade processes such as manufacturing of chemicals, pesticides, steel and paints, pulp and paper bleaching, exhaust emissions and incineration. For example, when chlorinated waste is burned in an uncontrolled way in an incinerator, the emissions to the air contain dioxins. Dioxin is a colourless, odourless organic compound containing carbon, hydrogen, oxygen and chlorine. The term dioxin refers to a broad family of chemicals. Of the 210 different dioxin compounds, only 17 are of toxicological concern.

What are PCBs?

PCBs, or polychlorinated biphenyls are another group of chemicals. They are chlorinated aromatic hydrocarbons which are synthesized by direct chlorinating of biphenyls. Technical PCB mixtures are still widespread and present today, such as in transformers, building materials, lubricants, coatings, plasticizers and inks. Some of the PCB compounds have toxicological properties that are similar to dioxins and are therefore often termed “dioxin-like” PCBs.

What is the problem with dioxins and PCBs?

Dioxins and PCBs are toxic chemicals that can provoke serious health effects such as cancer, hormone disruption, reduced ability to reproduce, skin toxicity and immune system disorders. They are not soluble in water and are highly soluble in fat. This means that they bind to sediment and organic matter in the environment and are absorbed in animal and human fatty tissue. In addition they are not biodegradable so they are persistent and bio-accumulate in the food chain. This means that once released into the environment, via air or via water, they pile up in the fat tissue of animals and humans, causing toxicological damage over time.

What are the sources of human exposure to dioxins?

Dioxin is ubiquitous in the environment: it is found throughout the industrialized world in air, water and soil, as well as in food. Human exposure to dioxin can occur through working in industries where dioxin is a by-product, industrial accidents, through food, human breast milk and drinking water. Overall, skin contact or breathing represents very small sources of dioxin exposure. Dioxins accumulate in the body mostly through the consumption of dioxin contaminated food. As in animals, dioxin is stored in human adipose tissue. Certain population groups, such as nursing babies and people who eat a diet high in animal fat or in contaminated foods because of their proximity to dioxin release sites, are exposed to higher than average levels of dioxin.

What is the “body burden” for dioxins?

The “body burden” for dioxins relates to the amount of dioxins accumulated in the body during a lifetime. It is used for the assessment of toxic effects of dioxins as it is a more relevant and reliable estimate of the continuous exposure than the daily intake.

How do dioxins get into the food chain?

Food – and mostly food of animal origin - contributes to 90% of daily intake of dioxins. Dioxin concentrates in the fatty tissues of beef and dairy cattle, poultry, pork or seafood for example. The dioxin level in food originating in farmed animals is largely the result of dioxin in feed. Feed contamination occurs either through certain production practices e.g. inappropriate drying practices, illegal use of PCB-oils in feed etc, or through environmental contamination.

The contamination of the environment by dioxins is primarily caused by the aerial transportation and deposition of emissions from various sources (waste incineration, production of chemicals, traffic, etc.). The use and disposal of chemicals can contribute to more severe localised contamination. Soil is a natural sink for dioxins. Apart from atmospheric deposition, soils may be polluted by sewage sludge or composts, spills and erosion from nearby contaminated areas. Soil is absorbed, directly or indirectly via dust deposits on vegetables, by free-range grazing cattle, goats, sheep and chicken and burrowing/grazing pig and wild boar.

Which food products are most affected?

The contamination can vary widely depending on the origin of the foodstuff. Meat, eggs, milk, farmed fish and other food products may be contaminated by dioxins from feeding-stuffs. Such contamination may be due to a high level of local environmental contamination, for example from a local waste incinerator, or result from a high content of dioxins in some feed materials such as fishmeal and fish oil. Wild fish from certain polluted areas may also be highly contaminated.

What limits currently exist for dioxins and dioxin-like PCBs?

EU-wide maximum levels were set for dioxins in 2001 (see IP/01/1698), but due to a lack of sufficient data on dioxin-like PCBs at that time, these chemicals were not included in the legislation. Since then, more information on the presence of dioxin-like PCBs in feed and food has become available, allowing the Commission to now set mandatory limits for the combined level of dioxins and dioxin-like PCBs, based on World Health Organisation (WHO) toxic equivalency factors for these substances. The maximum levels set for dioxins alone will remain in force for a transitional period, but by the end of 2008, it is foreseen that the Commission will consider abolishing these and lowering the combined maximum levels set for dioxins and PCBs.

What has been done at EU level to try to reduce dioxins and PCBs?

The overall goal of the EU policy on dioxins is to reduce the contamination levels of dioxins and PCBs in the environment, in feed and in foodstuffs in order to ensure a high level of public health protection. This requires taking action at each level of the food chain, as well as implementing measures to reduce dioxin contamination levels in the environment.

Following the 1999 dioxin crisis in Belgium, the European Council held in Feira (Portugal) in June 2000 asked the Commission to propose harmonized rules for such contaminants. In October 2001, the Commission put forward a strategy to reduce the presence of dioxins and polychlorinated biphenyls (PCBs) in the environment, animal feed and food. The objectives of the strategy were to reduce human intake levels below the scientifically recommended levels, to assess the current state of the environment and the ecosystem, to reduce the environmental effects from dioxins and PCBs.

On July 1 2002, legally binding maximum limits on the presence of dioxin in food and in animal feed entered into effect (see IP/02/959). Any food or feed exceeding these limits is excluded from the food chain.

A number of legislative measures have been taken to reduce dioxins and PCBs in the environment also. They are covered, to a greater or lesser degree, in legislation on waste incineration, integrated pollution prevention and control (IPPC), the Water Framework Directive, and chemicals legislation. The European Community and Member States are also signatories to the Stockholm Convention on Persistent Organic Pollutants (POPs). Regulation 850/2004 on POPs, which entered into force in May 2004, lists dioxins and PCBs as unintentionally released POPs against which action must be continuously and effectively taken to reduce their presence in the environment.

Why are dioxins and PCBs not prohibited?

The production and use of PCBs has been discontinued in almost all industrial countries. At EU level, Directive 76/769 prohibits the use of most PCBs. However, as a result of their widespread use in the past, large amounts of PCBs are still present today in electrical equipment, plastic products, buildings and in the environment, which is why PCBs are still ending up in waste streams. Council Directive 96/59/EC on the disposal of polychlorinated biphenyls and polychlorinated terphenyls (PCB/PCT) sets a deadline for taking all PCB-containing equipment out of service by the end of 2010.

Dioxins are not produced intentionally. These contaminants have a ubiquitous distribution due to their formation as unwanted and often unavoidable by-products in a number of activities. It is impossible to prohibit dioxins, but strict levels have been set for dioxins in products that are to be put on the EU market.

Are the maximum levels for dioxins in food and feed scientifically based?

Two scientific opinions formed the scientific basis for the development of the EU strategy on dioxins. An opinion of the Scientific Committee on Animal nutrition (SCAN) on the “Dioxin contamination of feeding-stuffs and their contribution to the contamination of food of animal origin” was adopted in November 2000. In its opinion, the SCAN identified the most heavily contaminated feed materials (fish meal, fish oils, animal fat and, depending on location, roughage). It recommended, amongst other things, that emphasis should be placed on reducing the impact of the most contaminated feed materials on overall diet contamination.

In May 2001, the Scientific Committee on Food (SCF) adopted a report on the “Risk assessment of dioxins and Dioxin-like PCBs in Food” (updating its previous opinion of November 2000). The SCF fixed a tolerable weekly intake of 14 picograms WHO-TEQ/kg body weight for dioxins and dioxin-like PCBs.

It was on the basis of these scientific risk assessments that the Commission formulated its initial measures to limit the presence of dioxins throughout the whole food and feed chain, and it is continually reviewing the measures and limits in line with new or updated scientific advice.

What are the WHO-TEQs, used to set the maximum limits for dioxins and dioxin-like PCBs?

The EU maximum levels set for dioxins and dioxin-like PCBs are based on the World Health Organisation (WHO) toxic equivalents (TEQs), which are used to express the toxicological concentrations of these chemicals and enable risk assessments to be carried out.

Who is responsible for making sure the maximum levels are respected?

All operators in the food and feed chain must do everything necessary to limit the presence of dioxins and PCBs in the feed and food chain. This could include reviewing processing, drying and other chemical based techniques, or using decontamination techniques to remove dioxins and dioxin-like PCBs where possible. Member State authorities are responsible for carrying out checks to ensure the maximum limits are being respected, and must report back to the Commission on results of the samples taken.

Why was there a delay in setting maximum levels for dioxin-like PCBs?

When the maximum levels for dioxins in foodstuffs (Regulation 466/2001) and feedstuffs (Directive 2002/32/EC) were set, there was not enough data available on the prevalence of dioxin-like PCBs to be able to include them in the legislation. However, there was provision in the legislation for dioxin-like PCBs to eventually be covered by maximum levels. More data on the presence of dioxin-like PCBs in food and feed subsequently became available, thereby allowing the Commission to set maximum levels for the sum of dioxins and dioxin-like PCBs.

If there are strict limits for dioxins and PCBs, why do crises related to these chemicals still occur from time to time in some Member States?

Legislation cannot completely exclude all possibility of contamination in the food chain – it can only help to prevent and reduce it. The recent dioxin incident in certain Member States has demonstrated that when such a contamination does occur, the EU has comprehensive legislation in place to adequately manage the situation.

It is of major importance for the protection of public health that any contamination is detected at a very early stage, and that proper provisions are in place to remove and avoid the spread of the contamination within the food chain. Such monitoring programs for dioxins and PCBs in feed and food have been put in place across the EU. Tracing and tracking systems are also in place to identify potentially affected companies and farms, and there are restrictive measures which can be taken against such establishments to avoid potentially contaminated feed and food entering the food chain.

The Rapid Alert System for Food and Feed is also a highly effective tool for the exchange of information between competent authorities, and has played a key part in dealing with and minimising food crises that have occurred.

The established EU maximum levels on dioxins played a key role for the management of this contamination incident, as they ensured that there was a trigger point at which the contamination was quickly identified and dealt with, and they were used as a legal tool for taking decisions to protect public health.
For more information, see:

http://ec.europa.eu/food/food/chemicalsafety/contaminants/dioxins_en.htm


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