Chemicals in food

Chemicals are essential building blocks for everything in the world. All living matter, including people, animals and plants, consists of chemicals. All food is made up of chemical substances. Chemicals in food are largely harmless and often desirable – for example, nutrients such as carbohydrates, protein, fat and fibre are composed of chemical compounds. Many of these occur naturally and contribute both to a rounded diet and to our eating experience.

Chemicals can, however, have a variety of toxicological properties, some of which might cause effects in humans and animals. Usually, these are not harmful unless we are exposed to them for a long time and at high levels. Scientists help to safeguard against these harmful effects by establishing safe levels. This scientific advice informs decision-makers who regulate the use of chemicals in food or seek to limit their presence in the food chain.

Topics: Completed work

Chemical substances can play an important role in food production and preservation. Food additives can, for example, prolong the shelf life of foods; others, such as colours, can make food more attractive. Flavourings are used to make food tastier. Food supplements are used as sources of nutrition.

Food packaging materials and containers such as bottles, cups and plates, used to improve food handling and transport, can contain chemical substances such as plastic, elements of which can migrate into food. Other chemicals can be used to fight diseases in farm animals or crops, or can sometimes be found in food as a result of a production process such as heating/cooking or decontamination treatment.

Some plants and fungi naturally produce toxins that can contaminate crops and be a concern for human and animal health. People can also be exposed to both naturally occurring and man-made chemical compounds present at various levels in the environment, e.g. in soil, water and the atmosphere. Examples include industrial pollutants such as dioxins and PCBs. A variety of metals can be present naturally in the environment or as a result of human activity.

EFSA carries out risk assessments on a wide range of substances, including those that are deliberately added to food and feed, chemical residues that can be present in food and feed due to production, distribution, packaging or consumption, and those that might be present through contact with the environment.

Regulated food ingredients

Some chemicals are added to food for a variety of technical reasons, including to make them taste better, last longer or be more nutritional.

Food chain residues

Sometimes traces of chemicals are unintentionally present in food because of food production and preparation methods, such as residues of pesticides or additives used in animal feed. Small traces of chemicals from packaging and other food contact materials can also unintentionally end up in food.

Contaminants in food and feed

Naturally occurring chemical compounds such as metals and nitrates can be present at various levels in the environment, e.g. soil, water and the atmosphere. They can also occur as residues in food because of their presence as environmental pollutants, as a result of human activities such as farming, industry or car exhausts, or as a result of food production such as high-temperature cooking. People can be exposed to them from the environment or by ingesting contaminated food or water.

EFSA provides scientific advice in the form of risk assessments and other technical assistance on chemicals in food and feed to European Union risk managers (European Commission, European Parliament, Member States). Risk managers take EFSA’s scientific advice into account together with other factors when making decisions about the safety of these substances for human and animal health and the environment.

  • Market authorisation of chemical substances used in the food chain. Before chemicals can be authorised in the EU for use in food and feed, EFSA carries out strict risk assessments to determine which substances can be used safely and at which levels.
  • Risk assessments are also carried out in relation to contaminants that are considered to be a possible concern for human and/or animal health. Risk managers may take measures to limit human and animal exposure to such substances if EFSA indicates a potential health impact.

1. Why are there chemicals present in food?

All foods, living matter and, indeed, our bodies themselves are made up of chemicals. Many of the chemicals found in food occur naturally and include nutrients such as carbohydrates, protein, fat, fibre and a host of other elements and compounds.

Chemical substances can play an important role in food production and preservation. Food additives can, for example, prolong the shelf life of foods or can make food more attractive, such as colours. Flavourings are used to make food tastier. Food packaging materials and containers such as bottles, cups and plates contain chemical substances such as plastic, elements of which can migrate into food. Other chemicals can be used to fight diseases in farm animals or crops.

All chemical substances authorised for use in foods must first undergo a thorough risk assessment to ensure that they are safe. The possible effect of such chemicals on our health and safety depends on our level of exposure to them, for instance through the foods we eat or other sources of environmental exposure. That is why regulatory bodies carry out strict risk assessments of all chemicals proposed for use in food to determine which substances can be used and at which levels. This ensures that the use of chemicals in foods or on crops (for instance, pesticides) will not have adverse effects on animal and human health, and on the environment.

People can also be exposed to both naturally occurring and man-made chemical compounds present at various levels in the environment, e.g. in soil, water and the atmosphere, for instance environmental pollutants such as dioxins and PCBs. The presence of these substances in the body can lead to harmful effects over time. Risk assessment bodies such as EFSA, therefore, also evaluate possible adverse health effects from exposure to these environmental chemicals, which may also be found in food.

2. What role does EFSA play in assessing the safety of chemicals in food?

There is a robust regulatory system in place in the European Union to protect consumers from possible risks related to chemicals in foods.

EFSA has an important role to play in this system. EFSA, as risk assessor, provides independent scientific advice to support the risk managers (EU Institutions and Member States) in defining appropriate regulatory frameworks and making decisions to protect consumers. These may involve adopting or revising European legislation on food or feed safety, or deciding whether to approve regulated substances such as pesticides and food additives, and if so in which foods or crops, and at what levels.

A number of EFSA’s Scientific Panels, composed of experts from across Europe, and several EFSA units are involved in the risk assessment of chemicals in food. They are responsible for EFSA’s risk assessment work, including delivering scientific opinions at the request of risk managers or on their own initiative.

  • The ANS Panel deals with questions on the safety of the use of food additives, nutrient sources and other substances deliberately added to food, excluding flavourings and enzymes.
  • The CEF Panel deals with questions on the safety of use of materials in contact with food, enzymes, flavourings and processing aids, and also with questions related to the safety of processes.
  • The FEEDAP Panel deals with additives and products or substances used in animal feed.
  • The PPR Panel deals with plant protection products (commonly known as pesticides) and their residues.
  • In addition, the Pesticides Unit is responsible for the EU peer review of active substances used in plant protection products and deals with tasks related to the setting of Maximum Residue Levels (MRLs)for these products.
  • The CONTAM Panel provides scientific advice on contaminants, undesirable substances and residues of unauthorised substances in the food chain, not covered by the other Panels.

3. How does EFSA assess the safety of chemicals in food?

EFSA’s advice helps inform the decisions and policies of risk managers - so EFSA carries out much of its work in response to requests from the European Commission, European Parliament and EU Member States, as well as initiating its own scientific activities.

EFSA’s main task is to carry out scientific risk assessments on possible hazards associated with the food chain, including potential risks posed by chemicals in food. The evaluation stage is the main part of the risk assessment. It is carried out by scientific experts tasked to deliver opinions on specific issues. Their work involves the review of relevant data including the results of studies on experimental animals and, where possible, observations in humans. With respect to regulated substances, experts review applications submitted by industry (such as those from food or feed manufacturers ). These applications must be prepared according to the data requirements laid down in EFSA’s guidance documents outlining the risk assessment methodology followed by EFSA Panels . When considering industry applications, experts assess all available information and data to determine what risk, if any, and in what amounts the substance may pose a risk for human and animal health, and where appropriate, the environment.

4. What is meant by an Acceptable Daily Intake (ADI)?

The Acceptable Daily Intake (or ADI) is the amount of a specific substance (for instance a food additive, or a residue of pesticide) in food or drinking water that can be ingested daily over a lifetime without an appreciable health risk.

ADIs are expressed by body weight, usually in milligrams (of the substance) per kilograms of body weight per day.

ADIs are based on a scientific review of all toxicological data available at the time on a specific chemical, including long-term tests on animals to determine the No Observed Adverse Effect Level (the NOAEL). This is the greatest concentration or amount of a substance, found by observation or experiment, which causes no detectable adverse effect in the exposed population.

The NOAEL is scaled by a safety factor, conventionally of 100, to account for the differences between test animals and humans (factor of 10) and possible differences in sensitivity between humans (another factor of 10).

Exceeding the ADI on an occasional basis is not necessarily a cause for concern as such because the ADI takes into account daily exposure of a substance over a lifetime.

5. Is a Tolerable Daily Intake (TDI) the same thing as an ADI?

They are similar but not the same. ADIs relate to chemical substances which are deliberately added to a product or ingredient or which can be found on food following for instance treatment of crops with pesticide sprays or antifungal agents. A Tolerable Daily Intake (TDI), on the other hand, is an estimate of the quantity of a chemical contaminant to which we may be exposed through environmental contamination, and which when found in food can be ingested daily over a lifetime without posing a significant risk to health. Exposure to such contaminants whilst not desirable may not be avoidable as some may be found in foods as a result of environmental pollution (e.g. lead, dioxins, etc.).

This measure can also be expressed in terms of the Tolerable Weekly Intake (TWI) of a substance.

6. How can EFSA be sure it is using the best scientific methodologies when it carries out its risk assessment?

EFSA uses internationally recognised approaches in its risk assessments in order to help safeguard the health of consumers and animals and to help protect the environment.

EFSA has developed a comprehensive body of good risk assessment practices to guide the experts on its Scientific Committee and its Scientific Panels and to help ensure that EFSA opinions respect the highest scientific standards.

The Scientific Committee is responsible for general co-ordination to ensure consistency in the scientific opinions prepared by the Scientific Panels. It focuses on developing harmonised risk assessment methodologies in fields where EU-wide approaches are not already defined.

The Scientific Committee has also laid down guidance for EFSA and its Panels with respects to the transparency of its risk assessments. In the interests of transparency, EFSA's risk assessments must be understandable and use standardised procedures and terminology. Amongst the other requirements, it must also document all data used, the source of the data, their quality and relevance, and any assumptions made by experts in their analysis of them. Importantly, risk assessments should indicate clearly what is known and what is not known, highlighting areas of scientific uncertainty including gaps in the data and evidence base.

Of course, science does not stand still. EFSA continually seeks to build on good risk assessment practices and develops further guidance, recommendations and processes to enhance its approaches.

7. Does EFSA evaluate food additives such as food colours?

Under a regulation issued by the European Commission in 2008, all food additives must undergo a safety evaluation by EFSA before they can be authorised by EU risk managers. The same law also requires that EFSA re-evaluates all food additives authorised for use in the EU before 20 January 2009 using current risk assessment methods. The Commission has set deadlines for re-evaluating various groups of additives, including food colours, sweeteners, preservatives, etc. The deadline for all such re-evaluations is 31 December 2020, but many re-evaluations have already been completed.

EFSA may also be required to carry out ad hoc requests from the European Commission to review certain food additives in the light of new scientific information and/or changing conditions of use or to prioritise work.

For example, in 2007 EFSA assessed the effect of mixtures of certain food colours and the preservative sodium benzoate on children’s behaviour following publication of a study by researchers at Southampton University in the United Kingdom. EFSA scientists, with the help of experts in behaviour, child psychiatry, allergy and statistics, concluded that the study provided limited evidence that the mixtures of additives tested had a small effect on the activity and attention of some children.

In another case, EFSA revised the previously established ADIs for a group of four caramel colours and set a group ADI covering all four. The Panel also looked at the safety of some by-products resulting from the production of these colours and recommended to keep their levels in caramel colours as low as technologically possible.

8. Has EFSA done any work recently on artificial sweeteners?

EFSA assesses the safety of artificial sweeteners.

In December 2013 EFSA published its full risk assessment of aspartame.

The ANS Panel has also recently looked at steviol glycosides, sweeteners extracted from the leaves of the stevia plant. In an opinion published in April 2010, it concluded that these substances are neither genotoxic (damaged genetic material of cells), nor carcinogenic and established an ADI of 4 mg per kg body weight per day. Following a request from the European Commission, in January 2011, EFSA reviewed its previous assessment of consumer exposure to these sweeteners based on revised levels of use proposed by applicants. EFSA concluded that although the revised exposure estimates are slightly lower than those of the April 2010 opinion, adults and children who are high consumers of foods containing these sweeteners, could still exceed the ADI established by the Panel if the sweeteners are used at maximum levels.

9. What about flavourings used in food? Are they safe?

Flavourings have a long history of safe use and are used in comparatively small amounts so that consumer exposure is relatively low.

The regulatory framework on food flavourings is now harmonised throughout the EU and EFSA’s risk assessments support the European Commission and Member States in establishing a list of flavouring substances which can be used in the EU.

In 2010, the Panel on food contact materials, enzymes, flavourings and processing aids (the CEF Panel) completed the first stage of a comprehensive safety review of 2,067 flavouring substances used in the EU.

10. Has the Panel raised any concerns over flavourings?

The Panel found that the majority of flavouring substances (1,667) do not give rise to safety concerns. EFSA has asked manufacturers to provide further data on around 400 substances. These have been put on hold and EFSA will re-assess those substances once the required data have been received.

The Panel in 2009 also completed the first ever review of the safety of 11 smoke flavourings used in the EU. Two of the smoke flavourings did not give rise to safety concerns. However, the experts concluded that the use of eight smoke flavourings at the proposed uses and use levels would be of safety concern due to low margins of safety. Additionally, based on the available data the experts could not rule out concerns regarding possible genotoxicity (damage to the genetic material of cells) for one of these eight smoke flavourings and could not assess the safety of one further smoke flavouring due to the lack of adequate data available.

Based on EFSA’s work, the European Commission will establish a list of smoke flavouring products authorised for use in foods.

11. Has an assessment ever led to any food additive being removed from the market?

Yes, EFSA’s advice can lead to a ban. For example, in 2007, EFSA’s experts advised that the food colour Red 2G (E 128) – which was permitted in certain breakfast sausages and burger meat – raised potential health concerns as it was found to be carcinogenic and genotoxic in animals. Within a month of EFSA’s advice being adopted, the European Commission and EU Member States suspended the use of this colour in foods.

12. Does EFSA assess the safety of food contact materials?

Food contact materials are all materials and articles intended to come into contact with food, such as packaging and containers, kitchen equipment, cutlery and dishes. The safety of these materials must be evaluated as molecules can migrate from them into food.

One prominent example is bisphenol A (BPA). BPA is a chemical mainly used together with other chemicals to manufacture plastics and resins used to make food containers, such as returnable beverage bottles, tableware (plates and mugs) and storage containers.

EFSA updated its advice on BPA in September 2010. Following a detailed and comprehensive review of recent scientific literature and studies on the toxicity of BPA at low doses, scientists of EFSA’s CEF Panel concluded they could not identify any new evidence which would lead them to revise the current TDI for BPA of 0.05 mg/kg body weight set by EFSA in its 2006 opinion and re-confirmed in its 2008 opinion. The Panel also stated that the data currently available do not provide convincing evidence of neurobehavioural toxicity of BPA.

One Panel member expressed a minority opinion, saying some recent studies point to uncertainties regarding adverse health effects below the level used to determine the current TDI. Although the Panel member agreed with the rest of the Panel's general view that these studies could not be used to establish a lower TDI, the expert recommended that the current TDI should become a temporary TDI.

In the light of scientific uncertainty and in order to further reduce exposure of infants to BPA, the European Commission deemed it both necessary and appropriate to ban the manufacture in the EU of plastic infant feeding bottles containing BPA, starting from 1 March, 2011.

In November 2011, following a preliminary review of new literature emerging from EFSA’s ongoing monitoring of the scientific literature, the CEF Panel published a statement confirming that it will reconsider its opinion on BPA following further evaluations of new studies and after new data from low dose studies being conducted in the United States (US) become available in 2012.

13. How are EU consumers protected from the possible harmful effects of pesticides and their residues?

There is a long history of legislation in place in the EU to protect consumers, operators such as farm workers, animals and the environment from any adverse effects that are posed by pesticides and their residues.

Since August 2002, EFSA has been responsible for the EU peer review of risk assessments of active substances used in plant protection products.

For each substance an initial draft risk assessment is carried out by experts in one Member State. This evaluation is then peer-reviewed by EFSA in cooperation with all Member States in order to guarantee the highest possible standards.

EFSA drafts conclusions summarising the outcome of the peer review process, which are sent to the European Commission.

The European Commission and EU Member States take a decision on whether or not to include an active substance in the list of authorised active substances in the EU.

EFSA is also responsible for proposing Maximum Residue Levels (MRLs) for pesticides.

14. What are Maximum Residue Levels (MRLs)?

Consumers are exposed to pesticides because small amounts can be found on harvested crops. These amounts are called pesticide residues.

MRLs are the upper levels of pesticide residues that are legally tolerated in or on food or feed. These must be safe for all consumers and are set as low as possible to protect vulnerable consumers such as children. MRLs are based on good agricultural practices, that is the minimum amount of pesticide needed to protect crops.

MRLs are set for a wide range of food types, such as fruit and vegetable, and also animal products such as milk, and they usually apply to the product as put on the market.

These levels are kept under constant review and if new data emerge indicating a possible risk, they can be lowered to reduce the exposure of operators, consumers and/or the environment.

15. What is the situation in Europe with respect to pesticide residues on foods?

Member States control the compliance with MRLs of pesticides in food and feed and submit the results to the Commission and EFSA. EFSA then prepares an annual report that provides an overview of pesticide residues in food observed throughout the EU and assesses the exposure of consumers through their diets. The outcomes serve as a basis for decision makers to possibly consider new or revised management measures.

The last report (based on 2008 figures) found that 96.5% of samples were within the MRL limits. The majority of the remaining 3.5% of samples that exceeded the MRLs limits were detected in foods imported into the EU . In total more that 70.000 samples of nearly 200 different types of food were analysed for pesticide residues.

16. Is EFSA considering the possible risk of exposure to mixtures of chemicals – sometimes called “cocktail effects”?

Yes, EFSA is working on refining assessment methodologies to evaluate possible risks from simultaneous exposure to chemicals found in the diet. EFSA is working with regulatory bodies, scientists and policymakers in Europe and around the world to improve methodologies for the assessment of these types of risks. These methodologies will provide risk assessors with new tools to measure possible combined effects deriving from exposure to multiple chemicals.

In the area of pesticides, EFSA’s work looks at groups of pesticides which have similar chemical structure and mode of action to see if their impact on human health should be assessed collectively rather than solely on an individual basis. As part of its ongoing work in this area, EFSA’s Panel on Plant Protection and their Residues (PPR) selected some pesticides from the group of triazole fungicides to test possible methodologies to assess cumulative effects from exposure through food.

EFSA is also pursuing such work for other chemicals found in food such as food additives, contaminants and food contact materials.

17. Does EFSA look at the environmental contamination of food?

Naturally occurring chemical compounds such as metals and nitrates can be present at various levels in the environment, e.g. soil, water and the atmosphere. They can also occur as residues in food because of their presence as environmental pollutants, as a result of human activities such as farming, industry or car exhausts or from contamination during food processing and storage. People can be exposed to them from the environment or by ingesting contaminated food or water. Their accumulation in the body can lead to harmful effects over time.

In 2009, EFSA’s CONTAM Panel carried out a risk assessment on cadmium in food and established a Tolerable Weekly Intake (TWI) of 2.5 micrograms per kilogram of body weight (µg/kg bw). Foodstuffs are the main source of cadmium exposure for the non-smoking general population. Cadmium is a metal that may be absorbed through the roots of plants to edible leaves, fruits and seeds, or build up in animal tissue destined for human consumption.

In 2011, the CONTAM Panel reaffirmed its previous conclusions with respect to the TWI for cadmium. Experts reconfirmed that whilst adverse effects are unlikely to occur in an individual with current dietary exposure, there is a need to reduce exposure to cadmium at the population level.

EFSA has also provided advice on nitrates in vegetables. Nitrate is a naturally occurring compound present in vegetables, the consumption of which can contribute significantly to nitrate dietary exposure.

EFSA’s CONTAM Panel published a statement in 2010 on the possible acute health effects of nitrate in infants and young children consuming spinach and lettuce. The Panel concluded that levels of nitrate in these vegetables are not of health concern for most children. It also stated, however, that infants and young children aged 1-3 years who consume high amounts of spinach with high nitrate levels could at times reach an intake level at which a risk of methaemoglobinaemia (or “blue baby syndrome”, a condition that reduces oxygen supply to the body) cannot be excluded.

18. What happens when there is concern over unforeseen chemical contamination in the food chain?

When a new hazard is found in the food chain – for instance the recent cases of dioxin contamination of pig meat or melamine found in various foods – scientists must quickly assess who is exposed, through which foods and at what levels. This is in order to provide a rapid and reliable risk assessment and to help risk managers take appropriate action to protect consumers.

For example, in December 2008, EFSA provided urgent scientific and technical assistance to the European Commission on the risks for human health following the discovery of dioxin contamination in Irish pig meat.

EFSA’s advice allowed the European Commission and Member States to rule on conditions to be met for food products to be put back on the market. Such a rapid reaction procedure shows how cooperation between Member States, EFSA and the European Commission can work to the benefit of both consumers and industry.

Also in 2008, following the discovery of melamine-contaminated milk powder in China, the European Commission asked EFSA to provide urgent scientific advice on the risks for human health from the possible presence of melamine in foods such as chocolate and biscuits.

EFSA’s advice was delivered in less than five working days and helped inform the measures taken by the European Commission to protect consumers including the banning of all products for infants and young children containing milk originating in China.

For further information on urgent requests for scientific advice see:

19. How does EFSA ensure the independence of its scientific advice?

EFSA’s policy on Declarations of Interest (DoI) is one of the most rigorous in force in the world. EFSA applies a robust set of internal mechanisms and working processes to safeguard the independence of the scientific work of its experts.

All experts are required to provide and keep updated an annual Declaration of Interests for each EFSA group of which they are members. EFSA recognises that high quality scientific expertise is by nature based on prior experience. It also recognises that having an interest does not necessarily imply that there is a conflict of interest.

Members of EFSA’s Scientific Committee, Scientific Panels and their Working Groups, as well as other external experts contributing to the work of EFSA, are selected based on their scientific competence and expertise, and according to objective and transparent criteria. During the selection process, interests declared by the applicants are also reviewed. In addition, independent external evaluators review the assessment of applications for scientific panel membership to ensure that the selection process is coherent.

EFSA’s opinions are the outcome of collective deliberations, each member having an equal say. No one expert can unduly influence the decisions of the Panel, and minority views are recorded.