Food can contain a wide range of metallic elements (metals) such as sodium, potassium, iron, calcium, magnesium, copper and zinc. These metals in trace quantities are essential in the human diet for normal bodily functions.
However, other metallic elements (referred to as “metals” from here on) have no functional effects in the body and can be harmful to health if foodstuffs containing them are consumed regularly in the diet. The majority of all metals are natural components of the earth’s crust. Metals and other elements can be naturally present in food due to their uptake from the environment or can enter food as a result of human activities such as industrial and agricultural processes.
The metals of particular concern in relation to harmful effects on health are: Mercury (Hg), Lead (Pb), Cadmium (Cd), Tin (Sn), Nickel (Ni) and Arsenic (As).
Questions and answers about each metal
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Mercury
Is mercury dangerous to consumers?
Yes, excessive exposure to mercury is associated with several adverse health effects including damage to the central nervous system (neurotoxicity) and the kidneys.
There are two forms of mercury, organic and inorganic, and the organic form methylmercury is more toxic. The main concern for methylmercury is potential neurotoxicity in young children. Organic forms of mercury can potentially pass from the mother to the unborn baby through the placenta, and if exposure is high enough can cause adverse effects on the developing brain.
What are the sources of exposure to Mercury in food?
Contamination of food with mercury arises from the natural presence of mercury in the environment and due to human activities, including mining, industrial processes, and burning of fossil fuels.
Mercury exposure mainly occurs through dietary sources, where it is evenly distributed in food at very low concentrations, as well as through dental amalgam (i.e. fillings).
The main sources of mercury in the diet are fish, particularly predatory fish species (e.g. shark, swordfish, marlin and tuna), other fish such as cod and whiting, and shellfish (molluscs and crustaceans).
What dietary advice does the FSAI have for pregnant and breastfeeding women, women of childbearing age and young children?
Due to the high levels of mercury in predatory fish, the FSAI advises pregnant and breastfeeding women, women of childbearing age and young children to avoid consumption of shark, swordfish and marlin, and to limit their intake of tuna steak and canned tuna, while continuing to consume other fish as part of a balanced diet. More information is available on the FSAI’s webpage on Mercury and Fish Consumption and the Healthy Eating Guidelines.
What should food businesses do to limit Mercury in foods?
All food businesses, i.e., food business operators, have a legal responsibility under the General Food Law (Regulation (EC) No 178/2002) to ensure the food they place on the market is safe and complies with all relevant legal requirements.
The implementation of a food safety management system based on the principles of Hazard Analysis and Critical Control Point (HACCP) is also a legal requirement for most food businesses under Article 5 of Regulation (EC) No 852/2004.
A HACCP system enables hazards such as mercury to be identified and controlled by the food business, before they become a food safety issue. In that regard, in those food businesses where mercury have been identified as a hazard, it must be ensured that food placed on the market complies with the maximum levels for mercury. These maximum limits are laid down in the following legislation depending on the food type:
- Regulation (EU) 2023/915 establishes maximum levels for mercury in the muscle meat of fish, bivalve molluscs, crustaceans, food supplements and salt.
- Regulation (EC) No 396/2005 establishes maximum residue levels for various mercury compounds used in pesticides which are not authorised for use in the European Union. The maximum residue level is established at a level which is not quantifiable by laboratories in the European Union.
- Commission Delegated Regulation (EU) 2016/128 establishes a maximum residue level for mercury compounds in food for special medical purposes to protect against its unauthorised use in pesticides. The maximum residue level is established at a level which is not quantifiable by laboratories in the European Union.
- Commission Directive 2006/125/EC establishes a maximum residue level for mercury compounds in processed cereal-based foods and baby foods for infants and young children to protect against its unauthorised use in pesticides. The maximum residue level is established at a level which is not quantifiable by laboratories in the European Union.
- Commission Regulation (EU) No 231/2012 establishes maximum levels for mercury in specific food additives.
- Regulation (EC) No 853/2004 establishes maximum levels for mercury in gelatine and collagen.
- Commission Implementing Regulation (EU) No 1321/2013 establishes maximum levels for mercury in smoke flavourings.
- Commission Implementing Regulation (EU) 2017/2470 establishes maximum levels for mercury in novel foods.
How are foods sampled and monitored for Mercury?
There are detailed rules provided in Regulation (EC) No 333/2007 for the sampling and analysis of foods for mercury. These rules include the sampling procedures to be followed by those taking the samples, the precautions to be taken during sampling and the methods of analysis to be used in the laboratories.
How do you minimise the presence and level of Mercury in food?
Mercury can accumulate in food from the environment during the early stages of production. For consumers, there are few options to reduce the levels of the mercury during preparation and cooking.
In general, consumers can lower their exposure to mercury by eating a healthy and balanced diet.
Some specific measures to reduce exposure to mercury in food includes:
- Avoid regularly consuming food known to contain high levels of mercury. For example, predatory fish such as shark, swordfish and marlin. It is particularly important to avoid consuming fish known to contain high levels of mercury if you are pregnant or breastfeeding. Maximum levels are established in legislation to encourage the application of good practices by industry, to remove contaminated food from sale and protect consumers.
- If you have a private drinking water supply, it is recommended to test the water annually for heavy metals to ensure it does not contain excessive levels.
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Lead
Lead
Is lead dangerous to consumers?
Yes, the toxic effects of lead are a consequence of its accumulation in the body, particularly in the skeleton. Even after exposure ends, lead is released back into the bloodstream.
Lead affects virtually every system in the body. The critical target is the central nervous system, especially the developing brain.
Sources of exposure
Food and water represent the major sources of exposure. Lead contamination arises from industrial releases such as mining, smelting, battery manufacturing and past use of leaded petrol.
Main dietary sources include alcoholic drinks, cereals, vegetables, tap water, fish, shellfish and edible offal.
Food business responsibilities
Food businesses must comply with General Food Law and HACCP requirements.
- Regulation (EU) 2023/915 – maximum levels for lead in many foods.
- Commission Regulation (EU) No 231/2012 – food additives.
- Regulation (EC) No 853/2004 – gelatine and collagen.
- Commission Implementing Regulation (EU) No 1321/2013 – smoke flavourings.
- Directive (EU) 2015/2203 – caseins and caseinates.
- Commission Implementing Regulation (EU) 2017/2470 – novel foods.
- Council Directive 84/500/EEC – migration limits from ceramic articles.
Sampling and monitoring
Regulation (EC) No 333/2007 provides rules for sampling and analysis of foods for lead.
Minimising lead
- Avoid foods known to contain high levels of lead.
- Follow manufacturer instructions for food contact materials.
- Limit use of ceramic vessels with lead glazes and leaded crystal glass.
- Test private drinking water supplies annually.
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Cadium
Is cadmium dangerous?
Yes, cadmium is primarily toxic to the kidneys and can cause renal dysfunction or failure. It can also cause bone demineralisation.
Sources of exposure
Cadmium is present at low levels in most foods. Highest levels occur in seaweed, cocoa products, crustaceans, offal, mushrooms, oilseeds and molluscs.
Food business responsibilities
Food businesses must comply with General Food Law and HACCP.
- Regulation (EU) 2023/915 – maximum levels for cadmium in many foods.
- Commission Regulation (EU) No 231/2012 – food additives.
- Regulation (EC) No 853/2004 – gelatine and collagen.
- Commission Implementing Regulation (EU) No 1321/2013 – smoke flavourings.
- Commission Implementing Regulation (EU) 2017/2470 – novel foods.
- Council Directive 84/500/EEC – migration limits from ceramic articles.
Sampling and monitoring
Regulation (EC) No 333/2007 provides rules for sampling and analysis.
Minimising cadmium
- Avoid foods known to contain high levels of cadmium.
- Follow manufacturer instructions for food contact materials.
- Peel fruit and vegetables.
- Test private drinking water supplies annually.
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Arsenic
Is arsenic dangerous?
Yes, long-term exposure to inorganic arsenic is associated with cancers, cardiovascular disease, respiratory disease, kidney disease, neurodevelopmental effects and impacts on unborn babies.
Sources of exposure
Arsenic is naturally occurring in soil, groundwater and plants.
Main sources of total arsenic: fish and seafood.
Main sources of inorganic arsenic: rice, grain products and drinking water.
Dietary advice
- Limit consumption of hijiki seaweed.
- Avoid rice milk for infants and young children.
Food business responsibilities
- Regulation (EU) 2023/915 – cereals, infant foods, fruit juices, salt.
- Commission Regulation (EU) No 231/2012 – food additives.
- Regulation (EC) No 853/2004 – gelatine and collagen.
- Commission Implementing Regulation (EU) No 1321/2013 – smoke flavourings.
- Commission Implementing Regulation (EU) 2017/2470 – novel foods.
Sampling and monitoring
Regulation (EC) No 333/2007 provides rules for sampling and analysis.
Minimising arsenic
- Avoid foods known to contain high levels of arsenic.
- Wash or soak rice before cooking.
- Peel fruit and vegetables.
- Test private drinking water supplies annually.
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Nickel
Is nickel dangerous?
Yes, long-term exposure can affect gastrointestinal, blood, neurological and immune systems. Nickel can trigger reactions in nickel-sensitized individuals.
Sources of exposure
Nickel is widely distributed in nature. Main dietary sources include grain products, beans, coffee, soups, chocolate and breakfast cereals.
Food business responsibilities
- Regulation (EU) 2023/915 – maximum levels for nickel in nuts, vegetables, legumes, seaweed, cereals, cocoa products, fruit juices and infant foods.
Sampling and monitoring
Regulation (EC) No 333/2007 provides rules for sampling and analysis.
Minimising nickel
- Avoid foods known to contain high levels of nickel.
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Tin
Is tin dangerous?
Tin is relatively less toxic. Gastrointestinal effects occur at high concentrations in canned foods and beverages.
Sources of exposure
Tin is used as a coating for cans. Food in tin-plated cans is the main source of exposure.
Food business responsibilities
- Regulation (EU) 2023/915 – maximum levels for inorganic tin in canned foods and beverages.
Sampling and monitoring
Regulation (EC) No 333/2007 provides rules for sampling and analysis.
Minimising tin
- Transfer leftover food from opened cans into other containers.
- Choose lacquered cans.
- Do not re-use cans.