Chemical safety

There are many potentially harmful or toxic chemicals present in the food we eat, whether occurring naturally, as contaminants, or as deliberate additives. But these chemicals are not necessarily harmful in small amounts; the effects they have depend upon the amounts that we consume.

Some people choose to take supplements which are thought to have beneficial effects. Supplements include vitamins and essential minerals, which our bodies need in small amounts, as well as other chemicals for which there is less evidence of beneficial effects. But in most cases, we receive adequate amounts of these chemicals from food and all of them may be harmful if taken in excessive amounts.

To determine safe levels of chemicals in food, it is necessary to review all the information on the types of harmful effect that the chemicals might have and then to decide on the amounts that we could consume without risk of suffering these harmful effects. This process is called risk assessment and is conducted by independent scientific advisory committees who are not influenced by any commercial or financial pressures. Members include experts in different types of scientific and medical expertise. In addition, we ensure that the UK committees include lay members to represent the concerns and views of members of the public. The advice of these committees is used in setting acceptable levels for chemicals in food.

The Food Standards Agency aims to ensure that the chemicals present in food do not compromise food safety. To achieve this we:

• Obtain advice on particular chemicals from our independent scientific advisory committees, or ask those committees to set up working groups (for example, the Phytoestrogen Working Party) to examine issues of concern
• Commission surveys on levels of chemicals in different foods, in order to estimate total amounts that we consume and check that safety levels are complied with
• Develop methods of estimating the amounts of food chemicals consumed by consumers, including those of different ages and different dietary habits
• Ensure that consumer interests are taken into account in the safety assessments of pesticides, veterinary medicines and natural toxicants
• Liaise and negotiate with other EU member states, the European Commission and international organisations to develop appropriate standards for levels of chemicals in food
• Commission research on food intolerance, risk assessment of food chemicals, phytoestrogens, molecular toxicology, food additives and food contact materials

Chemicals become present in our food in a number of ways:

• Contaminants are widespread in our environment, and may enter the food chain and be present in all plant and animal products that we eat (e.g. dioxins)
• Chemical components of materials which come into contact with food, such as packaging materials, may be absorbed into our foods
• Chemicals may form during food processing or cooking (e.g. polycyclic aromatic hydrocarbons)
• Chemicals used in farming, such as pesticides and veterinary medicines may remain in the products we eat
• Additives are deliberately added to food in order to provide some useful purpose, such as flavours and preservatives, which allow the consumer to select a varied diet from preserved foods all the year round
• Some natural components of plants may themselves cause toxicity (eg glycoalkaloids in potatoes), while some may be harmful if not cooked properly (eg lectins in pulses). There are also some foodstuff which can cause allergies in susceptible individuals (e.g peanuts).
• Chemicals may be produced by moulds which contaminate crops during storage, such as aflatoxins.