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Contaminants, additives, residues and Codex

New foods, new technologies
Other Codex documents
Thailand: A success story

"A well-prepared dish of food should appeal to the eye by its colouring, to the nose by its smell, to the ear by its sound and to the mouth by its flavor. "
- Old Chinese saying

Residues of veterinary drugs must be controlled to ensure safe foods

To the above saying might be added "and to the chemist by its purity". But things get into foods. Nature itself is a polluter, allowing not only bacteria but also pests, moulds, and even toxic heavy metals to mix with the things we eat. Synthetic chemicals further complicate the situation.

All of this represents a continuing challenge to food producers, technologists, regulators and the Codex Alimentarius Commission. The job that Codex does in meeting this challenge is of major importance to the health of the world because few countries have the capability of assessing the risks that can be caused by chemicals that become, intentionally or unintentionally, part of foods.

Codex's work is important to international trade, too, for as has been noted, improperly applied science may be used to prevent foods from entering a country.

The international effort in this area actually predates Codex Alimentarius. The first Joint FAO/WHO Conference on Food Additives was held in 1955. A year later, the Joint FAD/WHO Expert Committee on Food Additives (JECFA) was formed to advise the two organizations with the aim of formulating general principles on the use of food additives and recommending methods of analysis. Since 1963 JECFA's advice has also been used by the Codex Committee on Food Additives and Contaminants.

JECFA first defined a food additive as simply a "non-nutritive substance added intentionally to food, generally in small quantities to improve appearance, flavor, texture or storage properties". However, the work of JECFA has gradually been expanded to incorporate other substances, including contaminants and processing materials. In addition, JECFA has taken on veterinary drugs, and its reports are used by the Codex Committee on Residues of Veterinary Drugs in Foods, which was formed in 1985.

JECFA evaluates additives on an acceptable daily intake (ADI) basis. ADI is the amount of an additive that can be ingested on a daily basis, even for a lifetime, without affecting the health of an individual - i.e. without significant risk. ADI is expressed in milligrams per kilogram of body weight.

The JECFA work on food additives is a key step in developing Codex standards for additives, standards that can assure consumers that the levels of additivies used are safe and that their use is justified to meet the processing and marketing demands of modern society.

JECFA has examined more than 700 chemicals as well as 25 contaminants, including such common environmental ones as lead, mercury and aflatoxins.

JECFA members are selected from the scientific community on the basis of their expertise. If they agree to serve, and if their country approves, they work as individuals and not as representatives of their governments or employers. Consultants and advisers are hired to review the literature for the committee and provide members with synopses. The committee members then do peer reviews not only of the published literature but also of any available unpublished industry data. The reviewed materials are discussed at JECFA meetings, and recommendations are developed for Codex.

Advising the Codex Committee on Pesticide Residues are two groups of scientists who collaborate in the Joint FAD/WHO Meetings on Pesticide Residues (JMPR).

These are the FAO Panel of Experts on Pesticide Residues in Food and the Environment and the WHO Expert Group on Pesticide Residues. Together they have a role similar to that of JECFA, doing technical evaluations of scientific data and making recommendations to the Codex residue committee.

The recommendations are in the form of ADIs for the pesticide residues and MRLs for specific pesticide/food combinations. JMPR has evaluated more than 180 pesticides and set over 3000 MRLs.

The Codex Committee on Residues of Veterinary Drugs in Foods reviews drugs that are used in animals to treat and protect against disease or to improve production. In addition to acting on the monographs on residue levels supplied by JECFA, the veterinary drug committee establishes an annual priority list of drugs to be evaluated, develops codes of practice and determines criteria for analytical methods used to control veterinary drug residues in food.

A farmer sprays a pesticide on rice seedlings in Laos

Safe use of food additives is a major aspect of Codex work

New foods, new technologies

JECFA and the Codex Committee on Food Additives and Contaminants have taken the position that new or novel foods and new technologies such as genetic engineering need to be assessed for safety as if they were food additives. The definition may well be debatable, but it puts Codex in the position of being able to evaluate the safety of new or newly distributed products.

A case in point is the class of textured vegetable proteins. Their wide use led to Codex's creation of a commodity committee on vegetable proteins. The committee's purpose was to control the composition, quality and level of use of the proteins in other foods. That committee has since finished its work.

But the most important of all among new "food additives" will probably be products prepared with biotechnology. This technology is bringing about modifications in the composition of traditional foods and is expected to lead to the introduction of entirely new foods. Other changes being explored for crops include engineered resistance against disease and climatic conditions. Such accomplishments could lessen the need for pesticides and fertilizers.

Other Codex documents

Other publications that Codex has developed over the years include documents dealing with principles on methods of analysis and sampling, on establishing and applying microbiological criteria for foods and on the use of food additives; specifications for identity and purity of food additives, a guide to Codex recommendations on pesticide residues; and a code of practice for operating an irradiation facility used to treat foods. There is also a Code of Ethics for International Trade in Food, which is aimed at stopping the practice of dumping foods rejected by one country on another country.

Thailand: A success story

Like many developing countries in tropical areas, Thailand has had a great potential for improving its food export business. The southeast Asian country grows pineapple and other tropical fruits, cashew nuts, many types of mushrooms and baby corn. It also harvests shrimp and other marine products, and its rice is considered by many to be the best in the world.

Since establishment of its National Codex Alimentarius Committee in 1969, Thailand has seen its food exports grow nearly 12-fold to more than US$4000 million. However, the growth has been haphazard: exports increased by about 30 percent between 1980 and 1981, but then dropped back to less than the 1980 level for the next four years, as food products were continually rejected by foreign countries.

Noting that products were being refused because of contamination and improper labelling, the country called upon FAO and the United Nations Development Programme for help. FAO experts were sent to the country, as they often are upon request. Using Codex Alimentarius standards and guidelines, they set up a pilot export control programme, trained inspectors, designed voluntary inspection systems and brought in laboratory people to train Thai workers. Video programmes were developed for training projects, and a Memorandum of Understanding ensuring inspection and certification procedures for monitoring and sampling was signed with one of the world's major importing countries. At the same time, WHO experts assisted Thailand in building up its domestic food safety capabilities.

Thailand's food exports grew from US$2500 million to US$4800 million between 1985 and 1989, contributing greatly to the country's 10 percent economic growth rate during the period.

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