Frequently asked Questions and Answers on Sudan Red in Foodstuffs

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International Food Safety Authorities Network (INFOSAN)

Avian influenza: Food Safety Issues

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Food Fortification

Iodine Deficiency Disorders

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Genetically Modified Foods 

In view of the recent controversy and debate over the issue of food aid including GM foods to southern African countries, WHO has developed "20 questions on Genetically Modified (GM) foods" in response to questions and concerns by a number of WHO Member State Governments with regard to the nature and safety of genetically modified food. 

Pesticides and Food

Health Problems Pesticides May Pose

Laboratory studies show that pesticides can cause health problems, such as birth defects, nerve damage, cancer, and other effects that might occur over a long period of time. However, these effects depend on how toxic the pesticide is and how much of it is consumed. For these reasons, the Department of Agriculture, in cooperation with the Department of Health, carefully regulates pesticides to ensure that their use does not pose unreasonable risks to human health or the environment. In particular, the process is designed to ensure that these products can be used with a reasonable certainty that they will pose no harm to infants, children and adults.

Before allowing a pesticide to be used on a foodstuff, the Department of Health sets maximum residue limits to protect you from harmful levels of pesticides in/on your food.

What is a Pesticide?

Pesticide, as referred to in the Foodstuffs, Cosmetics and Disinfectants Act, 1972 (Act 54 of 1972) is defined by the Department of Agriculture, in the Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act, 1947 (Act 36 of 1947) as follows: "Any chemical substance or biological remedy, or any mixture or combination of any substance or remedy intended or offered to be used:

  1. for the destruction, control, repelling, attraction or prevention of any undesired microbe, alga, nematode, fungus, insect, plant, vertebrate, invertebrate, or any product thereof, but excluding any chemical substance, biological remedy or other remedy in so far as it is controlled under the Medicines and Related Substances Control Act, 1965 (Act No. 101 of 1965), or the Hazardous Substances Act, 1973 (Act No. 15 of 1973; or
  2. as plantgrowth regulator, defoliant, desiccant or legume inoculant,
    and anything else which the Minister of Agriculture has by notice in the Gazette declared an agricultural remedy for the purposes of Act 36 of 1947."

In brief, a pesticide is any substance or mixture of substances used to kill, drive away or prevent a pest.

What does Maximum Residue Limit (MRL) mean?

MRL means the maximum concentration of a pesticide residue (expressed as mg/kg), as set by the Minister of Health in regulations in terms of Act 54 of 1972 that may be legally present in or on foodstuffs and animal feeds. MRLs are based on Good Agricultural Practice (GAP) data and foods derived from commodities that comply with the respective MRLs are intended to be toxicologically acceptable.

MRLs and Consumer Intake

How MRLs are set

  1. Supervised trials
    In keeping with the definition of an MRL, the Department of Health in collaboration with the Department of Agriculture seeks and evaluates information on the nature and level of residues resulting from the use of the pesticide in Good Agricultural Practice (GAP). This information is generally derived from supervised field trials carried out in accordance with guidelines developed by the Department of Agriculture for foodstuffs of plant origin.

    These residues depend on two factors:
    1. The initial deposit and
    2. The rate of disappearance of the pesticide (and its metabolites)

    For details on residue trial data requirements visit the Agricultural Remedy Residue Trial Data Requirements Document. (outside link)

  2. Food consumption data
    By using appropriate consumer consumption data, the daily residue intake can be estimated for the population. Estimates of consumption data may be obtained from various kinds of monitoring studies including the analysis of individual foods. The South African consumption data can be obtained from:
    the "Report on South African Food Consumption studies undertaken amongst different population groups (1983 - 2000): Average intakes of Foods most commonly Consumed"

    Average data on available food for utilization, can be found in the Food and Agricultural Organization's (FAO) Food Balance Sheets (FBSs) (available food for utilization equals production plus imports minus exports). FBS data has been shown to usually overestimate the average food consumption of a population by about 15%.

  3. Acceptable Daily Intake (ADI)
    Data from toxicological tests on the pesticide allow for allocating an ADI. This is the daily dosage of a chemical, which, during an entire lifetime (chronic), appears to be without appreciable risk on the basis of all the facts known at the time. The ADI is expressed in milligrams of the chemical, as it appears in the food, per kilogram of body weight (mg/kg.

Theoretical Maximum Daily Intake (TMDI)

MRLs are based on maximum residue limits estimated from data from supervised trials and/or selective studies. Therefore it is possible to calculate the maximum theoretical daily intake by simply multiplying the MRL for each foodstuff by the daily intake per person's consumption of foodstuff in the country. The calculation assumes that:

The calculated figures are likely to be greatly in excess of the actual intakes. More important to the successful prediction of consumer intake is the information on the disappearance of the residue during the preparation and cooking or processing of the foodstuff. If in the absence of data, no losses are assumed during transport and storage (there are usually some) and the average losses of residues on preparation, cooking or processing are assumed to be about 80%, then the realistic prediction of consumer intake is about one hundredth of the maximum theoretical daily intake.

If the estimated daily consumer intake for all foodstuffs calculated as the TMDI is lower than the ADI calculated under (iii) then the residue limit under (i) is set as the MRL.

The following formula is used:

Formula

For more information on the registration procedure of pesticides, visit the website of the Department of Agriculture.

To learn what the pesticide residue limits are for your favourite foods, you can download a zipped MS Excel spreadsheet:

Three very important points to remember about the spreadsheets:

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