5. In recent years, concerns on the genotoxic potentials of Sudan dyes have been raised. Several national bodies and food authorities consider Sudan dyes as genotoxic carcinogens while others regard these Sudan dyes as possible carcinogens.
Sudan I (also commonly known as CI Solvent Yellow 14 and Solvent Orange R), is a lysochrome, a diazo-conjugate dye with the chemical formula of 1-phenylazo-2-naphthol. Sudan I is a powdered substance with an orange-red appearance. The additive is mainly used to colour waxes, oils, petrol, solvents and polishes. Sudan I has also been adopted for colouring various foodstuffs, including particular brands of curry powder and chili powder (Eastern Curry Powder, Admali, Kerala, India), although the use of Sudan I in foods is now banned in many countries, because Sudan I, Sudan III, and Sudan IV have been classified as category 3 carcinogens (not classifiable as to its carcinogenicity to humans) by the International Agency for Research on Cancer.
Sudan I is a rodent carcinogen — laboratory tests on rats showed growth of cancerous tumours in the liver and bladder. These tests have led to the additive being banned from use in foods throughout the EU, as it may pose an increased risk of cancer.Comparisons between experimental animals and human Cytochrome P450 (CYP) strongly suggest animal carcinogenicity data can be extrapolated to humans.
Sudan I is also present as an impurity in Sunset Yellow, which is its disulfonated water-soluble version.
Sudan Dye Colourings In Food
Sudan dyes are red dyes that are used for colouring solvents, oils, waxes, petrol, and shoe and floor polishes. They have also been discovered in some imported chilli powder from India and most recently finding their way into relishes, chutneys and seasonings containing chilli powder. Sudan dyes are not permitted in food in the UK, EU and Australia and New Zealand due to concerns that the dyes may be carcinogenic in animals. There is limited evidence that exposure to products may be a health risk.
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Leeder Consulting has a validated laboratory procedure which can assist importers, local producers, regulators and governments with detection of Sudan I, II, III, and IV. The Sudan dyes are analysed utilising Liquid Chromatography with a diode array detector. Confirmation is performed using Liquid Chromatography / Mass Spectrometry (LC/MS) Methods which provides high selectivity and sensitivity. The LC/MS allows for the detection of these contaminants at parts per billion levels in processed foods. This means that trace levels of Sudan dyes present due to adulterated ingredients can be detected.
Properties
Sudan dyes are synthetic chemical dyes of similar chemical structure. They are aromatic compounds containing azo group ( - N=N - ).
Sudan I, II, III and IV are kinds of the Sudan red dyes. They can be generally applied for colouring substances such as hydrocarbon solvents, oils, fats, waxes and plastics.
Sudan II and III can also be used in cosmetics and drugs applied externally whereas Sudan IV (also known as scarlet red) can be used in veterinary and human medicine as an ointment or dressings for stimulating wound healing.
Toxicity
1. Sudan I was considered by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1973 to be unsafe for use in food, on the basis of toxicological evidence.
2. Although Sudan dyes have been reported as contact allergens and sensitisers, the greatest concern has been on their possible carcinogenicity.
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3. International Agency for Research on Cancer (IARC) conducted evaluation on Sudan dyes in 1975 and considered that Sudan I was carcinogenic in mice following its subcutaneous administration, producing tumours of the liver and that it also produced bladder tumours in mice following its implantation into the urinary bladder.
4. In its subsequent evaluation in 1987, IARC considered that there was no adequate data for carcinogenicity in humans and limited evidence in experimental animals for Sudan I and II, and inadequate evidence in experimental animals for Sudan III and IV. IARC considered that Sudan I, II, III, IV were unclassifiable as to their carcinogenicity to humans (Group 3).
Attention
1. Purchase food from reliable retailers and caterers.
2. When shopping for foods, read carefully information on labels.
3. When selecting foods, in particular chilli and chilli products, avoid those with abnormally red colour or sold at unreasonably low price.
4. In case you find any foods particularly chilli and chilli products with unnatural or abnormal colour, inform the Food and Environmental Hygiene Department (hotline 2868 0000) for investigation and other follow-up actions.
5. Maintain a balanced diet to avoid excessive exposure to contaminants or additives from a small range of food items.
