Certain industrial red dyes - such as Para Red and the four Sudan dyes (Sudan I, Sudan II, Sudan III and Sudan IV, otherwise know as scarlet red) - are not permitted for use in food, as they are carcinogenic. however, Sudan dyes are used legally in shoe and floor polish, solvents, oils, waxes and petrol.
Sudan dyes have been used illegally in spices, sauces, chutneys, vinegars and palm oil, among many other products and, in some of these cases, food products have been recalled.
Food alerts about illegal dyes
The Food Standards Agency (FSA) publishes information on food alerts, where food has been recalled due to the presence of illegal dyes.
Other illegal dyes are:
- butter yellow
- metanil yellow
- orange G
- rhodamine B
- orange II
- toluidine red
Food imports and Sudan dyes
Since 2003, all imports of dried, crushed and ground spices, curry powders, curcumin and palm oil have had to be accompanied by test certificates showing that they do not contain Sudan dyes. Any consignment without relevant documentation is detained for sampling and analysis.
Random sampling must also be carried out by port and district councils. Any consignment found to contain Sudan is destroyed.