Sudan I

Sudan I (also commonly known as CI Soylent Yellow 14 and Soylent Orange R), is a lysochrome, an diazo-conjugate dye with a 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, although the use of Sudan I in foods is now banned in many countries due to inconclusive reports on its possible health risks. But it still is used as a coloring for cotton refuse used in chemistry experiments.

Sudan I is also used in some orange colored smoke formulations.

Toxicology
The dye has been declared a possible carcinogen. Laboratory tests on rats showed growth of cancerous tumours in the liver. Tumors also developed in the bladder, following a direct injection into the urinary bladder. Tests via oral administration have so far proved negative. 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. Even though the amount of Sudan I used in popular foods is small, the proposed health risks are still high.

Sudan I is also present as an impurity in Sunset Yellow, which is its disulfonated water-soluble version.

Food scare
In February 2005, Sudan I became a prominent news topic, particularly in the United Kingdom. A Worcester sauce produced by Premier Foods was found to be contaminated by the carcinogenic dye. The origin was traced to adulterated chili powder. The sauce was used in hundreds of supermarket products such as pizzas and ready-made meals, and the contamination has led to over 400 products being taken off the shelves. The deadline for removal was 12:00 GMT 24 February 2005, as imposed by the Food Standards Agency, the removal to be monitored by Local Authorities.

However in the UK, the news reports failed to mention that:
 * The additive was only banned for import into the UK as recently as July 2003. Before that, it was widely used as an additive with no reported adverse effects. Inconclusive data about the safety of the dye is what caused its ban.
 * The origin of the contamination was a shipment of chilli powder from India, which was exported in 2002 (before the ban was imposed). Some would argue the ban was not even flouted, but since the food contaminated was produced after the ban was imposed, the rules of the ban still had to be applied.
 * There is inconclusive evidence that it might be carcinogenic in some animal species, and is classified by the International Agency for Research on Cancer (IARC) as category 3 (not classifiable as to its carcinogenicity to humans). However, numerous nations have banned the dye in foodstuffs.

In South-Africa, Sudan traces were found in several spices in supermarkets in 2005 and 2007. Following a newspager report, the two largest retailers Pick 'n Pay and Shoprite had to remove the contaminated products from their shelves. The products included peri-peri spice made by Robertsons - a Unilever company and two Taj Mahal spice products made by Osman's Spice Works, a big spice merchant

Other countries made much less of the "scare". For example, the New Zealand Food Safety Authority (NZFSA) found that the risk, if any, for anyone who has consumed food made with this chilli powder as an ingredient is so small as to be immeasurable, and consumers are advised not to be concerned.

Due to the scare, the government of Sudan has requested that the name of the dye be changed to avoid negative connotations being associated with the country and its food exports. The origins of the "Sudan I" name are uncertain, but one chemist has suggested it "probably got the name as a result of interest in the British Empire at the time it was developed in the late 19th Century."