Allura Red AC

Allura Red AC is a red azo dye that goes by several names including: Allura Red, Food Red 17, C.I. 16035, FD&C Red 40, 2-naphthalenesulfonic acid, 6-hydroxy-5-((2-methoxy-5-methyl-4-sulfophenyl)azo)-, disodium salt, and disodium 6-hydroxy-5-((2-methoxy-5-methyl-4-sulfophenyl)azo)-2-naphthalene-sulfonate. It is used as a food dye and has the E number E129. Allura Red AC was originally introduced in the United States as a replacement for the use of E123 as a food coloring. Its CAS registry number is 025956-17-6.

It has the appearance of a dark red powder. It usually comes as a sodium salt, but can be also be used as both calcium and potassium salts. It is soluble in water. In water solution, its maximum absorbance lies at about 504 nm. Its melting point is at >300 degrees Celsius.

Allura Red AC is one of many High Production Volume Chemicals. Some manufacturers of Allura Red AC include: Asim Products, Sanchi Chemicals Pvt. Ltd., and Warner-Jenkinson Europe Ltd.

Despite the popular misconception, Allura Red AC is not derived from the cochineal insect. Red AC is derived from coal tar. However, the red coloring carmine is derived from the female Dactylopius coccus, a South and Central American beetle.

Related dyes include Sunset Yellow FCF, Scarlet GN, tartrazine, and Orange B.

Health effects
In Europe, Allura Red AC is not recommended for consumption by children. It is banned in Denmark, Belgium, France, Germany, Switzerland, Sweden, and Austria. The European Union approves Allura Red AC as a food colorant, but EU countries' local laws banning food colourants are preserved. . In Norway it was banned between 1978 and 2001. In this period azo dyes were only legally used in alcoholic beverages and some fish products. .

In the United States, Allura Red AC is approved by the Food and Drug Administration for use in cosmetics, drugs, and food. It is used in some tattoo inks and is used in many products, such as orange soda.

Allura Red AC has few health risks associated with it in comparison to other azo dyes. Upon its introduction onto the market, there were fears that Allura Red AC was carcinogenic; however, studies have since shown that this is not the case. The initial reports of its consumption causing tumors have since been shown to have been caused by the presence of para-cresidine. Although para-cresidine is an important reactant in the manufacture of Allura Red AC and is a known carcinogen, further studies conducted since have found no trace of para-cresidine to be present in food-grade Allura Red AC.

In dogs and rats, Allura Red AC is found to be mainly excreted through the feces, with some of the compound coming through the urinary tract. It is believed that significant retention in the intestinal contents is due to adhesion of the compound to the intestinal wall.

Cresidinesulfonic acid is a major metabolite in urine, as well as two other unidentifiable metabolites. In dogs, a third unknown metabolite was discovered.

Allura Red AC, when applied to human skin has not been found to cause irritation or sensitization. Taken orally, it has induced a positive reaction for hypersensitivity in 15% of human subjects in an experiment conducted on 52 people.

Allura Red AC may cause an adverse reaction in the small number of people with an aspirin intolerance or allergy, manifesting itself as a skin rash (urticaria) and/or nausea.

A study commissioned by the UK's Food Standards Agency found that when used in a mixture of other preservatives, increased levels of hyperactivity in children were observed.