Allura Red, FD&C Red No. 40 is manufactured by coupling diazotized 5-amino-4-methoxy-2-toluenesulfonic acid with 6-hydroxy-2-naphthalene sulfonic acid in an
azo coupling reaction.[3]
Use as a consumable coloring agent
Allura Red AC is a popular dye used worldwide. Annual production in 1980 was greater than 2.3 million kilograms.[4] It was originally introduced as a replacement for
amaranth in the United States.[5]
The
European Union approves Allura Red AC as a food colorant, but EU countries' local laws banning food colorants are preserved.[6]
In the United States, Allura Red AC is approved by the FDA for use in
cosmetics, drugs, and food. When prepared as a
lake pigment it is disclosed as Red 40 Lake or Red 40 Aluminum Lake. It is used in some tattoo inks and is used in many products, such as
cotton candy,
soft drinks,
cherry-flavored products, children's medications, and
dairy products. It is occasionally used to dye medicinal pills, such as the
antihistaminefexofenadine, for purely aesthetic reasons.[7] It is by far the most commonly used red dye in the United States,[8] completely replacing
amaranth (Red 2) and also replacing
erythrosine (Red 3) in most applications due to the negative health effects of those two dyes.[9]
Studies on safety
Allura Red has been heavily studied by food safety groups in North America and Europe, and remains in wide use.
The UK's Food Standards Agency commissioned a study of six food dyes (
tartrazine, Allura red,
Ponceau 4R,
Quinoline Yellow,
sunset yellow,
carmoisine (dubbed the "Southampton 6")), and
sodium benzoate (a preservative) on children in the general population, who consumed them in beverages.[10][11] The study found "a possible link between the consumption of these artificial colours and a sodium benzoate preservative and increased hyperactivity" in the children;[10][11] the advisory committee to the FSA that evaluated the study also determined that because of study limitations, the results could not be extrapolated to the general population, and further testing was recommended.[10]
The
European Food Safety Authority (EFSA), with a stronger emphasis on the
precautionary principle, required labelling and temporarily reduced the
acceptable daily intake (ADI) for the food colorings; the UK FSA called for voluntary withdrawal of the colorings by food manufacturers.[10][11] However, in 2009, the EFSA re-evaluated the data at hand and determined that "the available scientific evidence does not substantiate a link between the color additives and behavioral effects",[10] and in 2014, after further review of the data, the EFSA restored the prior ADI levels.[12] In 2015, the EFSA found that the exposure estimates did not exceed the ADI of 7 mg/kg per day in any population.[13]
The US FDA did not make changes following the publication of the Southampton study, but following a citizen petition filed by the
Center for Science in the Public Interest in 2008, requesting the FDA ban several food additives, the FDA commenced a review of the available evidence, but found no evidence to justify changes.[10]
Allura Red AC has previously been banned in
Denmark,
Belgium,
France,
Switzerland, and
Sweden.[14] This changed in 2008, when the EU adopted a common framework for authorising food additives,[15] under which Allura Red AC is not currently banned.[13] In
Norway and
Iceland, it was banned between 1978 and 2001, a period in which azo dyes were only legally used in alcoholic beverages and some fish products.[16]
Chronic exposure to the dye has been shown to increase susceptibility to bowel disorders in mice. [17]
^Zvi Rappoport, ed. (2004). The Chemistry of Phenols. Chichester: John Wiley & Sons.
ISBN9780470869451.
^PubChem.
"Allura Red AC". pubchem.ncbi.nlm.nih.gov. Retrieved 21 October 2021.
^Sharma, Vinita; McKone, Harold T.; Markow, Peter G. (2011). "A Global Perspective on the History, Use, and Identification of Synthetic Food Dyes". Journal of Chemical Education. 88 (1): 24–28.
Bibcode:
2011JChEd..88...24S.
doi:
10.1021/ed100545v.
^
abcSarah Chapman of Chapman Technologies on behalf of Food Standards Agency in Scotland. March 2011 [Guidelines on approaches to the replacement of Tartrazine, Allura Red, Ponceau 4R, Quinoline Yellow, Sunset Yellow and Carmoisine in food and beverages]