Allura Red AC

"E129" redirects here. For the train, see E129 series.

Allura Red AC
Names
Preferred IUPAC name
Disodium 7-hydroxy-5-[(2-methoxy-5-methyl-4-sulfonatophenyl)diazenyl]naphthalene-2-sulfonate
Other names
  • Disodium 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfophenyl)azo]-2-naphthalenesulfonate
  • Allura Red
  • Food Red 17
  • C.I. 16035
  • FD&C Red 40
  • E129
  • 2-Naphthalenesulfonic acid, 6-hydroxy-5-((2-methoxy-5-methyl-4-sulfophenyl)azo)-, disodium salt
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.043.047 Edit this at Wikidata
E number E129 (colours)
UNII
  • InChI=1S/C18H16N2O8S2.2Na/c1-10-7-14(16(28-2)9-17(10)30(25,26)27)19-20-18-13-5-4-12(29(22,23)24)8-11(13)3-6-15(18)21;;/h3-9,21H,1-2H3,(H,22,23,24)(H,25,26,27);;/q;2*+1/p-2/b20-19+;; checkY
    Key: CEZCCHQBSQPRMU-LLIZZRELSA-L checkY
  • InChI=1/C18H16N2O8S2.2Na/c1-10-7-14(16(28-2)9-17(10)30(25,26)27)19-20-18-13-5-4-12(29(22,23)24)8-11(13)3-6-15(18)21;;/h3-9,21H,1-2H3,(H,22,23,24)(H,25,26,27);;/q;2*+1/p-2/b20-19+;;
    Key: CEZCCHQBSQPRMU-JGGVBICHBN
  • [Na+].[Na+].COc3cc(c(C)cc3/N=N/c1c2ccc(cc2ccc1O)S([O-])(=O)=O)S([O-])(=O)=O
Properties
C18H14N2Na2O8S2
Molar mass 496.42 g·mol−1
Appearance Red powder
Melting point > 300 °C (572 °F; 573 K)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Allura Red AC, also known as FD&C Red 40 or E129, is a red azo dye commonly used in food. It was developed in 1971 by the Allied Chemical Corporation, who gave the substance its name.[1][2]

It is usually supplied as its red sodium salt but can also be used as the calcium and potassium salts. These salts are soluble in water. In solution, its maximum absorbance lies at about 504 nm.[3]: 921 

Allura Red AC is manufactured by coupling diazotized 5-amino-4-methoxy-2-toluenesulfonic acid with 6-hydroxy-2-naphthalene sulfonic acid in an azo coupling reaction.[4]

  1. ^ "From Shampoo to Cereal: Seeing to the Safety of Color Additives". Archived from the original on 15 January 2008. Retrieved 4 June 2008. "Food Color Facts". Archived from the original on 1 October 2007. Retrieved 18 August 2006.
  2. ^ Barrows, Julie N. (2016). Wallin, Harriet (ed.). "Allura Red AC". 82nd Joint FAO/WHO Expert Committee on Food Additives (JECFA) - Chemical and Technical Assessment (CTA) – via Food and Agriculture Organization of the United Nations.
  3. ^ Zvi Rappoport, ed. (2004). The Chemistry of Phenols. Chichester: John Wiley & Sons. ISBN 9780470869451.
  4. ^ PubChem. "Allura Red AC". pubchem.ncbi.nlm.nih.gov. Retrieved 21 October 2021.