Red 2G

Red 2G
Skeletal formula of Red 2G as a sodium salt
Space-filling model of the Red 2G molecule as a sodium salt
Names
Other names
  • Acid Red 1
  • Food Red 10
  • Amidonaphthol red G
  • azogeranine
  • azophloxine
  • azofloxin
  • C.I. 18050
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.020.999 Edit this at Wikidata
E number E128 (colours)
UNII
  • InChI=1S/C18H15N3O8S2/c1-10(22)19-14-9-13(30(24,25)26)7-11-8-15(31(27,28)29)17(18(23)16(11)14)21-20-12-5-3-2-4-6-12/h2-9,23H,1H3,(H,19,22)(H,24,25,26)(H,27,28,29)/p-2/b21-20+ checkY
    Key: RSNSKUBBVCGSND-QZQOTICOSA-L checkY
  • InChI=1/C18H15N3O8S2/c1-10(22)19-14-9-13(30(24,25)26)7-11-8-15(31(27,28)29)17(18(23)16(11)14)21-20-12-5-3-2-4-6-12/h2-9,23H,1H3,(H,19,22)(H,24,25,26)(H,27,28,29)/p-2/b21-20+
    Key: RSNSKUBBVCGSND-OLKPTRFBBB
  • CC(=O)Nc2cc(cc3cc(c(/N=N/c1ccccc1)c(O)c23)S([O-])(=O)=O)S([O-])(=O)=O
Properties
C18H13N3O8S2
Molar mass 463.44 g·mol−1
18 g/100 mL (20 °C)
Solubility 1 g/ 100 mL glycerol
Negligible in ethanol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Red 2G is a synthetic red azo dye. It is soluble in water and slightly soluble in glycerol. It usually comes as a disodium salt of 8-acetamido-1-hydroxy-2-phenylazonaphthalene-3,6 disulfonate.

Preparation

Red 2G is produced by azo coupling of Acetyl-H acid and diazonium derivative of Aniline under basic conditions:[1]

Synthesis of Red 2G

Uses

Food dye

In the European Union, Red 2G was used as a food dye (E number E128). However, it was only permitted for use in breakfast sausages with a minimum cereal content of 6% and burger meat with a minimum vegetable and/or cereal content of 4%.[2]

Following safety concerns raised by EFSA in its opinion of 5 July 2007,[3] the European Commission has prepared a draft Regulation to suspend use of E128 as a food colouring. This proposed course of action was unanimously approved by European Union Member States at a meeting of the Standing Committee of the Food Chain and Animal Health (Section Toxicological Safety of the Food Chain) on 20 July 2007.[4] and Commission Regulation (EC) No 884/2007[5] on emergency measures suspending the use of E 128 Red 2G as food colour was published in the Official Journal of the European Union on 27 July 2007.

Red 2G is also banned in Australia, Canada, Japan, Norway,[6] and Malaysia.[7] It was banned in Israel in July 2007 [citation needed].

It is relatively insensitive to the bleaching effect of sulfur dioxide (E220) and sodium metabisulfite (E223). In the intestines, Red 2G can be converted to the toxic compound aniline,[8] so there are concerns Red 2G may ultimately interfere with blood haemoglobin, as well as cause cancer.

Inks

It is also used as a dye for coatings, inks, paper, crepe paper, and fine tissue.

Histology

Red 2G can be also used for staining in histology, though rarely, e.g. as a component of Masson's trichrome.

Potential health risks

In July 2007, the EFSA established that E128 is potentially carcinogenic because it forms aniline in the body when consumed.[9] The pressure group, The Food Commission, said there had been concerns about Red 2G going back decades and it was suspected of being a carcinogen in the 1980s.[10]

References

  1. ^ H.E. Fierz-David, L. Blangey (1949), Fundamental Processes of Dye Chemistry, Translation of the 5. Austrian Edition by P.W. Vittum, Interscience Publishers, Inc., New York, pp. 263–264
  2. ^ "European Parliament and council directive 94/36/EC of june 1994 on colours for use in foodstuffs" (PDF). Archived from the original (PDF) on 2009-02-06. Retrieved 2007-07-10.
  3. ^ "EFSA re-evaluates safety of food colours and adopts first opinion: Food colour Red 2G raises potential safety concerns". 9 July 2007.
  4. ^ "Novel Food and Toxicological Safety - Food Safety - European Commission" (PDF). Food Safety.
  5. ^ "Official Journal of the European Union". eur-lex.europa.eu. 27 July 2007. Retrieved 12 June 2023.
  6. ^ "Mattilsynet". Archived from the original on 2012-08-04. Retrieved 2007-12-11.
  7. ^ "Dye used in burgers and sausages banned". Retrieved 12 June 2023.
  8. ^ Hickman, Martin (10 July 2007). "Additive used in sausages and burgers may cause cancer". The Independent. London. Archived from the original on 2008-05-22. Retrieved 22 May 2010.
  9. ^ "Sausage additive linked to cancer". 10 July 2007 – via news.bbc.co.uk.
  10. ^ Hickman, Martin (10 July 2007). "Additive used in sausages and burgers may cause cancer". The Independent. London. Archived from the original on July 12, 2007. Retrieved 2007-07-10.