:Red 2G
{{chembox
| Verifiedfields = changed
| verifiedrevid = 464380478
| ImageFile = Red 2G structure.svg
| ImageAlt = Skeletal formula of Red 2G as a sodium salt
| ImageFile1 = Red 2G sodium 3D spacefill.png
| ImageAlt1 = Space-filling model of the Red 2G molecule as a sodium salt
| IUPACName =
| OtherNames = {{Unbulleted list|Acid Red 1|Food Red 10|Amidonaphthol red G|azogeranine|azophloxine|azofloxin|C.I. 18050}}
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 21106472
| 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+
| InChIKey = RSNSKUBBVCGSND-OLKPTRFBBB
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 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+
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = RSNSKUBBVCGSND-QZQOTICOSA-L
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 3734-67-6
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 3365R6427R
| PubChem = 6507024
| SMILES = CC(=O)Nc2cc(cc3cc(c(/N=N/c1ccccc1)c(O)c23)S([O-])(=O)=O)S([O-])(=O)=O
}}
|Section2={{Chembox Properties
| C=18 | H=13 | N=3 | O=8 | S=2
| Appearance =
| Density =
| MeltingPt =
| BoilingPt =
| Solubility = 18 g/100 mL (20 °C)
| Solubility1 = 1 g/ 100 mL glycerol
Negligible in ethanol
}}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt =
}}
}}
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:{{citation|author=H.E. Fierz-David, L. Blangey|date=1949|pages=263–264|publisher=Interscience Publishers, Inc., New York|title=Fundamental Processes of Dye Chemistry, Translation of the 5. Austrian Edition by P.W. Vittum}}
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%.{{cite web|url=http://www.greencouncil.org/doc/ResourcesCentre/EC_Directive_30_June_1994_on_colours_for_use_in_foodstuffs.pdf|title=European Parliament and council directive 94/36/EC of june 1994 on colours for use in foodstuffs|access-date=2007-07-10|archive-date=2009-02-06|archive-url=https://web.archive.org/web/20090206175213/http://www.greencouncil.org/doc/ResourcesCentre/EC_Directive_30_June_1994_on_colours_for_use_in_foodstuffs.pdf|url-status=dead}}
Following safety concerns raised by the European Food Safety Authority (EFSA) in its opinion of 5 July 2007,{{cite web|url=http://www.efsa.europa.eu/en/press/news/070709|title=EFSA re-evaluates safety of food colours and adopts first opinion: Food colour Red 2G raises potential safety concerns|date=9 July 2007}} 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.{{cite web|url=http://ec.europa.eu/food/committees/regulatory/scfcah/toxic/summary20072007_en.pdf|title=Novel Food and Toxicological Safety - Food Safety - European Commission|website=Food Safety}} and Commission Regulation (EC) No 884/2007{{cite web|url=http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2007:195:0008:0009:EN:PDF|title=Official Journal of the European Union|website=eur-lex.europa.eu|date=27 July 2007|access-date=12 June 2023}} 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,{{cite web|url=http://www.mattilsynet.no/aktuelt/nyhetsarkiv/regelverk/fargestoffet_r_d_2g_forbys_49769|title=Mattilsynet|access-date=2007-12-11|archive-date=2012-08-04|archive-url=https://archive.today/20120804031822/http://www.mattilsynet.no/aktuelt/nyhetsarkiv/regelverk/fargestoffet_r_d_2g_forbys_49769|url-status=dead}} and Malaysia.{{Cite web|url=http://thestar.com.my/news/story.asp?file=/2007/10/12/nation/19148893&sec=nation|title=Dye used in burgers and sausages banned|accessdate=12 June 2023}} It was banned in Israel in July 2007 {{Citation needed|date=December 2011}}.
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,{{cite news| url=https://www.independent.co.uk/living/food_and_drink/news/article2750462.ece| archive-url=https://web.archive.org/web/20080522115106/http://www.independent.co.uk/life-style/food-and-drink/news/additive-used-in-sausages-and-burgers-may-cause-cancer-456608.html| archive-date=2008-05-22 | work=The Independent | location=London | title=Additive used in sausages and burgers may cause cancer | first1=Martin | last1=Hickman | date=10 July 2007 | url-status=dead| access-date=22 May 2010}} 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.{{cite news|url=http://news.bbc.co.uk/2/hi/health/6286834.stm|title=Sausage additive linked to cancer|date=10 July 2007|via=news.bbc.co.uk}} 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.{{cite news | first=Martin | last=Hickman | title= Additive used in sausages and burgers may cause cancer | date= 10 July 2007| url =https://www.independent.co.uk/living/food_and_drink/news/article2750462.ece | archive-url =https://web.archive.org/web/20070712193359/http://www.independent.co.uk/living/food_and_drink/news/article2750462.ece | url-status =dead | archive-date =July 12, 2007 | work =The Independent | access-date = 2007-07-10 | location=London}}