Erythrosine

History

The colorant was discovered by the Swiss chemist Karl Kussmaul at the University of Basel in 1876 and soon commercialized by the local Bindschedler & Busch company for dyeing wool and silk. Its use as a textile dye was soon superseded due to its propensity to fade in sunlight.

Its use as a food dye was legalized in the US by the Pure Food and Drug Act of 1906. By early 1920s, it was produced mainly for the food industry, with 2170 lb made in America in 1924, rising to 9468 lb in 1938 and approximately 50 tons in 1967.

Production

Erythrosine is synthesized from resorcinol and phthalic anhydride, which are processed into fluorescein. Fluorescein then undergoes iodination, producing the bright red dye.

Uses

It is used as a food coloring, printing ink, biological stain, dental plaque disclosing agent, radiopaque medium, sensitizer for orthochromatic photographic films, and visible light photoredox catalyst.

Erythrosine is commonly used in sweets, such as some candies, ice pops and cherries, and in cake-decorating gels. It was also used to color pistachio shells. As a food additive, it has the E number E127.

Safety assessment and regulation

Laboratory studies in the late 20th century suggested that "chronic erythrosine ingestion may promote thyroid tumor formation in rats via chronic stimulation of the thyroid by TSH" at concentrations of 4% erythrosine. Toxicology tests combined with a review of other reported studies concluded that erythrosine is non-genotoxic and any tumor growth results from a non-genotoxic mechanism.

In the United States, laboratory evidence of carcinogenicity of extremely high doses of erythrosine renders it as "unsafe" under federal law by a provision called the Delaney Clause, despite conclusions by the federal Center for Food Safety and Applied Nutrition and Cancer Assessment Committee that the risk of developing cancer in humans is unlikely at the low erythrosine levels consumed as a food color.

Throughout the early 21st century, the World Health Organization and several national food safety agencies permitted use of erythrosine as a color additive when used in amounts below acceptable daily intake levels for certain foods, such as for packaged cherries; countries having restricted-use provisions were the European Union, United States, Canada, and Australia/New Zealand.

Since 1994, the European Food Safety Authority has only allowed erythrosine in processed cherries, and up to 25 ppm in toothpaste. In the United Kingdom, it is also allowed for coloring eggshells. It may not be sold directly to consumers.

In the United States, the use of erythrosine in cosmetics, topical drugs, some foods, and in all uses as its lake variant have been banned by the Food and Drug Administration (FDA) since 1990. In January 2025, the FDA banned the use of erythrosine in all foods and ingested drugs, with enforcement beginning on 15 January 2027 and 18 January 2028, respectively.

In 2025, Health Canada stated that erythrosine "does not pose a health risk to the general Canadian population at the levels set out in the List of Permitted Food Colours."

Synonyms

Erythrosine B; Erythrosin B; Acid Red 51; C.I. 45430; FD&C Red No. 3; E127; 2',4',5',7'-Tetraiodo-3',6'-dihydroxy-spiro[3H-isobenzofuran-1,9'-xanthen]-3-one disodium salt; Tetraiodofluorescein sodium salt; Calcoid Erythrosine N; 2,4,5,7-Tetraiodo-3,6-dihydroxyxanthene-9-spiro-1'-3H-isobenzofuran-3'-one disodium salt; 2',4',5',7'-Tetraiodofluorescein, disodium salt; C.I. Food Red 14; Aizen Erythrosine; Tetraiodifluorescein, disodium salt; Spiro[isobenzofuran- 1(3H),9'-[9H]xanthen]-3-one, 3',6'-dihydroxy-2',4',5',7'-tetraiodo-, disodium salt.

Classification

It is listed under the following number systems:

• FD&C Red No. 3
• E number E127 (Food Red 14)
• Colour Index no. 45430 (Acid Red 51)
• Bureau of Indian Standards No. 1697

References

References

1. "Erythrosine B product description". The Chemical Book.
2. (11 January 2025). "Erythrosine sodium anhydrous". PubChem, US National Library of Medicine.
3. "Iodine and Iodine Compounds".
4. (1878). "Le Moniteur scientifique du Docteur Quesneville: journal des sciences pures et appliquées". Le Moniteur scientifique.
5. (1892). "A Dictionary of the Coal Tar Colours". Heywood and Company.
6. "Erythrosine - CAMEO".
7. "Dye - Synthetic, Organic, Colorants {{!}} Britannica". Encyclopedia Britannica.
8. Deshpande, S. S.. (2002-08-29). "Handbook of Food Toxicology". CRC Press.
9. (1922). "The Emergency Tariff and Its Effect on Cattle and Beef, Sheep and Mutton, Wool, Pork, and Miscellaneous Meats". U.S. Government Printing Office.
10. (1925). "Census of Dyes and Other Synthetic Organic Chemicals". [[United States Government Publishing Office.
11. (13 July 1940). "Organic Chemicals". [[United States Department of Commerce.
12. Gunther, Francis A.. (1983-05-11). "Residue Reviews: Residues of Pesticides and Other Contaminants in the Total Environment". Springer New York.
13. (October 2012). "Genotoxic and mutagenic effects of erythrosine B, a xanthene food dye, on HepG2 cells". Food and Chemical Toxicology.
14. Gurr, Edward. (2012). "Synthetic Dyes in Biology, Medicine And Chemistry". elsevier.
15. (April 2006). "Erythrosine is a potential photosensitizer for the photodynamic therapy of oral plaque biofilms". The Journal of Antimicrobial Chemotherapy.
16. (1993). "Dictionary of Analytical Reagents". CRC Press.
17. (October 2018). "Organic Dye-Catalyzed, Visible-Light Photoredox Bromination of Arenes and Heteroarenes Using N-Bromosuccinimide". ACS Omega.
18. (15 January 2025). "FD&C Red No. 3". US Food and Drug Administration.
19. Day, Chris. (2023-01-16). "The Almost-Forgotten Era Of Red Pistachios".
20. EFSA Panel on Additives and Products or Substances used in Animal Feed. (January 2011). "Scientific Opinion on the re-evaluation of Erythrosine (E 127) as a food additive". EFSA Journal.
21. (May 1990). "Effects of oral erythrosine (2′,4′,5′,7′-tetraiodofluorescein) on the pituitary-thyroid axis in rats". Toxicology and Applied Pharmacology.
22. (October 1987). "Lifetime toxicity/carcinogenicity study of FD & C Red No. 3 (erythrosine) in rats". Food and Chemical Toxicology.
23. (July 1986). "Mutagenicity studies on FD&C red No.3". Mutagenesis.
24. (2018). "FD and C RED No. 3". Joint FAO/WHO Expert Committee on Food Additives, World Health Organization.
25. (15 January 2025). "Red dye No. 3 banned from foods, U.S. regulator says". CBC News.
26. (2021-03-26). "Australia New Zealand Food Standards Code – Schedule 8 – Food additive names and code numbers (for statement of ingredients)". Office Parliamentary Counsel; Locked Bag 30 Kingston ACT 2604, [[Food Standards Australia New Zealand]].
27. (1994-06-30). "European Parliament and Council Directive 94/36/EC of 30 June 1994 on colours for use in foodstuffs".
28. EFSA Panel on Additives and Products or Substances used in Animal Feed. (2019). "Safety of erythrosine for ornamental fish". EFSA Journal.
29. SCCS (Scientific Committee on Consumer Safety). (22 January 2010). "Opinion on CI 45 430 (erythrosine)". [[European Commission]].
30. (15 October 2021). "'Sprinklegate' sinks a U.K. Bakery's top sellers after topping is found to be illegal". NPR.
31. (29 January 1990). "FDA Bans Some Uses of Red No. 3 Additive". [[Los Angeles Times]].