The Chemical Identity of Red Dye 2
To understand what is red dye 2 made of, we must first identify it by its chemical name. Red Dye #2 is known in the chemical world as Amaranth, a synthetic red azo dye. An azo dye is characterized by its distinctive nitrogen-nitrogen double bond (-N=N-), which is responsible for its vibrant color. Historically, amaranth was produced from coal tar, but modern synthetic versions are typically derived from petroleum.
The chemical formula for Amaranth is C20H11N2Na3O10S3, and it typically exists as a trisodium salt. This chemical composition is what gives it a dark red to purple water-soluble powder form, which decomposes at 120°C without melting. Its water solution has an absorption maximum of about 520 nm, which explains its bluish-red hue. The name "Amaranth" is inspired by the vibrant color of certain plant species, but the dye itself is a laboratory creation with no direct relation to the amaranth plant.
The Controversial History of the 1976 Ban
The story of Red Dye #2 is one of regulatory caution and public anxiety. For decades, it was a widely used colorant in the U.S. food supply, found in everything from soft drinks and candy to cereals and maraschino cherries. However, concerns about its safety began to build in the early 1970s.
The final push for the ban came after a controversial Soviet study, whose findings—that high doses of the dye caused tumors in rats—were translated and released. While the FDA's own studies were largely inconclusive and American scientists criticized the Soviet methodology, the public outcry became significant.
- The Delaney Clause: The decisive factor in the ban was the strict interpretation of the Delaney Clause, a U.S. law that prohibits the FDA from approving a color additive shown to cause cancer in animals or humans, regardless of the dose.
- Lack of Proof of Safety: As the FDA could not definitively certify the dye as safe, Commissioner Alexander Schmidt delisted it, effectively banning its use in food, drugs, and cosmetics.
- Public Awareness: The ban, though based on inconclusive science, significantly raised public awareness about synthetic additives and contributed to a growing consumer preference for more natural ingredients.
Global Status and the Case for International Differences
Despite the U.S. ban, Amaranth (E123) is still approved for use in many countries around the world. International regulatory bodies, such as those in Canada, Australia, New Zealand, and parts of Europe, reviewed the same evidence and came to different conclusions.
These agencies often found the original U.S. and Soviet studies to have significant limitations. For example, Canada's health authorities considered the scientific basis for the U.S. ban to be insufficient, and Amaranth continues to be permitted under specific conditions. The UK, in particular, famously continues to use E123 to color glacé cherries.
Red Dye 2 vs. Red Dye 40: A Comparison
After Red Dye #2 was banned in the U.S., food manufacturers turned to alternatives. The most prominent replacement was Red Dye #40 (Allura Red AC), another synthetic azo dye derived from petroleum. A comparison helps to clarify why one was banned while the other remains widely used.
| Feature | Red Dye 2 (Amaranth, E123) | Red Dye 40 (Allura Red AC) |
|---|---|---|
| Composition | Trisodium salt of a specific sulfonic acid compound (C20H11N2Na3O10S3). | A different synthetic red azo dye (C18H14N2Na2O8S2). |
| Production Origin | Derived from coal tar, later from petroleum byproducts. | Derived from petroleum. |
| U.S. Status | Banned as a food additive in 1976 due to suspected carcinogenicity. | Approved and widely used. |
| Primary Concerns | Suspected carcinogen based on inconclusive rat studies, though later reviews questioned this. | Some studies suggest links to hyperactivity and behavioral issues in children, but it has not been officially linked to cancer in humans by the FDA. |
| Metabolism | Can break down into potentially carcinogenic aromatic amines in the body. | Has a different metabolic pathway and chemical structure compared to Red Dye 2. |
| Global Status | Banned in the U.S. and some other countries, but approved in Canada, Europe (E123), and Australia. | Approved in the U.S. and most parts of the world. |
Conclusion
Red Dye 2, chemically known as Amaranth, was made from petroleum byproducts and was widely used as a synthetic red food coloring for decades. Its story serves as a critical case study in food regulation, demonstrating the complexities of proving safety and the influence of public perception on regulatory decisions. While the U.S. ban in 1976 removed it from the American food supply, its continued use in many other countries highlights the different approaches and interpretations of scientific evidence by international health authorities. The controversy surrounding Amaranth ultimately led to increased consumer awareness and the development of alternative colorants, forever changing the landscape of food production. For more information on the history of food additives, one might consult regulatory resources. The History of Food Additive Regulation in the United States
