Red Dye No. 3, also known as Erythrosine, is a synthetic food colorant used in various food products, pharmaceuticals, and cosmetics.
Erythrosine, also known as Red No. 3, is an organoiodine compound, specifically a derivative of fluorone.
It is a red-pink dye used for food coloring, cosmetics, hair coloring, pet products, and diverse industrial colorings.
It is the disodium salt of 2,4,5,7-tetraiodofluorescein.
It is a poly-iodinated xanthene dye, which imparts a red color to the products it is added to.
It has had the lowest acceptable daily intake (ADI) among FDA-approved food colorants, set at 0.1 mg/kg body weight/day.
Erythrosine is synthesized from phenol and phthalic anhydride, which are processed into fluorescein: Fluorescein then undergoes iodination, producing the bright red dye.
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, candies, ice pops and cherries, and in cake-decorating gels.
It was also used to color pistachio shells.
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.
Laboratory evidence of carcinogenicity of extremely high doses of erythrosine renders it as unsafe under federal law 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.
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.
An October 2023 bill passed in the state of California also banned the use of erythrosine in foods with enforcement beginning on 1 January 2027.
Red Dye No. 3 has been associated with several health risks: Neurotoxicity including oxidative stress, neurotransmitter imbalances, mitochondrial dysfunction, and inflammatory responses, which can impact brain function and overall neurological health.
it has been shown to have reproductive toxicity in animal models, specifically affecting spermatogenesis in male mice.
Additionally, erythrosine has been identified as a promiscuous inhibitor of several protein-protein interactions, which may contribute to its cytotoxic effects.
Red Dye No. 3 exhibits estrogen-like properties and has been shown to increase DNA damage in human breast cancer cells, suggesting a potential risk for breast carcinogenesis.
Red Dye No. 3 is active in assays related to neurodevelopmental processes, particularly those associated with attention deficit and hyperactivity disorder (ADHD).
Studies in rats have demonstrated that Red Dye No. 3 can lead to significant decreases in body weight, hemoglobin concentration, and red blood cell count, as well as increases in liver enzymes and markers of kidney function, indicating broad toxic effects.
Red Dye No. 3 has been recognized to elicit allergic hypersensitivity reactions, which can include skin reactions and potentially more severe responses.
It is advisable to limit the use of Red Dye No. 3, especially in populations such as children who may be more susceptible to its adverse effects.
The FDA has banned Red Dye No. 3 (erythrosine), a synthetic food coloring linked to cancer in lab animals, hyperactivity in children, and other health concerns.
Previously banned in cosmetics, it remains in many foods, beverages, and medications.
Food manufacturers must remove it by 2027, and pharmaceutical companies by 2028.
Already prohibited in the EU, Australia, and New Zealand, the dye is used for its bright red color but has no nutritional value.
It is identified by the color index number 45430 and is certified for use by the U.S. Food and Drug Administration (FDA) as FD&C Red No. 3.
Erythrosine is a poly-iodinated xanthene dye, and its chemical structure includes iodine atoms, which contribute to its vibrant red color.
Research has indicated that erythrosine may have estrogenic and DNA-damaging activities in human breast cancer cells.
Additionally, studies have shown that erythrosine can affect reproductive toxicity in male mice, impacting spermatogenesis and sperm morphology.
Red Dye No. 3 (Erythrosine) is a widely used synthetic food dye with potential health risks that have prompted regulatory scrutiny and scientific investigation.