Erythrosine is an organoiodine compound, specifically a derivative of fluorone. It is cherry-pink synthetic, primarily used for food coloring. It is the disodium salt of 2,4,5,7-tetraiodofluorescein. Its maximum absorbance is at 530 nm in an aqueous solution, and it is subject to photodegradation. It is used as a food coloring, in printing inks, as a biological stain, a dental plaque disclosing agent and a radiopaque medium. It was used as a sensitizer for orthochromatic photographic films. Erythrosine is commonly used in sweets such as some candies and popsicles, and even more widely used in cake-decorating gels. It is also used to color pistachio shells. As a food additive, it has the E number E127. A series of toxicology tests combined with a review of other reported studies concluded that erythrosine is non-mutagenic. Erythrosine can be used in colored food in USA without any restriction.