Erythrosine, also known as Red No. 3, is an organoiodine compound, specifically a derivative of fluorone. It is cherry-pink synthetic, primarily used for food coloring. It can be used as food coloring, printing ink, biological stain, dental plaque disclosing agent, radiopaque medium and sensitizer for orthochromatic photographic films. In 1990 the U.S. FDA had instituted a partial ban on erythrosine. In June 2008, the Center for Science in the Public Interest (CSPI) petitioned the FDA for a complete ban on erythrosine in the United States.