Red 40, also known as Allura Red AC, FD&C Red 40, or E129 in Europe, is a synthetic red azo dye commonly used as a food colorant. It is manufactured through a chemical reaction involving sulfonic acids and typically supplied as its red sodium salt, which is water-soluble

. It is widely used to add or enhance red color in various consumable products such as candies, soft drinks, dairy products, children's medications, frostings, and cotton candy. It is also used in cosmetics, drugs, and some tattoo inks. When combined with aluminum, it forms "Red 40 Lake," a pigment used in products like chewing gum and frostings to prevent color bleeding

. Red 40 is approved by the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) for use in foods and beverages. It is one of the most commonly used synthetic food dyes in the United States, having replaced older dyes like amaranth (Red 2) and erythrosine (Red 3) due to their negative health effects

. Regarding safety, Red 40 is generally considered safe for consumption within established limits. The FDA sets an acceptable daily intake (ADI) of about 7 mg per kilogram of body weight. However, some studies and reports suggest potential health concerns, including allergic reactions, behavioral effects in children, and possible links to inflammation and DNA damage in animal studies, though more research is needed to confirm these effects in humans

. In summary, Red 40 is a synthetic red food dye widely used to color foods and beverages, approved by regulatory agencies but with some ongoing debate about its health impacts