Red 40 (Allura Red AC, E129)

What is Red 40?

Red 40 is an azo dye — a synthetic color produced from petroleum-derived chemicals. It gives candy, drinks and snacks a bright cherry-red to orange-red shade and is sold under the names FD&C Red No. 40 in the US and Allura Red AC (E129) in Europe.

It comes in two forms: a water-soluble dye used in drinks and syrups, and an insoluble "lake" (Red 40 Lake) bound to aluminum, which is used where color must not bleed — coated candies, frosting and cereal pieces. Every batch sold in the US must pass FDA batch certification.

Why is Red 40 used in food?

Manufacturers use Red 40 because it is cheap, stable under heat and light, and produces an intense color at tiny doses. Natural alternatives such as beet juice, paprika extract, lycopene or carmine cost more, fade faster or change taste — which is why reformulated products sometimes look paler than the originals.

Is Red 40 safe? What the research says

What regulators say. FDA lists Red 40 as a permitted color additive and says most children have no adverse effects from color additives, though some may be sensitive to them. EFSA re-evaluated it in 2009 and kept the acceptable daily intake (ADI) of 7 mg/kg of body weight; the WHO/FAO expert committee (JECFA) uses the same limit. The 2009 review warned that some young children with very high intakes could exceed the ADI, but EFSA's refined 2015 assessment, based on actual use levels, found no population group above it.

Hyperactivity in children. The best-known evidence is the 2007 Southampton study (McCann et al., The Lancet): mixtures of synthetic colors, including Allura Red, together with the preservative sodium benzoate, increased hyperactive behavior in the general population of 3- and 8–9-year-old children. The effect was small and varied between children, but it led the EU to require a warning label. In 2021, California's Office of Environmental Health Hazard Assessment (OEHHA) reviewed the evidence and concluded that synthetic food dyes can cause or worsen neurobehavioral problems in some children.

Other research. Animal studies have linked long-term Allura Red exposure to gut inflammation (for example, Kwon et al., 2022, in mice). These results have not been confirmed in humans.

Cancer. Red 40 is not classified as a carcinogen. Past concerns about contaminants in the dye are addressed by FDA purity specifications.

Bottom line: occasional intake within normal amounts is considered safe by regulators. Parents of children who seem sensitive to dyes may reasonably choose dye-free products — the evidence supports trying it.

Red 40 regulation: US vs EU

On April 22, 2025, HHS and FDA announced a plan to work with industry to remove Red 40 and five other petroleum-based dyes from the US food supply. FDA's own tracker, updated in September 2026, gives the target as the end of 2027 and lists 28 companies and trade associations that have made commitments. The phase-out is voluntary: FDA has not revoked the authorization for Red 40, which remains an approved color additive and appears on FDA's list of chemicals under post-market review. Only Red 3 is under a federal ban, with a food deadline of January 15, 2027.

Several states have gone further. California's AB 2316 bars six dyes including Red 40 from food served or sold in public schools from December 31, 2027. West Virginia's HB 2354 restricts seven dyes in school nutrition programs, in effect since August 1, 2025; its statewide retail ban, due January 1, 2028, was blocked by a preliminary injunction in December 2025. Check the latest status: rules are changing quickly.

Who should limit or avoid Red 40?

• Children with ADHD or who react to dyes. Parents often report behavior changes; a short dye-free trial is a reasonable, low-risk step. Discuss it with your pediatrician.
• People with dye sensitivity. Rare allergic-type reactions (hives, swelling) have been reported.
• Anyone watching ultra-processed food intake. Red 40 almost always appears in highly processed products — candy, soda, frosted cereals — so avoiding it usually improves the overall diet too.