Yellow Dye 5 vs Butylated Hydroxyanisole: which is worse?

What is Yellow Dye 5?

Yellow Dye 5 (tartrazine) is a synthetic lemon-yellow azo dye derived from petroleum. It produces a bright, stable yellow color in acidic conditions and is one of the most widely used yellow dyes globally. Its chemical formula is C16H9N4Na3O9S2.

What is Butylated Hydroxyanisole?

Butylated hydroxyanisole (BHA) is a synthetic phenolic antioxidant preservative derived from petroleum (see also bha entry). It is a mixture of 2-BHA and 3-BHA isomers, used to prevent oxidative rancidity in fats, oils, and fat-containing foods. Chemical formula C11H16O2.

Documented risks

Yellow Dye 5: Yellow Dye 5 was one of six dyes studied in the landmark 2007 McCann et al. study in The Lancet. The study found statistically significant increases in hyperactivity in children ages 3 and 8–9 given a mixture containing tartrazine and sodium benzoate. EFSA reviewed the evidence and confirmed the effect was real, mandating the EU warning label from 2010. A 2012 review in Neurotherapeutics (Arnold et al.) confirmed that artificial food colors including tartrazine have a small but statistically significant adverse effect on children's behavior that is not confined to those with diagnosed ADHD. Tartrazine is one of the most documented causes of food dye hypersensitivity. Cross-reactivity with aspirin (acetylsalicylic acid, ASA) is well established in allergy literature: individuals with aspirin hypersensitivity have elevated risk of reacting to tartrazine. Symptoms include urticaria, angioedema, rhinitis, and in rare cases anaphylaxis. Prevalence of tartrazine sensitivity is estimated at 0.1% of the population but higher in aspirin-sensitive individuals. Because of this known hypersensitivity risk, the FDA specifically requires Yellow No. 5 to be declared by name on US food labels — an exceptional requirement not applied to most other additives, reflecting the FDA's acknowledgment of this real clinical concern. EFSA's 2009 re-evaluation found no evidence of genotoxicity in standard test systems at food use levels, setting an ADI of 7.5 mg/kg body weight, but noted in vitro evidence at higher doses. In April 2025, the FDA announced plans to phase out Yellow 5 along with other petroleum-based dyes.

Butylated Hydroxyanisole: IARC classifies BHA as Group 2B (possible human carcinogen) based on forestomach tumor studies in rodents at high doses. The NTP lists it as 'reasonably anticipated to be a human carcinogen.' EFSA's 2012 review found endocrine-disrupting potential. Japan banned it for food use. The FDA permits it at 0.02% of fat content. Concerns about estrogen-receptor interaction have been documented in animal studies. Contact dermatitis from cosmetic use is reported.