Butylated Hydroxytoluene
The short version
A synthetic phenolic antioxidant (BHT), the close relative of BHA, used to prevent rancidity in fats and packaged foods.
A synthetic antioxidant that keeps fats from going rancid. Animal studies raised questions about its safety at high doses, and its effects are still debated at food levels. That's why we flag it.
Where it comes from
Developed in the 1940s alongside BHA as a synthetic antioxidant for petroleum products. Adapted for food and feed use in the 1950s. Produced from p-cresol and isobutylene.
How it's used
Used in cereals, snack foods, chewing gum, animal fats, and packaging materials in contact with food. Often combined with BHA (E320) and citric acid for synergistic antioxidant effect. Typical use 0.001–0.02%.
Safety profile
ADI of 0.25 mg/kg body weight. Animal studies have raised concerns about endocrine and hepatic effects at high doses; human relevance debated. Some studies suggest anti-tumor activity, others suggest tumor-promoting. Several jurisdictions are progressively reducing permitted uses.
Physical & chemical properties
White crystalline solid, soluble in fats and oils, insoluble in water. Volatile at elevated temperatures — can sublime from packaging into food.
Regulation worldwide
Permitted in the EU and US with restricted maximum levels. Banned for certain uses in Japan and Australia.
Educational information only. Not medical or dietary advice.