Tert-Butylhydroquinone

tert-Butylhydroquinone (TBHQ, tertiary butylhydroquinone) is an aromatic organic compound which is a type of phenol. It is a derivative of hydroquinone, substituted with tert-butyl group.

Applications
TBHQ is a highly effective antioxidant for unsaturated vegetable oils and many edible animal fats. It does not cause discoloration even in the presence of iron, and does not change flavor nor odor of the material it is added to. It can be combined with other antioxidants such as butylated hydroxyanisole (BHA). As food additive, its E number is E319, where it is used as an antioxidant. It is added to a wide range of foods, with highest limit (1000 mg/kg) permitted for frozen fish and fish products. Its primary advantage is enhancing storage life.

It is used industrially as a stabilizer to inhibit autopolymerization of organic peroxides. In perfumery, it is used as a fixative to lower the evaporation rate and improve stability. It is also added to varnishes, lacquers, resins, and oil field additives.

Carcinogenicity
In high doses, it has some negative health effects on lab animals, such as precursors to stomach tumors and damage to DNA. A number of studies have shown that prolonged exposure to TBHQ may induce carcinogenity. Other studies, however, have shown protective effects for TBHQ and other phenolic antioxidants.