tert-Butylhydroquinone (TBHQ, tertiary butylhydroquinone) is a synthetic aromatic organic compound which is a type of phenol.

[4] The FDA[5] and European Union[4] both set an upper limit of 0.02% (200mg/kg) of the oil or fat content in foods.

At very high doses, it has some negative health effects on lab animals, such as producing precursors to stomach tumors and damage to DNA.

[6] A number of studies have shown that prolonged exposure to very high doses of TBHQ may be carcinogenic,[7] especially for stomach tumors.

[4] A 1986 review of scientific literature concerning the toxicity of TBHQ determined that a wide margin of safety exists between the levels of intake by humans and the doses that produce adverse effects in animal studies.