tert-Butylhydroquinone (TBHQ)

Additive · E 319

TBHQ is an antioxidant added to fats, oils and some packaged foods to slow rancidity. Its full name is tertiary butylhydroquinone. Labels may also show E 319 or INS 319. It helps preserve flavor and extend a food’s shelf life.

Also known as

TBHQ · tert-butylhydroquinone · tertiary butylhydroquinone · t-butylhydroquinone · mono-tert-butylhydroquinone · mono-tertiarybutylhydroquinone · MTBHQ · 2-tert-butylhydroquinone · 2-(1,1-dimethylethyl)-1,4-benzenediol · tert-butyl-1,4-benzenediol · E 319 · E319 · INS 319

Why PRūF tracks it

Animal experiments raise concern about immune responses and food-allergen reactions, while limited human studies and reassuring long-term cancer tests leave the health effects of ordinary dietary TBHQ exposure uncertain.

Read the research

TBHQ helps keep fats from becoming rancid, but its effects in the body deserve separate assessment. Long-term animal feeding studies found no evidence of cancer, while much higher dietary doses caused other adverse effects. JECFA established an acceptable daily intake of up to 0.7 milligrams per kilogram of body weight, and EFSA’s 2016 refined exposure estimates stayed below that value. Those older evaluations do not resolve newer immune questions.

A 2025 study found that mice eating a low concentration of TBHQ had stronger sensitization and more severe reactions to an experimental food allergen. This is a meaningful animal signal, but it does not show that TBHQ causes food allergy or anaphylaxis in people. A 2026 mouse study also changed immune-cell responses, using a much higher dietary concentration. Human evidence is emerging: one small study associated urinary TBHQ with poorer cognitive function, without establishing that food was the source or that TBHQ caused the impairment.

A randomized study comparing oils with and without TBHQ found no statistically clear differences in liver or kidney blood markers. These findings do not establish lifelong safety or settle the immune concern. Food-use limits and Japan’s recorded lack of authorization are separate from the strength of the health evidence.

Research reviewed on September 5, 2026 · 12 sources