An aromatic organic compound, TBHQ or tert-Butylhydroquinone or tertiary butylhydroquinone is a type of phenol. Chemically TBHQ is a derivative of hydroquinone, substituted by the tert-butyl group.
TBHQ has antioxidant properties. It is used as preservative in foods especially for unsaturated vegetable oils as well as many other edible animal fats. An excellent quality of TBHQ is that it does change the color, flavor or odor of the food to which it is added. It can also be used in combination with other food preservatives like butylated hydroxyanisole (BHA). Its E number is E319 as an additive in foods. Its primary advantage is that it enhances storage life of food products.
Industrially TBHQ is used as a stabilizer and it helps in the inhibition of autopolymerization of organic peroxides. In biodiesel it is used to inhibit corrosion. It is used as a fixative and lowers the rate of evaporation and improves stability in perfumes. TBHQ is also used as an additive in resins, lacquers, varnishes and oil field additives.
TBHQ is evaluated by both the European Food Safety Authority (EFSA) and the United States Food and Drug Administration (FDA) and it is found that the concentration of TBHQ allowed in foods is safe to consume. An upper limit of 0.02% of the fat or oil content in foods is set by FDA. In concentrations higher than this, TBHQ can cause adverse effect on the health.
Various symptoms which can occur due to consuming high doses (1-4 g) of TBHQ include nausea and vomiting, collapse, delirium, and ringing sound in ears. It can also cause asthma, dermatitis, and rhinitis. It can also worsen the symptoms of ADHD and restlessness.