TBHQ (tert-Butylhydroquinone) E319
phenolic — Primarily synthetic.
Tertiary butylhydroquinone
CAS: 1948-33-0
Factual Regulatory Reference
This database provides factual regulatory information compiled from official government sources. It does not constitute medical, nutritional, or safety advice. Regulatory status varies by country and is subject to change. Always refer to your local regulatory authority for the most current information.
What Is TBHQ (tert-Butylhydroquinone)?
Tertiary butylhydroquinone (TBHQ) is a synthetic phenolic antioxidant used in vegetable oils, animal fats, fried snacks, and processed foods to prevent oxidative rancidity. JECFA established an ADI of 0–0.7 mg/kg body weight. EFSA evaluated TBHQ in 2004 and maintained the same ADI, while also identifying it as a possible allergen. Some animal studies at high doses showed precancerous stomach lesions, leading EFSA to note the need for continued monitoring. It is approved in the USA (GRAS up to 0.02% of fat content), Japan, Canada, and Australia, but it is not listed in the EU's permitted antioxidants.
? Did You Know?
Beyond food, TBHQ (tert-Butylhydroquinone) is also used in cosmetics, medicine, industrial applications. Its versatility makes it one of the most multi-purpose chemical compounds in everyday life.
Regulatory Analysis
TBHQ (E319) illustrates how jurisdictional differences in what triggers re-evaluation can produce lasting approval gaps. The FDA approved TBHQ under 21 CFR 172.185 in 1972; JECFA established an ADI of 0–0.7 mg/kg body weight per day in 1998. However, TBHQ is not listed among the antioxidants authorized under EU Regulation (EC) No 1333/2008 — it was never included in the EU positive list when the regulation was consolidated. EFSA conducted a technical review in 2004 but did not generate a full opinion establishing an ADI, meaning the compound lacks the positive authorization required under EU law for food additives. Canada and Australia permit TBHQ. This situation — where a substance is approved in the USA, Japan, and elsewhere but absent from the EU's authorized list — results not necessarily from a concluded regulatory finding against it but from an absence of a completed EFSA evaluation establishing its acceptability.
Detailed Regulatory Assessment
European Union (EFSA)
Maximum 200 mg/kg alone or in combination with BHA (E320) and BHT (E321)
United States (FDA)
Limited to 0.02% of oil or fat content
Japan (MHLW)
Compliant with Japanese food sanitation law.
Acceptable Daily Intake (ADI)
International Standard (JECFA)
mg/kg body weight per day
European Standard (EFSA)
Everyday Perspective
For a 60kg adult, this limit is roughly equivalent to consuming:
Natural Occurrence
This additive is not known to occur naturally in significant quantities.
Manufacturing
Synthesized by alkylation of hydroquinone with isobutylene in the presence of an acid catalyst.
Applications Beyond Food
Antioxidant in lipstick and other cosmetics
Antioxidant in vitamin preparations
Stabilizer for biodiesel