Last reviewed: 11 May 2026
The UK label-reader's guide to a synthetic antioxidant in frying oils and processed snacks
E319 is approved in the UK and EU as an antioxidant for fats, oils and processed foods, with an EFSA Acceptable Daily Intake of 0.7mg/kg body weight per day — a restrictive ADI for an antioxidant, reflecting the limitations of the long-term toxicology dataset. It is banned in Japan. UK approval is for narrow uses in fats and frying oils. Most published animal evidence for adverse effects sits well above realistic dietary intakes; published human data is limited.
E319 is tert-butylhydroquinone (TBHQ), a synthetic phenolic antioxidant. Like BHA (E320) and BHT (E321), its job is to suppress the free-radical oxidation that turns fats and oils rancid. TBHQ is unusually effective in unsaturated frying oils and is heat-stable enough to survive deep-fat frying temperatures, which is why it appears in the long-chain fats used by industrial fryers and in the seasoning oils of crisps, fried snacks and instant noodles. Permitted use levels in UK and EU food are low — typically a maximum of 100–200mg/kg of the fat fraction, depending on the food category.
Use is concentrated in foods that are deep-fat fried or carry oily seasoning, particularly where extended shelf life is needed:
It also appears outside food in cosmetics (as an oil stabiliser), some pharmaceuticals, and industrial coatings — those uses are outside the EFSA food ADI.
The EFSA Acceptable Daily Intake of 0.7mg/kg body weight per day is set on a long-term rat study showing liver enzyme changes at higher doses, with a substantial uncertainty factor applied. By the standards of food antioxidants this is a restrictive ADI — comparable to BHA's 1mg/kg and tighter than many sweeteners — and reflects EFSA's view that the existing long-term dataset has limitations, not that intake at the ADI is hazardous. EFSA's most recent re-evaluation (2024) retained the ADI and flagged that high consumers of fried snacks and instant-noodle products can approach a meaningful fraction of it.
Several published rodent studies, including work by the US Environmental Working Group and academic groups, have reported that TBHQ at higher doses modulates T-cell function and may suppress immune responses, including responses to viral infection and to flu vaccination in animal models. The published human evidence is limited; the relevance of the animal effects to human dietary exposure is an open question that the regulators have not closed. We mention it because it is the published concern most often cited in consumer coverage of TBHQ.
Case reports of acute TBHQ ingestion at gram-level doses describe nausea, vomiting, tinnitus and, in industrial accidents, transient vision disturbance. These doses are several thousand times higher than realistic dietary intake from food and are not directly comparable to typical exposure from a packet of crisps.
UK / EU: approved as a food antioxidant under Regulation (EC) No 1333/2008 with an EFSA ADI of 0.7mg/kg body weight per day. Permitted in specific food categories at maximum levels of 100–200mg/kg of the fat fraction.
US: FDA permits use up to 0.02% of the oil or fat content (200ppm) as an antioxidant for fats and oils.
Japan: banned in food.
Australia / New Zealand: permitted as Food Additive 319 with similar limits to UK / EU.
Look for "E319", "TBHQ" or "tert-butylhydroquinone" in the ingredients list, usually nested inside a fat or oil ingredient — for example "palm oil (with antioxidant: E319)". On UK crisp and noodle packs it often appears alongside E320 (BHA) or E321 (BHT) in the same fat blend. Products that have moved to natural antioxidants typically list tocopherols (E306–E309 / vitamin E) or rosemary extract (E392) instead.
Scan UK barcodes to spot E319 in frying-oil ingredient lists, alongside the rest of the synthetic antioxidant family.
Get NutraSafe on the App StoreLast updated: 11 May 2026
Free to log up to 25 foods/day · NutraSafe Pro £3.99/month for AI Coach, allergen warning detail and full reaction history.