E319 — TBHQ
E319 (TBHQ), a antioxidant, is rated "avoid": worth avoiding. A synthetic, petroleum-derived antioxidant in frying oils, instant noodles, and crackers. Its safe daily limit is one of the lowest of any antioxidant additive, set after animal studies showed immune-system and liver effects. Natural alternatives do the same job.
What is TBHQ?
A synthetic antioxidant made from petroleum feedstock, used to stop fats and oils turning rancid. You find it in vegetable shortenings and frying oils, instant noodles, crackers, and a lot of fried fast food — often unlisted, because it can be carried over in the frying oil rather than added to the final product.
What does it do to the body?
At the amounts in a normal diet there is no established harm to you. The caution comes from the animal record: high-dose feeding studies showed effects on the immune system, the liver, and the forestomach (a structure humans don't have). That evidence is why the permitted daily intake is set very low — 0.7 mg per kg of body weight, roughly 50 mg a day for an adult — leaving little headroom for a diet heavy in fried and packaged food.
What regulators say
EFSA confirmed an acceptable daily intake of 0.7 mg per kg of body weight per day, and its 2016 refined exposure assessment concluded that typical European intakes stay under it. The FDA permits it at up to 0.02% of the fat or oil content. So it is legally allowed — the flag reflects the low safety margin and the animal immune findings, not a regulatory ban.
Risk rating: Avoid
Known or suspected to cause harm: a substance EFSA or another regulator has flagged, or one restricted in some jurisdictions. Best kept out of a regular diet.
Source: EFSA — refined exposure assessment of TBHQ (E 319) (2016) ↗