CAUTION — -8 pts

TBHQ (tert-Butylhydroquinone)

Flags: F-O04

Also known as: tert-Butylhydroquinone, E319

Kids Food & Snacks

What it is

TBHQ is a synthetic antioxidant preservative used to extend the shelf life of oils, fats, and fat-containing processed foods including crackers, microwave popcorn, fast food, and frozen products.

CAUTION

EWG has flagged TBHQ for immune system effects at high doses. FDA restricts it to 0.02% of the fat/oil content in food. Animal studies show immune system modulation that may affect vaccine response and allergy development.

Why it matters

Immune system modulation: may impair immune response and affect vaccine efficacy at high doses
Nausea, vomiting, and delirium at very high doses
Some evidence of tumor promotion (not initiation) in animal studies
Allergic dermatitis in sensitive individuals

The research

Immunotoxicity of food preservatives

Nishihara T, et al. Environmental Health and Preventive Medicine, 2020. Various studies compiled by EWG [Source]

"EWG assessment identified immune system effects from TBHQ at doses relevant to heavy processed food consumers"

Who should care most

Children consuming multiple processed food products containing TBHQ daily. Cumulative exposure from multiple sources is the primary concern.

How other countries handle it

Country	Status
United States	Permitted. FDA limits to 0.02% of fat or oil content.
European Union	Permitted (E319) with limits.
Canada	Permitted with limits.
Australia	Permitted as E319.

Sources

Immunotoxicity of food preservatives. Nishihara T, et al. Environmental Health and Preventive Medicine, 2020. Various studies compiled by EWG. https://www.ewg.org/foodscores/content/natural-vs-artificial-preservatives/

For informational purposes only. Not medical or dietary advice. Consult your pediatrician. Data current as of March 24, 2026.