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Butylated Hydroxytoluene (BHT) (E321) — What You Need to Know

Caution(5/10)Synthetic

The score is an eNumbers.org editorial summary, not an official agency rating or medical advice. Start with the regulatory status and primary sources below.

What Is Butylated Hydroxytoluene (BHT)?

BHT is a synthetic antioxidant closely related to BHA, used to prevent oxidation and rancidity in fats, oils, and fat-containing foods. Unlike BHA, it has not been classified as carcinogenic by IARC, but EFSA has set a very low ADI reflecting some safety concerns. It is also used as a stabilizer in cosmetics, pharmaceuticals, and plastics.

What Is It Used For?

Prevents oxidation and rancidity in fats, oils, and fat-containing foods. Also used as a stabilizer in food packaging materials to prevent migration of off-flavors.

Function: Antioxidant, fat preservative
0.4 mg
Dataset exposure estimate
18 mg
ADI-derived reference (70 kg)
2.3%
of ADI (typical diet)

Exposure figures are population-level references, not personal limits. Actual intake varies by diet, product and jurisdiction.

Regulatory & Editorial Context

📊
Acceptable Daily Intake (ADI)
0.25 mg/kg bw/day
🏛️
Regulatory Status
🇪🇺 EU: Authorized
🇺🇸 US: Approved
🇯🇵 JP: Restricted
🇦🇺 AU: Approved
🇨🇦 CA: Approved
⚠️ Key Concerns

Less controversial than BHA — IARC has NOT classified BHT as carcinogenic (unlike BHA which is Group 2B). However, EFSA set a very low ADI (0.25 mg/kg bw/day) and noted that some population groups may exceed this. Animal studies show liver enlargement and effects on blood clotting at high doses. Some studies show tumor-promoting activity at high doses, while others show anti-cancer effects — results are contradictory. Also used in cosmetics, pharmaceuticals, and as a stabilizer in plastics and rubber. Being replaced by natural alternatives in many products.

Editorial context score

eNumbers.org currently assigns Butylated Hydroxytoluene (BHT) an editorial context label of Caution with a score of 5/10. This is 2.1 points below the database average for antioxidants (7.1/10). Dataset reference year: 2018. The dataset's population estimate equals about 2.3% of the listed ADI.

This score is not issued by EFSA, FDA, WHO or another regulator.

Commonly Found In

CerealsChewing gumSnack foodsButterCooking oilsPackaging materials
Example brands:
General MillsKellogg'sFrito-Lay

Always check the label for E321 or 'Butylated Hydroxytoluene (BHT)'

▶Chemical Information
Formula: C15H24O
Molecular Weight: 220.35 g/mol
CAS Number: 128-37-0
INS Number: 321
Also known as: E321, INS 321, BHT, Butylated hydroxytoluene, 2,6-Di-tert-butyl-4-methylphenol, Dibutylhydroxytoluene

Frequently Asked Questions about Butylated Hydroxytoluene (BHT)

Current dataset status: FDA — GRAS; EFSA/EU — Authorized. Reported concerns: Less controversial than BHA — IARC has NOT classified BHT as carcinogenic (unlike BHA which is Group 2B). However, EFSA set a very low ADI (0.25 mg/kg bw/day) and noted that some population groups may exceed this. Animal studies show liver enlargement and effects on blood clotting at high doses. Some studies show tumor-promoting activity at high doses, while others show anti-cancer effects — results are contradictory. Also used in cosmetics, pharmaceuticals, and as a stabilizer in plastics and rubber. Being replaced by natural alternatives in many products. Regulatory status and individual risk are not the same; check the primary sources and permitted conditions of use.

Quick Facts

E-Number
E321
INS Number
321
Category
Antioxidants
Origin
Synthetic
FDA Status
GRAS
EFSA Status
Authorized
ADI
0.25 mg/kg bw/day
Dataset Review
2018
Ingredient-level Dietary Notes
Vegan: ✅ YesHalal: ✅ YesKosher: ✅ YesGluten-Free: ✅ Yes

Carriers, processing aids and product certification can change suitability. Verify the final label and certifier.

Quick Links

Disclaimer: This information is for educational purposes only and is not medical advice. Always consult a healthcare professional for health-related decisions.

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