E324 - Ethoxyquin

At a glance

• What it is: A man‑made antioxidant that slows fat oxidation (rancidity).
• Where you’ll see it: Common in animal feed (for example, fish meal); rarely on human food labels.
• Label names: “Ethoxyquin” or “E324.”
• Diet notes: Made by chemical synthesis; not animal‑derived.
• Regulatory snapshot: Approved as an antioxidant in animal feed in the United States; the European Union suspended its authorization in feed pending further data.

Why is Ethoxyquin added to food?

Manufacturers use ethoxyquin to keep fats and oils from turning rancid and to help protect sensitive nutrients from oxidation. In practice, this role is mainly in animal nutrition (such as fish meal and compound feed), where U.S. regulations explicitly authorize its use as an antioxidant with conditions and limits on how it is added.¹

EFSA, the European Food Safety Authority, has described its purpose similarly in feed: to prevent lipid peroxidation and maintain quality during storage and transport.²

What foods contain Ethoxyquin?

You are unlikely to see ethoxyquin listed on the ingredient panel of retail human foods in many markets. Instead, it is primarily used in animal feed to stabilize fats (for example, in fish meal and some compound feeds). EFSA’s re‑evaluation notes this focus on feed use,² and the European Union suspended its authorization as a feed additive in 2017 pending additional safety data.³

Because regulations vary, always check local rules and product labels. Where used, it should appear as “Ethoxyquin” or “E324.”

What can replace Ethoxyquin?

Several antioxidants can perform a similar role, depending on the food or feed and the local rules:

• Natural-source options like ascorbic acid and mixed tocopherols (vitamin E; see also alpha‑tocopherol)
• Extracts of rosemary, used for antioxidant function in some foods (extracts of rosemary)
• Other permitted synthetic antioxidants such as BHA, BHT, or TBHQ

The best substitute depends on flavor impact, heat stability, the fat source, labeling goals, and regulatory limits.

How is Ethoxyquin made?

Ethoxyquin is produced by standard chemical synthesis and formulated to meet purity specifications set in regulations or approvals for its intended use. In practice, manufacturers supply it as a stabilized liquid or premix that disperses into fat‑rich materials. Specifications typically address purity and control of relevant impurities or by‑products.²

Is Ethoxyquin safe to eat?

Safety conclusions depend on the use and the jurisdiction:

• EFSA’s 2015 re‑evaluation of ethoxyquin as a feed additive could not finalize consumer safety due to data gaps, including questions about certain oxidation products and impurities.²
• Following that, the European Commission suspended ethoxyquin’s authorization in feed across the European Union as a precaution while more data are collected.³
• In the United States, the Food and Drug Administration (FDA) authorizes ethoxyquin as an antioxidant in animal feed under specific conditions and limits listed in the Code of Federal Regulations (CFR).¹

If you are concerned about exposure, check local rules and product labels, and speak with your health professional for personal advice.

Does Ethoxyquin have any benefits?

Where it is allowed, ethoxyquin helps:

• Slow rancidity in fats and oils, especially in fish meal and other fat‑rich feed materials
• Maintain product quality during storage and transport by limiting peroxide formation²

These benefits are technological (product stability), not nutritional for humans.

Who should avoid Ethoxyquin?

• People who prefer to avoid synthetic antioxidants may choose foods and supplements that use alternatives (for example, tocopherols or ascorbic acid).
• If you are managing special diets during pregnancy, for infants, or for specific medical conditions, discuss any concerns about additives and residues with a healthcare professional.
• Pet owners can check feed labels if seeking “ethoxyquin‑free” formulations.

Myths & facts

• Myth: “Ethoxyquin is banned everywhere.” Fact: The EU suspended its authorization in animal feed pending more data, but other jurisdictions still allow controlled uses.³
• Myth: “It’s approved the same way in all countries.” Fact: In the U.S., it is authorized as a feed antioxidant under defined conditions in the CFR.¹
• Myth: “Antioxidants all work the same.” Fact: Different antioxidants vary in heat stability, flavor impact, solubility, and legal limits; formulators often choose among BHA, BHT, TBHQ, tocopherols, and ascorbic acid to fit the product.

Ethoxyquin in branded foods

We do not commonly see E324 on ingredient lists of retail human foods. If it appears, it should be listed as “Ethoxyquin” or “E324,” and its use will depend on local regulations.

References

Footnotes

1. 21 CFR 573.380 — Ethoxyquin in animal feed. U.S. Food and Drug Administration via eCFR. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-E/part-573/section-573.380 ↩ ↩² ↩³

2. Scientific Opinion on the safety and efficacy of ethoxyquin for all animal species — EFSA FEEDAP Panel, EFSA Journal 2015;13(11):4246. European Food Safety Authority. https://www.efsa.europa.eu/en/efsajournal/pub/4246 ↩ ↩² ↩³ ↩⁴ ↩⁵

3. Commission Implementing Regulation (EU) 2017/962 — Suspending the authorisation of ethoxyquin as a feed additive. Official Journal of the European Union. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32017R0962 ↩ ↩² ↩³