Ethoxyquin

CAS 91-53-2

Listed as an antioxidant by the US.

Listed as antioxidants (US)
Chemical structure of Ethoxyquin, from PubChem compound 3293
Structure from PubChem CID 3293 (National Library of Medicine, public domain). A depiction of one compound: where a listing covers a family, or a substance has no single structure, this page shows none.

Ethoxyquin is an antioxidant used to protect the colour of chilli powder, paprika and ground chilli. It is more widely used as an antioxidant in animal feed and fish meal.

Where it is and isn’t permitted

Status of Ethoxyquin by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
Australia and New ZealandFood Standards Australia New ZealandNo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
CanadaHealth CanadaPermitted, with conditions

highest permitted level 100 mg/kg

In: Ground chili pepper; Paprika. Purpose: To promote colour retention. Limit: 100 ppm.

Health Canada, List of Permitted Food Additives with Other Purposes of Use (List 8), item E.1retrieved 2026-10-17
European UnionEuropean Commission / EFSANo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
Great BritainFood Standards Agency / Food Standards ScotlandNo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
JapanConsumer Affairs AgencyNo listing matchedThis site imports only Japan’s list of designated additives (Appended Table 1 to the Regulations for Enforcement of the Food Sanitation Act), matched by English name. Existing additives, natural flavouring agents and ordinary foods used as additives are permitted outside that list and are not imported, so an empty row does not show that Japan does not permit the substance.
South KoreaMinistry of Food and Drug SafetyNo listing matchedThis site imports Part III of South Korea’s Standards and Specifications for Food Additives, matched by CAS number, then INS number, then exact name. Mixed preparations and sanitisers are not imported, and an entry whose identifiers disagreed with a page’s is held for review, so an empty row does not show that South Korea does not permit the substance.
United StatesFood and Drug AdministrationPermitted, with conditions21 CFR 172.140retrieved 2026-10-17
Codex AlimentariusCodex Alimentarius Commission / JECFANot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.

How much is permitted

A listing usually limits the quantity as well as the food. Only one of the forms that takes is a figure: quantum satis and good manufacturing practice permit the amount the technological effect requires and no more, which is a limit rather than the absence of one. Figures below are the range across every food category this page is listed in, and categories differ between regulators — see how much is permitted.

Canada100 mg/kg1 numeric limit
United States—1 no quantity stated

What it is made from

Produced by chemical synthesis from aniline derivatives.

  • Vegan
  • Vegetarian

Compare other additives on the dietary indexes.

CAS registry number
91-53-2
InChIKey
DECIPOUIJURFOJ-UHFFFAOYSA-N
PubChem
CID 3293

Every name it appears under

62 recorded names. A label may use any of them.

E number

  • E0237
  • E324
  • E7329

CAS registry number

  • 91-53-2

As it appears in regulation

  • Ethoxyquin

Other names

  • 1,2,4-trimethyl-6-ethoxyquinoline
  • 1,2-Dihydro-2,2,4-trimethyl-6-ethoxyquinoline
  • 1,2-DIHYDRO-2,2,4-TRIMETHYLQUINOLIN-6-YL ETHYL ETHER
  • 1,2-Dihydro-6-ethoxy-2,2,4-trimethylquin oline
  • 1,2-Dihydro-6-ethoxy-2,2,4-trimethylquinoline
  • 2,2,4-Trimethyl-6-ethoxy-1,2-dihydroquinoline
  • 2,4-Trimethyl-6-ethoxy-1,2-dihydroquinoline
  • 6-(ethyloxy)-2,2,4-trimethyl-1,2-dihydroquinoline
  • 6-Ethoxy-1,2,4-trimethylquinoline
  • 6-Ethoxy-1,2-dihydro-2,2,4-trimethyl-Quinoline
  • 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline
  • 6-Ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, 9CI, 8CI
  • 6-Ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline
  • 6-ethoxy-2,2,4-trimethyl-1H-quinoline
  • 6-Ethoxy-2,4-trimethyl-1,2-dihydroquinoline
  • 6-ETMDQ
  • Alterungsschutzmittel EC
  • Amea 100
  • Antage AW
  • Antioxidant EC
  • Aries Antox
  • CAS-91-53-2
  • Caswell No. 427D
  • CCRIS 2513
  • Dawe's nutrigard
  • EMQ
  • EPA Pesticide Chemical Code 055501
  • Ethoxychin
  • Ethoxyquin
  • Ethoxyquin (Standard)
  • Ethoxyquin, >=75% (capillary GC)
  • Ethoxyquin, PESTANAL(R), analytical standard
  • Ethoxyquin, Vetec(TM) reagent grade, 75%
  • Ethoxyquine
  • Ethyl 2,2,4-trimethyl-1,2-dihydro-6-quinolinyl ether
  • Ethyl 2,2,4-trimethyl-1,2-dihydro-6-quinolinyl ether #
  • HMS500J05
  • HSDB 400
  • Niflex
  • Niflex D
  • Nix-Scald
  • Nocrac AW
  • Nocrack AW
  • Permanax 103
  • Quinol ED
  • Quinoline, 6-ethoxy-1,2-dihydro-2,2,4-trimethyl-
  • Santoflex
  • Santoflex A
  • Santoflex AW
  • Santoquin
  • Santoquine
  • Santoquine (VAN)
  • SantoquinEQ
  • Stop-Scald
  • Usaf B-24
  • WLN: T66 BM CHJ C1 C1 E1 HO2

Systematic names

  • 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline

Hazard reference values

No reference value for this substance in the sources we hold.

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated rather than machine-read, and none has been written for this substance yet.

Common questions

Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.

What is Ethoxyquin?
Ethoxyquin is an antioxidant used to protect the colour of chilli powder, paprika and ground chilli. It is more widely used as an antioxidant in animal feed and fish meal.
What is Ethoxyquin used for in food?
It is listed as an antioxidant — the role the US assigns it. This page shows every function each regulator records, with the citation for each.
Is Ethoxyquin banned in Europe?
No. Ethoxyquin does not appear on the EU's list of authorised food additives, which is not the same as being banned: the EU permits an additive only where it has authorised it, and usually the reason for an absence is that no one applied. The EU has made no finding against this substance. It does mean it may not be used as a food additive in the EU today.
Where is Ethoxyquin permitted?
Of the seven regulators this site reads, Canada and the US permit it. Each permission is for named foods at named levels, not a blanket one; the table on this page gives them with citations.
Is Ethoxyquin vegan?
Yes. Ethoxyquin is not derived from animals, and is suitable for vegetarians. This page says what it is made from and how.

Sources for this page

  • ca retrieved 2026-10-17
  • ecfr retrieved 2026-10-17

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable: a JSON record of this additive is given on request —how to ask for access.

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