Flavor ingredient regulatory record
2-Acetylthiazole
2-Acetylthiazole is a thiazole in the savory family, FEMA GRAS under FEMA number 3328 (CAS 24295-03-2). Its odor is nutty, roasted, popcorn, savory, earthy.
- FEMA
- 3328
- CAS
- 24295-03-2
- JECFA
- 1041
- EU FL
- 15.020
- Formula
- C5H5NOS
- EC
- 246-134-5
GRAS status: FEMA GRAS, publication 6. Recorded by FDA in the Substances Added to Food inventory under CAS 24295-03-2.
Structure
Identity
Also known as: Ethanone, 1-(2-thiazolyl)-, Ketone, methyl 2-thiazolyl, 1-(2-Thiazolyl)ethanone, 2-Acetyl-1,3-thiazole, 1-(Thiazol-2-yl)ethanone, 1-(1,3-Thiazol-2-yl)ethanone, 1-(1,3-Thiazol-2-yl)ethan-1-one, 1-(1,3-thiazol-2-yl)ethan-1-one, 1-(1,3-thiazol-2-yl)ethanone, ethanone, 1-(2-thiazolyl)-, methyl 2-thiazolyl ketone, 1-(thiazol-2-yl)ethan-1-one.
Can 2-Acetylthiazole be labeled natural?
2-Acetylthiazole occurs in nature, so the label depends on the route: 2-Acetylthiazole won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized 2-Acetylthiazole is artificial. In the EU and UK the natural claim likewise needs the natural route, while Mercosur and Mexico keep a third class, identical-to-natural, for the synthetic material.
- United States
- Natural or artificial, by process
- European Union and UK
- Natural only from natural material
- Mercosur and Mexico
- Natural or identical-to-natural
How each market defines the classes: natural vs artificial flavor under 21 CFR 101.22.
Regulatory status, with citations
United States
2-Acetylthiazole is FEMA GRAS under FEMA number 3328. It is cited in the Code of Federal Regulations at 21 CFR 172.515.
European Union and United Kingdom
Listed on the Union List of flavouring substances as FL 15.020, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 1041, evaluated at the 59th meeting in 2002. No safety concern at current levels of intake when used as a flavouring agent.
Other US flags
Not on the California Proposition 65 list.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. 2-Acetylthiazole appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 24295-03-2, where EPA names it Ethanone, 1-(2-thiazolyl)-.
Active in US commerce
EPA designates this substance active, so no Notice of Activity Form B is required before manufacturing. What active and inactive mean.
EPA publishes no regulatory flags on this listing. What the flags mean.
From the EPA non-confidential TSCA Inventory, July 2026 release. EPA also maintains a confidential portion it does not publish. Search the Inventory by CAS number.
Odor and taste
Odor: Nutty, roasted, popcorn, savory, earthy.
Taste: Umami, savory, slightly nutty.
Where it is used
2-Acetylthiazole is used in snack foods, seasonings, sauces and meat products, typically as a savory note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 2-Acetylthiazole by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| 2-Furyl methyl ketone | 3163 | 86% | In nature |
| 2-Propionylthiazole | 3611 | 78% | In nature |
| 4-Methyl-5-vinylthiazole | 3313 | 76% | In nature |
| 2,4-Dimethyl-5-acetylthiazole | 3267 | 74% | In nature |
| 2-Thienylmethanol | 4642 | 72% | In nature |
More thiazoles in this index
2-Propionylthiazole · 2,4-Dimethyl-5-acetylthiazole · 2-Pentylthiazole · 2,4,5-Trimethylthiazole · 2,4-Dimethyl-5-vinylthiazole · 2-Methyl-5-methoxythiazole
2-Acetylthiazole FAQ
Does 2-Acetylthiazole have FEMA GRAS status?
2-Acetylthiazole holds FEMA GRAS status under FEMA number 3328. It is also codified at 21 CFR 172.515.
How do I cite 2-Acetylthiazole by FEMA or CAS number?
Cite 2-Acetylthiazole as FEMA 3328 or CAS 24295-03-2; both point to the same entry. FEMA files it in the savory flavor category.
Can 2-Acetylthiazole be labeled a natural flavor?
Since 2-Acetylthiazole is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when 2-Acetylthiazole is synthesized. In the EU and UK the natural claim likewise needs the natural route, while Mercosur and Mexico keep a third class, identical-to-natural, for the synthetic material.
Can 2-Acetylthiazole be used in the EU and UK?
2-Acetylthiazole is on the EU Union List of flavouring substances as FL 15.020 (Annex I Part A) under Regulation 1334/2008.
Has JECFA evaluated 2-Acetylthiazole?
Yes. JECFA number 1041, evaluated at the 59th meeting in 2002. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
What does 2-Acetylthiazole smell and taste like, and where is it used?
The odor of 2-Acetylthiazole is nutty, roasted, popcorn, savory, earthy. On the palate it is umami, savory, slightly nutty. Typical uses are snack foods, seasonings, sauces and meat products.
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Sources and attribution. The identity and regulatory facts on this page are taken from the FDA Substances Added to Food inventory, a US government record, which lists this substance as 2-ACETYLTHIAZOLE under CAS 24295-03-2 and carries its FEMA number, its JECFA flavor number. The inventory is searchable at FDA. FDA records its technical effect as antioxidant, flavor enhancer, flavoring agent or adjuvant, processing aid, surface-finishing agent.
A FEMA GRAS conclusion is reached by the Expert Panel of the Flavor and Extract Manufacturers Association of the United States, and the FEMA number names that conclusion. FEMA publishes its own entry for this substance in the FEMA Flavor Library, which is the authoritative record of what the Panel decided and is worth reading alongside this page.
Ambrose Compliance is not affiliated with, endorsed by, or sponsored by FEMA. FEMA and FEMA GRAS are used here as identifiers for a published regulatory determination, not as marks of any relationship between FEMA and Ambrose.
About this page. Facts come from the FDA Substances Added to Food inventory, the Code of Federal Regulations, the EPA TSCA Inventory, the EU Union List, JECFA and the Ambrose database, with FEMA's published determination cited where it applies; parts of the text are written by Ambrose AI, which can make mistakes. Check the cited source before relying on anything here. This is not regulatory or legal advice.