Flavor ingredient regulatory record
S-Methyl thiofuroate
S-Methyl thiofuroate is a thiol in the fruity family, FEMA GRAS under FEMA number 3311 (CAS 13679-61-3). Its odor is sweet, fruity, sulfurous, herbal, earthy.
- FEMA
- 3311
- CAS
- 13679-61-3
- JECFA
- 1083
- EU FL
- 13.142
- Formula
- C6H6O2S
- EC
- 237-177-0
GRAS status: FEMA GRAS, publication 5. Recorded by FDA in the Substances Added to Food inventory under CAS 13679-61-3.
Structure
Identity
Also known as: 2-Furancarbothioic acid, S-methyl ester, 2-Furoic acid, thio-, S-methyl ester, Methyl 2-thiofuroate, Methylthiol furoate, S-Methyl 2-furancarbothioate, (Furan-2-yl)(methylsulfanyl)methanone, methyl 2-thiofuroate, s-methyl 2-furancarbothioate, methyl thiofuroate, 2-furancarbothioic acid, s-methyl ester, methylthiol furoate, 2-furoic acid, thio-, s-methyl ester.
Can S-Methyl thiofuroate be labeled natural?
The process decides for S-Methyl thiofuroate. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic S-Methyl thiofuroate is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic S-Methyl thiofuroate identical-to-natural.
- 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
S-Methyl thiofuroate is FEMA GRAS under FEMA number 3311. 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 13.142, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 1083, 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. S-Methyl thiofuroate appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 13679-61-3, where EPA names it 2-Furancarbothioic acid, S-methyl ester.
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: Sweet, fruity, sulfurous, herbal, earthy.
Where it is used
S-Methyl thiofuroate is used in beverage, savory dishes, seasonings and snacks, typically as a fruity note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to S-Methyl thiofuroate by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| Furfuryl methyl sulfide | 3160 | 85% | In nature |
| 2-Methyl-5-(methylthio)furan | 3366 | 81% | In nature |
| Furfuryl methyl ether | 3159 | 72% | In nature |
| 2-Propionylthiazole | 3611 | 70% | In nature |
| S-Methyl benzothioate | 3857 | 68% | In nature |
More thiols in this index
(+/-)-2,8-Epithio-cis-p-menthane · S-Furfuryl thiopropionate · (S)-1-Methoxy-3-heptanthiol · (+/-) 4-Methyl-2-propyl-1,3-oxathiane · 2-Pentenyl-4-propyl-1,3-oxathiane · (+/-)-cis- and trans-2-Pentyl-4-propyl-1,3-oxathiane
S-Methyl thiofuroate FAQ
Is S-Methyl thiofuroate on the FEMA GRAS list?
It is. FEMA number 3311 covers S-Methyl thiofuroate. The Code of Federal Regulations lists it at 21 CFR 172.515.
What is the FEMA number for S-Methyl thiofuroate?
The FEMA number for S-Methyl thiofuroate is 3311 and its CAS registry number is 13679-61-3. Its flavor category is fruity.
What is S-Methyl thiofuroate used for?
S-Methyl thiofuroate is described as sweet, fruity, sulfurous, herbal, earthy. It shows up in beverage, savory dishes, seasonings and snacks.
What did JECFA conclude about S-Methyl thiofuroate?
JECFA evaluated S-Methyl thiofuroate at the 59th meeting in 2002 under JECFA number 1083. The panel concluded: No safety concern at current levels of intake when used as a flavouring agent.
Is S-Methyl thiofuroate approved in the EU?
Yes. FL 13.142 is the Union List entry for S-Methyl thiofuroate, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.
Is S-Methyl thiofuroate natural or artificial?
Nature makes S-Methyl thiofuroate, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial S-Methyl thiofuroate, same molecule. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.
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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 METHYL 2-THIOFUROATE under CAS 13679-61-3 and carries its FEMA number, its JECFA flavor number. The inventory is searchable at FDA. FDA records its technical effect as flavoring agent or adjuvant.
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.