Flavor ingredient regulatory record
4-(Methylthio)butanal
4-(Methylthio)butanal is a thiol in the sulfur family, FEMA GRAS under FEMA number 3414 (CAS 42919-64-2). Its odor is garlic, onion, savory, pungent, earthy.
- FEMA
- 3414
- CAS
- 42919-64-2
- JECFA
- 468
- EU FL
- 12.061
- Formula
- C5H10OS
GRAS status: FEMA GRAS, publication 7. Recorded by FDA in the Substances Added to Food inventory under CAS 42919-64-2.
Structure
Identity
Also known as: Butanal, 4-(methylthio)-, 4-(Methylthio)butyraldehyde, 4-(methylsulfanyl)butanal, 4-(methylthio)butyraldehyde, butanal, 4-(methylthio)-, gamma-(methylthio)butyraldehyde, gamma-(methylmercapto)butyraldehyde, 4-methyl thiobutyraldehyde, 4-(methylthio)butanal [fhfi], .gamma.-(methylthio)butyraldehyde, .gamma.-(methylmercapto)butyraldehyde, butyraldehyde, 4(methylthio).
Can 4-(Methylthio)butanal be labeled natural?
Since 4-(Methylthio)butanal is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when 4-(Methylthio)butanal 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.
- 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
4-(Methylthio)butanal is FEMA GRAS under FEMA number 3414. 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 12.061, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 468, evaluated at the 53rd meeting in 1999. No safety concern at current levels of intake when used as a flavouring agent.
Other US flags
Not on the California Proposition 65 list.
Odor and taste
Odor: Garlic, onion, savory, pungent, earthy.
Where it is used
4-(Methylthio)butanal is used in savory dishes, seasoning, sauces and meat products, typically as a sulfur note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 4-(Methylthio)butanal by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| cis-4-Hexenal | 3496 | 93% | In nature |
| trans-4-Hexenal | 4046 | 93% | In nature |
| Hexanal | 2557 | 92% | In nature |
| 3-Hexenal | 3923 | 92% | In nature |
| cis-3-Hexenal | 2561 | 92% | In nature |
More thiols in this index
3-(Methylthio)propylamine · 3-Mercaptopropionic acid · Benzenethiol · Furfuryl mercaptan · Furfuryl isopropyl sulfide · Benzyl mercaptan
4-(Methylthio)butanal FAQ
Is 4-(Methylthio)butanal FEMA GRAS?
Yes. The FEMA Expert Panel lists 4-(Methylthio)butanal as GRAS under FEMA number 3414. It is also codified at 21 CFR 172.515.
What are the FEMA and CAS numbers for 4-(Methylthio)butanal?
4-(Methylthio)butanal is FEMA 3414, CAS 42919-64-2. FEMA files it in the sulfur flavor category.
Does 4-(Methylthio)butanal count as natural in the US and the EU?
4-(Methylthio)butanal occurs in nature, so the label depends on the route: 4-(Methylthio)butanal won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized 4-(Methylthio)butanal is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 4-(Methylthio)butanal identical-to-natural.
Is 4-(Methylthio)butanal on the EU Union List?
4-(Methylthio)butanal is on the EU Union List of flavouring substances as FL 12.061 (Annex I Part A) under Regulation 1334/2008.
Has JECFA evaluated 4-(Methylthio)butanal?
Yes. JECFA number 468, evaluated at the 53rd meeting in 1999. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
How is 4-(Methylthio)butanal described, and where does it show up?
Flavorists describe 4-(Methylthio)butanal as garlic, onion, savory, pungent, earthy. It is used in savory dishes, seasoning, 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 4-(METHYLTHIO)BUTANAL under CAS 42919-64-2 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.