Flavor ingredient regulatory record
3-Methylcrotonic acid
3-Methylcrotonic acid is an acid in the fruity family, FEMA GRAS under FEMA number 3187 (CAS 541-47-9). Its odor is fruity, sour, tangy, green.
- FEMA
- 3187
- CAS
- 541-47-9
- JECFA
- 1204
- EU FL
- 08.070
- Formula
- C5H8O2
- EC
- 208-782-7
GRAS status: FEMA GRAS, publication 4. Recorded by FDA in the Substances Added to Food inventory under CAS 541-47-9.
Structure
Identity
Also known as: 2-Butenoic acid, 3-methyl-, Crotonic acid, 3-methyl-, 3-Methyl-2-butenoic acid, β,β-Dimethylacrylic acid, Senecioic acid, β-Methylcrotonic acid, 3,3-Dimethylacrylic acid, NSC 2549, NSC 97179, 3,3-dimethylacrylic acid, senecioic acid, 2-butenoic acid, 3-methyl-.
Can 3-Methylcrotonic acid be labeled natural?
The process decides for 3-Methylcrotonic acid. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic 3-Methylcrotonic acid 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
3-Methylcrotonic acid is FEMA GRAS under FEMA number 3187. 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 08.070, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 1204, evaluated at the 61st meeting in 2003. 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. 3-Methylcrotonic acid appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 541-47-9, where EPA names it 2-Butenoic acid, 3-methyl-.
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: Fruity, sour, tangy, green.
Taste: Sour, acidic, fruity.
Where it is used
3-Methylcrotonic acid is used in beverage, confection, sauces and dressings, typically as a fruity note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 3-Methylcrotonic acid by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| Isovaleric acid | 3102 | 96% | In nature |
| 4-Methyl-3-penten-2-one | 3368 | 84% | In nature |
| Butyric acid | 2221 | 83% | In nature |
| 3-Methyl-2-oxobutanoic acid | 3869 | 76% | In nature |
| trans-2-Methyl-2-butenoic acid | 3599 | 74% | In nature |
More acids in this index
2-Oxo-3-phenylpropionic acid sodium salt · 3-Hexenoic acid · 3,7-Dimethyl-6-octenoic acid · 2,4-Dihydroxybenzoic acid · Decanedioic acid · 3,4-Dihydroxybenzoic acid
3-Methylcrotonic acid FAQ
Does 3-Methylcrotonic acid have FEMA GRAS status?
3-Methylcrotonic acid holds FEMA GRAS status under FEMA number 3187. The Code of Federal Regulations lists it at 21 CFR 172.515.
How do I cite 3-Methylcrotonic acid by FEMA or CAS number?
Cite 3-Methylcrotonic acid as FEMA 3187 or CAS 541-47-9; both point to the same entry. Its flavor category is fruity.
What does 3-Methylcrotonic acid smell and taste like, and where is it used?
The odor of 3-Methylcrotonic acid is fruity, sour, tangy, green. On the palate it is sour, acidic, fruity. Typical uses are beverage, confection, sauces and dressings.
What did JECFA conclude about 3-Methylcrotonic acid?
JECFA evaluated 3-Methylcrotonic acid at the 61st meeting in 2003 under JECFA number 1204. The panel concluded: No safety concern at current levels of intake when used as a flavouring agent.
Can 3-Methylcrotonic acid be used in the EU and UK?
Yes. FL 08.070 is the Union List entry for 3-Methylcrotonic acid, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.
Can 3-Methylcrotonic acid be labeled a natural flavor?
Nature makes 3-Methylcrotonic acid, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial 3-Methylcrotonic acid, same molecule. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 3-Methylcrotonic acid 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 3-METHYLCROTONIC ACID under CAS 541-47-9 and carries its FEMA number, its JECFA flavor number. The inventory is searchable at FDA. FDA records its technical effect as flavor enhancer, 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.