Flavor ingredient regulatory record
2-Methyl-4-pentenoic acid
2-Methyl-4-pentenoic acid is an acid in the fruity family, FEMA GRAS under FEMA number 3511 (CAS 1575-74-2). Its odor is fruity, sour, green, tangy.
- FEMA
- 3511
- CAS
- 1575-74-2
- JECFA
- 355
- EU FL
- 08.059
- Formula
- C6H10O2
GRAS status: FEMA GRAS, publication 10. Recorded by FDA in the Substances Added to Food inventory under CAS 1575-74-2.
Structure
Identity
Also known as: 4-Pentenoic acid, 2-methyl-, (±)-2-Methyl-4-pentenoic acid, α-Methyl-4-pentenoic acid, 2-methylpent-4-enoic acid, 4-pentenoic acid, 2-methyl-, 2-methylpent-4-en-1-oic acid, 2-methylpent-4-enoate, .alpha.-methyl-4-pentenoic acid, 2-methyl-4-pentenoic acid [fhfi], alpha-methyl-4-pentenoic acid, (+-)-2-methyl-4-pentenoic acid, 2-methyl-4-pentenoic acid, (+-)-.
Can 2-Methyl-4-pentenoic acid be labeled natural?
The process decides for 2-Methyl-4-pentenoic acid. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic 2-Methyl-4-pentenoic 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
2-Methyl-4-pentenoic acid is FEMA GRAS under FEMA number 3511. 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 08.059, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 355, evaluated at the 51st meeting in 1998. 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-Methyl-4-pentenoic acid appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 1575-74-2, where EPA names it 4-Pentenoic acid, 2-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, green, tangy.
Where it is used
2-Methyl-4-pentenoic acid is used in beverage, confection, fruit flavors and savory dishes, typically as a fruity note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 2-Methyl-4-pentenoic acid by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| Methyl-3-pentenoic acid | 3464 | 93% | In nature |
| 4-Pentenoic acid | 2843 | 92% | In nature |
| 2-Methyl-2-pentenoic acid | 3195 | 91% | In nature |
| 2-Methylvaleric acid | 2754 | 89% | In nature |
| (E)-2-Pentenoic acid | 4193 | 78% | In nature |
More acids in this index
cis-4-(2,2,3-Trimethylcyclopentyl)butanoic acid · Undecanoic acid · (E)-2-Pentenoic acid · 2-Methylheptanoic acid · 2-Methylvaleric acid · Oleic acid
2-Methyl-4-pentenoic acid FAQ
Does 2-Methyl-4-pentenoic acid have FEMA GRAS status?
2-Methyl-4-pentenoic acid holds FEMA GRAS status under FEMA number 3511. The Code of Federal Regulations lists it at 21 CFR 172.515.
How do I cite 2-Methyl-4-pentenoic acid by FEMA or CAS number?
Cite 2-Methyl-4-pentenoic acid as FEMA 3511 or CAS 1575-74-2; both point to the same entry. Its flavor category is fruity.
What does 2-Methyl-4-pentenoic acid smell and taste like, and where is it used?
The odor of 2-Methyl-4-pentenoic acid is fruity, sour, green, tangy. Typical uses are beverage, confection, fruit flavors and savory dishes.
What did JECFA conclude about 2-Methyl-4-pentenoic acid?
JECFA evaluated 2-Methyl-4-pentenoic acid at the 51st meeting in 1998 under JECFA number 355. The panel concluded: No safety concern at current levels of intake when used as a flavouring agent.
Can 2-Methyl-4-pentenoic acid be used in the EU and UK?
Yes. FL 08.059 is the Union List entry for 2-Methyl-4-pentenoic acid, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.
Can 2-Methyl-4-pentenoic acid be labeled a natural flavor?
Nature makes 2-Methyl-4-pentenoic acid, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial 2-Methyl-4-pentenoic acid, same molecule. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 2-Methyl-4-pentenoic 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 2-METHYL-4-PENTENOIC ACID under CAS 1575-74-2 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.