Flavor ingredient regulatory record

2-Methyl-2-pentenal

2-Methyl-2-pentenal is an aldehyde in the fruity family, FEMA GRAS under FEMA number 3194 (CAS 623-36-9). Its odor is sweet, fruity, green, nutty, fresh.

FEMA
3194
CAS
623-36-9
JECFA
1209
EU FL
05.090
Formula
C6H10O
EC
210-789-5

GRAS status: FEMA GRAS, publication 4. Recorded by FDA in the Substances Added to Food inventory under CAS 623-36-9.

Structure

2D structure of 2-Methyl-2-pentenal
Structure of 2-Methyl-2-pentenal, C6H10O. Drawn from the canonical SMILES.

Identity

IUPAC name 2-methylpent-2-enal
CAS number 623-36-9
FEMA number 3194
Molecular formula C6H10O
Molecular weight 98.14 g/mol
SMILES CCC=C(C)C=O
InChIKey IDEYZABHVQLHAF-UHFFFAOYSA-N
PubChem CID 12177
EC number 210-789-5
FDA UNII 947O3MC76M
EPA DTXSID DTXSID3052301
Chemical class Aldehyde
Boiling point 69 °C
Flash point 17 °C

Also known as: 2-Pentenal, 2-methyl-, α-Methyl-β-ethylacrolein, 2-Methyl-2-pentene-1-al, 2-Methyl-3-ethylacrolein, β-Ethyl-α-methylacrolein, 2-Methyl-2-penten-1-al, NSC 9464, 2,4-Dimethylcrotonaldehyde, 2-Methyl-2-pentanal, 2-methylpent-2-enal, 2-pentenal, 2-methyl-, alpha-methyl-beta-ethylacrolein.

Can 2-Methyl-2-pentenal be labeled natural?

Since 2-Methyl-2-pentenal is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when 2-Methyl-2-pentenal is synthesized. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material 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

2-Methyl-2-pentenal is FEMA GRAS under FEMA number 3194. It is cited in the Code of Federal Regulations at 21 CFR 172.515.

21 CFR 172.515

European Union and United Kingdom

Listed on the Union List of flavouring substances as FL 05.090, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.

Purity. At least 92%; secondary components 1.5-2.5% propionaldehyde and 3.5-4.5% propionic acid

JECFA (WHO / FAO)

JECFA number 1209, evaluated at the 61st meeting in 2003. No safety concern at current levels of intake when used as a flavouring agent.

JECFA monograph

Other US flags

Not on the California Proposition 65 list.

TSCA Inventory status

A flavor ingredient is also an industrial chemical. 2-Methyl-2-pentenal appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 623-36-9, where EPA names it 2-Pentenal, 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: Sweet, fruity, green, nutty, fresh.

Where it is used

2-Methyl-2-pentenal is used in beverage, confection, flavoring and fruit flavors, typically as a fruity note.

Structurally similar flavor ingredients

Flavor ingredients with a GRAS determination closest to 2-Methyl-2-pentenal by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.

MaterialFEMASimilarityOccurrence
2-Methylpentanal341396%In nature
Pent-2-enal321892%In nature
4-Methyl-2-pentenal351090%In nature
Valeraldehyde309884%In nature
3-Penten-2-one341783%In nature

More aldehydes in this index

(E,E)-2,4-Hexadienal · 2-(Methylthiomethyl)-3-phenylpropenal · Decanal dimethyl acetal · 9-Undecenal · 10-Undecenal · Myristaldehyde

2-Methyl-2-pentenal FAQ

Is 2-Methyl-2-pentenal on the FEMA GRAS list?

It is. FEMA number 3194 covers 2-Methyl-2-pentenal. It is also codified at 21 CFR 172.515.

What is the FEMA number for 2-Methyl-2-pentenal?

The FEMA number for 2-Methyl-2-pentenal is 3194 and its CAS registry number is 623-36-9. FEMA files it in the fruity flavor category.

Is 2-Methyl-2-pentenal natural or artificial?

2-Methyl-2-pentenal occurs in nature, so the label depends on the route: 2-Methyl-2-pentenal won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized 2-Methyl-2-pentenal 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.

Is 2-Methyl-2-pentenal approved in the EU?

2-Methyl-2-pentenal is on the EU Union List of flavouring substances as FL 05.090 (Annex I Part A) under Regulation 1334/2008.

Has JECFA evaluated 2-Methyl-2-pentenal?

Yes. JECFA number 1209, evaluated at the 61st meeting in 2003. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.

What is 2-Methyl-2-pentenal used for?

2-Methyl-2-pentenal is described as sweet, fruity, green, nutty, fresh. It shows up in beverage, confection, flavoring and fruit flavors.

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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-2-PENTENAL under CAS 623-36-9 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.