Flavor ingredient regulatory record

Pent-2-enal

Pent-2-enal is an aldehyde in the fruity family, FEMA GRAS under FEMA number 3218 (CAS 764-39-6). Its odor is green, fruity, fresh, herbaceous.

FEMA
3218
CAS
764-39-6
JECFA
1364
EU FL
05.102
Formula
C5H8O
EC
212-120-2

GRAS status: FEMA GRAS, publication 4. Recorded by FDA in the Substances Added to Food inventory under CAS 764-39-6.

Structure

2D structure of Pent-2-enal
Structure of Pent-2-enal, C5H8O. Drawn from the canonical SMILES.

Identity

IUPAC name pent-2-enal
CAS number 764-39-6
FEMA number 3218
Molecular formula C5H8O
Molecular weight 84.12 g/mol
SMILES CCC=CC=O
InChIKey DTCCTIQRPGSLPT-UHFFFAOYSA-N
PubChem CID 12993
EC number 212-120-2
Chemical class Aldehyde
Boiling point 124 °C
Flash point 46 °C

Also known as: 2-Pentenal, γ-Methylcrotonaldehyde, 2-Penten-1-al, 2-pentenal, 3-ethyl-2-propenal, 3-ethylacrolein, gamma-methylcrotonaldehyde, alpha-pentenal, n-pentenal, epitope id:143636, db-043361.

Can Pent-2-enal be labeled natural?

Since pent-2-enal is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when pent-2-enal 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

Pent-2-enal is FEMA GRAS under FEMA number 3218. 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 05.102, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 1364, evaluated at the 63rd meeting in 2004. 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. Pent-2-enal appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 764-39-6, where EPA names it 2-Pentenal.

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: Green, fruity, fresh, herbaceous.

Where it is used

Pent-2-enal is used in beverage, flavoring, confection and savory dishes, typically as a fruity note.

Structurally similar flavor ingredients

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

MaterialFEMASimilarityOccurrence
Valeraldehyde309897%In nature
4-Pentenal426293%In nature
4-Methyl-2-pentenal351093%In nature
2-Methyl-2-pentenal319489%In nature
2,4-Pentadienal321789%In nature

More aldehydes in this index

Octadec-9-enal · 2-Phenylpropionaldehyde dimethyl acetal · 2,4-Nonadienal · Tolualdehyde glyceryl acetal · 3-(Methylthio)-decanal · 4-Methyl-2-pentenal

Pent-2-enal FAQ

Is pent-2-enal on the FEMA GRAS list?

It is. FEMA number 3218 covers pent-2-enal. It is also codified at 21 CFR 172.515.

What is the FEMA number for pent-2-enal?

The FEMA number for pent-2-enal is 3218 and its CAS registry number is 764-39-6. FEMA files it in the fruity flavor category.

Is pent-2-enal natural or artificial?

Pent-2-enal occurs in nature, so the label depends on the route: pent-2-enal won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized pent-2-enal 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 pent-2-enal approved in the EU?

Pent-2-enal is on the EU Union List of flavouring substances as FL 05.102 (Annex I Part A) under Regulation 1334/2008.

Has JECFA evaluated pent-2-enal?

Yes. JECFA number 1364, evaluated at the 63rd meeting in 2004. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.

What is pent-2-enal used for?

Pent-2-enal is described as green, fruity, fresh, herbaceous. It shows up in beverage, flavoring, confection and savory dishes.

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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-PENTENAL under CAS 764-39-6 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.