Flavor ingredient regulatory record

2,4-Hexadienyl propionate

2,4-Hexadienyl propionate is an ester in the fruity family, FEMA GRAS under FEMA number 4131 (CAS 16491-25-1). Its odor is sweet, fruity, green, tropical, estery.

FEMA
4131
CAS
16491-25-1
JECFA
1781
Formula
C9H14O2

GRAS status: FEMA GRAS, publication 22. Recorded by FDA in the Substances Added to Food inventory under CAS 16491-25-1.

Structure

2D structure of 2,4-Hexadienyl propionate
Structure of 2,4-Hexadienyl propionate, C9H14O2. Drawn from the canonical SMILES.

Identity

IUPAC name [(2E,4E)-hexa-2,4-dienyl] propanoate
CAS number 16491-25-1
FEMA number 4131
Molecular formula C9H14O2
Molecular weight 154.21 g/mol
SMILES C/C=C/C=C/COC(=O)CC
InChIKey ZVBREIRNEOXCKQ-TWTPFVCWSA-N
PubChem CID 6386721
Chemical class Ester
Boiling point 120 °C
Flash point 44 °C

Also known as: 2,4-Hexadien-1-ol, 1-propanoate, 2,4-Hexadien-1-ol, propionate, 2,4-Hexadien-1-ol, propanoate, 2,4-Hexadienol monopropionate, NSC 195138, sorbyl propionate, 2,4-hexadienol monopropionate, 2,4-hexadien-1-ol, propionate, 2,4-hexadienyl propionate, (2e,4e)-, (e,e)-2,4-hexadienyl propionate, 2,4-hexadien-1-ol, propanoate, (e,e)-, hexa-2,4-dien-1-yl propanoate.

Can 2,4-Hexadienyl propionate be labeled natural?

Nature occurrence: Not yet found in nature (provisional).

Nature occurrence has not been settled for this substance, so the natural or artificial class is not stated here. The FEMA GRAS status does not depend on it.

Regulatory status, with citations

United States

2,4-Hexadienyl propionate is FEMA GRAS under FEMA number 4131. It is cited in the Code of Federal Regulations at 21 CFR 172.515.

21 CFR 172.515

European Union and United Kingdom

No EU FL number is on file for 2,4-Hexadienyl propionate. That is not a finding either way. The Union List covers defined flavouring substances, so natural complex materials are handled as flavouring preparations under Parts B to F and never receive a number, and substances used as additives sit under Regulation 1333/2008 instead. Confirm the position before EU or UK use.

JECFA (WHO / FAO)

JECFA number 1781.

Other US flags

Not on the California Proposition 65 list.

TSCA Inventory status

A flavor ingredient is also an industrial chemical. 2,4-Hexadienyl propionate appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 16491-25-1, where EPA names it 2,4-Hexadien-1-ol, 1-propanoate.

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, tropical, estery.

Where it is used

2,4-Hexadienyl propionate is used in beverage, confection, fruit flavors, bakery and desserts, typically as a fruity note.

Structurally similar flavor ingredients

Flavor ingredients with a GRAS determination closest to 2,4-Hexadienyl propionate by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.

MaterialFEMASimilarityOccurrence
cis-Hexenyl propionate393395%Not determined
2,4-Hexadienyl isobutyrate413487%Not determined
trans-3-Hexenyl formate335383%In nature
Ethyl sorbate245981%In nature

More esters in this index

3-Mercapto-3-methylbutyl formate · Furfuryl pentanoate · Phenethyl propionate · Phenethyl phenylacetate · Cyclotene butyrate · Allyl cinnamate

2,4-Hexadienyl propionate FAQ

Is 2,4-Hexadienyl propionate FEMA GRAS?

Yes. The FEMA Expert Panel lists 2,4-Hexadienyl propionate as GRAS under FEMA number 4131. The Code of Federal Regulations lists it at 21 CFR 172.515.

What are the FEMA and CAS numbers for 2,4-Hexadienyl propionate?

2,4-Hexadienyl propionate is FEMA 4131, CAS 16491-25-1. Its flavor category is fruity.

How is 2,4-Hexadienyl propionate described, and where does it show up?

Flavorists describe 2,4-Hexadienyl propionate as sweet, fruity, green, tropical, estery. It is used in beverage, confection, fruit flavors, bakery and desserts.

What did JECFA conclude about 2,4-Hexadienyl propionate?

JECFA evaluated 2,4-Hexadienyl propionate under JECFA number 1781.

Is 2,4-Hexadienyl propionate approved in the EU?

No EU FL number is on file for 2,4-Hexadienyl propionate. It has a JECFA evaluation (JECFA 1781), which the EU list draws on, but the Union List entry itself should be confirmed before EU use.

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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 2,4-HEXADIENYL PROPIONATE under CAS 16491-25-1 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.