Flavor ingredient regulatory record

(Z)-3-Hexenyl 2-oxopropionate

(Z)-3-Hexenyl 2-oxopropionate is an ester in the fruity family, FEMA GRAS under FEMA number 3934 (CAS 68133-76-6). Its odor is sweet, fruity, green, fresh, herbaceous.

FEMA
3934
CAS
68133-76-6
JECFA
1846
EU FL
09.565
Formula
C9H14O3
EC
268-703-7

GRAS status: FEMA GRAS, publication 19. Recorded by FDA in the Substances Added to Food inventory under CAS 68133-76-6.

Structure

2D structure of (Z)-3-Hexenyl 2-oxopropionate
Structure of (Z)-3-Hexenyl 2-oxopropionate, C9H14O3. Drawn from the canonical SMILES.

Identity

IUPAC name [(Z)-hex-3-enyl] 2-oxopropanoate
CAS number 68133-76-6
FEMA number 3934
Molecular formula C9H14O3
Molecular weight 170.21 g/mol
SMILES CC/C=C\CCOC(=O)C(C)=O
InChIKey LKNXTZXOBHAYSR-PLNGDYQASA-N
PubChem CID 5363291
EC number 268-703-7
FDA UNII 74TLP5254U
EPA DTXSID DTXSID20887178
Chemical class Ester
Boiling point 77 °C
Flash point 21 °C

Also known as: Propanoic acid, 2-oxo-, (3Z)-3-hexen-1-yl ester, Propanoic acid, 2-oxo-, 3-hexenyl ester, (Z)-, Propanoic acid, 2-oxo-, (3Z)-3-hexenyl ester, (Z)-3-Hexenyl 2-oxopropanoate, cis-3-Hexenyl pyruvate, cis-3-hexenyl pyruvate, (z)-3-hexenyl pyruvate, (z)-hex-3-enyl pyruvate, 3-hexenyl pyruvate, (3z)-, propanoic acid, 2-oxo-, (3z)-3-hexen-1-yl ester, (3z)-hex-3-en-1-yl 2-oxopropanoate, propanoic acid, 2-oxo-, (3z)-3-hexenyl ester.

Can (Z)-3-Hexenyl 2-oxopropionate be labeled natural?

Since (Z)-3-Hexenyl 2-oxopropionate is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when (Z)-3-Hexenyl 2-oxopropionate is synthesized. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic (Z)-3-Hexenyl 2-oxopropionate 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

(Z)-3-Hexenyl 2-oxopropionate is FEMA GRAS under FEMA number 3934. 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 09.565, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 1846, evaluated at the 69th meeting in 2008. no safety concern at current levels of intake.

JECFA monograph

Other US flags

Not on the California Proposition 65 list.

TSCA Inventory status

A flavor ingredient is also an industrial chemical. (Z)-3-Hexenyl 2-oxopropionate appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 68133-76-6, where EPA names it Propanoic acid, 2-oxo-, (3Z)-3-hexen-1-yl ester.

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, fresh, herbaceous.

Where it is used

(Z)-3-Hexenyl 2-oxopropionate is used in beverage, confection, fruit flavors, flavoring agents and desserts, typically as a fruity note.

Structurally similar flavor ingredients

Flavor ingredients with a GRAS determination closest to (Z)-3-Hexenyl 2-oxopropionate by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.

MaterialFEMASimilarityOccurrence
cis-Hexenyl propionate393390%Not determined
2,4-Hexadienyl propionate413167%Not determined
cis-Hexenyl tiglate393166%In nature

More esters in this index

Isoamyl hexanoate · trans-3-Hexenyl formate · Triethyl citrate · Hexadecyl lactate · Citronellyl anthranilate · Butyl isobutyrate

(Z)-3-Hexenyl 2-oxopropionate FAQ

Does (Z)-3-Hexenyl 2-oxopropionate have FEMA GRAS status?

(Z)-3-Hexenyl 2-oxopropionate holds FEMA GRAS status under FEMA number 3934. It is also codified at 21 CFR 172.515.

How do I cite (Z)-3-Hexenyl 2-oxopropionate by FEMA or CAS number?

Cite (Z)-3-Hexenyl 2-oxopropionate as FEMA 3934 or CAS 68133-76-6; both point to the same entry. FEMA files it in the fruity flavor category.

Can (Z)-3-Hexenyl 2-oxopropionate be labeled a natural flavor?

(Z)-3-Hexenyl 2-oxopropionate occurs in nature, so the label depends on the route: (Z)-3-Hexenyl 2-oxopropionate won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized (Z)-3-Hexenyl 2-oxopropionate is artificial. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.

Can (Z)-3-Hexenyl 2-oxopropionate be used in the EU and UK?

(Z)-3-Hexenyl 2-oxopropionate is on the EU Union List of flavouring substances as FL 09.565 (Annex I Part A) under Regulation 1334/2008.

Has JECFA evaluated (Z)-3-Hexenyl 2-oxopropionate?

Yes. JECFA number 1846, evaluated at the 69th meeting in 2008. Conclusion: no safety concern at current levels of intake.

What does (Z)-3-Hexenyl 2-oxopropionate smell and taste like, and where is it used?

The odor of (Z)-3-Hexenyl 2-oxopropionate is sweet, fruity, green, fresh, herbaceous. Typical uses are beverage, confection, fruit flavors, flavoring agents and desserts.

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Guides: What Is FEMA GRAS? · Natural vs artificial · Filing a GRAS notification

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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 (Z)-3-HEXENYL PYRUVATE under CAS 68133-76-6 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.