Flavor ingredient regulatory record
(E,Z)-4-Octen-3-one
(E,Z)-4-Octen-3-one is a ketone in the fruity family, FEMA GRAS under FEMA number 4328 (CAS 14129-48-7). Its odor is fruity, green, cucumber, fresh, herbaceous.
- FEMA
- 4328
- CAS
- 14129-48-7
- JECFA
- 1843
- Formula
- C8H14O
GRAS status: FEMA GRAS, publication 23. Recorded by FDA in the Substances Added to Food inventory under CAS 14129-48-7.
Structure
Identity
Also known as: 4-Octen-3-one, oct-4-en-3-one, 4-octen-3-one, (e)-oct-4-en-3-one, 4-octen-3-one [fhfi], methylheptenon, oct-4-en-3-one;4-octen-3-one.
Can (E,Z)-4-Octen-3-one be labeled natural?
(E,Z)-4-Octen-3-one occurs in nature, so the label depends on the route: (E,Z)-4-Octen-3-one won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized (E,Z)-4-Octen-3-one is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic (E,Z)-4-Octen-3-one 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
(E,Z)-4-Octen-3-one is FEMA GRAS under FEMA number 4328. It is cited in the Code of Federal Regulations at 21 CFR 172.515.
European Union and United Kingdom
No EU FL number is on file for (E,Z)-4-Octen-3-one. 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 1843, evaluated at the 69th meeting in 2008. 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. (E,Z)-4-Octen-3-one appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 14129-48-7, where EPA names it 4-Octen-3-one.
Inactive in US commerce
EPA designates this substance inactive, so a Notice of Activity Form B is required before anyone manufactures or processes it again. Being FEMA GRAS does not change that. 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, green, cucumber, fresh, herbaceous.
Taste: Slightly sweet, fruity, refreshing.
Where it is used
(E,Z)-4-Octen-3-one 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 (E,Z)-4-Octen-3-one by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| 2-Octen-4-one | 3603 | 95% | In nature |
| 3-Octen-2-one | 3416 | 86% | In nature |
| 3-Hepten-2-one | 3400 | 78% | In nature |
| (E,E)-3,5-Octadien-2-one | 4008 | 78% | In nature |
| 1-Octen-3-one | 3515 | 78% | In nature |
More ketones in this index
3-Heptanone · 2-Pentanone · 3-Decen-2-one · beta-Damascone · cis-1-(2,6,6-Trimethyl-2-cyclohexenyl)-2-butenone · Epoxy oxophorone
(E,Z)-4-Octen-3-one FAQ
Is (E,Z)-4-Octen-3-one on the FEMA GRAS list?
It is. FEMA number 4328 covers (E,Z)-4-Octen-3-one. It is also codified at 21 CFR 172.515.
What is the FEMA number for (E,Z)-4-Octen-3-one?
The FEMA number for (E,Z)-4-Octen-3-one is 4328 and its CAS registry number is 14129-48-7. FEMA files it in the fruity flavor category.
Is (E,Z)-4-Octen-3-one natural or artificial?
Since (E,Z)-4-Octen-3-one is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when (E,Z)-4-Octen-3-one is synthesized. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic (E,Z)-4-Octen-3-one identical-to-natural.
Is (E,Z)-4-Octen-3-one approved in the EU?
No EU FL number is on file for (E,Z)-4-Octen-3-one. It has a JECFA evaluation (JECFA 1843), which the EU list draws on, but the Union List entry itself should be confirmed before EU use.
Has JECFA evaluated (E,Z)-4-Octen-3-one?
Yes. JECFA number 1843, evaluated at the 69th meeting in 2008. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
What is (E,Z)-4-Octen-3-one used for?
(E,Z)-4-Octen-3-one is described as fruity, green, cucumber, fresh, herbaceous. On the palate it is slightly sweet, fruity, refreshing. It shows up in beverage, confection, fruit flavors 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 4-OCTEN-3-ONE under CAS 14129-48-7 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.