Flavor ingredient regulatory record

1-Octen-3-one

1-Octen-3-one is a ketone in the fruity family, FEMA GRAS under FEMA number 3515 (CAS 4312-99-6). Its odor is mushroom, earthy, green, fruity.

FEMA
3515
CAS
4312-99-6
JECFA
1148
EU FL
07.081
Formula
C8H14O
EC
224-327-5

GRAS status: FEMA GRAS, publication 10. Recorded by FDA in the Substances Added to Food inventory under CAS 4312-99-6.

Structure

2D structure of 1-Octen-3-one
Structure of 1-Octen-3-one, C8H14O. Drawn from the canonical SMILES.

Identity

IUPAC name oct-1-en-3-one
CAS number 4312-99-6
FEMA number 3515
Molecular formula C8H14O
Molecular weight 126.2 g/mol
SMILES C=CC(=O)CCCCC
InChIKey KLTVSWGXIAYTHO-UHFFFAOYSA-N
PubChem CID 61346
EC number 224-327-5
FDA UNII 7LT7Z4Q9XR
EPA DTXSID DTXSID5047162
Chemical class Ketone
Boiling point 174 °C
Flash point 72 °C

Also known as: Vinyl amyl ketone, Pentyl vinyl ketone, Amyl vinyl ketone, n-Amyl vinyl ketone, oct-1-en-3-one, vinyl amyl ketone, amyl vinyl ketone, pentyl vinyl ketone, n-amyl vinyl ketone, 1-octene-3-one, n-pentyl vinyl ketone, ai3-37821.

Can 1-Octen-3-one be labeled natural?

The process decides for 1-Octen-3-one. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic 1-Octen-3-one is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 1-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

1-Octen-3-one is FEMA GRAS under FEMA number 3515. 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 07.081, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 1148, evaluated at the 59th meeting in 2002. 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. 1-Octen-3-one appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 4312-99-6, where EPA names it 1-Octen-3-one.

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: Mushroom, earthy, green, fruity.

Where it is used

1-Octen-3-one is used in savory dishes, sauces, seasonings and snacks, typically as a fruity note.

Structurally similar flavor ingredients

Flavor ingredients with a GRAS determination closest to 1-Octen-3-one by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.

MaterialFEMASimilarityOccurrence
(E)-1,5-Octadien-3-one440597%In nature
1-Octen-3-ol280593%In nature
(R)-(-)-1-Octen-3-ol449293%In nature
Allyl hexanoate203292%In nature
8-Nonen-2-one440886%In nature

More ketones in this index

2-Methylacetophenone · 2-Methylcyclohexanone · 2,3,3-Trimethylindan-1-one · 4-Methylheptan-3-one · 4-Acetyl-2-methylpyrimidine · 1-(4-Methoxyphenyl)-4-methyl-1-penten-3-one

1-Octen-3-one FAQ

Is 1-Octen-3-one on the FEMA GRAS list?

It is. FEMA number 3515 covers 1-Octen-3-one. The Code of Federal Regulations lists it at 21 CFR 172.515.

What is the FEMA number for 1-Octen-3-one?

The FEMA number for 1-Octen-3-one is 3515 and its CAS registry number is 4312-99-6. Its flavor category is fruity.

What is 1-Octen-3-one used for?

1-Octen-3-one is described as mushroom, earthy, green, fruity. It shows up in savory dishes, sauces, seasonings and snacks.

What did JECFA conclude about 1-Octen-3-one?

JECFA evaluated 1-Octen-3-one at the 59th meeting in 2002 under JECFA number 1148. The panel concluded: No safety concern at current levels of intake when used as a flavouring agent.

Is 1-Octen-3-one approved in the EU?

Yes. FL 07.081 is the Union List entry for 1-Octen-3-one, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.

Is 1-Octen-3-one natural or artificial?

Nature makes 1-Octen-3-one, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial 1-Octen-3-one, same molecule. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.

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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 1-OCTEN-3-ONE under CAS 4312-99-6 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.