Flavor ingredient regulatory record

5-Methyl-2-hepten-4-one

5-Methyl-2-hepten-4-one is a ketone in the fruity family, FEMA GRAS under FEMA number 3761 (CAS 81925-81-7). Its odor is fruity, sweet, floral, ripe, tropical.

FEMA
3761
CAS
81925-81-7
JECFA
1133
EU FL
07.139
Formula
C8H14O

GRAS status: FEMA GRAS, publication 15, 16, 22. Recorded by FDA in the Substances Added to Food inventory under CAS 81925-81-7.

Structure

2D structure of 5-Methyl-2-hepten-4-one
Structure of 5-Methyl-2-hepten-4-one, C8H14O. Drawn from the canonical SMILES.

Identity

IUPAC name (E)-5-methylhept-2-en-4-one
CAS number 81925-81-7
FEMA number 3761
Molecular formula C8H14O
Molecular weight 126.2 g/mol
SMILES C/C=C/C(=O)C(C)CC
InChIKey ARJWAURHQDJJAC-GQCTYLIASA-N
PubChem CID 5362588
Chemical class Ketone
Boiling point 170 °C
Flash point 70 °C

Also known as: 2-Hepten-4-one, 5-methyl-, 5-methylhept-2-en-4-one, 2-hepten-4-one, 5-methyl-, (e)-, 2-hepten-4-one, 5-methyl-, filbertone, (e)-5-methyl-2-hepten-4-one, (e)-5-methylhept-2-en-4-one, 5-methyl-(e)-2-hepten-4-one, (2e)-5-methyl-2-hepten-4-one, 5-methyl-2-hepten-4-one [fhfi], 5-methyl-2-hepten-4-one, (+/-)-, 2-hepten-4-one, 5-methyl-, (2e)-.

Can 5-Methyl-2-hepten-4-one be labeled natural?

Nature makes 5-Methyl-2-hepten-4-one, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial 5-Methyl-2-hepten-4-one, same molecule. 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.

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

5-Methyl-2-hepten-4-one is FEMA GRAS under FEMA number 3761. 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 07.139, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 1133, evaluated at the 59th meeting in 2002. 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. 5-Methyl-2-hepten-4-one appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 81925-81-7, where EPA names it 2-Hepten-4-one, 5-methyl-.

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 regulatory flags

Flag EPA definition What it obliges
PMN Indicates a commenced PMN substance. Nothing new. The substance already went through premanufacture review and someone filed a notice of commencement, which is why it is on the Inventory. It is an existing chemical and needs no new premanufacture notice. Read more

PMN does not establish: The flag records how the substance arrived, not what may be done with it. Check the flags beside it.

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, sweet, floral, ripe, tropical.

Where it is used

5-Methyl-2-hepten-4-one 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 5-Methyl-2-hepten-4-one by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.

MaterialFEMASimilarityOccurrence
2-Hepten-4-one339991%In nature
2-Ethyl-2-hexenal461290%In nature
4-Hexen-3-one335273%In nature
3-Heptanone254572%In nature
2-Methylheptan-3-one400070%In nature

More ketones in this index

1,3-Diphenyl-2-propanone · 5-Methyl-5-hexen-2-one · 9-Decen-2-one · 1-(2-Hydroxy-4-methoxyphenyl)-3-(pyridin-2-yl)propan-1-one · 2-Methylheptan-3-one · Methyl 2-pyrrolyl ketone

5-Methyl-2-hepten-4-one FAQ

Is 5-Methyl-2-hepten-4-one on the FEMA GRAS list?

It is. FEMA number 3761 covers 5-Methyl-2-hepten-4-one. The Code of Federal Regulations lists it at 21 CFR 172.515.

What is the FEMA number for 5-Methyl-2-hepten-4-one?

The FEMA number for 5-Methyl-2-hepten-4-one is 3761 and its CAS registry number is 81925-81-7. Its flavor category is fruity.

What is 5-Methyl-2-hepten-4-one used for?

5-Methyl-2-hepten-4-one is described as fruity, sweet, floral, ripe, tropical. It shows up in beverage, confection, fruit flavors, bakery and desserts.

What did JECFA conclude about 5-Methyl-2-hepten-4-one?

JECFA evaluated 5-Methyl-2-hepten-4-one at the 59th meeting in 2002 under JECFA number 1133. The panel concluded: no safety concern at current levels of intake.

Is 5-Methyl-2-hepten-4-one approved in the EU?

Yes. FL 07.139 is the Union List entry for 5-Methyl-2-hepten-4-one, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.

Is 5-Methyl-2-hepten-4-one natural or artificial?

The process decides for 5-Methyl-2-hepten-4-one. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic 5-Methyl-2-hepten-4-one 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.

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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 5-METHYL-2-HEPTEN-4-ONE under CAS 81925-81-7 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.