Flavor ingredient regulatory record

d,l-Isomenthone

d,l-Isomenthone is a ketone in the fruity family, FEMA GRAS under FEMA number 3460 (CAS 491-07-6). Its odor is sweet, minty, herbal, fresh.

FEMA
3460
CAS
491-07-6
JECFA
430
EU FL
07.078
Formula
C10H18O
EC
207-727-4

GRAS status: FEMA GRAS, publication 9. Recorded by FDA in the Substances Added to Food inventory under CAS 491-07-6.

Structure

2D structure of d,l-Isomenthone
Structure of d,l-Isomenthone, C10H18O. Drawn from the canonical SMILES.

Identity

IUPAC name 5-methyl-2-propan-2-ylcyclohexan-1-one
CAS number 491-07-6
FEMA number 3460
Molecular formula C10H18O
Molecular weight 154.25 g/mol
SMILES CC1CCC(C(C)C)C(=O)C1
InChIKey NFLGAXVYCFJBMK-UHFFFAOYSA-N
PubChem CID 6986
EC number 207-727-4
FDA UNII 9WZ3E2G6CL
EPA DTXSID DTXSID7044475
Chemical class Ketone
Boiling point 209 °C
Flash point 90 °C

Also known as: Cyclohexanone, 5-methyl-2-(1-methylethyl)-, (2R,5R)-rel-, Cyclohexanone, 5-methyl-2-(1-methylethyl)-, cis-, p-Menthan-3-one, cis-, rel-(2R,5R)-5-Methyl-2-(1-methylethyl)cyclohexanone, Isomenthone, cis-p-Menthan-3-one, cis-Menthone, (±)-Isomenthone, dl-Isomenthone, α-Isomenthone, cis-p-Menthone, p-menthan-3-one.

Can d,l-Isomenthone be labeled natural?

d,l-Isomenthone occurs in nature, so the label depends on the route: d,l-Isomenthone won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized d,l-Isomenthone 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.

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

d,l-Isomenthone is FEMA GRAS under FEMA number 3460. 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 07.078, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 430, evaluated at the 51st meeting in 1998. 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. d,l-Isomenthone appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 491-07-6, where EPA names it Cyclohexanone, 5-methyl-2-(1-methylethyl)-, (2R,5R)-rel-.

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, minty, herbal, fresh.

Taste: Sweet, minty, cooling.

Where it is used

d,l-Isomenthone is used in beverage, confection, flavoring, personal care and candy, typically as a fruity note.

Structurally similar flavor ingredients

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

MaterialFEMASimilarityOccurrence
Pulegone296395%In nature
l-Piperitone420091%In nature
Thymol306680%In nature
2,6-Dimethyl-4-heptanone353776%In nature
Isopulegone296476%In nature

More ketones in this index

4-Hydroxyacetophenone · 2-cyclohexenone · 2-Butanone · 3-Hepten-2-one · 2,6,10-Trimethyl-2,6,10-pentadecatrien-14-one · Hydroxyacetone

d,l-Isomenthone FAQ

Does d,l-Isomenthone have FEMA GRAS status?

d,l-Isomenthone holds FEMA GRAS status under FEMA number 3460. It is also codified at 21 CFR 172.515.

How do I cite d,l-Isomenthone by FEMA or CAS number?

Cite d,l-Isomenthone as FEMA 3460 or CAS 491-07-6; both point to the same entry. FEMA files it in the fruity flavor category.

Can d,l-Isomenthone be labeled a natural flavor?

Since d,l-Isomenthone is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when d,l-Isomenthone is synthesized. 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.

Can d,l-Isomenthone be used in the EU and UK?

d,l-Isomenthone is on the EU Union List of flavouring substances as FL 07.078 (Annex I Part A) under Regulation 1334/2008.

Has JECFA evaluated d,l-Isomenthone?

Yes. JECFA number 430, evaluated at the 51st meeting in 1998. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.

What does d,l-Isomenthone smell and taste like, and where is it used?

The odor of d,l-Isomenthone is sweet, minty, herbal, fresh. On the palate it is sweet, minty, cooling. Typical uses are beverage, confection, flavoring, personal care and candy.

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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 DL-ISOMENTHONE under CAS 491-07-6 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.