Flavor ingredient regulatory record
4-Methyl-2-pentanone
4-Methyl-2-pentanone is a ketone in the fruity family, FEMA GRAS under FEMA number 2731 (CAS 108-10-1). Its odor is sweet, fruity, caramel, nutty, solvent-like.
- FEMA
- 2731
- CAS
- 108-10-1
- JECFA
- 301
- EU FL
- 07.017
- Formula
- C6H12O
- EC
- 203-550-1
GRAS status: FEMA GRAS, publication 3. Recorded by FDA in the Substances Added to Food inventory under CAS 108-10-1.
Structure
Identity
Also known as: 2-Pentanone, 4-methyl-, Isobutyl methyl ketone, Methyl isobutyl ketone, 2-Methyl-4-pentanone, MIBK, MIK, Hexone, 4-Methyl-2-oxopentane, Isopropylacetone, 2-Methylpropyl methyl ketone, Methyl iso-butyl ketone, Methyl 2-methylpropyl ketone.
Can 4-Methyl-2-pentanone be labeled natural?
The process decides for 4-Methyl-2-pentanone. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic 4-Methyl-2-pentanone 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
4-Methyl-2-pentanone is FEMA GRAS under FEMA number 2731. It is cited in the Code of Federal Regulations at 21 CFR 172.515.
European Union and United Kingdom
Listed on the Union List of flavouring substances as FL 07.017, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 301, evaluated at the 51st meeting in 1998. No safety concern at current levels of intake when used as a flavouring agent.
Other US flags
Listed under California Proposition 65 for developmental toxicity since March 28, 2014; a warning may be required in California depending on exposure.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. 4-Methyl-2-pentanone appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 108-10-1, where EPA names it 2-Pentanone, 4-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 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, caramel, nutty, solvent-like.
Where it is used
4-Methyl-2-pentanone is used in beverage, confection, baked goods and flavoring agents, typically as a fruity note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 4-Methyl-2-pentanone by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| 4-Methyl-3-penten-2-one | 3368 | 95% | In nature |
| 2-Pentanone | 2842 | 92% | In nature |
| Isovaleric acid | 3102 | 84% | In nature |
| 3-Penten-2-one | 3417 | 82% | In nature |
| 4-Methyl-cis-2-pentene | 4650 | 80% | Not determined |
More ketones in this index
3,4-Dimethyl-1,2-cyclo-pentanedione · Dehydrodihydroionone · 2-Methylheptan-3-one · 2-Furyl methyl ketone · trans-alpha-Damascone · 9-Decen-2-one
4-Methyl-2-pentanone FAQ
Does 4-Methyl-2-pentanone have FEMA GRAS status?
4-Methyl-2-pentanone holds FEMA GRAS status under FEMA number 2731. The Code of Federal Regulations lists it at 21 CFR 172.515.
How do I cite 4-Methyl-2-pentanone by FEMA or CAS number?
Cite 4-Methyl-2-pentanone as FEMA 2731 or CAS 108-10-1; both point to the same entry. Its flavor category is fruity.
What does 4-Methyl-2-pentanone smell and taste like, and where is it used?
The odor of 4-Methyl-2-pentanone is sweet, fruity, caramel, nutty, solvent-like. Typical uses are beverage, confection, baked goods and flavoring agents.
What did JECFA conclude about 4-Methyl-2-pentanone?
JECFA evaluated 4-Methyl-2-pentanone at the 51st meeting in 1998 under JECFA number 301. The panel concluded: No safety concern at current levels of intake when used as a flavouring agent.
Can 4-Methyl-2-pentanone be used in the EU and UK?
Yes. FL 07.017 is the Union List entry for 4-Methyl-2-pentanone, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.
Can 4-Methyl-2-pentanone be labeled a natural flavor?
Nature makes 4-Methyl-2-pentanone, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial 4-Methyl-2-pentanone, same molecule. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 4-Methyl-2-pentanone 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 METHYL ISOBUTYL KETONE under CAS 108-10-1 and carries its FEMA number, its JECFA flavor number and its 21 CFR citations. 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.