Flavor ingredient regulatory record

Isoamyl propionate

Isoamyl propionate is an ester in the fruity family, FEMA GRAS under FEMA number 2082 (CAS 105-68-0). Its odor is fruity, rum-like, pineapple.

FEMA
2082
CAS
105-68-0
JECFA
44
EU FL
09.136
Formula
C8H16O2
EC
203-322-1

GRAS status: FEMA GRAS, publication 3. Recorded by FDA in the Substances Added to Food inventory under CAS 105-68-0.

Structure

2D structure of Isoamyl propionate
Structure of Isoamyl propionate, C8H16O2. Drawn from the canonical SMILES.

Identity

IUPAC name 3-methylbutyl propanoate
CAS number 105-68-0
FEMA number 2082
Molecular formula C8H16O2
Molecular weight 144.21 g/mol
SMILES CCC(=O)OCCC(C)C
InChIKey XAOGXQMKWQFZEM-UHFFFAOYSA-N
PubChem CID 7772
EC number 203-322-1
FDA UNII 2A8739M82Z
EPA DTXSID DTXSID5047613
Chemical class Ester
Boiling point 156 °C
Flash point 62 °C

Also known as: 1-Butanol, 3-methyl-, 1-propanoate, Isopentyl alcohol, propionate, 1-Butanol, 3-methyl-, propanoate, Propionic acid, isopentyl ester, 3-Methylbutyl propionate, iso-Pentyl propionate, Isopentyl propionate, Isoamyl propanoate, Isopentyl propanoate, 3-Methylbutyl propanoate, NSC 7932, 3-Methyl-1-butanol propanoate.

Can Isoamyl propionate be labeled natural?

Since isoamyl propionate is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when isoamyl propionate 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.

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

Isoamyl propionate is FEMA GRAS under FEMA number 2082. 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 09.136, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 44, evaluated at the 46th meeting in 1996. 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. Isoamyl propionate appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 105-68-0, where EPA names it 1-Butanol, 3-methyl-, 1-propanoate.

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: Fruity, rum-like, pineapple.

Taste: Fruity, rum, tropical.

Where it is used

Isoamyl propionate is used in rum, pineapple and fruit, typically as a fruity note.

Structurally similar flavor ingredients

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

MaterialFEMASimilarityOccurrence
Isoamyl 2-methylbutyrate350590%In nature
Butyl isobutyrate218885%In nature
Butyl isovalerate221875%In nature
Isoamyl acetate205572%In nature

More esters in this index

cis-Hexenyl tiglate · Cyclotene butyrate · Ethyl 2-(methylthio)acetate · Methyl 3-(methylthio)propionate · Ethyl 3-phenyl-2,3-epoxypropionate · l-Menthyl butyrate

Isoamyl propionate FAQ

Is isoamyl propionate FEMA GRAS?

Yes. The FEMA Expert Panel lists isoamyl propionate as GRAS under FEMA number 2082. It is also codified at 21 CFR 172.515.

What are the FEMA and CAS numbers for isoamyl propionate?

Isoamyl propionate is FEMA 2082, CAS 105-68-0. FEMA files it in the fruity flavor category.

Does isoamyl propionate count as natural in the US and the EU?

Isoamyl propionate occurs in nature, so the label depends on the route: isoamyl propionate won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized isoamyl propionate is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic isoamyl propionate identical-to-natural.

Is isoamyl propionate on the EU Union List?

Isoamyl propionate is on the EU Union List of flavouring substances as FL 09.136 (Annex I Part A) under Regulation 1334/2008.

Has JECFA evaluated isoamyl propionate?

Yes. JECFA number 44, evaluated at the 46th meeting in 1996. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.

How is isoamyl propionate described, and where does it show up?

Flavorists describe isoamyl propionate as fruity, rum-like, pineapple. On the palate it is fruity, rum, tropical. It is used in rum, pineapple and fruit.

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Guides: What Is FEMA GRAS? · Natural vs artificial · Filing a GRAS notification

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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 ISOAMYL PROPIONATE under CAS 105-68-0 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.