Flavor ingredient regulatory record

2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one

2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one is a lactone in the fruity family, FEMA GRAS under FEMA number 3941 (CAS 68555-63-5). Its odor is sweet, fruity, tropical, creamy, caramel.

FEMA
3941
CAS
68555-63-5
JECFA
1483
Formula
C9H10O4
EC
271-440-0

GRAS status: FEMA GRAS, publication 19. Recorded by FDA in the Substances Added to Food inventory under CAS 68555-63-5.

Structure

2D structure of 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one
Structure of 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one, C9H10O4. Drawn from the canonical SMILES.

Identity

IUPAC name (2-methyl-4-oxopyran-3-yl) propanoate
CAS number 68555-63-5
FEMA number 3941
Molecular formula C9H10O4
Molecular weight 182.17 g/mol
SMILES CCC(=O)Oc1c(C)occc1=O
InChIKey NBKYPRRBTKRGLE-UHFFFAOYSA-N
PubChem CID 110543
EC number 271-440-0
FDA UNII SO5F79G1MJ
EPA DTXSID DTXSID90887463
Chemical class Lactone
Boiling point 153 °C
Flash point 61 °C

Also known as: 4H-Pyran-4-one, 2-methyl-3-(1-oxopropoxy)-, Maltol propionate, 2-Methyl-4-oxo-4H-pyran-3-yl propanoate, maltol propionate, 4h-pyran-4-one, 2-methyl-3-(1-oxopropoxy)-, 2-methyl-4-oxo-4h-pyran-3-yl propanoate, veltol propionate, maltol propionate [fhfi], 2-methyl-4-oxo-4h-pyran-3-yl propionate, (2-methyl-4-oxopyran-3-yl) propanoate, maltolpropionate, (2-methyl-4-oxo-pyran-3-yl) propanoate.

Can 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one be labeled natural?

Nature makes 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial 2-Methyl-3-(1-oxopropoxy)-4H-pyran-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

2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one is FEMA GRAS under FEMA number 3941. It is cited in the Code of Federal Regulations at 21 CFR 172.515.

21 CFR 172.515

European Union and United Kingdom

No EU FL number is on file for 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one. That is not a finding either way. The Union List covers defined flavouring substances, so natural complex materials are handled as flavouring preparations under Parts B to F and never receive a number, and substances used as additives sit under Regulation 1333/2008 instead. Confirm the position before EU or UK use.

JECFA (WHO / FAO)

JECFA number 1483, evaluated at the 65th meeting in 2005. No safety concern (conditional) 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. 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 68555-63-5, where EPA names it 4H-Pyran-4-one, 2-methyl-3-(1-oxopropoxy)-.

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, tropical, creamy, caramel.

Where it is used

2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one is used in beverage, confection, desserts and fruit flavors, typically as a fruity note.

Structurally similar flavor ingredients

Flavor ingredients with a GRAS determination closest to 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.

MaterialFEMASimilarityOccurrence
Maltyl isobutyrate346289%Not determined
Guaiacol propionate460986%In nature
Ethyl maltol isobutyrate453481%Not determined
Guaiacyl acetate368778%In nature
Guaiacol butyrate460766%Not determined

More lactones in this index

epsilon-Decalactone · 2-(2-Hydroxyphenyl)-cyclopropanecarbocyclic acid delta-lactone · 4,4-Dibutyl-gamma-butyrolactone · Octahydrocoumarin · gamma-Undecalactone · (+/-) 3-Methyl-gamma-decalactone

2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one FAQ

Is 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one on the FEMA GRAS list?

It is. FEMA number 3941 covers 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one. The Code of Federal Regulations lists it at 21 CFR 172.515.

What is the FEMA number for 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one?

The FEMA number for 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one is 3941 and its CAS registry number is 68555-63-5. Its flavor category is fruity.

What is 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one used for?

2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one is described as sweet, fruity, tropical, creamy, caramel. It shows up in beverage, confection, desserts and fruit flavors.

What did JECFA conclude about 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one?

JECFA evaluated 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one at the 65th meeting in 2005 under JECFA number 1483. The panel concluded: No safety concern (conditional) at current levels of intake when used as a flavouring agent.

Is 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one approved in the EU?

No EU FL number is on file for 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one. It has a JECFA evaluation (JECFA 1483), which the EU list draws on, but the Union List entry itself should be confirmed before EU use.

Is 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one natural or artificial?

The process decides for 2-Methyl-3-(1-oxopropoxy)-4H-pyran-4-one. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic 2-Methyl-3-(1-oxopropoxy)-4H-pyran-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 MALTOL PROPIONATE under CAS 68555-63-5 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.