Flavor ingredient regulatory record

Hydroxynonanoic acid delta-lactone

Hydroxynonanoic acid delta-lactone is a lactone in the fruity family, FEMA GRAS under FEMA number 3356 (CAS 3301-94-8). Its odor is sweet, creamy, coconut, fruity, floral.

FEMA
3356
CAS
3301-94-8
JECFA
230
EU FL
10.014
Formula
C9H16O2
EC
221-974-5

GRAS status: FEMA GRAS, publication 6. Recorded by FDA in the Substances Added to Food inventory under CAS 3301-94-8.

Structure

2D structure of Hydroxynonanoic acid delta-lactone
Structure of Hydroxynonanoic acid delta-lactone, C9H16O2. Drawn from the canonical SMILES.

Identity

IUPAC name 6-butyloxan-2-one
CAS number 3301-94-8
FEMA number 3356
Molecular formula C9H16O2
Molecular weight 156.22 g/mol
SMILES CCCCC1CCCC(=O)O1
InChIKey PXRBWNLUQYZAAX-UHFFFAOYSA-N
PubChem CID 18698
EC number 221-974-5
FDA UNII DMB99B4WCF
EPA DTXSID DTXSID70863149
Chemical class Lactone
Boiling point 115 °C
Flash point 41 °C

Also known as: 2H-Pyran-2-one, 6-butyltetrahydro-, Nonanoic acid, 5-hydroxy-, δ-lactone, Nonanoic acid, 5-hydroxy-, lactone, 6-Butyltetrahydro-2H-pyran-2-one, 5-Hydroxynonanoic acid δ-lactone, δ-Nonalactone, δ-Butylvalerolactone, Nonan-1,5-olide, δ-Butyl-δ-valerolactone, 5-Nonanolide, (±)-δ-Nonalactone, (RS)-δ-Nonalactone.

Can Hydroxynonanoic acid delta-lactone be labeled natural?

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

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

Hydroxynonanoic acid delta-lactone is FEMA GRAS under FEMA number 3356. 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 10.014, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 230, evaluated at the 49th meeting in 1997. 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. Hydroxynonanoic acid delta-lactone appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 3301-94-8, where EPA names it 2H-Pyran-2-one, 6-butyltetrahydro-.

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, creamy, coconut, fruity, floral.

Where it is used

Hydroxynonanoic acid delta-lactone is used in beverage, confection, dairy, desserts and flavoring, typically as a fruity note.

Structurally similar flavor ingredients

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

MaterialFEMASimilarityOccurrence
delta-Decalactone236195%In nature
5-Hydroxyundecanoic acid lactone329492%In nature
gamma-Nonalactone278190%In nature
gamma-Decalactone236088%In nature
delta-Octalactone321482%Not determined

More lactones in this index

4,4-Dibutyl-gamma-butyrolactone · 3,9-Dimethyl-6-(1-methylethyl)-1,4-dioxaspiro[4.5]decan-2-one · Octahydrocoumarin · 5-Hydroxyundecanoic acid lactone · Dehydromenthofurolactone · 2-(4-Methyl-2-hydroxyphenyl)propionic acid-gamma-lactone

Hydroxynonanoic acid delta-lactone FAQ

Is hydroxynonanoic acid delta-lactone on the FEMA GRAS list?

It is. FEMA number 3356 covers hydroxynonanoic acid delta-lactone. It is also codified at 21 CFR 172.515.

What is the FEMA number for hydroxynonanoic acid delta-lactone?

The FEMA number for hydroxynonanoic acid delta-lactone is 3356 and its CAS registry number is 3301-94-8. FEMA files it in the fruity flavor category.

Is hydroxynonanoic acid delta-lactone natural or artificial?

Since hydroxynonanoic acid delta-lactone is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when hydroxynonanoic acid delta-lactone is synthesized. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic hydroxynonanoic acid delta-lactone identical-to-natural.

Is hydroxynonanoic acid delta-lactone approved in the EU?

Hydroxynonanoic acid delta-lactone is on the EU Union List of flavouring substances as FL 10.014 (Annex I Part A) under Regulation 1334/2008.

Has JECFA evaluated hydroxynonanoic acid delta-lactone?

Yes. JECFA number 230, evaluated at the 49th meeting in 1997. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.

What is hydroxynonanoic acid delta-lactone used for?

Hydroxynonanoic acid delta-lactone is described as sweet, creamy, coconut, fruity, floral. It shows up in beverage, confection, dairy, desserts and flavoring.

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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 HYDROXYNONANOIC ACID, DELTA-LACTONE under CAS 3301-94-8 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.