Flavor ingredient regulatory record
3-Hexenal
3-Hexenal is an aldehyde in the green family, FEMA GRAS under FEMA number 3923 (CAS 4440-65-7). Its odor is fresh, grassy, green, cucumber, fruity.
- FEMA
- 3923
- CAS
- 4440-65-7
- JECFA
- 1271
- EU FL
- 05.192
- Formula
- C6H10O
- EC
- 224-659-0
GRAS status: FEMA GRAS, publication 19. Recorded by FDA in the Substances Added to Food inventory under CAS 4440-65-7.
Structure
Identity
Also known as: Hydrosorbaldehyde, (e)-hex-3-enal, trans-3-hexenal, 3-hexenal, (e)-, hex-3-enal, (3e)-hex-3-enal, 3-hexenal, trans-, (e)-3-hexenal, 3-hexenal, (3e)-, (e)-3-hexen-1-al, (z)-hex-3-enal, 50% in triacetin, (3e)-hexenal.
Can 3-Hexenal be labeled natural?
The process decides for 3-Hexenal. It occurs in nature, so a natural-source, natural-process material is natural flavor in the US and synthetic 3-Hexenal is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 3-Hexenal 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
3-Hexenal is FEMA GRAS under FEMA number 3923. 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 05.192, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
Purity. At least 80% (total of cis- and trans-isomers); secondary component 18-20% trans-2-hexenal.
JECFA (WHO / FAO)
JECFA number 1271, evaluated at the 61st meeting in 2003. No safety concern at current levels of intake when used as a flavouring agent.
Other US flags
Not on the California Proposition 65 list.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. 3-Hexenal appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 4440-65-7, where EPA names it 3-Hexenal.
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: Fresh, grassy, green, cucumber, fruity.
Taste: Green, fresh, slightly bitter.
Where it is used
3-Hexenal is used in beverage, snack foods, flavoring agents and fruity flavors, typically as a green note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 3-Hexenal by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| cis-3-Hexenal | 2561 | 100% | In nature |
| trans-4-Hexenal | 4046 | 99% | In nature |
| cis-4-Hexenal | 3496 | 99% | In nature |
| 2-Hexenal | 2560 | 98% | In nature |
| (E,E)-2,4-Hexadienal | 3429 | 97% | In nature |
More aldehydes in this index
2-Hexenal · Hexanal · 2-Hydroxy-4-methylbenzaldehyde · 5-Methyl-2-thiophenecarboxaldehyde · 2-Ethyl-2-hexenal · 5-Methyl-2-(methylthiomethyl)-2-hexenal
3-Hexenal FAQ
Is 3-Hexenal on the FEMA GRAS list?
It is. FEMA number 3923 covers 3-Hexenal. The Code of Federal Regulations lists it at 21 CFR 172.515.
What is the FEMA number for 3-Hexenal?
The FEMA number for 3-Hexenal is 3923 and its CAS registry number is 4440-65-7. Its flavor category is green.
What is 3-Hexenal used for?
3-Hexenal is described as fresh, grassy, green, cucumber, fruity. On the palate it is green, fresh, slightly bitter. It shows up in beverage, snack foods, flavoring agents and fruity flavors.
What did JECFA conclude about 3-Hexenal?
JECFA evaluated 3-Hexenal at the 61st meeting in 2003 under JECFA number 1271. The panel concluded: No safety concern at current levels of intake when used as a flavouring agent.
Is 3-Hexenal approved in the EU?
Yes. FL 05.192 is the Union List entry for 3-Hexenal, annex I Part A, under Regulation 1334/2008, and the UK keeps the same list.
Is 3-Hexenal natural or artificial?
Nature makes 3-Hexenal, which is why the US label turns on process. A natural route gives natural flavor; synthesis gives artificial 3-Hexenal, same molecule. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.
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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 3-HEXENAL under CAS 4440-65-7 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.