Flavor ingredient regulatory record
alpha-Ionol
alpha-Ionol is a terpene in the floral family, FEMA GRAS under FEMA number 3624 (CAS 25312-34-9). Its odor is floral, sweet, rose, violet, fruity.
- FEMA
- 3624
- CAS
- 25312-34-9
- JECFA
- 391
- EU FL
- 02.105
- Formula
- C13H22O
- EC
- 246-815-7
GRAS status: FEMA GRAS, publication 12. Recorded by FDA in the Substances Added to Food inventory under CAS 25312-34-9.
Structure
Identity
Also known as: 3-Buten-2-ol, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-, (3E)-, 3-Buten-2-ol, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-, (3E)-4-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-3-buten-2-ol, α-Ionol, (3E)-4-(2,6,6-Trimethyl-2-cyclohexenyl)-3-buten-2-ol, Latilure, 4-(2,6,6-Trimethyl-2-cyclohexenyl)but-3-en-2-ol, (e)-4-(2,6,6-trimethylcyclohex-2-en-1-yl)but-3-en-2-ol, alpha-lonol, latilure, .alpha.-ionol, 3-buten-2-ol, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-, (3e)-.
Can alpha-Ionol be labeled natural?
alpha-Ionol occurs in nature, so the label depends on the route: alpha-Ionol won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized alpha-Ionol is artificial. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material 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
alpha-Ionol is FEMA GRAS under FEMA number 3624. 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 02.105, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 391, evaluated at the 51st meeting in 1998. 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. alpha-Ionol appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 25312-34-9, where EPA names it 3-Buten-2-ol, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-, (3E)-.
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: Floral, sweet, rose, violet, fruity.
Taste: Sweet, floral, delicate.
Where it is used
alpha-Ionol is used in fragrance, beverage, confection, bakery and cosmetics, typically as a floral note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to alpha-Ionol by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| beta-Ionol | 3625 | 98% | In nature |
| Dihydro-beta-ionol | 3627 | 91% | In nature |
| alpha-Ionone | 2594 | 91% | In nature |
| Dihydro-alpha-ionone | 3628 | 89% | In nature |
| Dehydrodihydroionone | 3447 | 88% | In nature |
More terpenes in this index
alpha -Bisabolene · beta-Bisabolene · (+/-)-Dihydrofarnesol · alpha-Irone · Bisabolene · Nerol oxide
alpha-Ionol FAQ
Is alpha-Ionol FEMA GRAS?
Yes. The FEMA Expert Panel lists alpha-Ionol as GRAS under FEMA number 3624. It is also codified at 21 CFR 172.515.
What are the FEMA and CAS numbers for alpha-Ionol?
alpha-Ionol is FEMA 3624, CAS 25312-34-9. FEMA files it in the floral flavor category.
Does alpha-Ionol count as natural in the US and the EU?
Since alpha-Ionol is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when alpha-Ionol is synthesized. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.
Is alpha-Ionol on the EU Union List?
alpha-Ionol is on the EU Union List of flavouring substances as FL 02.105 (Annex I Part A) under Regulation 1334/2008.
Has JECFA evaluated alpha-Ionol?
Yes. JECFA number 391, evaluated at the 51st meeting in 1998. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
How is alpha-Ionol described, and where does it show up?
Flavorists describe alpha-Ionol as floral, sweet, rose, violet, fruity. On the palate it is sweet, floral, delicate. It is used in fragrance, beverage, confection, bakery and cosmetics.
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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 ALPHA-IONOL under CAS 25312-34-9 and carries its FEMA number, its JECFA flavor number. The inventory is searchable at FDA. FDA records its technical effect as antioxidant, 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.