Flavor ingredient regulatory record
Dihydro-alpha-ionone
Dihydro-alpha-ionone is a ketone in the fruity family, FEMA GRAS under FEMA number 3628 (CAS 31499-72-6). Its odor is sweet, floral, fruity, woody, earthy.
- FEMA
- 3628
- CAS
- 31499-72-6
- JECFA
- 393
- EU FL
- 07.132
- Formula
- C13H22O
- EC
- 250-657-4
GRAS status: FEMA GRAS, publication 12. Recorded by FDA in the Substances Added to Food inventory under CAS 31499-72-6.
Structure
Identity
Also known as: 2-Butanone, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-, 4-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-2-butanone, Dihydro-α-ionone, 3,4-Dihydro-α-ionone, α-7,8-Dihydroionone, 4-(2,6,6-trimethylcyclohex-2-en-1-yl)butan-2-one, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-2-butanone, dihydro-.alpha.-ionone, 2-butanone, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-, alpha-dihydroionone, .alpha.-7,8-dihydroionone, .alpha.-dihydroionone.
Can Dihydro-alpha-ionone be labeled natural?
Dihydro-alpha-ionone occurs in nature, so the label depends on the route: dihydro-alpha-ionone won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized dihydro-alpha-ionone 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.
- 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
Dihydro-alpha-ionone is FEMA GRAS under FEMA number 3628. 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 07.132, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (JECFA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 393, evaluated at the 51st meeting in 1998. no safety concern at current levels of intake.
Other US flags
Not on the California Proposition 65 list.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. Dihydro-alpha-ionone appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 31499-72-6, where EPA names it 2-Butanone, 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-.
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, floral, fruity, woody, earthy.
Where it is used
Dihydro-alpha-ionone is used in beverage, confection, fragrance, flavoring and cosmetics, typically as a fruity note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to Dihydro-alpha-ionone by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| Dehydrodihydroionone | 3447 | 97% | In nature |
| alpha-Ionone | 2594 | 97% | In nature |
| Dihydro-beta-ionone | 3626 | 96% | In nature |
| beta-Ionone | 2595 | 96% | In nature |
| Ionone | 3175 | 90% | In nature |
More ketones in this index
(+/-)-2-Hydroxypiperitone · 8-Nonen-2-one · 3-(3-Hydroxy-4-methoxyphenyl)-1-(2,4,6-trihydroxyphenyl) propan-1-one · 6-Hydroxycarvone · 2-Heptanone · Methyl beta-naphthyl ketone
Dihydro-alpha-ionone FAQ
Does dihydro-alpha-ionone have FEMA GRAS status?
Dihydro-alpha-ionone holds FEMA GRAS status under FEMA number 3628. It is also codified at 21 CFR 172.515.
How do I cite dihydro-alpha-ionone by FEMA or CAS number?
Cite dihydro-alpha-ionone as FEMA 3628 or CAS 31499-72-6; both point to the same entry. FEMA files it in the fruity flavor category.
Can dihydro-alpha-ionone be labeled a natural flavor?
Since dihydro-alpha-ionone is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when dihydro-alpha-ionone 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.
Can dihydro-alpha-ionone be used in the EU and UK?
Dihydro-alpha-ionone is on the EU Union List of flavouring substances as FL 07.132 (Annex I Part A) under Regulation 1334/2008.
Has JECFA evaluated dihydro-alpha-ionone?
Yes. JECFA number 393, evaluated at the 51st meeting in 1998. Conclusion: no safety concern at current levels of intake.
What does dihydro-alpha-ionone smell and taste like, and where is it used?
The odor of dihydro-alpha-ionone is sweet, floral, fruity, woody, earthy. Typical uses are beverage, confection, fragrance, flavoring 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 DIHYDRO-ALPHA-IONONE under CAS 31499-72-6 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.