Flavor ingredient regulatory record
4-(p-Hydroxyphenyl)-2-butanone
4-(p-Hydroxyphenyl)-2-butanone is a terpene alcohol in the floral family, FEMA GRAS under FEMA number 2588 (CAS 5471-51-2). Its odor is lilac, floral, pine, woody, citrus.
- FEMA
- 2588
- CAS
- 5471-51-2
- JECFA
- 728
- EU FL
- 07.055
- Formula
- C10H12O2
- EC
- 226-806-4
GRAS status: FEMA GRAS, publication 3. Recorded by FDA in the Substances Added to Food inventory under CAS 5471-51-2.
Structure
Identity
Also known as: 2-Butanone, 4-(4-hydroxyphenyl)-, 2-Butanone, 4-(p-hydroxyphenyl)-, 4-(4-Hydroxyphenyl)-2-butanone, (p-Hydroxybenzyl)acetone, 1-(p-Hydroxyphenyl)-3-butanone, Rheosmin, Raspberry ketone, Frambinone, 1-(4-Hydroxyphenyl)-3-butanone, 4-(4′-Hydroxyphenyl)-2-butanone, 4-(3-Oxobutyl)phenol, Oxyphenylon.
Can 4-(p-Hydroxyphenyl)-2-butanone be labeled natural?
4-(p-Hydroxyphenyl)-2-butanone occurs in nature, so the label depends on the route: 4-(p-Hydroxyphenyl)-2-butanone won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized 4-(p-Hydroxyphenyl)-2-butanone is artificial. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 4-(p-Hydroxyphenyl)-2-butanone 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
4-(p-Hydroxyphenyl)-2-butanone is FEMA GRAS under FEMA number 2588. 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 07.055, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 728, evaluated at the 55th meeting in 2000. 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. 4-(p-Hydroxyphenyl)-2-butanone appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 5471-51-2, where EPA names it 2-Butanone, 4-(4-hydroxyphenyl)-.
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: Lilac, floral, pine, woody, citrus.
Taste: Floral, slightly citrus.
Where it is used
4-(p-Hydroxyphenyl)-2-butanone is used in floral, lilac and pine, typically as a floral note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 4-(p-Hydroxyphenyl)-2-butanone by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| Zingerone | 3124 | 82% | In nature |
| 4-(p-Tolyl)-2-butanone | 3074 | 80% | In nature |
| 4-Hydroxy-3-methoxycinnamic acid | 3812 | 66% | In nature |
| Vanillylidene acetone | 3738 | 63% | In nature |
| 3-Hydroxy-4-phenylbutan-2-one | 4052 | 54% | In nature |
More terpene alcohols in this index
Geraniol · Linalool · Nerol · alpha-Terpineol · l-Menthol
4-(p-Hydroxyphenyl)-2-butanone FAQ
Is 4-(p-Hydroxyphenyl)-2-butanone on the FEMA GRAS list?
It is. FEMA number 2588 covers 4-(p-Hydroxyphenyl)-2-butanone. It is also codified at 21 CFR 172.515.
What is the FEMA number for 4-(p-Hydroxyphenyl)-2-butanone?
The FEMA number for 4-(p-Hydroxyphenyl)-2-butanone is 2588 and its CAS registry number is 5471-51-2. FEMA files it in the floral flavor category.
Is 4-(p-Hydroxyphenyl)-2-butanone natural or artificial?
Since 4-(p-Hydroxyphenyl)-2-butanone is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when 4-(p-Hydroxyphenyl)-2-butanone is synthesized. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 4-(p-Hydroxyphenyl)-2-butanone identical-to-natural.
Is 4-(p-Hydroxyphenyl)-2-butanone approved in the EU?
4-(p-Hydroxyphenyl)-2-butanone is on the EU Union List of flavouring substances as FL 07.055 (Annex I Part A) under Regulation 1334/2008.
Has JECFA evaluated 4-(p-Hydroxyphenyl)-2-butanone?
Yes. JECFA number 728, evaluated at the 55th meeting in 2000. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
What is 4-(p-Hydroxyphenyl)-2-butanone used for?
4-(p-Hydroxyphenyl)-2-butanone is described as lilac, floral, pine, woody, citrus. On the palate it is floral, slightly citrus. It shows up in floral, lilac and pine.
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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 4-(P-HYDROXYPHENYL)-2-BUTANONE under CAS 5471-51-2 and carries its FEMA number, its JECFA flavor number and its 21 CFR citations. 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.