Flavor ingredient regulatory record

4-Hydroxyacetophenone

4-Hydroxyacetophenone is a ketone in the fruity family, FEMA GRAS under FEMA number 4330 (CAS 99-93-4). Its odor is sweet, floral, fruity, caramel, vanilla.

FEMA
4330
CAS
99-93-4
JECFA
2040
EU FL
07.243
Formula
C8H8O2
EC
202-802-8

GRAS status: FEMA GRAS, publication 23. Recorded by FDA in the Substances Added to Food inventory under CAS 99-93-4.

Structure

2D structure of 4-Hydroxyacetophenone
Structure of 4-Hydroxyacetophenone, C8H8O2. Drawn from the canonical SMILES.

Identity

IUPAC name 1-(4-hydroxyphenyl)ethanone
CAS number 99-93-4
FEMA number 4330
Molecular formula C8H8O2
Molecular weight 136.15 g/mol
SMILES CC(=O)c1ccc(O)cc1
InChIKey TXFPEBPIARQUIG-UHFFFAOYSA-N
PubChem CID 7469
EC number 202-802-8
FDA UNII G1L3HT4CMH
EPA DTXSID DTXSID0029133
Chemical class Ketone
Boiling point 146 °C
Flash point 57 °C

Also known as: Ethanone, 1-(4-hydroxyphenyl)-, Acetophenone, 4′-hydroxy-, Acetophenone, p-hydroxy-, 1-(4-Hydroxyphenyl)ethanone, 4-Acetylphenol, Piceol, Methyl p-hydroxyphenyl ketone, p-Hydroxyacetophenone, p-Hydroxyphenyl methyl ketone, p-Acetylphenol, 4′-Hydroxyacetophenone, 4-Hydroxyphenyl methyl ketone.

Can 4-Hydroxyacetophenone be labeled natural?

Since 4-Hydroxyacetophenone is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when 4-Hydroxyacetophenone is synthesized. The EU and UK follow the same logic without a middle class; Mercosur and Mexico label synthetic 4-Hydroxyacetophenone 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-Hydroxyacetophenone is FEMA GRAS under FEMA number 4330. 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 07.243, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.

JECFA (WHO / FAO)

JECFA number 2040, evaluated at the 73rd meeting in 2010. 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. 4-Hydroxyacetophenone appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 99-93-4, where EPA names it Ethanone, 1-(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: Sweet, floral, fruity, caramel, vanilla.

Where it is used

4-Hydroxyacetophenone is used in beverage, confection, bakery and dairy, typically as a fruity note.

Structurally similar flavor ingredients

Flavor ingredients with a GRAS determination closest to 4-Hydroxyacetophenone by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.

MaterialFEMASimilarityOccurrence
4-Hydroxybenzoic acid398687%In nature
4-Hydroxybenzyl alcohol398781%In nature
4-Hydroxy-3-methoxy benzoic acid398879%In nature
2,4-Dihydroxybenzoic acid379877%In nature
4-Hydroxybenzaldehyde398473%In nature

More ketones in this index

1-Ethyl-2-acetylpyrrole · 2-Methoxyacetophenone · 3,5-Undecadien-2-one · Acetophenone · 6,10-Dimethyl-5,9-undecadien-2-one · Vanillylidene acetone

4-Hydroxyacetophenone FAQ

Does 4-Hydroxyacetophenone have FEMA GRAS status?

4-Hydroxyacetophenone holds FEMA GRAS status under FEMA number 4330. It is also codified at 21 CFR 172.515.

How do I cite 4-Hydroxyacetophenone by FEMA or CAS number?

Cite 4-Hydroxyacetophenone as FEMA 4330 or CAS 99-93-4; both point to the same entry. FEMA files it in the fruity flavor category.

Can 4-Hydroxyacetophenone be labeled a natural flavor?

4-Hydroxyacetophenone occurs in nature, so the label depends on the route: 4-Hydroxyacetophenone won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized 4-Hydroxyacetophenone is artificial. The EU and UK grant the natural claim only to that natural route; Mercosur and Mexico call synthetic material identical-to-natural.

Can 4-Hydroxyacetophenone be used in the EU and UK?

4-Hydroxyacetophenone is on the EU Union List of flavouring substances as FL 07.243 (Annex I Part A) under Regulation 1334/2008.

Has JECFA evaluated 4-Hydroxyacetophenone?

Yes. JECFA number 2040, evaluated at the 73rd meeting in 2010. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.

What does 4-Hydroxyacetophenone smell and taste like, and where is it used?

The odor of 4-Hydroxyacetophenone is sweet, floral, fruity, caramel, vanilla. Typical uses are beverage, confection, bakery and dairy.

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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-HYDROXYACETOPHENONE under CAS 99-93-4 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.