Flavor ingredient regulatory record
4-Ethylguaiacol
4-Ethylguaiacol is a phenol in the smoky family, FEMA GRAS under FEMA number 2436 (CAS 2785-89-9). Its odor is smoky, spicy, clove, medicinal.
- FEMA
- 2436
- CAS
- 2785-89-9
- JECFA
- 716
- EU FL
- 04.008
- Formula
- C9H12O2
- EC
- 220-500-4
GRAS status: FEMA GRAS, publication 3. Recorded by FDA in the Substances Added to Food inventory under CAS 2785-89-9.
Structure
Identity
Also known as: Phenol, 4-ethyl-2-methoxy-, Guaiacol, 4-ethyl-, 4-Ethyl-2-methoxyphenol, p-Ethylguaiacol, 4-Hydroxy-3-methoxyethylbenzene, 2-Methoxy-4-ethylphenol, Guaiacyl ethane, 4-Hydroxy-3-methoxyphenylethane, NSC 82313, 4-ethyl-2-methoxyphenol, 2-methoxy-4-ethylphenol, p-ethylguaiacol.
Can 4-Ethylguaiacol be labeled natural?
4-Ethylguaiacol occurs in nature, so the label depends on the route: 4-Ethylguaiacol won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized 4-Ethylguaiacol 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
4-Ethylguaiacol is FEMA GRAS under FEMA number 2436. 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 04.008, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 716, 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. Listed on the EPA TSCA inventory.
TSCA Inventory status
A flavor ingredient is also an industrial chemical. 4-Ethylguaiacol appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 2785-89-9, where EPA names it Phenol, 4-ethyl-2-methoxy-.
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: Smoky, spicy, clove, medicinal. Detectable at about 0.05 ppm.
Taste: Savory, spicy, earthy. Taste threshold about 0.1 ppm.
Where it is used
4-Ethylguaiacol is used in beverage, meat products, seasonings and smoked foods, typically as a smoky note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to 4-Ethylguaiacol by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| Vanillyl alcohol | 3737 | 86% | In nature |
| 2-Methoxy-4-vinylphenol | 2675 | 78% | In nature |
| o-Propylphenol | 3522 | 76% | In nature |
| 2-Methoxy-4-methylphenol | 2671 | 73% | In nature |
| 1-Phenyl-1-propanol | 2884 | 72% | In nature |
More phenols in this index
2,6-Dimethoxyphenol · Guaiacol · Anisole · p-Propylphenol · p-Dimethoxybenzene · 1,2-Dimethoxybenzene
4-Ethylguaiacol FAQ
Is 4-Ethylguaiacol FEMA GRAS?
Yes. The FEMA Expert Panel lists 4-Ethylguaiacol as GRAS under FEMA number 2436. It is also codified at 21 CFR 172.515.
What are the FEMA and CAS numbers for 4-Ethylguaiacol?
4-Ethylguaiacol is FEMA 2436, CAS 2785-89-9. FEMA files it in the smoky flavor category.
Does 4-Ethylguaiacol count as natural in the US and the EU?
Since 4-Ethylguaiacol is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when 4-Ethylguaiacol 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 4-Ethylguaiacol on the EU Union List?
4-Ethylguaiacol is on the EU Union List of flavouring substances as FL 04.008 (Annex I Part A) under Regulation 1334/2008.
Has JECFA evaluated 4-Ethylguaiacol?
Yes. JECFA number 716, evaluated at the 55th meeting in 2000. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
How is 4-Ethylguaiacol described, and where does it show up?
Flavorists describe 4-Ethylguaiacol as smoky, spicy, clove, medicinal. On the palate it is savory, spicy, earthy. Its odor threshold is about 0.05 ppm. It is used in beverage, meat products, seasonings and smoked foods.
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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-ETHYLGUAIACOL under CAS 2785-89-9 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 flavor enhancer, 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.