Flavor ingredient regulatory record
Guaiacol
Guaiacol is a phenol in the smoky family, FEMA GRAS under FEMA number 2532 (CAS 90-05-1). Its odor is smoky, phenolic, sweet, bacon.
- FEMA
- 2532
- CAS
- 90-05-1
- JECFA
- 713
- EU FL
- 04.005
- Formula
- C7H8O2
- EC
- 201-964-7
GRAS status: FEMA GRAS, publication 3. Recorded by FDA in the Substances Added to Food inventory under CAS 90-05-1.
Structure
Identity
Also known as: Phenol, 2-methoxy-, Phenol, o-methoxy-, 2-Methoxyphenol, o-Hydroxyanisole, o-Methoxyphenol, Pyroguaiac acid, 2-Hydroxyanisole, 1-Hydroxy-2-methoxybenzene, O-Methyl catechol, Anastil, Guaiastil, o-Guaiacol.
Can Guaiacol be labeled natural?
Guaiacol occurs in nature, so the label depends on the route: guaiacol won from a natural source by a physical, enzymatic or microbiological process is natural flavor in the United States, and synthesized guaiacol 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
Guaiacol is FEMA GRAS under FEMA number 2532. 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 04.005, Annex I Part A under Regulation (EC) 1334/2008, evaluation status approved (EFSA). The UK retains the same list.
JECFA (WHO / FAO)
JECFA number 713, 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. Guaiacol appears on the EPA Toxic Substances Control Act Chemical Substance Inventory under CAS 90-05-1, where EPA names it Phenol, 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, phenolic, sweet, bacon. Detectable at about 0.03 ppm.
Taste: Smoky, phenolic, slightly sweet. Taste threshold about 0.08 ppm.
Where it is used
Guaiacol is used in smoke, bacon, whiskey and BBQ, typically as a smoky note.
Structurally similar flavor ingredients
Flavor ingredients with a GRAS determination closest to Guaiacol by structure. Whether one can replace it is a sensory and regulatory call; the reformulation tool works that through.
| Material | FEMA | Similarity | Occurrence |
|---|---|---|---|
| 1-Methoxy-2-methylbenzene | 2680 | 91% | In nature |
| Anisole | 2097 | 90% | In nature |
| 2-Methoxy-4-methylphenol | 2671 | 85% | In nature |
| Benzyl alcohol | 2137 | 83% | In nature |
| alpha-Methylbenzyl alcohol | 2685 | 76% | In nature |
More phenols in this index
2,6-Dimethoxyphenol · 4-Ethylguaiacol · Magnolol · p-Propylanisole · Thymol · 4-(1,1-Dimethylethyl)phenol
Guaiacol FAQ
Is guaiacol FEMA GRAS?
Yes. The FEMA Expert Panel lists guaiacol as GRAS under FEMA number 2532. It is also codified at 21 CFR 172.515.
What are the FEMA and CAS numbers for guaiacol?
Guaiacol is FEMA 2532, CAS 90-05-1. FEMA files it in the smoky flavor category.
Does guaiacol count as natural in the US and the EU?
Since guaiacol is found in nature, US labeling follows how it was obtained: natural flavor from a natural source and a natural process, artificial when guaiacol 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 guaiacol on the EU Union List?
Guaiacol is on the EU Union List of flavouring substances as FL 04.005 (Annex I Part A) under Regulation 1334/2008.
Has JECFA evaluated guaiacol?
Yes. JECFA number 713, evaluated at the 55th meeting in 2000. Conclusion: No safety concern at current levels of intake when used as a flavouring agent.
How is guaiacol described, and where does it show up?
Flavorists describe guaiacol as smoky, phenolic, sweet, bacon. On the palate it is smoky, phenolic, slightly sweet. Its odor threshold is about 0.03 ppm. It is used in smoke, bacon, whiskey and BBQ.
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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 GUAIACOL under CAS 90-05-1 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.