FlavScents AInsights Entry for 4-Ethyl Guaiacol (CAS: 2785-89-9)

1. Identity & Chemical Information

• Common Name(s): 4-Ethyl Guaiacol
• IUPAC Name: 2-Methoxy-4-ethylphenol
• CAS Number: 2785-89-9
• FEMA Number: 3177
• Other Identifiers: FL No. 02.013
• Molecular Formula: C9H12O2
• Molecular Weight: 152.19 g/mol

4-Ethyl guaiacol is a phenolic compound characterized by the presence of an ethyl group and a methoxy group attached to a benzene ring. The functional groups contribute to its distinctive smoky, spicy aroma, which is significant in both flavor and fragrance applications. The methoxy group enhances its solubility in organic solvents, while the ethyl group influences its volatility and sensory impact.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

4-Ethyl guaiacol is known for its smoky, spicy, and clove-like aroma, often described as reminiscent of roasted coffee or smoked meats. It exhibits moderate intensity and diffusion, making it a potent impact note in formulations. The compound's odor threshold is relatively low, allowing it to impart a noticeable effect even at minimal concentrations. In flavor systems, it is typically used to enhance the authenticity of smoke flavors or to add complexity to savory profiles.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

4-Ethyl guaiacol naturally occurs in various foods and beverages, particularly those subjected to fermentation or thermal processing. It is a key component in the aroma of smoked foods, roasted coffee, and certain alcoholic beverages like whiskey and wine. The compound is formed through the degradation of lignin during pyrolysis or fermentation processes, contributing to its designation as a "natural flavor" in regulatory contexts.

Citation hooks: FlavScents; food chemistry literature; EFSA/JECFA monographs

4. Use in Flavors

4-Ethyl guaiacol is widely used in flavor formulations to impart smoky, spicy, and savory notes. It is commonly found in barbecue sauces, smoked meats, and roasted coffee flavors. Typical use levels in finished food products range from 0.1 to 5 ppm, depending on the desired intensity and product type. The compound is stable under typical processing conditions, including moderate heat and pH variations, but may oxidize over time if not properly stored.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, 4-ethyl guaiacol is valued for its ability to add depth and complexity to woody, spicy, and oriental fragrance families. It serves as a trace realism note or modifier, enhancing the authenticity of natural wood and smoke accords. Typical concentration ranges in perfumes are from 0.01% to 0.1%, contributing primarily to the middle notes due to its moderate volatility.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Recognized as GRAS by FEMA for flavor use.
• European Union: Approved under Regulation (EC) No 1334/2008 with FL No. 02.013.
• United Kingdom: Aligns with EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific concentration limits.
• Latin America: Generally accepted in MERCOSUR countries, with some variability in national regulations.

Explicit approvals exist for flavor use, while fragrance applications are subject to IFRA guidelines. There are no significant known uncertainties, but formulators should verify compliance with local regulations.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 4-ethyl guaiacol is considered safe at typical flavor use levels, with an acceptable daily intake (ADI) not specifically established but implied under GRAS status. Dermal exposure in fragrance use is generally safe, with low potential for irritation or sensitization, as per IFRA standards. Inhalation exposure is minimal due to its moderate volatility, but occupational safety measures should be observed during handling.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

4-Ethyl guaiacol is a valuable material for adding authenticity and complexity to both flavors and fragrances. It synergizes well with other smoky and spicy notes, enhancing overall profile depth. Common pitfalls include overuse, leading to overpowering or unbalanced formulations. It is frequently under-utilized in applications where subtlety and nuance are desired.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on 4-ethyl guaiacol is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though some regional regulatory nuances may require further verification. No significant data gaps are noted, but ongoing research may refine understanding of its sensory and safety profiles.

Citation hooks: FlavScents

QA Check

• All required sections 1–9 are present
• "Citation hooks:" line is present under each section
• Flavor section includes ppm ranges
• Toxicology section covers oral, dermal, inhalation
• Regulatory section mentions US, EU, UK, Asia, Latin America
• If complex natural material: includes section 5a (not applicable here)

About FlavScents AInsights (Disclosure)
FlavScents AInsights integrates information from authoritative government, scientific, academic, and industry sources to provide applied, exposure-aware insight into flavor and fragrance materials. Data are drawn from regulatory bodies, expert safety panels, peer-reviewed literature, public chemical databases, and long-standing professional practice within the flavor and fragrance community. Where explicit published values exist, they are reported directly; where gaps remain, AInsights reflects widely accepted industry-typical practice derived from convergent sensory behavior, historical commercial use, regulatory non-objection, and expert consensus. All such information is clearly labeled to distinguish documented data from professional guidance or informed estimation, with the goal of offering transparent, practical, and scientifically responsible context for researchers, formulators, and regulatory specialists. This section is generated using advanced computational language modeling to synthesize and structure information from established scientific and regulatory knowledge bases, with the intent of supporting—not replacing—expert review and judgment.

Generated 2026-01-23 15:16:14 GMT (p2)