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

1. Identity & Chemical Information

4-Ethyl guaiacol is a single chemical compound commonly known in the industry for its distinctive sensory properties. The IUPAC name for this compound is 2-methoxy-4-ethylphenol. It is registered under the CAS number 2785-89-9. While a specific FEMA number is not available, it is recognized in various flavor and fragrance databases. The molecular formula for 4-ethyl guaiacol is C9H12O2, and it has a molecular weight of 152.19 g/mol. Structurally, it features an ethyl group attached to a guaiacol moiety, which contributes to its characteristic smoky and spicy aroma, making it relevant in both flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

4-Ethyl guaiacol is noted for its potent smoky, spicy, and clove-like aroma, often described as having a phenolic character. It is a key impact compound in the sensory profile of smoked foods and certain alcoholic beverages, such as whiskey and wine, where it contributes to the complexity and depth of flavor. The odor threshold for 4-ethyl guaiacol is relatively low, allowing it to impart noticeable sensory effects even at minimal concentrations. Its role in formulations is typically as an impact note, providing a distinctive character that can enhance the overall sensory experience.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

4-Ethyl guaiacol naturally occurs in various sources, including smoked foods, roasted coffee, and certain alcoholic beverages like whiskey and wine. It is primarily formed through the thermal degradation of lignin, a complex polymer found in wood, during processes such as smoking and roasting. This compound is also produced during fermentation, contributing to the flavor profile of fermented products. Its presence in natural sources supports its designation as a "natural flavor" in regulatory contexts.

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

4. Use in Flavors

In flavor applications, 4-ethyl guaiacol is utilized across various categories, including savory, meat, and alcoholic beverage flavors. It serves as a functional component that imparts a smoky, spicy character, enhancing the authenticity and depth of flavor profiles. Typical use levels in finished food or beverage products range from 0.1 to 5 ppm, depending on the desired intensity and product type. It is generally stable under typical processing conditions, though it may degrade under extreme heat or oxidative environments.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

4-Ethyl guaiacol is employed in fragrance formulations, particularly within the woody and spicy fragrance families. It acts as a modifier or impact note, providing a smoky, phenolic character that enhances the complexity of the fragrance. Typical concentration ranges in fragrance products are from trace amounts up to 0.5%, depending on the desired effect and product type. Its volatility allows it to contribute primarily to the middle notes of a fragrance composition.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

In the United States, 4-ethyl guaiacol is generally recognized as safe (GRAS) for use in flavors by FEMA. In the European Union, it is regulated under Regulation (EC) No 1334/2008, with specific FL number status. The United Kingdom follows similar regulations post-Brexit. In Asia, including Japan and China, it is subject to national food safety standards, while in Latin America, countries like Brazil and MERCOSUR have their own regulatory frameworks. Explicit approvals and harmonized assumptions vary, with some country-specific variability noted.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 4-ethyl guaiacol is considered safe within the typical use levels in food and beverages, with no specific ADI or MSDI established. Dermal exposure in fragrance applications is generally low risk, with no significant irritation or sensitization reported, aligning with IFRA guidelines. Inhalation exposure, relevant to occupational settings, should be managed to minimize potential respiratory irritation. Overall, the risk profiles for food and fragrance applications are similar, with safety ensured through adherence to established use levels.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

4-Ethyl guaiacol is valued for its ability to impart a distinctive smoky and spicy character, making it a versatile component in both flavor and fragrance formulations. It synergizes well with other phenolic compounds and can enhance the complexity of savory and alcoholic flavors. Formulators should be cautious of its potent aroma, as overuse can lead to an overpowering sensory profile. It is often under-utilized in applications where a subtle smoky note could enhance product appeal.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 4-ethyl guaiacol is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though some variability in natural occurrence and formation pathways may exist. Known data gaps are minimal, with regulatory ambiguities primarily related to regional differences in approval and usage guidelines.

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 2026-09-02 15:33:34 GMT (p2)