FlavScents AInsights Entry for 4-Methyl Guaiacol (CAS: 93-51-6)

1. Identity & Chemical Information

4-Methyl guaiacol, also known as creosol, is a phenolic compound with the IUPAC name 2-methoxy-4-methylphenol. It is identified by the CAS number 93-51-6. The FEMA number for 4-methyl guaiacol is 3658. Other identifiers include the FL number 02.013 and CoE number 206. Its molecular formula is C8H10O2, and it has a molecular weight of 138.17 g/mol. The compound features a methoxy group and a methyl group attached to a phenolic ring, contributing to its characteristic smoky and spicy odor profile, which is significant in both flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

4-Methyl guaiacol is known for its distinctive smoky, spicy, and phenolic odor, often described as reminiscent of smoked bacon or roasted coffee. It has a moderate intensity and good diffusion properties, making it a valuable impact note in flavor formulations. The taste threshold of 4-methyl guaiacol is relatively low, allowing it to impart a noticeable flavor even at low concentrations. It is typically used to enhance the authenticity of smoked, roasted, or grilled flavor profiles in food products.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

4-Methyl guaiacol naturally occurs in various sources, including smoked foods, roasted coffee, and certain types of wood smoke. It is formed through the pyrolysis of lignin, a major component of wood, during smoking or roasting processes. This compound is often associated with the "natural flavor" designation due to its presence in naturally smoked or roasted products, aligning with consumer preferences for natural ingredients.

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

4. Use in Flavors

In flavor applications, 4-methyl guaiacol is used across various categories, including savory, meat, and coffee flavors. It serves as an impact note, providing authenticity and depth to smoked and roasted profiles. Typical use levels in finished food products range from 0.5 to 5 ppm, with higher concentrations used in more intense flavor systems. It is relatively stable under heat and acidic conditions, although it may oxidize over time, affecting its sensory properties.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

4-Methyl guaiacol is utilized in fragrance formulations, particularly within the woody and smoky fragrance families. It acts as a modifier or impact note, contributing to the realism and complexity of the scent. Typical concentration ranges in fragrances are from trace amounts up to 0.1%, depending on the desired intensity. Its volatility allows it to function as a middle note, providing a warm, smoky character that enhances the overall fragrance profile.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

In the United States, 4-methyl guaiacol is recognized as GRAS (Generally Recognized As Safe) by FEMA for flavor use. In the European Union, it is approved under Regulation (EC) No 1334/2008 with the FL number 02.013. The United Kingdom follows similar regulations post-Brexit. In Asia, including Japan and China, it is generally accepted for use in flavors, although specific regulations may vary. In Latin America, countries like Brazil and those in MERCOSUR also permit its use, aligning with international standards.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 4-methyl guaiacol is considered safe within the established ADI and MSDI limits, with a wide margin of safety. Dermal exposure in fragrance applications is generally low risk, with minimal reports of irritation or sensitization. Inhalation exposure, primarily relevant in occupational settings, is considered safe at typical usage levels, although adequate ventilation is recommended to minimize exposure. The risk profiles for food and fragrance applications are similar, with no significant differences noted.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

4-Methyl guaiacol is valued for its ability to impart a realistic smoky character to both flavors and fragrances. It synergizes well with other phenolic compounds and can enhance the complexity of savory and woody profiles. Formulators should be cautious of its potent aroma, as overuse can lead to an overpowering or artificial note. It is often underutilized in subtle applications where a hint of smokiness can add depth without dominating the overall profile.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 4-methyl guaiacol is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, although some variability exists in regional regulatory interpretations. Known data gaps are minimal, primarily related to specific regional regulatory nuances.

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 2026-06-24 10:15:00 GMT (p2)