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

1. Identity & Chemical Information

• Common Name(s): 4-Methyl Guaiacol
• IUPAC Name: 2-Methoxy-4-methylphenol
• CAS Number: 93-51-6
• FEMA Number: 3654
• Other Identifiers: FL No. 02.013
• Molecular Formula: C8H10O2
• Molecular Weight: 138.17 g/mol

4-Methyl guaiacol is a phenolic compound characterized by a methoxy group and a methyl group attached to a benzene ring. Its structure contributes to its smoky, spicy aroma, which is significant in both flavor and fragrance applications. The presence of the methoxy group is crucial for its odor profile, providing a sweet, vanilla-like note that complements its smoky character.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

4-Methyl guaiacol is known for its distinctive smoky, spicy, and sweet aroma, often described as reminiscent of smoked bacon or roasted coffee. It has a moderate to high intensity and is used to impart a smoky character to various flavor profiles. The compound also has a sweet, vanilla-like undertone that enhances its complexity. While specific taste and odor thresholds are not widely reported, it is typically used in low concentrations due to its potent aroma.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

4-Methyl guaiacol naturally occurs in various smoked foods and beverages, such as smoked meats and roasted coffee. It is also found in the essential oils of certain plants. The compound is primarily formed through the pyrolysis of lignin, a major component of wood, during smoking or roasting processes. This formation pathway is significant for its designation as a "natural flavor" in products that undergo such treatments.

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

4. Use in Flavors

4-Methyl guaiacol is extensively used in flavor formulations to impart a smoky, roasted character. It is commonly found in savory applications, such as barbecue sauces, smoked meats, and roasted coffee flavors. Typical use levels in finished food products range from 0.1 to 5 ppm, with higher concentrations used in more robust flavor profiles. The compound is stable under typical processing conditions but may degrade under extreme heat or prolonged exposure to air.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, 4-methyl guaiacol is used to add depth and warmth to compositions, particularly in woody and oriental fragrance families. It serves as a trace realism note or a modifier, enhancing the complexity of the fragrance. Typical concentrations range from 0.01% to 0.1% in finished products. Due to its moderate volatility, it contributes primarily to the middle notes of a fragrance composition.

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 restrictions varying by country.
• Latin America: Generally accepted in Brazil and MERCOSUR countries, subject to local regulations.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 4-methyl guaiacol is considered safe at typical use levels, with an acceptable daily intake (ADI) not specifically established but generally recognized as safe under FEMA GRAS. Dermal exposure in fragrances is considered low risk, with no significant irritation or sensitization reported at typical use levels. Inhalation exposure is minimal due to its moderate volatility, but occupational exposure should be managed with standard safety practices.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

4-Methyl guaiacol is valued for its ability to impart a natural smoky character to both flavors and fragrances. It synergizes well with other phenolic compounds and vanilla notes. Formulators should be cautious of its potency, as overuse can lead to an overpowering aroma. It is often underutilized in sweet applications, where its vanilla undertone can enhance complexity.

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, though specific numeric thresholds for sensory perception are less frequently reported. Regulatory ambiguities are minimal, with harmonized approvals across major regions.

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

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 19:00:52 GMT (p2)