FlavScents AInsights Entry for Ortho-Guaiacol (CAS: 90-05-1)

1. Identity & Chemical Information

• Common Name(s): Ortho-guaiacol, 2-Methoxyphenol
• IUPAC Name: 2-Methoxyphenol
• CAS Number: 90-05-1
• FEMA Number: 2532
• Other Identifiers: FL Number 02.013
• Molecular Formula: C7H8O2
• Molecular Weight: 124.14 g/mol

Ortho-guaiacol is characterized by a methoxy group attached to a phenol ring, which contributes to its distinctive smoky, phenolic odor. This structure is crucial for its role in flavor and fragrance applications, where it imparts a warm, spicy note.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Ortho-guaiacol is known for its smoky, phenolic, and slightly medicinal odor, often described as reminiscent of smoked wood or vanilla. It has a moderate intensity and is used to impart a warm, spicy character in both flavors and fragrances. The taste threshold is not well-documented, but its odor threshold is typically low, making it effective even at minimal concentrations.

In flavor systems, ortho-guaiacol serves as an impact note, adding depth and complexity to compositions such as vanilla, caramel, and smoky profiles.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Ortho-guaiacol naturally occurs in various plant sources, including guaiac wood and certain types of vanilla. It is also a product of the pyrolysis of lignin, a major component of wood, which explains its presence in smoked foods and beverages. Additionally, it can form through the Maillard reaction during the roasting of coffee and cocoa.

Its natural occurrence and formation pathways make it a candidate for "natural flavor" designation, depending on the extraction and processing methods used.

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

4. Use in Flavors

Ortho-guaiacol is widely used in flavor formulations, particularly in categories such as vanilla, caramel, and smoke flavors. It acts as a key impact note, providing a smoky, phenolic character that enhances the overall profile. Typical use levels in finished food or beverage products range from 0.5 to 5 ppm, with higher concentrations used in more robust applications like barbecue sauces or smoked meats.

Stability considerations include moderate resistance to heat and pH variations, although it may oxidize over time, leading to changes in flavor profile.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, ortho-guaiacol is utilized in various fragrance families, including woody, spicy, and oriental compositions. It serves as a modifier or impact note, contributing to the smoky, warm aspects of a fragrance. Typical concentration ranges are from trace amounts to 0.5% in the final product, depending on the desired intensity.

Ortho-guaiacol is moderately volatile, contributing 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: Listed under Regulation (EC) No 1334/2008 with FL number 02.013.
• United Kingdom: Follows EU regulations post-Brexit with no significant divergence reported.
• Asia: Approved for use in Japan and China, with specific concentration limits varying by country.
• Latin America: Generally accepted in Brazil and MERCOSUR countries, subject to local regulations.

Explicit approvals and harmonized assumptions are common, but formulators should verify specific country requirements due to potential variability.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Ortho-guaiacol is considered safe for use in food and fragrance applications at typical exposure levels. For oral exposure, it has a high margin of safety, with no specific ADI or MSDI established, but it is generally recognized as safe under FEMA GRAS. Dermal exposure in fragrances is monitored by IFRA, with no significant irritation or sensitization reported at typical use levels. Inhalation exposure is minimal due to its moderate volatility, but occupational safety measures should be observed in manufacturing settings.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Ortho-guaiacol is valued for its ability to impart a smoky, phenolic character, making it a versatile component in both flavor and fragrance formulations. It synergizes well with vanilla, caramel, and woody notes, enhancing depth and complexity. Formulators should be cautious of its potent odor, which can easily dominate a composition if overused. It is often under-utilized in lighter, floral compositions where a subtle smoky note could add unexpected depth.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on ortho-guaiacol is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, although specific use levels may vary by application. Known data gaps include precise taste thresholds and detailed toxicological profiles, which are areas for further research.

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 2026-09-01 10:22:55 GMT (p2)