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 No. 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 and phenolic odor. The presence of the methoxy group is crucial for its odor profile, influencing both its volatility and sensory impact.

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 tar. It has a moderate to strong intensity and is used to impart a smoky note in both flavors and fragrances. The taste threshold is not well-documented, but its odor threshold is relatively low, making it effective even at low concentrations. It typically serves as an impact note, providing depth and complexity to formulations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Ortho-guaiacol naturally occurs in various plant sources, including guaiacum and creosote bush. It is also a product of the pyrolysis of lignin, a major component of wood, which explains its presence in smoked foods and beverages. The compound can be formed through the Maillard reaction during the roasting of coffee and cocoa, contributing to their characteristic flavors. Its presence in natural sources allows it to be designated as a "natural flavor" in certain regulatory contexts.

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

4. Use in Flavors

Ortho-guaiacol is widely used in flavor formulations to impart smoky, roasted, and phenolic notes. It is commonly found in smoked meats, barbecue sauces, and roasted coffee flavors. Typical use levels in finished food products range from 0.5 to 5 ppm, with higher concentrations potentially leading to overpowering and undesirable flavors. It is relatively stable under heat but can oxidize over time, which may alter its sensory characteristics.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In perfumery, ortho-guaiacol is utilized for its smoky and woody notes, fitting well within the woody and oriental fragrance families. It acts as a modifier or impact note, providing depth and complexity. Typical concentration ranges in fragrance formulations are from trace amounts up to 0.5%, depending on the desired intensity. It contributes 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: Listed 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, but specific regulations may vary across countries like Brazil and MERCOSUR members.

Explicit approvals and harmonized assumptions are common, though country-specific variability exists, particularly in Asia and Latin America.

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.

• Oral Exposure: The compound has a high margin of safety when used within recommended flavor concentrations. No specific ADI or MSDI is established, but it is generally recognized as safe.
• Dermal Exposure: In fragrance applications, it is not a known skin irritant or sensitizer at typical use levels. IFRA guidelines do not list specific restrictions.
• Inhalation Exposure: Due to its moderate volatility, inhalation exposure is limited, with no significant occupational hazards reported.

Risk profiles do not significantly differ between food and fragrance applications.

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, enhancing the authenticity of smoked and roasted profiles. It synergizes well with other phenolic compounds and can be used to balance sweetness in formulations. Common pitfalls include overuse, leading to an overpowering medicinal note. It is often under-utilized in complex flavor systems where subtle smokiness is desired.

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, though specific numeric thresholds for taste are less frequently reported. Regulatory ambiguities are minimal, with clear guidelines in major markets.

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 2026-01-21 13:44:28 GMT (p2)