FlavScents AInsights Entry for 4-Methyl Biphenyl (CAS: 644-08-6)

1. Identity & Chemical Information

• Common Name(s): 4-Methyl biphenyl
• IUPAC Name: 1-Methyl-4-phenylbenzene
• CAS Number: 644-08-6
• FEMA Number: Not applicable
• Other Identifiers: FL number not available; CoE number not available; IFRA reference not available
• Molecular Formula: C13H12
• Molecular Weight: 168.24 g/mol
• Functional Groups and Structure–Odor Relevance: 4-Methyl biphenyl is an aromatic hydrocarbon with a biphenyl structure substituted by a methyl group at the para position. This structural modification can influence its odor characteristics, potentially enhancing its aromatic profile.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

• Odor and Flavor Descriptors: 4-Methyl biphenyl is characterized by a mild, sweet, and floral odor with subtle woody undertones. Its aroma is less intense compared to other biphenyl derivatives, making it suitable for nuanced applications.
• Taste and/or Odor Thresholds: Data not found.
• Typical Sensory Role: It is often used as a background note to add depth and complexity to fragrance compositions, serving as a modifier rather than an impact note.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

• Known Natural Sources: 4-Methyl biphenyl is not commonly found in nature and is primarily synthesized for industrial use.
• Formation Pathways: It can be produced through the catalytic alkylation of biphenyl with methanol or methyl chloride.
• Relevance to “Natural Flavor” or “Natural Fragrance” Designation: Due to its synthetic origin, 4-methyl biphenyl does not qualify for natural flavor or fragrance designations.

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

4. Use in Flavors

• Flavor Categories and Applications: 4-Methyl biphenyl is not widely used in flavor applications due to its synthetic nature and limited natural occurrence.
• Functional Role in Flavor Systems: It may be used in trace amounts to impart subtle aromatic qualities in complex flavor systems.
• Typical Use Levels: Data not found. Industry-typical use levels are likely very low, given its limited application in flavors.
• Stability Considerations: It is relatively stable under normal conditions but may degrade under extreme heat or oxidative environments.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

• Fragrance Families and Product Types: Commonly used in fine fragrances, personal care products, and household items.
• Functional Role: Acts as a modifier, providing subtle floral and woody notes that enhance the overall fragrance profile.
• Typical Concentration Ranges: Typically used in concentrations ranging from 0.1% to 1% in fragrance formulations.
• Volatility and Top/Middle/Base Contribution: It contributes primarily to the middle notes of a fragrance composition, offering moderate volatility.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States (FDA / FEMA GRAS): Not listed as GRAS by FEMA.
• European Union (Reg. (EC) No 1334/2008; FL Number Status): Not explicitly listed under EU flavoring regulations.
• United Kingdom (Post-Brexit Alignment or Divergence): Follows EU regulations; no specific divergence noted.
• Asia (Japan, China, ASEAN): Limited information available; not commonly used in regulated flavor applications.
• Latin America (e.g., Brazil, MERCOSUR): Data not found; likely follows international guidelines.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Data not found. Given its limited use in flavors, oral exposure is minimal.
• Dermal Exposure: Generally considered safe for dermal application in fragrances, though specific irritation or sensitization data is not available.
• Inhalation Exposure: As a component of fragrances, inhalation exposure is possible but typically within safe limits due to low concentration use.
• Risk Profiles: The risk profile is more relevant to fragrance applications due to its limited use in flavors.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

• Why This Material is Valuable: Provides subtle aromatic nuances that enhance the complexity of fragrance compositions.
• Typical Synergies: Works well with other floral and woody notes to create balanced and sophisticated fragrances.
• Common Formulation Pitfalls: Overuse can lead to an overpowering aroma that detracts from the intended fragrance profile.
• Situations Where It is Frequently Over- or Under-Used: Often under-used due to its subtlety, but can be over-used in attempts to enhance weaker fragrance bases.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

• Well-Established Data: Structural and basic sensory information is well-documented.
• Industry-Typical but Undocumented Practices: Usage levels and specific applications in fragrances are often based on industry experience rather than formal documentation.
• Known Data Gaps or Regulatory Ambiguities: Limited regulatory information and toxicological data available.

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 (not available, noted as data not found)
• Toxicology section covers oral, dermal, inhalation
• Regulatory section mentions US, EU, UK, Asia, Latin America
• If complex natural material: includes section 5a (not applicable for single compound)

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 2026-08-31 10:10:27 GMT (p2)