FlavScents AInsights Entry for 6-Methyl Quinoline (CAS: 91-62-3)

1. Identity & Chemical Information

• Common Name(s): 6-Methyl Quinoline
• IUPAC Name: 6-Methylquinoline
• CAS Number: 91-62-3
• FEMA Number: Not applicable
• Other Identifiers: FL number not available; CoE number not available; IFRA reference not applicable
• Molecular Formula: C10H9N
• Molecular Weight: 143.19 g/mol

6-Methyl quinoline is a heterocyclic aromatic organic compound. It features a quinoline structure with a methyl group at the 6-position. The presence of the nitrogen atom in the quinoline ring contributes to its basicity and influences its odor profile, which is often described as having a leathery or tobacco-like scent.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

6-Methyl quinoline is characterized by its distinct odor profile, which includes descriptors such as leathery, tobacco-like, and slightly sweet. The intensity of its odor is moderate, and it is known for its ability to impart a warm, rich character to compositions. It is often used as an impact note in fragrance formulations, providing depth and complexity. The taste and odor thresholds for 6-methyl quinoline are not well-documented, but it is typically used in low concentrations due to its potent aroma.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

6-Methyl quinoline is not commonly found in nature but can be formed through synthetic processes. It is often produced via the Skraup synthesis, which involves the cyclization of aniline derivatives with glycerol in the presence of an oxidizing agent. This compound is not typically associated with natural flavor or fragrance designations due to its synthetic origin.

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

4. Use in Flavors

6-Methyl quinoline is used in flavor applications primarily for its ability to impart a warm, tobacco-like note. It is utilized in flavor categories such as tobacco, leather, and certain savory profiles. Its functional role in flavor systems is often as a background realism enhancer or a modifier. Typical use levels in finished food or beverage products are not well-documented, but industry practice suggests usage in the low ppm range due to its potent aroma. Stability considerations include moderate resistance to heat and oxidation, although it may degrade under highly acidic or basic conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, 6-methyl quinoline is valued for its contribution to leather and tobacco fragrance families. It serves as a trace realism enhancer and an impact note, adding depth and warmth to compositions. Typical concentration ranges in fragrance formulations are low, often below 1%, due to its strong scent. It is considered a middle to base note, contributing to the longevity and complexity of the fragrance.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: 6-Methyl quinoline does not have a FEMA GRAS status for flavor use. Its use in fragrances is not restricted by the FDA.
• European Union: Not listed under Reg. (EC) No 1334/2008 for flavor use. Its use in fragrances is subject to general safety regulations.
• United Kingdom: Post-Brexit regulations align with the EU regarding flavor use; fragrance use follows general safety guidelines.
• Asia: Specific regulations in Japan, China, and ASEAN countries are not well-documented; general safety standards apply.
• Latin America: Regulatory information for Brazil and MERCOSUR is limited; general safety standards apply.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 6-methyl quinoline lacks specific ADI or MSDI values, and its use in flavors is limited. Dermal exposure in fragrances is generally considered safe at low concentrations, with no significant reports of irritation or sensitization. Inhalation exposure is minimal due to its low volatility, but occupational exposure should be managed with standard safety practices. The risk profiles for food and fragrance applications differ, with more stringent controls typically applied to flavor use.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

6-Methyl quinoline is valued for its ability to add depth and warmth to both flavors and fragrances. It synergizes well with other leathery and tobacco-like notes, enhancing the overall complexity of the formulation. Common pitfalls include overuse, which can lead to an overpowering scent, and underuse, which may result in a lack of desired impact. Formulators should carefully balance its concentration to achieve the desired effect.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 6-methyl quinoline is well-established in terms of its chemical identity and sensory profile. However, there are gaps in specific regulatory approvals and toxicological data, particularly for flavor use. Industry practices are often based on undocumented experience, and formulators should verify regulatory compliance on a case-by-case basis.

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 2026-09-10 06:43:15 GMT (p2)