FlavScents AInsights Entry for 2-ethyl-4-methyl thiazole (CAS: 15679-12-6)

1. Identity & Chemical Information

• Common Name(s): 2-ethyl-4-methyl thiazole
• IUPAC Name: 2-ethyl-4-methyl-1,3-thiazole
• CAS Number: 15679-12-6
• FEMA Number: 3455
• Other Identifiers: FL No. 15.079
• Molecular Formula: C6H9NS
• Molecular Weight: 127.21 g/mol

2-ethyl-4-methyl thiazole is a heterocyclic compound characterized by a thiazole ring, which is a five-membered ring containing both sulfur and nitrogen atoms. The presence of the ethyl and methyl groups contributes to its distinctive odor profile, which is significant in flavor and fragrance applications. The thiazole ring is known for imparting roasted, nutty, and meaty notes, making it valuable in savory flavor formulations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

2-ethyl-4-methyl thiazole is known for its potent, roasted, nutty, and meaty aroma, often described as reminiscent of popcorn or roasted peanuts. It has a strong odor intensity and is typically used as an impact note in flavor formulations. The compound's sensory threshold is relatively low, allowing it to impart significant flavor characteristics even at minimal concentrations. Its diffusion is moderate, making it suitable for both top and middle notes in fragrance compositions.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

2-ethyl-4-methyl thiazole is naturally found in various roasted and cooked foods, including coffee, roasted peanuts, and cooked beef. It is primarily formed through the Maillard reaction, a complex chemical reaction between amino acids and reducing sugars that occurs during the cooking process. This compound's presence in natural foods supports its designation as a "natural flavor" in regulatory contexts.

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

4. Use in Flavors

2-ethyl-4-methyl thiazole is extensively used in savory flavor applications, particularly in meat, roasted, and nutty profiles. It serves as an impact note, providing authenticity and depth to flavor systems. 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 cooking conditions, including heat and pH variations, but may be susceptible to oxidation over extended storage periods.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, 2-ethyl-4-methyl thiazole is used to impart a roasted, nutty character, often enhancing gourmand and savory fragrance families. It acts as a modifier, adding complexity and realism to compositions. Typical concentration ranges in fragrances are from trace amounts up to 0.5%, depending on the desired intensity and product type. Its volatility allows it to contribute primarily to the top and middle notes of a fragrance.

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. 15.079.
• 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.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 2-ethyl-4-methyl thiazole is considered safe at typical flavor use levels, with an established ADI not clearly reported but generally recognized as safe under FEMA GRAS. Dermal exposure in fragrance applications shows low irritation potential, with no significant sensitization reported. Inhalation exposure is minimal due to its low volatility, but occupational safety measures should be observed during handling to prevent overexposure.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

2-ethyl-4-methyl thiazole is valued for its ability to impart authentic roasted and nutty notes, enhancing the realism of savory flavors. It synergizes well with other Maillard reaction compounds and can be used to mask undesirable notes in complex formulations. Formulators should be cautious of its potent aroma, as overuse can lead to an overpowering effect. It is often under-utilized in sweet applications, where it can add depth and complexity.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 2-ethyl-4-methyl thiazole is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though specific numeric safety thresholds may not be explicitly reported. Known data gaps include detailed toxicological studies, which are supplemented by industry-typical safety assessments.

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 2026-01-20 06:59:19 GMT (p2)