FlavScents AInsights Entry: Benzothiazole (CAS: 95-16-9)

1. Identity & Chemical Information

• Common Name(s): Benzothiazole
• IUPAC Name: 1,3-Benzothiazole
• CAS Number: 95-16-9
• FEMA Number: Not applicable
• Other Identifiers: FL No. 13.008
• Molecular Formula: C7H5NS
• Molecular Weight: 135.19 g/mol

Benzothiazole is a heterocyclic aromatic compound characterized by a benzene ring fused to a thiazole ring. The presence of sulfur and nitrogen in the thiazole ring contributes to its distinctive odor profile, which is often described as rubbery or sulfurous. This structural feature is crucial for its sensory characteristics and functional applications in both flavors and fragrances.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Benzothiazole is known for its unique sensory attributes, often described as having a rubbery, sulfurous odor with a slight floral undertone. Its intensity is moderate, and it can be perceived at low concentrations, although specific odor thresholds are not well-documented. In flavor and fragrance formulations, benzothiazole typically serves as a background note, adding complexity and realism to compositions.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Benzothiazole is not commonly found in nature but can be formed through various chemical processes, including the degradation of rubber and other sulfur-containing compounds. It is not typically associated with "natural flavor" or "natural fragrance" designations due to its synthetic origins and formation pathways.

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

4. Use in Flavors

In flavor applications, benzothiazole is used sparingly due to its potent odor. It is primarily employed in savory and umami flavor profiles, where it enhances the depth and authenticity of the flavor. Typical use levels in finished food products are low, often ranging from 0.1 to 1 ppm, depending on the desired intensity and the complexity of the flavor system. Benzothiazole is stable under typical processing conditions but may degrade under extreme heat or acidic environments.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

Benzothiazole is utilized in fragrance formulations to impart a unique, rubbery note that can add realism to leather and tobacco accords. It is often used in trace amounts, typically less than 0.1% of the total fragrance composition, due to its strong odor. 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: Benzothiazole is not listed as a FEMA GRAS substance for flavor use. Its use in fragrances is subject to IFRA guidelines.
• European Union: Not specifically listed under Regulation (EC) No 1334/2008 for flavor use. Its use in fragrances must comply with the EU Cosmetics Regulation.
• United Kingdom: Follows EU regulations post-Brexit with no significant divergence reported.
• Asia: Regulatory status varies; not commonly used in flavors or fragrances in Japan or China.
• Latin America: Limited information available; typically follows international guidelines.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Benzothiazole is not typically used in food applications, and no ADI or MSDI values are established.
• Dermal Exposure: In fragrance applications, benzothiazole is considered safe at low concentrations, with no significant reports of irritation or sensitization. IFRA guidelines should be consulted for specific use limits.
• Inhalation Exposure: Due to its volatility, inhalation exposure is possible, but occupational exposure limits are not well-defined. Proper ventilation and handling practices are recommended.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Benzothiazole is valued for its ability to impart a distinctive, rubbery note that can enhance the realism of certain flavor and fragrance compositions. It synergizes well with other sulfur-containing compounds and can be used to add depth to leather and tobacco accords. Formulators should be cautious of its potent odor and potential for overpowering other notes if used excessively.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on benzothiazole is well-established in terms of its chemical identity and sensory characteristics. However, there are gaps in specific regulatory approvals and toxicological data, particularly concerning oral exposure. Industry practices often rely on informed estimates and adherence to general safety guidelines.

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 2026-01-27 13:55:21 GMT (p2)