FlavScents AInsights Entry for Ethyl Mercaptan (CAS: 75-08-1)

1. Identity & Chemical Information

• Common Name(s): Ethyl Mercaptan, Ethanethiol
• IUPAC Name: Ethanethiol
• CAS Number: 75-08-1
• FEMA Number: 3685
• Other Identifiers: FL No. 12.001
• Molecular Formula: C2H6S
• Molecular Weight: 62.13 g/mol

Ethyl mercaptan is a volatile sulfur compound characterized by its thiol functional group, which significantly contributes to its potent odor. The structure-odor relationship is primarily influenced by the presence of the sulfur atom, which imparts a strong, skunky smell even at low concentrations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Ethyl mercaptan is renowned for its intense, skunky odor, often described as resembling rotten cabbage or garlic. It is detectable at extremely low concentrations, with an odor threshold reported as low as 0.2 ppb. In sensory applications, it serves as an impact note due to its powerful and distinctive aroma, often used to impart authenticity or realism in flavor profiles.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Ethyl mercaptan occurs naturally in some foods and beverages, including certain wines and cheeses, where it can form through microbial activity or enzymatic degradation. It is also a byproduct of the Maillard reaction, contributing to the complex aroma profiles of cooked foods. Its presence in natural products can qualify it for "natural flavor" designation under certain regulatory frameworks.

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

4. Use in Flavors

Ethyl mercaptan is utilized in various flavor categories, including savory, meat, and vegetable flavors, where it acts as a potent impact note. Typical use levels in finished food products range from 0.1 to 1 ppm, with higher concentrations potentially overwhelming other flavor components. It is relatively stable under typical food processing conditions but can oxidize, leading to changes in flavor profile.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, ethyl mercaptan is used sparingly due to its intense odor. It can be found in trace amounts in certain fragrance families, such as fougère and chypre, where it adds a unique sulfurous note. Its high volatility makes it a top note, contributing to the initial impression 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: Listed under Regulation (EC) No 1334/2008 with an assigned FL number.
• United Kingdom: Aligns with EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific concentration limits.
• Latin America: Generally accepted in Brazil and MERCOSUR countries, subject to local regulations.

Explicit approvals and harmonized assumptions are common, though country-specific variations may exist.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, ethyl mercaptan is considered safe at low concentrations typical in food applications, with an ADI not specifically established but generally recognized as safe. Dermal exposure in fragrance use is limited due to potential irritation and sensitization, with IFRA guidelines advising caution. Inhalation exposure is primarily a concern in occupational settings due to its volatility, necessitating adequate ventilation and protective measures.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Ethyl mercaptan is valued for its ability to impart a realistic sulfurous note, enhancing authenticity in savory flavors. It synergizes well with other sulfur compounds but can easily dominate a formulation if not carefully balanced. Common pitfalls include overuse, leading to an overpowering aroma, and underuse, resulting in a lack of desired impact.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on ethyl mercaptan is well-established, with comprehensive sensory and regulatory information available. Industry practices are documented, though some variability in natural occurrence data may exist. Known data gaps are minimal, with most regulatory ambiguities resolved through harmonized 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
• No section 5a required as ethyl mercaptan is a 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 2026-02-11 18:57:52 GMT (p2)