FlavScents AInsights Entry: Methyl Mercaptan (CAS: 74-93-1)

1. Identity & Chemical Information

• Common Name(s): Methyl Mercaptan, Methanethiol
• IUPAC Name: Methanethiol
• CAS Number: 74-93-1
• FEMA Number: 2746
• Other Identifiers: FL No. 12.001
• Molecular Formula: CH₄S
• Molecular Weight: 48.11 g/mol

Methyl mercaptan is a volatile sulfur compound characterized by a thiol functional group. Its structure consists of a methyl group attached to a sulfur atom, which is responsible for its strong, pungent odor reminiscent of rotten cabbage. This compound is significant in both flavor and fragrance applications due to its potent odor profile, which can be used in trace amounts to impart complexity and authenticity to formulations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Methyl mercaptan is known for its intense, sulfurous odor, often described as resembling rotten cabbage or garlic. It is a high-impact compound with a low odor threshold, detectable at concentrations as low as 0.002 ppm. In flavor applications, it serves as an impact note, providing authenticity and depth to savory profiles, particularly in meat and vegetable flavors. Its potent aroma requires careful handling to avoid overpowering the desired sensory outcome.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Methyl mercaptan occurs naturally in various biological processes and is found in the tissues of plants and animals. It is a byproduct of the decomposition of organic matter and is produced during the fermentation process. In the context of natural flavors, it can be derived from enzymatic degradation of sulfur-containing amino acids. Its presence in natural sources allows it to be used in "natural flavor" designations, provided it is sourced appropriately.

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

4. Use in Flavors

Methyl mercaptan is utilized in flavor formulations to enhance savory notes, particularly in meat, cheese, and vegetable flavors. It acts as a functional impact note, contributing to the authenticity and complexity of the flavor profile. Typical use levels in finished food products range from 0.1 to 1 ppm, with higher concentrations potentially leading to undesirable off-notes. Its stability is generally good under typical processing conditions, but it can be sensitive to oxidation.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, methyl mercaptan is used sparingly due to its potent odor. It can contribute to the realism of certain fragrance compositions, particularly those mimicking natural environments or complex accords. Its volatility makes it a top note, providing an initial burst of sulfurous aroma that can be modulated by other fragrance components. Typical concentrations are very low, often in the trace range, to avoid overwhelming the fragrance profile.

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: Follows EU regulations post-Brexit with no significant divergence reported.
• Asia: Approved for use in Japan and China, with specific regulatory frameworks in place.
• Latin America: Generally accepted under MERCOSUR regulations, with country-specific variations.

Explicit approvals exist for its use in both flavor and fragrance applications, though harmonized assumptions may vary. Known uncertainties are minimal, with most regions recognizing its utility under controlled conditions.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Methyl mercaptan's safety profile is well-documented, with oral exposure considered safe at low concentrations typical of flavor use. The ADI is not explicitly defined, but industry practices ensure margins of safety are maintained. Dermal exposure in fragrance applications is limited due to potential irritation, and IFRA guidelines should be consulted. Inhalation exposure is a consideration in occupational settings due to its volatility, necessitating adequate ventilation and handling precautions.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Methyl mercaptan is valued for its ability to impart authenticity and complexity to savory flavors. It synergizes well with other sulfur compounds and umami enhancers. Formulators should be cautious of its potent aroma, which can easily dominate a formulation if not balanced correctly. It is often under-used due to its challenging odor profile, but when used judiciously, it can significantly enhance the sensory experience.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on methyl mercaptan is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though some regional regulatory nuances may require further clarification. Overall, the data quality is high, with minimal gaps or ambiguities noted.

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 2026-03-26 18:12:25 GMT (p2)