FlavScents AInsights Entry for Geosmin (CAS: 23333-91-7)

1. Identity & Chemical Information

• Common Name(s): Geosmin
• IUPAC Name: (4S,4aS,8aR)-4,8a-Dimethyloctahydronaphthalen-4a-ol
• CAS Number: 23333-91-7
• FEMA Number: 4717
• Other Identifiers: FL No. 02.015
• Molecular Formula: C12H22O
• Molecular Weight: 182.31 g/mol

Geosmin is a bicyclic alcohol with a distinctive earthy odor, often associated with the smell of wet soil. Its structure includes a decalin ring system with a tertiary alcohol group, which is crucial for its characteristic odor. The presence of methyl groups contributes to its hydrophobic nature, influencing its volatility and sensory perception.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Geosmin is renowned for its earthy, musty odor reminiscent of freshly turned soil or beets. It is a potent odorant with a low detection threshold, often reported in the range of 5 to 10 ng/L in water. This compound serves as an impact note in flavor and fragrance formulations, providing authenticity and depth to earthy profiles. Its intensity and diffusion are moderate, making it suitable for use as a background realism enhancer or a character-defining note in complex blends.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Geosmin is naturally produced by microorganisms such as cyanobacteria and actinobacteria, particularly in soil and aquatic environments. It is formed through the enzymatic degradation of carotenoids and other organic matter. Geosmin's presence in nature is a key factor in the "natural flavor" designation for products aiming to replicate earthy or root-like aromas.

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

4. Use in Flavors

Geosmin is utilized in flavor formulations to impart earthy, root-like notes, commonly found in beet, mushroom, and potato flavors. It plays a functional role as an impact note, enhancing the authenticity of natural profiles. Typical use levels in food and beverages range from 0.01 to 0.1 ppm, with higher concentrations potentially leading to overpowering or undesirable effects. Geosmin is relatively stable under neutral pH conditions but may degrade under acidic or high-temperature conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In perfumery, geosmin is used to create earthy, natural accords, often in chypre and fougère fragrance families. It acts as a modifier or trace realism note, contributing to the base or middle notes of a fragrance composition. Typical concentrations range from trace amounts to 0.05%, depending on the desired intensity and application. Geosmin's volatility is moderate, allowing it to linger and provide depth to 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: Approved under Regulation (EC) No 1334/2008 with FL No. 02.015.
• United Kingdom: Follows EU regulations post-Brexit.
• Asia: Generally accepted in Japan and China, though specific regulations may vary.
• Latin America: Accepted in Brazil and MERCOSUR countries, with harmonized assumptions across the region.

Explicit approvals exist for flavor use, while fragrance applications are subject to IFRA guidelines. Country-specific variability is minimal, but formulators should verify local regulations.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Geosmin is considered safe for use in flavors and fragrances at typical exposure levels. Oral exposure through flavor use is supported by a high margin of safety, with no specific ADI or MSDI established. Dermal exposure in fragrances is generally non-irritating, with no significant sensitization reported. Inhalation exposure is minimal due to its low volatility, though occupational exposure should be monitored in manufacturing settings. Risk profiles are consistent across food and fragrance applications.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Geosmin is valued for its ability to impart authentic earthy notes, enhancing the realism of natural profiles. It synergizes well with other root and soil-like aromas, such as patchouli and vetiver. Formulators should be cautious of its potency, as overuse can lead to undesirable mustiness. It is often under-utilized in complex blends where subtlety is required.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on geosmin is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though specific use levels may vary by application. Known data gaps are minimal, with ongoing research focusing on its formation and degradation pathways.

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 2026-08-19 04:28:25 GMT (p2)