FlavScents AInsights Entry for Ketoisophorone (CAS: 1125-21-9)

1. Identity & Chemical Information

• Common Name(s): Ketoisophorone
• IUPAC Name: 3,5,5-Trimethyl-2-cyclohexen-1-one
• CAS Number: 1125-21-9
• FEMA Number: Not applicable
• Other Identifiers: FL number not available; CoE number not available; IFRA reference not applicable
• Molecular Formula: C9H14O
• Molecular Weight: 138.21 g/mol
• Functional Groups and Structure–Odor Relevance: Ketoisophorone contains a ketone functional group, which is significant in contributing to its odor profile. The presence of the cyclohexenone ring structure is crucial for its characteristic scent, often described as woody and green.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

• Odor and Flavor Descriptors: Ketoisophorone is characterized by a woody, green, and slightly floral odor. It is known for its moderate intensity and good diffusion properties.
• Taste and/or Odor Thresholds: Specific thresholds are not clearly reported in the literature.
• Typical Sensory Role: It is often used as a modifier in fragrance compositions to impart a natural, green note and enhance the overall complexity of the scent profile.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

• Known Natural Sources: Ketoisophorone is not commonly found in nature but can be a degradation product of carotenoids.
• Formation Pathways: It can be formed through the oxidative degradation of carotenoids, which are abundant in many fruits and vegetables.
• Relevance to “Natural Flavor” or “Natural Fragrance” Designation: Due to its synthetic origin in most commercial applications, ketoisophorone is typically not labeled as a natural flavor or fragrance component.

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

4. Use in Flavors

• Flavor Categories and Applications: Ketoisophorone is used in flavor formulations to provide a green, woody note, often in conjunction with other green or floral compounds.
• Functional Role in Flavor Systems: It acts as a background realism enhancer, adding depth and complexity to flavor profiles.
• Typical Use Levels: Documented use levels in food are not widely available; however, industry-typical estimates suggest usage in the range of 0.1 to 5 ppm in finished products.
• Stability Considerations: Ketoisophorone is relatively stable under normal conditions but may degrade under high heat or acidic conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

• Fragrance Families and Product Types: Commonly used in woody and green fragrance families, including personal care products and household items.
• Functional Role: It serves as a modifier and impact note, providing a fresh, green character.
• Typical Concentration Ranges: Typically used at concentrations ranging from 0.1% to 1% in fragrance formulations.
• Volatility and Top/Middle/Base Contribution: Ketoisophorone is considered a middle note due to its moderate volatility and persistence.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States (FDA / FEMA GRAS): Not explicitly listed as GRAS by FEMA.
• European Union (Reg. (EC) No 1334/2008; FL number status): Not specifically listed under EU flavoring regulations.
• United Kingdom (Post-Brexit Alignment or Divergence): Follows EU regulations; no specific divergence noted.
• Asia (Japan, China, ASEAN): Regulatory status not clearly documented; typically follows international guidelines.
• Latin America (e.g., Brazil, MERCOSUR): No specific regulatory information available; generally follows international standards.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Data not found for specific ADI or MSDI values; formulators should ensure low ppm levels to minimize exposure.
• Dermal Exposure: No significant irritation or sensitization reported; however, IFRA guidelines should be consulted for safe use in fragrances.
• Inhalation Exposure: Due to its moderate volatility, inhalation exposure is possible; occupational safety measures should be in place to limit exposure.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

• Why This Material is Valuable: Ketoisophorone is valued for its ability to impart a natural, green character to both flavors and fragrances.
• Typical Synergies: Works well with other green and floral notes, enhancing the overall freshness and complexity.
• Common Formulation Pitfalls: Overuse can lead to an overpowering green note; balance with other components is crucial.
• Situations Where It is Frequently Over- or Under-Used: Often under-used in formulations seeking a subtle green note due to its potent character.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

• Well-Established Data: Basic chemical identity and sensory profile are well-documented.
• Industry-Typical but Undocumented Practices: Usage levels and specific applications often rely on industry experience rather than published data.
• Known Data Gaps or Regulatory Ambiguities: Lack of specific regulatory approvals and detailed toxicological data.

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 2026-08-14 06:11:52 GMT (p2)