AInsights Entry for (Z)-2-undecene (CAS: 821-96-5)

1. Identity & Chemical Information

• Common Name(s): (Z)-2-undecene
• IUPAC Name: (Z)-undec-2-ene
• CAS Number: 821-96-5
• FEMA Number: Not applicable
• Other Identifiers: Not available
• Molecular Formula: C11H22
• Molecular Weight: 154.29 g/mol
• Functional Groups and Structure–Odor Relevance: (Z)-2-undecene is an unsaturated hydrocarbon with a double bond in the second position, contributing to its characteristic odor profile. The presence of the double bond in the (Z) configuration can influence its sensory properties, often imparting a subtle, waxy, or slightly green note.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

• Odor and Flavor Descriptors: (Z)-2-undecene is characterized by a mild, waxy, and slightly green odor. It is often described as having a subtle, oily scent with a hint of freshness.
• Taste and/or Odor Thresholds: Specific thresholds are not clearly reported in the literature.
• Typical Sensory Role: It is primarily used as a background note to enhance the realism of other components in a formulation, providing subtlety and depth without overpowering the primary fragrance or flavor.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

• Known Natural Sources: (Z)-2-undecene is not commonly found in nature and is typically synthesized for use in industrial applications.
• Formation Pathways: It can be produced through the catalytic hydrogenation of undecyne or via the oligomerization of ethylene.
• Relevance to “Natural Flavor” or “Natural Fragrance” Designation: Due to its synthetic origin, (Z)-2-undecene is not typically classified under natural flavor or fragrance categories.

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

4. Use in Flavors

• Flavor Categories and Applications: (Z)-2-undecene is used in flavor formulations to impart subtle waxy and green notes, often in conjunction with other compounds to create complex profiles.
• Functional Role in Flavor Systems: It acts as a background modifier, enhancing the overall depth and authenticity of the flavor profile.
• Typical Use Levels: Specific ppm ranges are not well-documented; however, it is generally used at low concentrations due to its subtle impact.
• Stability Considerations: (Z)-2-undecene is relatively stable under normal conditions but may be susceptible to oxidation, which can alter its sensory characteristics.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

• Fragrance Families and Product Types: Commonly used in fine fragrances and personal care products to add a subtle, fresh note.
• Functional Role: It serves as a modifier, providing trace realism and enhancing the complexity of the fragrance.
• Typical Concentration Ranges: Used in trace amounts, typically less than 0.1% of the total formulation.
• Volatility and Top/Middle/Base Contribution: (Z)-2-undecene is a middle note, contributing to the heart of the fragrance with moderate volatility.

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 unless otherwise specified.
• Asia (Japan, China, ASEAN): Limited specific regulatory information available; typically follows international guidelines.
• Latin America (e.g., Brazil, MERCOSUR): Regulatory status not clearly documented; generally aligns with 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. Generally considered safe at low concentrations typical in flavor applications.
• Dermal Exposure: No specific data on irritation or sensitization; however, it is used in trace amounts in fragrances, minimizing potential risks.
• Inhalation Exposure: Volatility suggests low risk in typical fragrance applications; occupational exposure should be managed with standard safety practices.
• Risk Profiles: Generally similar for both food and fragrance applications, with low risk at typical use levels.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

• Why This Material is Valuable: (Z)-2-undecene provides subtlety and depth, enhancing the realism of both flavor and fragrance formulations.
• Typical Synergies: Works well with other green and waxy notes, as well as floral and citrus components.
• Common Formulation Pitfalls: Overuse can lead to an undesirable oily or waxy character; balance is key.
• Situations Where It is Frequently Over- or Under-used: Often under-utilized due to its subtle impact, yet valuable for nuanced formulations.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

• Well-Established Data: Basic chemical and sensory properties are well-documented.
• Industry-Typical but Undocumented Practices: Usage levels and specific applications often rely on industry experience.
• Known Data Gaps or Regulatory Ambiguities: Limited specific regulatory and toxicological data available.

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 2026-04-01 09:36:26 GMT (p2)