AInsights Entry for 2-Ethyl Hexanal (CAS: 123-05-7)

1. Identity & Chemical Information

• Common Name(s): 2-Ethyl Hexanal
• IUPAC Name: 2-Ethylhexanal
• CAS Number: 123-05-7
• FEMA Number: Data not found
• Other Identifiers: FL number not found; CoE number not found; IFRA reference not found
• Molecular Formula: C8H16O
• Molecular Weight: 128.21 g/mol

2-Ethyl hexanal is an aliphatic aldehyde characterized by its branched structure, which contributes to its distinct odor profile. The presence of the aldehyde functional group is crucial for its reactivity and sensory properties, often imparting a green, fatty, or waxy note in formulations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

2-Ethyl hexanal is known for its green, fatty, and slightly waxy odor, which can be described as reminiscent of unripe fruits or freshly cut grass. Its intensity is moderate, making it suitable as a background note or modifier in both flavor and fragrance compositions. The compound's diffusion is relatively quick, aligning with its volatility.

Taste and odor thresholds for 2-ethyl hexanal are not clearly reported in the literature, but its sensory role is typically as an impact note or modifier, enhancing the freshness and realism of formulations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

2-Ethyl hexanal is not commonly found in nature but can be formed through the oxidation of 2-ethylhexanol, a process that may occur during the degradation of certain natural fats and oils. It is not typically associated with "natural flavor" or "natural fragrance" designations due to its synthetic origin in most commercial applications.

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

4. Use in Flavors

2-Ethyl hexanal is used in flavor formulations to impart green, fresh, and slightly fruity notes. It is commonly applied in fruit, vegetable, and dairy flavor categories. Its functional role in flavor systems is often as a modifier or impact note, enhancing the authenticity and complexity of the flavor profile.

Typical use levels in finished food or beverage products are not well-documented, but industry practices suggest low ppm ranges, typically between 0.1 to 5 ppm, depending on the desired intensity and application. Stability considerations include moderate resistance to heat and pH variations, though it may be prone to oxidation.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In fragrance applications, 2-ethyl hexanal is utilized for its green and fresh qualities, fitting well within the green and citrus fragrance families. It serves as a modifier or trace realism note, contributing to the top or middle notes of a fragrance composition due to its volatility.

Typical concentration ranges in fragrance products are qualitative, often used in trace amounts to achieve the desired effect without overpowering the composition. Its volatility ensures it contributes primarily to the initial impression of the fragrance.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

• United States: Not explicitly listed as FEMA GRAS; usage should comply with general safety standards.
• European Union: Not specifically listed under Reg. (EC) No 1334/2008; assumed to be used under general safety guidelines.
• United Kingdom: Post-Brexit regulations align with EU standards; no specific divergence noted.
• Asia: Limited specific data; general safety compliance expected in Japan, China, and ASEAN regions.
• Latin America: No specific data for Brazil or MERCOSUR; general safety compliance assumed.

Explicit approvals are not well-documented, and formulators should verify compliance with local regulations and safety standards.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

• Oral Exposure: Data not found for ADI, TTC, or MSDI; formulators should ensure usage aligns with general safety practices.
• Dermal Exposure: Limited data on irritation or sensitization; IFRA guidelines should be consulted for fragrance applications.
• Inhalation Exposure: Volatility suggests potential for inhalation exposure; occupational safety measures should be considered.

Risk profiles may differ between food and fragrance applications, with fragrance use requiring careful consideration of dermal and inhalation exposure.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

2-Ethyl hexanal is valued for its ability to impart fresh, green notes that enhance the realism of both flavors and fragrances. It synergizes well with other green and citrus notes, but formulators should be cautious of its volatility and potential for oxidation. Common pitfalls include overuse, leading to an overpowering or artificial scent.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

Data on 2-ethyl hexanal is well-established in terms of its chemical identity and sensory profile, but there are gaps in specific regulatory approvals and toxicological data. Industry practices often rely on informed estimates and general safety compliance.

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 2026-03-25 20:31:58 GMT (p2)