FlavScents AInsights Entry for Hexanal (Aldehyde C-6) (CAS: 66-25-1)

1. Identity & Chemical Information

• Common Name(s): Hexanal, Aldehyde C-6
• IUPAC Name: Hexanal
• CAS Number: 66-25-1
• FEMA Number: 2558
• Other Identifiers: FL No. 02.015
• Molecular Formula: C6H12O
• Molecular Weight: 100.16 g/mol

Hexanal is a saturated aliphatic aldehyde characterized by a six-carbon chain with a terminal aldehyde group. This structure is crucial for its odor profile, contributing to its grassy and fruity notes. The aldehyde group is reactive, influencing its stability and interactions in formulations.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Hexanal is known for its distinctive green, grassy odor, often described as fresh and aldehydic. It is a key impact note in many green and fruity compositions, providing a crisp, natural freshness. The odor threshold of hexanal is relatively low, making it effective even at minimal concentrations. It is typically used as an impact note or a modifier to enhance the freshness and realism of a fragrance or flavor profile.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Hexanal naturally occurs in various plants and fruits, including apples, bananas, and citrus fruits. It is also found in essential oils such as eucalyptus and is a product of lipid oxidation in plant tissues. This compound is often associated with the "green" aroma of freshly cut grass. Hexanal's presence in natural sources supports its designation as a "natural flavor" or "natural fragrance" component.

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

4. Use in Flavors

Hexanal is widely used in flavor formulations, particularly in fruit, vegetable, and green flavor profiles. It serves as a critical impact note, enhancing the freshness and authenticity of flavors. Typical use levels in food and beverages range from 0.1 to 5 ppm, depending on the desired intensity and application. Hexanal is relatively stable under acidic conditions but can degrade under high heat or oxidative environments, necessitating careful formulation considerations.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In perfumery, hexanal is utilized across various fragrance families, including green, citrus, and floral compositions. It acts as a top note, providing an initial burst of freshness and realism. Typical concentrations in fragrance formulations range from trace amounts to 0.5%, depending on the desired effect. Hexanal's volatility makes it an excellent choice for top note applications, although its reactivity requires stabilization in formulations.

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; listed with FL No. 02.015.
• United Kingdom: Follows EU regulations post-Brexit.
• Asia: Approved for use in Japan and China, with specific concentration limits.
• Latin America: Generally accepted in MERCOSUR countries, with harmonized regulations.

Hexanal is widely approved for use in both flavors and fragrances, with specific concentration limits varying by region. It is essential to verify local regulations for compliance.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Hexanal is considered safe for use in food and fragrance applications at typical concentrations. Oral exposure through flavor use is supported by an adequate margin of safety, with no significant adverse effects reported at typical use levels. Dermal exposure in fragrances is generally safe, although hexanal can cause irritation or sensitization in sensitive individuals. Inhalation exposure is minimal due to its rapid volatilization, but occupational exposure should be managed with appropriate ventilation.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Hexanal is valued for its ability to impart a fresh, green note to both flavors and fragrances. It synergizes well with other aldehydes and green notes, enhancing the overall freshness and complexity of a formulation. Common pitfalls include overuse, leading to an overpowering or harsh aroma. It is often underutilized in complex formulations where its subtlety can enhance realism without dominating the profile.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on hexanal is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, although specific use levels may vary by application. Known data gaps include detailed toxicological studies at high concentrations, which are generally not relevant to typical use scenarios.

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 2026-07-09 17:54:25 GMT (p2)