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

1. Identity & Chemical Information

Hexanal, also known as aldehyde C-6, is a volatile organic compound with the IUPAC name hexanal. It is registered under the CAS number 66-25-1. The FEMA number for hexanal is 2556. Other identifiers include the FL number 02.015 and CoE number 18. Hexanal has the molecular formula C6H12O and a molecular weight of 100.16 g/mol. It is characterized by an aldehyde functional group, which is crucial for its odor profile, imparting a grassy and green aroma that is significant in flavor and fragrance applications.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

Hexanal is known for its distinctive odor, often described as grassy, green, and reminiscent of freshly cut grass or unripe fruit. It has a moderate intensity and good diffusion properties, making it an impactful note in both flavors and fragrances. The odor threshold of hexanal is relatively low, allowing it to be perceived at minimal concentrations. In sensory applications, hexanal serves as an impact note, providing freshness and realism to compositions.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

Hexanal naturally occurs in a variety of plants and fruits, including apples, bananas, and tomatoes. It is formed through the oxidative degradation of linoleic acid, a common fatty acid in plant tissues. This process can occur during the ripening of fruits or when plant tissues are damaged. 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 acts as a key impact note, enhancing the freshness and authenticity of flavors. Typical use levels in finished food or beverage products range from 0.1 to 5 ppm, with variations depending on the desired intensity and product type. Hexanal is relatively stable under acidic conditions but can degrade under high heat or oxidative environments, which should be considered during formulation.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, hexanal is utilized in green and fresh fragrance families, contributing to the top notes of compositions. It serves as a modifier and impact note, providing a crisp, natural freshness. Typical concentration ranges in fragrance products are from trace amounts up to 0.5%, depending on the formulation. Hexanal's volatility makes it a prominent top note, contributing to the initial impression of a fragrance.

Citation hooks: FlavScents; IFRA; fragrance chemistry texts

6. Regulatory Status (Regional Overview)

In the United States, hexanal is recognized as GRAS (Generally Recognized As Safe) by FEMA for flavor use. In the European Union, it is approved under Regulation (EC) No 1334/2008 and assigned the FL number 02.015. The United Kingdom follows similar regulations post-Brexit. In Asia, hexanal is accepted in Japan and China, with specific use levels outlined by local authorities. In Latin America, countries like Brazil and members of MERCOSUR have harmonized regulations allowing its use in flavors and fragrances.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

Hexanal's safety profile varies with exposure routes. For oral exposure, it is considered safe at typical flavor use levels, with an ADI not specifically established but implied safe under GRAS status. Dermal exposure in fragrances is generally safe, with low irritation potential, though IFRA guidelines should be consulted for specific product types. Inhalation exposure is minimal due to its rapid volatility, but occupational exposure should be monitored in manufacturing settings. The risk profiles for food and fragrance applications are similar, with no significant differences noted.

Citation hooks: EFSA; FEMA; PubChem; toxicology literature

8. Practical Insights for Formulators

Hexanal is valued for its ability to impart freshness and authenticity to both flavors and fragrances. It synergizes well with other green and fruity notes, enhancing the overall profile. Formulators should be cautious of its volatility and potential for oxidation, which can alter its sensory characteristics. It is often under-used in complex formulations where its impact could enhance the freshness of the product.

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, though specific use levels may vary by application. Known data gaps are minimal, with most regulatory and safety information harmonized across major markets.

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 2026-04-21 06:49:25 GMT (p2)