FlavScents AInsights Entry for 2-Nonanone (CAS: 821-55-6)

1. Identity & Chemical Information

• Common Name(s): 2-Nonanone, Methyl heptyl ketone
• IUPAC Name: Nonan-2-one
• CAS Number: 821-55-6
• FEMA Number: 2781
• Other Identifiers: FL No. 07.061
• Molecular Formula: C9H18O
• Molecular Weight: 142.24 g/mol

2-Nonanone is a ketone characterized by a carbonyl group (C=O) located at the second carbon of a nine-carbon chain. This functional group is crucial for its odor profile, contributing to its fruity and floral notes. The structure-odor relationship is significant as the carbonyl group influences the volatility and sensory perception of the compound.

Citation hooks: FlavScents; PubChem; FEMA

2. Sensory Profile

2-Nonanone is known for its fruity, floral, and slightly fatty odor. It is often described as having a green, banana-like scent with nuances of citrus and a hint of waxiness. The intensity of its odor is moderate, making it suitable for both impact and background roles in formulations. The taste threshold is not well-documented, but its odor threshold is typically low, allowing it to be perceived at minimal concentrations.

Citation hooks: FlavScents; peer-reviewed sensory literature

3. Natural Occurrence & Formation

2-Nonanone occurs naturally in various fruits and essential oils. It is found in bananas, apples, and some citrus fruits, contributing to their characteristic aromas. The compound can also form through the enzymatic degradation of fatty acids, a common pathway in the ripening of fruits. Its presence in natural sources supports its designation as a "natural flavor" in certain regulatory contexts.

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

4. Use in Flavors

2-Nonanone is utilized in flavor formulations for its fruity and floral characteristics. It is commonly used in fruit flavors, particularly banana and apple, as well as in citrus blends. Its functional role includes acting as an impact note and providing background realism. Typical use levels in finished food or beverage products range from 0.1 to 5 ppm, with higher concentrations potentially leading to overpowering effects. The compound is stable under typical processing conditions but may degrade under extreme heat or acidic conditions.

Citation hooks: FlavScents; FEMA GRAS documentation; formulation literature

5. Use in Fragrances

In the fragrance industry, 2-Nonanone is valued for its ability to impart a fresh, fruity note. It is used in various fragrance families, including floral, fruity, and green compositions. Its role can vary from a trace realism enhancer to a modifier or impact note. Typical concentration ranges in fragrances are from 0.01% to 0.1%, depending on the desired effect. The compound contributes primarily to the top and middle notes due to its moderate volatility.

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 with FL No. 07.061.
• United Kingdom: Follows EU regulations post-Brexit with no significant divergence reported.
• Asia: Approved for use in Japan and China, with specific concentration limits varying by country.
• Latin America: Generally accepted in Brazil and MERCOSUR countries, subject to local regulations.

Explicit approvals and harmonized assumptions are common, but formulators should verify country-specific guidelines due to potential variability.

Citation hooks: FEMA; EFSA; national authority publications

7. Toxicology, Safety & Exposure Considerations

For oral exposure, 2-Nonanone is considered safe at typical flavor use levels, with no specific ADI or MSDI established. The compound is not known to cause significant irritation or sensitization upon dermal exposure, aligning with IFRA guidelines for fragrance use. Inhalation exposure is generally low risk due to its moderate volatility, but occupational safety measures should be observed 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

2-Nonanone is valued for its versatility in both flavor and fragrance formulations. It synergizes well with other fruity and floral compounds, enhancing the overall profile. Common pitfalls include overuse, leading to an overpowering or artificial scent. It is often under-utilized in complex blends where its subtlety can enhance realism without dominating the composition.

Citation hooks: FlavScents; industry practice

9. Confidence & Data Quality Notes

The data on 2-Nonanone is well-established, with comprehensive sensory and regulatory information available. Industry practices are well-documented, though some regional regulatory nuances may require further verification. Known data gaps are minimal, primarily concerning specific taste thresholds.

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 2026-08-24 16:02:59 GMT (p2)