Isononyl acetate (isomer unspecified) (CAS 40379-24-6) — Citrus Top Note Fragrance Ingredient
Isononyl acetate (isomer unspecified)
CAS 40379-24-6
What Is Isononyl acetate (isomer unspecified)?
Isononyl acetate is a synthetic fragrance ingredient rarely encountered by name, but sometimes used in consumer products for its fruity, slightly floral scent. It helps create fresh, modern fruit impressions in body care and household products. While not a major fragrance player, it contributes subtle nuance in formulations where its clean volatility is useful.
Safety Profile
GENERALLY SAFEWhat Does Isononyl acetate (isomer unspecified) Smell Like?
Isononyl acetate presents a crisp, slightly green fruity character reminiscent of underripe pears or apple skins, with a subtle floral undertone. The top note is sharp and diffusive, quickly giving way to a cleaner mid-phase that blends well with citrus and light floral notes. It lacks significant base character, fading cleanly without heavy residue. The overall effect is a transparent, modern fruit impression that avoids candy-like sweetness.
2D Molecular Structure
SMILES: CC(C)CCCCCCOC(C)=O
Chemistry, Properties & Perfumer Guide
The Chemistry
Isononyl acetate is a branched-chain ester formed by the reaction of acetic acid with isononanol. As an acetate ester, it belongs to a class known for fruity volatiles, though its branched structure gives it a cleaner profile than linear chain analogs. Industrial synthesis typically involves acid-catalyzed esterification. The unspecified isomer mixture means commercial material contains varying proportions of branched nonyl isomers, affecting exact olfactory properties.
Physical & Chemical Properties
| Boiling Point | Not well documented |
|---|---|
| Density | Approx. 0.86-0.88 g/cm³ (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-1% | Up to 3% | Background fruit modifier |
| Functional Fragrance | 0.5-5% | Up to 8% | Fresh top note component |
Classic Accords
Tip: Use to extend citrus top notes without adding excessive sweetness.
Alternatives & Comparisons
Linear chain version with stronger fruity character, more pear-like but less clean dry-down.
Shorter chain ester with more pronounced banana note, higher impact but less sophistication.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions as of Amendment 51 (2023).
RIFM Assessment
Not currently evaluated by RIFM due to limited commercial use.
Sustainability
Synthetic production from petrochemical feedstocks makes this a non-renewable material. No known major ecological hazards from production or use. Biodegradability expected to be moderate based on ester structure, but specific data lacking.
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References
- PubChem Compound Summary (2023). Isononyl acetate. PubChem
- Bauer et al. (2001). Common Fragrance and Flavor Materials.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPerfumer’s Notes
Odor: [‘fruity’, ‘orris’, ‘woody’]
MW: 186.29
LogP: 3.5
Ingredient Data Sheet
CAS 40379-24-6Physical Properties
| Molecular Weight | 186.29 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 3.5🔬 PubChem |
| Boiling Point | 220.8 °C🔬 EPA CompTox |
| Vapor Pressure | 0.1288 mmHg @ 25°C📊 OPERA |
| Flash Point | 82.9 °C🔬 EPA CompTox |
| Involatility Index | 0.0102💻 Calculated |
| log Kp (skin permeability) | -1.351💻 Calculated |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 1.7 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | fruityorriswoody• leffingwell |
Physical data: PubChem (NIH/NLM), U.S. EPA CompTox Dashboard, EPA OPERA models, RDKit. Odor & flavor: Arctander (Perfume & Flavor Chemicals), Fenaroli's Handbook of Flavor Ingredients, Leffingwell. Thresholds: van Gemert (Compilations of Odour Threshold Values). Regulatory: IFRA Standards 51st, FEMA GRAS. Trade names: Surburg (Common Fragrance & Flavor Materials). All data compiled and cross-referenced for perfumertools.com.
Physicochemical Properties
DTXSID: DTXSID4041577
Physical Properties
| Molecular Weight | 186.295 g/mol🔬 EPA CompTox |
| Density | 0.873 g/cm^3🔬 EPA CTX |
| Boiling Point | 220.8 °C🔬 EPA CTX |
| Melting Point | -26 °C🔬 EPA CTX |
| Flash Point | 83.781 °C📊 OPERA |
| Refractive Index | 1.425 Dimensionless📊 OPERA |
| Molar Volume | 213.969 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.222 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.222 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.222 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.56 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.125 mmHg📊 OPERA |
| Viscosity | 1.828 cP📊 OPERA |
| Surface Tension | 27.235 dyn/cm📊 OPERA |
| Thermal Conductivity | 136.091 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.3 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 7 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 54.744 cm^3/mol📊 OPERA |
| Polarizability | 21.702 Å^3📊 OPERA |
Data Sources:
🔬 EPA Experimental data from U.S. EPA CompTox Chemicals Dashboard & CTX APIs. 📊 OPERA Predicted using EPA's OPERA QSAR models. 💻 Computed Calculated from SMILES using RDKit.
