Isononyl propionate (CAS 65155-45-5) — Citrus Top to Middle Note Fragrance Ingredient
Isononyl propionate
CAS 65155-45-5
What Is Isononyl propionate?
Isononyl propionate is a synthetic ester used in fragrances to add fruity, floral, and slightly green nuances. It’s commonly found in perfumes, body lotions, and air fresheners. This ingredient matters because it enhances freshness and blends well with citrus and woody notes, making it versatile for modern scent compositions.
Safety Profile
GENERALLY SAFEWhat Does Isononyl propionate Smell Like?
Isononyl propionate offers a crisp, fruity top note reminiscent of pear and apple skins, with a subtle floral undertone. As it evolves, it reveals a green, slightly herbaceous heart, settling into a clean, woody base. The dry-down is smooth and slightly sweet, making it a versatile bridge between fresh and warm accords.
2D Molecular Structure
SMILES: CCC(=O)OCCCCCCC(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Isononyl propionate is an ester formed from isononyl alcohol and propionic acid. It is synthesized via esterification, a common reaction in fragrance chemistry. The molecule’s structure contributes to its fruity and floral odor profile, with moderate volatility making it suitable for top to middle notes in perfumery.
Physical & Chemical Properties
| Boiling Point | N/A |
|---|---|
| Density | N/A |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 2-5% | Up to 10% | Adds fruity freshness |
| Body Care | 1-3% | Up to 5% | Enhances floral notes |
Classic Accords
Tip: Use to brighten floral compositions or add a fruity twist to woody accords.
Alternatives & Comparisons
Offers a more pronounced banana-like fruity note, suitable for tropical or gourmand fragrances.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No restrictions under IFRA standards.
RIFM Assessment
RIFM has assessed isononyl propionate as safe for use in fragrances at current levels.
Sustainability
Isononyl propionate is synthetically produced, reducing reliance on natural resources. Its production is efficient, with minimal environmental impact when handled responsibly.
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References
- PubChem: Isononyl propionate PubChem
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPerfumer’s Notes
Odor: [‘floral’, ‘fresh’, ‘herbal’]
MW: 200.32
LogP: 4.3
Ingredient Data Sheet
CAS 65155-45-5Physical Properties
| Molecular Weight | 200.32 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 4.3🔬 PubChem |
| Boiling Point | 243 °C🔬 EPA CompTox |
| Vapor Pressure | 0.038 mmHg @ 25°C📊 OPERA |
| Flash Point | 94 °C🔬 EPA CompTox |
| Involatility Index | 0.0029💻 Calculated |
| log Kp (skin permeability) | -0.869💻 Calculated |
| SMILES | CCC(=O)OCCCCCCC(C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 3.1 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | floralfreshherbal• leffingwell |
| Functional Groups | esterether💻 RDKit |
| “For full chemical name and structure, see: The odor is almost free from any trace of Nopol and Nopyl acetate. piney note, and quite large proportions can CIIHI,—OOC—C2H5 be used in ordinary compositions. Warm-herbaceous, mildly spicy odor of Prod.: from Nopol and Propionic anhy - moderate tenacity.”📖 Arctander | |
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: DTXSID1070270
Physical Properties
| Molecular Weight | 200.322 g/mol🔬 EPA CompTox |
| Density | 0.866 g/cm^3📊 OPERA |
| Boiling Point | 234.993 °C📊 OPERA |
| Melting Point | -37.395 °C📊 OPERA |
| Flash Point | 92.38 °C📊 OPERA |
| Refractive Index | 1.429 Dimensionless📊 OPERA |
| Molar Volume | 230.475 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.53 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.53 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.53 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 5.74 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.045 mmHg📊 OPERA |
| Viscosity | 2.33 cP📊 OPERA |
| Surface Tension | 27.449 dyn/cm📊 OPERA |
| Thermal Conductivity | 136.075 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 | 8 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 59.377 cm^3/mol📊 OPERA |
| Polarizability | 23.539 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.
