Isoamyl propionate (CAS 105-68-0) — Sweet Top to mid Note Fragrance Ingredient
Isoamyl propionate
CAS 105-68-0
What Is Isoamyl propionate?
Isoamyl propionate is a synthetic ester commonly used in fruit-flavored products and perfumes. It’s found in chewing gums, candies, and some floral fragrances where a sweet, fruity note is desired. This ingredient matters because it provides a cost-effective way to create natural-smelling banana and pear aromas without relying on fruit extracts. Its stability makes it valuable for products needing long-lasting fruity top notes.
Safety Profile
GENERALLY SAFEWhat Does Isoamyl propionate Smell Like?
Isoamyl propionate bursts with an intensely sweet, ripe banana character that evolves into candied pear nuances. The opening is like biting into a banana Laffy Taffy – all sugary fruit with a slight rum-like depth. As it dries, the fruitiness softens into a more rounded, jammy quality reminiscent of pear drops candy, with just a whisper of floral undertone. The dry-down maintains this persistent fruity sweetness without becoming cloying, making it excellent for creating approachable, youthful accords.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as the primary banana note in this playful gourmand, creating an authentic candy-like fruitiness that blends with vanilla and sugar notes.
Provides the juicy pear component in this fruity floral, enhancing the cocktail-like fruitiness alongside raspberry and passionfruit notes.
2D Molecular Structure
SMILES: CCC(=O)OCCC(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Isoamyl propionate is an ester formed from isoamyl alcohol and propionic acid. As a synthetic material, it’s produced through acid-catalyzed esterification reactions, typically using sulfuric acid as a catalyst. The molecule features a five-carbon branched chain (isopentyl group) esterified with a three-carbon propionate group, giving it both good volatility and persistence. Its relatively simple structure makes it inexpensive to manufacture while delivering powerful fruity aroma characteristics.
Physical & Chemical Properties
| Boiling Point | 160-162 °C |
|---|---|
| Density | 0.866 g/cm³ |
| Refractive Index | 1.406-1.409 |
| Flash Point | 45 °C |
| Appearance | Colorless liquid |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Fruity top note enhancement |
| Flavors | 10-50 ppm | 5-100 ppm | Banana/candy flavoring |
| Body Care | 0.1-1% | Up to 3% | Fruity shower gel accents |
Classic Accords
Tip: Use in small quantities to avoid overwhelming compositions with its intense candy-like fruitiness.
Alternatives & Comparisons
Similar banana character but more volatile and slightly greener, better for fresh fruit effects rather than candy-like sweetness.
Offers a similar fruity profile but with more apple/rum nuances, useful when needing less banana dominance.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not restricted by IFRA. No usage limits specified in current standards.
RIFM Assessment
Evaluated by RIFM and considered safe for current fragrance use levels.
Sustainability
As a synthetic material, isoamyl propionate doesn’t rely on agricultural resources. Its production from petrochemical feedstocks raises typical synthetic chemistry environmental concerns, but its high potency means small quantities are effective. No known significant environmental hazards when used and disposed of properly in industrial settings.
Explore Isoamyl propionate
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781439852173
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPerfumer’s Notes
FEMA #: 2082 | IOFI #: Nature Identical
Isoamyl propionate has a pineapple-apricot odor. The taste is somewhat harsh when freshly distilled but subsequently yields a pleasant apricot-plum, bittersweet flavor.
Odor: [‘apricot’, ‘banana’, ‘fruity’, ‘pineapple’, ‘plum’, ‘sweet’, ‘tropical’]
MW: 144.21
LogP: 2.5
Ingredient Data Sheet
CAS 105-68-0Physical Properties
| Molecular Weight | 144.21 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.5🔬 PubChem |
| Boiling Point | 159 °C🔬 EPA CompTox |
| Flash Point | 41 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -1.805💻 Calculated |
| SMILES | CCC(=O)OCCC(C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
Odor & Flavor
| Primary Descriptors | apricotbananafruitypineappleplumsweettropical• leffingwell |
| Functional Groups | esterether💻 RDKit |
| “Very sweet-fruity, Apricot-Pineapple type odor with a somewhat harsh overtone and considerable radiance.”📖 Arctander | |
| Isoamyl propionate has a pineapple-apricot odor. The taste is somewhat harsh when freshly distilled but subsequently yields a pleasant apricot-plum, bittersweet flavor.📖 Fenaroli | |
Flavor Notes (Arctander)
| “Sweet-fruit taste, reminiscent of Apricot-Banana-Pineapple. Extensively used in flavor compositions for imitation Apple, Banana, Cherry, Grape, Peach, Pineapple, Raspberry, Rum, Strawberry, Tutti-frutti, etc.”📖 Arctander |
Sensory Thresholds
| Odor Detection Threshold | 1.0696 ppm (n=3)📖 van Gemert |
Regulatory Status
| FEMA Number | FEMA 2082⚖️ FEMA GRAS |
| GRAS Status | Generally Recognized as Safe⚖️ FEMA GRAS |
| IOFI Classification | Nature Identical📖 Fenaroli |
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: DTXSID5047613
Physical Properties
| Molecular Weight | 144.214 g/mol🔬 EPA CompTox |
| Density | 0.867 g/cm^3🔬 EPA CTX |
| Boiling Point | 160.39 °C🔬 EPA CTX |
| Melting Point | -71.55 °C🔬 EPA CTX |
| Flash Point | 43.66 °C🔬 EPA CTX |
| Refractive Index | 1.411 Dimensionless📊 OPERA |
| Molar Volume | 164.448 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.133 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 2.575 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.575 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 3.94 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 2.387 mmHg📊 OPERA |
| Viscosity | 0.907 cP📊 OPERA |
| Surface Tension | 25.208 dyn/cm📊 OPERA |
| Thermal Conductivity | 131.41 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 | 4 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 40.845 cm^3/mol📊 OPERA |
| Polarizability | 16.192 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.
