Octyl isobutyrate (CAS 109-15-9) — Citrus Top Note Fragrance Ingredient
Octyl isobutyrate
CAS 109-15-9
What Is Octyl isobutyrate?
Octyl isobutyrate is a synthetic fragrance ingredient commonly found in perfumes, soaps, and cosmetic products. It contributes a fruity, slightly floral aroma that enhances freshness in formulations. This ester is valued for its ability to add a crisp, clean top note that blends well with citrus and herbal scents, making it versatile for personal care products.
Safety Profile
GENERALLY SAFEWhat Does Octyl isobutyrate Smell Like?
Octyl isobutyrate opens with a bright, fruity burst reminiscent of ripe pears and fresh apples, with a subtle floral undertone. As it evolves, the scent softens into a clean, slightly sweet muskiness, maintaining its crisp character without becoming cloying. The dry-down is smooth and airy, leaving a faint trace of citrus-like freshness that lingers subtly on the skin.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as a top note to enhance the fruity freshness, blending seamlessly with bergamot and lemon for a vibrant opening.
Adds a crisp, clean edge to the floral heart, balancing the sweetness of jasmine and rose.
2D Molecular Structure
SMILES: CCCCCCCCOC(=O)C(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
Octyl isobutyrate is an ester formed from isobutyric acid and octanol. It is typically synthesized via esterification under acidic conditions. The molecule’s structure contributes to its volatility and fruity odor profile, making it ideal for top notes in fragrances. Its synthetic production ensures consistency in quality and aroma.
Physical & Chemical Properties
| Boiling Point | Not specified |
|---|---|
| Density | Not specified |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 1-5% | Up to 10% | Adds fruity freshness |
| Soaps | 0.5-2% | Up to 5% | Enhances clean scent |
Classic Accords
Tip: Use in small amounts to avoid overpowering other top notes.
Alternatives & Comparisons
Offers a similar fruity profile but with a more pronounced pear-like character.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No restrictions under current IFRA standards.
RIFM Assessment
Considered safe for use in fragrances by RIFM.
Sustainability
Synthetically produced, reducing reliance on natural resources. Production processes are optimized for minimal environmental impact.
Explore Octyl isobutyrate
Browse essential oils and aroma compounds.
Browse on iHerb →Affiliate disclosure: we may earn a small commission at no extra cost to you.
References
- PubChem Compound Summary for Octyl isobutyrate PubChem
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID6059364
Physical Properties
| Molecular Weight | 200.322 g/mol🔬 EPA CompTox |
| Density | 0.866 g/cm^3📊 OPERA |
| Boiling Point | 237 °C🔬 EPA CTX |
| Melting Point | -43.876 °C📊 OPERA |
| Flash Point | 94.842 °C📊 OPERA |
| Refractive Index | 1.429 Dimensionless📊 OPERA |
| Molar Volume | 230.475 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 4.572 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 4.572 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 4.572 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 | 0.042 mmHg📊 OPERA |
| Viscosity | 2.276 cP📊 OPERA |
| Surface Tension | 27.274 dyn/cm📊 OPERA |
| Thermal Conductivity | 135.955 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.
![4,7,7-Trimethyl-6-thiabicyclo[3.2.1]octane (CAS 68398-18-5) — Woody Top to Middle Note Fragrance Ingredient](https://thegoodscents.company/wp-content/uploads/2026/04/4-7-7-trimethyl-6-thiabicyclo-3-2-1-octane-1-768x439.webp)
