Butyl stearate (CAS 123-95-5) — Woody N/A Note Fragrance Ingredient
Butyl stearate
CAS 123-95-5
What Is Butyl stearate?
Butyl stearate is a synthetic ester commonly used as an emollient in cosmetics and personal care products. You’ll find it in lotions, creams, and some fragrance formulations where it acts as a solvent and fixative. This ingredient matters because it helps blend fragrance oils while providing a smooth, non-greasy feel to skincare products. Its mild nature makes it a versatile base in many formulations.
Safety Profile
GENERALLY SAFEWhat Does Butyl stearate Smell Like?
Butyl stearate has a very faint, waxy odor reminiscent of candle wax or paraffin. It’s more functional than aromatic, serving primarily as a solvent and carrier rather than a fragrance note. In formulations, it provides a neutral background that doesn’t interfere with other scent components. The odor profile is clean, slightly fatty, and disappears quickly when applied to skin.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Butyl stearate is primarily used as a functional ingredient rather than a fragrance component in commercial perfumes.
2D Molecular Structure
SMILES: CCCCCCCCCCCCCCCCCC(=O)OCCCC
Chemistry, Properties & Perfumer Guide
The Chemistry
Butyl stearate is an ester formed from butanol and stearic acid. As a synthetic compound, it’s produced through esterification reactions under controlled conditions. The molecule consists of a long hydrocarbon chain (stearate) attached to a butyl group, giving it both lipophilic and mild emollient properties. Its chemical stability makes it useful in formulations requiring neutral, non-reactive ingredients.
Physical & Chemical Properties
| Boiling Point | N/A |
|---|---|
| Density | N/A |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Cosmetics | 1-5% | Up to 10% | Emollient and solvent |
| Fragrance | 0.5-2% | Up to 5% | Carrier and fixative |
Classic Accords
Tip: Use as a neutral base for oil-soluble fragrance materials.
Alternatives & Comparisons
Lighter ester with similar solvent properties but faster skin absorption.
Natural alternative with excellent emollient properties and better sustainability profile.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions apply to butyl stearate.
RIFM Assessment
Considered safe for use in cosmetics and fragrances based on available data.
Sustainability
As a synthetic ingredient, butyl stearate’s environmental impact depends on manufacturing processes. While not derived from petrochemicals, its production does require energy inputs. Formulators seeking greener alternatives might consider plant-derived esters with similar functional properties.
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Physicochemical Properties
DTXSID: DTXSID5027013
Physical Properties
| Molecular Weight | 340.592 g/mol🔬 EPA CompTox |
| Density | 0.86 g/cm^3🔬 EPA CTX |
| Boiling Point | 343 °C🔬 EPA CTX |
| Melting Point | 27.071 °C🔬 EPA CTX |
| Flash Point | 173.46 °C🔬 EPA CTX |
| Refractive Index | 1.448 Dimensionless📊 OPERA |
| Molar Volume | 395.166 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 9.428 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 9.428 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 9.428 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 10.85 Log10 unitless📊 OPERA |
| Water Solubility | 0.005 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0.038 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0 mmHg🔬 EPA CTX |
| Viscosity | 9.288 cP📊 OPERA |
| Surface Tension | 30.283 dyn/cm📊 OPERA |
| Thermal Conductivity | 152.655 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 | 19 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 105.747 cm^3/mol📊 OPERA |
| Polarizability | 41.921 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.
