Stearic Acid (CAS 57-11-4) — Woody Base Note Fragrance Ingredient
Stearic Acid
CAS 57-11-4
What Is Stearic Acid?
Stearic acid is a waxy fatty acid naturally found in animal fats and vegetable oils. You encounter it in soaps, candles, and cosmetics where it acts as a thickener and stabilizer. While not strongly fragrant itself, it’s a key ingredient that helps other scents last longer in products. This versatile compound matters because it’s both biodegradable and derived from renewable sources, making it a sustainable choice for personal care formulations.
Safety Profile
GENERALLY SAFEWhat Does Stearic Acid Smell Like?
Stearic acid presents a faint, waxy aroma reminiscent of tallow or candle wax, with subtle animalic undertones. Its odor profile is more textural than pronounced—a smooth, slightly greasy sensation rather than a dominant scent. In formulations, it serves as a silent backbone, contributing body and longevity without asserting its own character. The dry-down is virtually odorless, making it an ideal carrier for other fragrance materials that need structural support without aromatic interference.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used as an emulsifier in the original parfum extrait formulation, helping stabilize the iconic floral-aldehyde accord while contributing subtle waxy notes that enhance the perfume’s skin-like quality.
Acts as a fixative in the vanilla-amber base, providing structural integrity to the complex oriental accord without competing with the dominant balsamic and powdery notes.
2D Molecular Structure
SMILES: CCCCCCCCCCCCCCCCCC(O)=O
Chemistry, Properties & Perfumer Guide
The Chemistry
Stearic acid is a saturated C18 fatty acid (octadecanoic acid) belonging to the carboxylic acid class. Naturally occurring in animal and vegetable fats, it’s typically derived commercially from palm oil or animal tallow through saponification and fractional distillation. The straight-chain hydrocarbon tail gives it excellent stability and high melting point. While not optically active itself, stearic acid often occurs in nature alongside its cis-unsaturated counterpart, oleic acid. Industrial production may involve hydrogenation of unsaturated fatty acids or hydrolysis of triglycerides followed by purification through crystallization.
Physical & Chemical Properties
| Boiling Point | 721 °F at 760 mmHg |
|---|---|
| Melting Point | 156.7 °F |
| Flash Point | 385 °F |
| Density | 0.86 at 68 °F |
| Vapor Pressure | 1 mmHg at 344.7 °F |
| Refractive Index | 1.4299 at 80 °C |
| Solubility | 1 to 10 mg/mL at 73 °F |
| Appearance | Monoclinic leaflets from alcohol |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Soaps & Detergents | 5-15% | Up to 30% | Provides hardness and lather stability |
| Candles | 10-20% | Up to 50% | Modifies wax crystallization |
| Cosmetics | 2-5% | Up to 10% | Emulsifier and viscosity modifier |
Classic Accords
Tip: Pre-dissolve in alcohol when creating solid perfume bases to ensure even distribution.
Alternatives & Comparisons
Shorter C16 chain with similar properties but slightly lower melting point, preferred when more fluidity is needed in formulations.
Fatty alcohol alternative that provides similar thickening effects without carboxylic acid functionality, useful in pH-sensitive systems.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. IFRA, REACH, EU Cosmetics Regulation standards update periodically. Consult current IFRA Standards Library before formulating. Not legal or regulatory advice.
IFRA Status
No IFRA restrictions – fully approved for all applications.
GHS Classification
RIFM Assessment
RIFM safety assessment confirms low risk in current cosmetic use patterns.
Sustainability
Stearic acid’s sustainability depends on its source—palm-derived versions raise deforestation concerns, while tallow is a byproduct of meat industry. Synthetic routes exist but are energy-intensive. The industry is moving toward RSPO-certified palm sources and upcycled animal fat recovery from food waste streams. Biodegradability is excellent (OECD 301B).
Explore Stearic Acid
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References
- PubChem Compound Summary for CID 5281 PubChem 5281
- EFSA Panel (2017). Safety of stearic acid. EFSA Journal. EFSA 2017
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID8021642
Physical Properties
| Molecular Weight | 284.484 g/mol🔬 EPA CompTox |
| Density | 0.887 g/cm^3🔬 EPA CTX |
| Boiling Point | 356.422 °C🔬 EPA CTX |
| Melting Point | 69.089 °C🔬 EPA CTX |
| Flash Point | 186.033 °C🔬 EPA CTX |
| Refractive Index | 1.456 Dimensionless📊 OPERA |
| Molar Volume | 320.283 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 8.23 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 7.507 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 5.745 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 10.62 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0 mmHg🔬 EPA CTX |
| Viscosity | 22.055 cP📊 OPERA |
| Surface Tension | 31.812 dyn/cm📊 OPERA |
| Thermal Conductivity | 154.232 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 37.3 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 16 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 87.005 cm^3/mol📊 OPERA |
| Polarizability | 34.491 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.
