1,2-Hexanediol (CAS 6920-22-5) — Sweet Non-aromatic Note Fragrance Ingredient
1,2-Hexanediol
CAS 6920-22-5
What Is 1,2-Hexanediol?
1,2-Hexanediol is a synthetic ingredient primarily used as a solvent and humectant in cosmetic formulations. Consumers encounter it in skincare products like moisturizers and serums where it helps retain moisture. While not a fragrance ingredient itself, it plays a supporting role in scent longevity by modulating evaporation rates.
Safety Profile
GENERALLY SAFEWhat Does 1,2-Hexanediol Smell Like?
1,2-Hexanediol is nearly odorless with only a faint, slightly sweet alcoholic character detectable at high concentrations. Its primary function is as a carrier rather than an aromatic contributor, though it may subtly influence fragrance diffusion when used as a solvent base.
2D Molecular Structure
SMILES: CCCCC(O)CO
Chemistry, Properties & Perfumer Guide
The Chemistry
1,2-Hexanediol is a diol compound with hydroxyl groups at the 1 and 2 positions of a six-carbon chain. Industrially produced via hydroformylation of 1-pentene followed by hydrogenation, this synthetic material serves primarily as a humectant and viscosity modifier. Its bifunctional structure allows hydrogen bonding with both water and organic compounds.
Physical & Chemical Properties
| Boiling Point | 223-224 °C |
|---|---|
| Density | 0.95 g/cm³ |
| Vapor Pressure | 0.001 mmHg at 25°C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Skincare | 1-5% | Up to 10% | Humectant and solvent |
| Fragrance Carrier | 2-8% | Up to 15% | Modulates evaporation |
Classic Accords
Tip: Use as a replacement for propylene glycol in fragrance bases requiring enhanced humectant properties.
Alternatives & Comparisons
Similar humectant properties but with higher volatility and slightly greasier feel.
Shorter carbon chain provides faster evaporation rate for quicker fragrance release.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions – classified as non-allergenic and non-sensitizing.
RIFM Assessment
RIFM considers 1,2-hexanediol safe for current cosmetic use patterns.
Sustainability
As a petrochemical derivative, 1,2-hexanediol’s environmental impact stems from fossil fuel use in production. However, its high efficiency at low concentrations and biodegradability profile make it preferable to some traditional glycol solvents.
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References
- Cosmetic Ingredient Review (CIR) Expert Panel. (2016). Safety Assessment of Alkane Diols as Used in Cosmetics. CIR Report
- PubChem Compound Summary for 1,2-Hexanediol PubChem
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 6920-22-5Physical Properties
| Molecular Weight | 118.17 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 0.7🔬 PubChem |
| Boiling Point | 228.3 °C🔬 EPA CompTox |
| Vapor Pressure | 0.0043 mmHg @ 25°C📊 OPERA |
| Flash Point | 114 °C🔬 EPA CompTox |
| Involatility Index | 0.0004💻 Calculated |
| log Kp (skin permeability) | -2.924💻 Calculated |
| SMILES | CCCCC(CO)O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 2.7 / 5💻 Calculated |
Odor & Flavor
| Functional Groups | alcohol💻 RDKit |
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: DTXSID40863959
Physical Properties
| Molecular Weight | 118.176 g/mol🔬 EPA CompTox |
| Density | 0.95 g/cm^3🔬 EPA CTX |
| Boiling Point | 228.3 °C🔬 EPA CTX |
| Melting Point | 2 °C🔬 EPA CTX |
| Flash Point | 119.333 °C🔬 EPA CTX |
| Refractive Index | 1.447 Dimensionless📊 OPERA |
| Molar Volume | 122.965 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 0.58 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 0.653 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 0.653 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.41 Log10 unitless📊 OPERA |
| Water Solubility | 0.962 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0.007 mmHg🔬 EPA CTX |
| Viscosity | 11.279 cP📊 OPERA |
| Surface Tension | 32.851 dyn/cm📊 OPERA |
| Thermal Conductivity | 163.683 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 40.46 Ų💻 Computed |
| H-Bond Donors | 2 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 4 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 32.875 cm^3/mol📊 OPERA |
| Polarizability | 13.032 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.
