2-Heptanol (CAS 543-49-7) — Green Top-middle Note Fragrance Ingredient
2-Heptanol
CAS 543-49-7
What Is 2-Heptanol?
2-Heptanol is a synthetic alcohol used in perfumery for its fresh, slightly green aroma. It’s found in trace amounts in some citrus and herbal fragrances. This ingredient matters because it adds a crisp, clean character to compositions, often working behind the scenes to enhance other notes without being detectable on its own.
Safety Profile
GENERALLY SAFEWhat Does 2-Heptanol Smell Like?
2-Heptanol presents a fresh, slightly green aroma with waxy undertones reminiscent of unripe banana peel. Its top note carries a crisp, almost metallic sharpness that quickly mellows into a clean laundry-like character. The dry-down reveals subtle herbal facets, like crushed grass stems after rain. While not dominant, it provides excellent lift to citrus accords and adds diffusion to green compositions.
2D Molecular Structure
SMILES: CCCCCC(C)O
Chemistry, Properties & Perfumer Guide
The Chemistry
2-Heptanol is a secondary alcohol with a seven-carbon chain. Industrially produced via oxidation of heptene or reduction of 2-heptanone. Its molecular structure allows moderate volatility while maintaining sufficient tenacity for perfumery use. The stereochemistry (chiral center at C-2) creates two enantiomers with slightly different olfactory profiles, though commercial material is typically racemic.
Physical & Chemical Properties
| Boiling Point | 160-162 °C |
|---|---|
| Density | 0.818 g/cm³ |
| Refractive Index | 1.421 |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Background modifier |
| Functional Products | 0.05-0.2% | Up to 0.5% | Freshness enhancer |
Classic Accords
Tip: Use to add diffusion and lift to green-floral compositions without adding sweetness.
Alternatives & Comparisons
Primary alcohol version with sharper green notes but less blending versatility.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions. Listed as safe for all applications.
GHS Classification
RIFM Assessment
RIFM evaluation confirms safe use at current industry levels.
Sustainability
Synthesized from petrochemical feedstocks via efficient catalytic processes. No known ecological concerns at production scale. Biodegradation occurs via standard alcohol metabolic pathways.
Explore 2-Heptanol
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References
- PubChem Compound Summary for 2-Heptanol PubChem CID 10976
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 543-49-7Physical Properties
| Molecular Weight | 116.2 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.3🔬 PubChem |
| Boiling Point | 158 °C🔬 EPA CompTox |
| Vapor Pressure | 1.23 mmHg @ 25°C📊 OPERA |
| Flash Point | 71.1 °C🔬 EPA CompTox |
| Involatility Index | 0.123💻 Calculated |
| log Kp (skin permeability) | -1.776💻 Calculated |
| SMILES | CCCCCC(C)O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Moderate💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | greenherballemon• leffingwell |
| Functional Groups | alcohol💻 RDKit |
| “Fresh, Lemon-like, grassy-herbaceous odor with a sweet-floral undertone. The overall "lift" is primarily fruity-green.”📖 Arctander | |
| 2-Heptanol has a brassy, herbaceous odor reminiscent of lemon and a fruity, green, somewhat bitter taste.📖 Fenaroli | |
Flavor Notes (Arctander)
| “Fruity and somewhat green, but also rather bitter taste.”📖 Arctander |
Sensory Thresholds
| Odor Detection Threshold | 0.0498 ppm (n=6)📖 van Gemert |
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: DTXSID1047158
Physical Properties
| Molecular Weight | 116.204 g/mol🔬 EPA CompTox |
| Density | 0.819 g/cm^3🔬 EPA CTX |
| Boiling Point | 159.525 °C🔬 EPA CTX |
| Melting Point | 25 °C🔬 EPA CTX |
| Flash Point | 65.085 °C🔬 EPA CTX |
| Refractive Index | 1.421 Dimensionless📊 OPERA |
| Molar Volume | 141.965 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.31 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 2.35 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.35 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.9 Log10 unitless📊 OPERA |
| Water Solubility | 0.028 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 1.05 mmHg🔬 EPA CTX |
| Viscosity | 3.474 cP📊 OPERA |
| Surface Tension | 26.203 dyn/cm📊 OPERA |
| Thermal Conductivity | 142.714 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 20.23 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 4 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 35.973 cm^3/mol📊 OPERA |
| Polarizability | 14.261 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.
