1H-Indene (CAS 95-13-6) — Woody Top Note Fragrance Ingredient
1H-Indene
CAS 95-13-6
What Is 1H-Indene?
1H-Indene is a synthetic aromatic hydrocarbon used in perfumery for its sharp, camphoraceous odor. Found in coal tar and petroleum, it’s chemically modified to create fragrance ingredients. It matters because it adds piercing brightness to masculine fougères and industrial-chic perfumes, despite being nearly undetectable to untrained noses.
Safety Profile
USE WITH AWARENESSWhat Does 1H-Indene Smell Like?
1H-Indene hits like a solvent-drenched rag – initially harsh with a gasoline-like punch that quickly settles into dry, woody bitterness. Imagine cracking open a vintage chemistry textbook next to a freshly tarred roof. The sharp top burns off within minutes, leaving an austere coal-tar skeleton that amplifies adjacent woody notes unnaturally.
2D Molecular Structure
SMILES: C1C=CC2=CC=CC=C12
Chemistry, Properties & Perfumer Guide
The Chemistry
1H-Indene is a polycyclic aromatic hydrocarbon (PAH) with a benzene ring fused to a cyclopentene ring. Industrially produced via coal tar distillation or petroleum refining, it serves as precursor for indane musks and resins. The planar structure allows π-stacking in perfume matrices, contributing to unusual diffusion properties.
Physical & Chemical Properties
| Boiling Point | 182-183 °C |
|---|---|
| Density | 0.996 g/cm³ |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Industrial Fragrances | 0.1-0.5% | Up to 1% | For harsh metallic effects |
| Leather Accords | 0.05-0.2% | trace-0.5% | Sparingly to imitate burnt notes |
Classic Accords
Tip: Use below 0.3% to avoid overwhelming compositions with petrochemical harshness.
Alternatives & Comparisons
Hydrogenated version with less aggressive odor profile, used when subtler petroleum notes are needed.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
Not currently restricted by IFRA.
GHS Classification
RIFM Assessment
No RIFM safety assessment available due to limited fragrance use.
Sustainability
Petroleum-derived with significant carbon footprint from refining processes. Some producers capture it from coal tar waste streams, slightly improving sustainability.
Explore 1H-Indene
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References
- PubChem Compound Summary for 1H-Indene CID 7219
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 95-13-6Physical Properties
| Molecular Weight | 116.16 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.9🔬 PubChem |
| Boiling Point | 181.7 °C🔬 EPA CompTox |
| Vapor Pressure | 1.1 mmHg @ 25°C📊 OPERA |
| Flash Point | 78.3 °C🔬 EPA CompTox |
| Involatility Index | 0.11💻 Calculated |
| log Kp (skin permeability) | -1.35💻 Calculated |
| SMILES | C1C=CC2=CC=CC=C21🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
| Volatility Class | Moderate💻 Calculated |
| Persistence Score | 0.5 / 5💻 Calculated |
Odor & Flavor
| Functional Groups | alkenearomatic💻 RDKit |
Sensory Thresholds
| Odor Detection Threshold | 0.0064 ppm (n=3)📖 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: DTXSID8042052
Physical Properties
| Molecular Weight | 116.163 g/mol🔬 EPA CompTox |
| Density | 0.995 g/cm^3🔬 EPA CTX |
| Boiling Point | 181.586 °C🔬 EPA CTX |
| Melting Point | -2.507 °C🔬 EPA CTX |
| Flash Point | 71.552 °C🔬 EPA CTX |
| Refractive Index | 1.596 Dimensionless📊 OPERA |
| Molar Volume | 111.818 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.928 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 2.966 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.966 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.31 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L📊 OPERA |
| Henry's Law Constant | 0.001 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 1.385 mmHg🔬 EPA CTX |
| Viscosity | 1.3 cP📊 OPERA |
| Surface Tension | 38.312 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 0 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 0 count💻 Computed |
| Rotatable Bonds | 0 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 38.031 cm^3/mol📊 OPERA |
| Polarizability | 15.077 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.
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