l-Citronellol (CAS 7540-51-4) — Floral Heart Note Fragrance Ingredient
l-Citronellol
CAS 7540-51-4
What Is l-Citronellol?
l-Citronellol is a naturally occurring alcohol found in rose and geranium oils, though most commercial versions are synthetically produced. You’ll encounter it in floral perfumes, soaps, and candles. This ingredient matters because it provides the fresh, rosy character that makes many floral fragrances smell simultaneously crisp and lush, acting as a bridge between citrus top notes and deeper floral heart notes.
Safety Profile
GENERALLY SAFEWhat Does l-Citronellol Smell Like?
l-Citronellol bursts with a dewy rose petal freshness underscored by a crisp green stemminess, like walking through a morning rose garden after rain. The initial impression is bright and slightly citrus-tinged, evolving into a rounded floral sweetness reminiscent of tea roses with a whisper of lemon zest. Unlike its heavier floral counterparts, it maintains an airy quality throughout evaporation, leaving behind a clean floral trail that never becomes cloying. In drydown, it reveals a subtle waxy character akin to the natural bloom on fresh rose petals.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Forms the sparkling rosy core, balancing peony’s freshness with the powderiness of traditional rose absolutes.
Used to brighten the lily-of-the-valley accord, preventing the floral bouquet from becoming too heavy.
Provides the initial rose impact that later merges with cumin and vetiver for a gender-bending effect.
Forms the entire rose character, demonstrating how l-Citronellol can convincingly recreate natural rose notes.
Used in overdose to create the signature ‘rose jam’ effect that defines this cult classic.
2D Molecular Structure
SMILES: C[C@H](CCO)CCC=C(C)C
Chemistry, Properties & Perfumer Guide
The Chemistry
l-Citronellol is a monoterpenoid alcohol with the molecular formula C10H20O. As the levorotatory enantiomer of citronellol, it exhibits different olfactory properties than its d-form counterpart, being perceived as more floral and less citrusy. Industrially produced through hydrogenation of geraniol or citral, or via biotechnological routes using engineered yeast strains. Its chiral center at C3 makes it particularly valuable in perfumery, as the l-form occurs naturally in rose oils and is generally preferred for floral reconstructions due to its superior odor characteristics compared to racemic mixtures.
Physical & Chemical Properties
| Boiling Point | 225 °C |
|---|---|
| Density | 0.855 g/cm³ |
| Refractive Index | 1.456 |
| Flash Point | 102 °C |
| Vapor Pressure | 0.01 mmHg at 25°C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 5-15% | Up to 20% | Core floral modifier |
| Soap/Cleansers | 1-3% | Up to 5% | Stable in alkaline media |
| Candles | 3-8% | Up to 12% | Good heat stability |
| Air Fresheners | 0.5-2% | Up to 4% | Provides initial floral impact |
Classic Accords
Tip: Combine with damascenones at 1:10 ratio to create a more dimensional rose effect.
Alternatives & Comparisons
More citrus-forward version, better suited for citrus colognes where rosy undertones should be subtle.
When a sweeter, honeyed rose character is desired without the green freshness of citronellol.
For a more complex, natural rose effect with additional linalool-like facets.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions under Amendment 49. Listed as safe for all applications at standard usage levels.
EU Allergen Declaration
Subject to EU allergen labeling requirements above 0.1% in leave-on products and 0.01% in rinse-off products (Regulation (EC) No 1223/2009).
GHS Classification
RIFM Assessment
RIFM safety assessment confirms safe use at current industry levels. No evidence of phototoxicity or significant sensitization potential.
Sustainability
Most commercial l-Citronellol is synthesized from petrochemical precursors, though sustainable routes via fermentation of plant sugars are emerging. As a key component in rose oil alternatives, its use reduces pressure on natural rose cultivation, which requires extensive land and water resources. Biodegradability is excellent (OECD 301D), with minimal aquatic toxicity.
Explore l-Citronellol
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References
- Bauer, K. et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH. ISBN 9783527616324
- IFRA Standards Library Amendment 49 IFRA 49
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID1041550
Physical Properties
| Molecular Weight | 156.269 g/mol🔬 EPA CompTox |
| Density | 0.855 g/cm^3🔬 EPA CTX |
| Boiling Point | 224.3 °C🔬 EPA CTX |
| Melting Point | 2.622 °C📊 OPERA |
| Flash Point | 107 °C🔬 EPA CTX |
| Refractive Index | 1.451 Dimensionless📊 OPERA |
| Molar Volume | 184.902 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.41 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 3.736 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.736 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.38 Log10 unitless📊 OPERA |
| Water Solubility | 0.002 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.065 mmHg🔬 EPA CTX |
| Viscosity | 4.153 cP📊 OPERA |
| Surface Tension | 27.663 dyn/cm📊 OPERA |
| Thermal Conductivity | 140.474 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 | 5 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 49.772 cm^3/mol📊 OPERA |
| Polarizability | 19.731 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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