Nerol (CAS 106-25-2) — Citrus Heart Note Fragrance Ingredient
Nerol
CAS 106-25-2
What Is Nerol?
Nerol is a naturally occurring terpene alcohol found in many essential oils like neroli, lemongrass, and rose. You’ll encounter its sweet, floral-citrus scent in perfumes, soaps, and flavored products. This delicate molecule matters because it adds a fresh, green floralcy to fragrances while being more stable than some other citrusy compounds.
Safety Profile
GENERALLY SAFE
What Does Nerol Smell Like?
Nerol opens with a bright, effervescent citrus-peel burst reminiscent of freshly peeled mandarins, quickly revealing a dewy rose petal heart with subtle green undertones. As it dries, the floral character softens into a honeyed sweetness with whisper-clean linen facets. Unlike its isomer geraniol, nerol maintains a crisp, almost metallic freshness throughout its evolution, making it ideal for uplifting citrus-floral compositions.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Nerol provides the sparkling citrus-floral bridge between bergamot and neroli in this historic cologne, creating the illusion of sun-warmed orange groves through its dual citrus and floral character.
Here nerol amplifies the natural neroli oil, adding vibrancy to the orange blossom absolute while preventing the composition from becoming overly powdery or indolic.
Nerol’s green floral facets harmonize with grapefruit and mango in this innovative fruity-floral, contributing to the ‘sunlit riverbank’ illusion with its watery freshness.
2D Molecular Structure
SMILES: CC(C)=CCC\C(C)=C/CO
Chemistry, Properties & Perfumer Guide
The Chemistry
Nerol (C10H18O) is an acyclic monoterpenoid alcohol and the cis-isomer of geraniol. It occurs naturally as a minor component in many essential oils, typically constituting 5-15% of neroli oil. Industrial production often involves the selective hydrogenation of myrcene or isomerization of geraniol. The molecule’s reactivity is influenced by its terminal double bond and allylic alcohol group, making it susceptible to oxidation. Unlike geraniol, nerol’s cis-configuration creates a more compact molecular shape that affects both its volatility and odor characteristics.
Physical & Chemical Properties
| Boiling Point | 224-225 °C |
|---|---|
| Density | 0.88 g/cm³ |
| Refractive Index | 1.474-1.478 |
| Flash Point | 102 °C |
| Solubility | Slightly soluble in water, miscible in alcohol |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-3% | Up to 5% | Fresh floral modifier |
| Soaps | 0.1-1% | Up to 2% | Stable floralcy |
| Flavors | 5-20 ppm | Up to 50 ppm | Citrus enhancer |
Classic Accords
+ Rose Oxide + Citronellol = Modern Rose
+ Linalool + Lavender = Floral Lavender
Tip: Use nerol to brighten rose compositions without adding heaviness – it cuts through waxiness like citrus through cream.
Alternatives & Comparisons
The trans-isomer with deeper rose character but less citrus freshness; better for full-bodied florals.
More minty-citrus with less floralcy; preferred when needing stronger tenacity in functional products.
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. Listed as safe under IFRA standards without limitations (as of 49th Amendment).
EU Allergen Declaration
Not listed as an EU allergen. No declaration required.
RIFM Assessment
RIFM safety assessment confirms nerol as safe for current fragrance use levels with no sensitization concerns at recommended concentrations.
Sustainability
Nerol is increasingly produced via bioengineering routes from sustainable sugar feedstocks, reducing reliance on petrochemical sources. Natural nerol remains available from responsibly harvested neroli oil, though synthetic production ensures consistent quality and reduces agricultural pressure on citrus crops. The molecule’s biodegradability makes it environmentally favorable compared to some synthetic musks or heavy aromatics.
Explore Nerol
Browse essential oils and aroma compounds.
Affiliate disclosure: we may earn a small commission at no extra cost to you.
Industry & Science Data
References
- Bauer, K. et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH. ISBN 978-3-527-30364-6
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Ingredient Data Sheet
CAS 106-25-2Physical Properties
| Molecular Weight | 154.25 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.9🔬 PubChem |
| Boiling Point | 225 °C🔬 EPA CompTox |
| Vapor Pressure | 0.03 mmHg @ 25°C📊 OPERA |
| Flash Point | 42.1 °C🔬 EPA CompTox |
| Involatility Index | 0.0026💻 Calculated |
| log Kp (skin permeability) | -1.582💻 Calculated |
| SMILES | CC(=CCCC(=CCO)C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 2.6 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | freshrosesweet• leffingwell |
| Functional Groups | alcoholalkene💻 RDKit |
| “Sweet rosy, refreshing and "wet" seashore odor of moderate tenacity. Dry notes vary with purity of material. A very pure Nerol will normally have more emphasis on the "fresh seashore" odor and less of the rosy notes, while products with high Geraniol content conceal their "maritime" notes in favor of the deep-rosy tones.”📖 Arctander | |
| Nerol has a fresh, sweet, rose-like odor and a bitter flavor.📖 Fenaroli | |
Flavor Notes (Arctander)
| “Sweet and rosy-fruity taste; in concentrations below 10 ppm the fruitiness dominates and become more Raspberry-like, less rosy. Nerol is also used in flavor compositions for its Raspberry-Strawberry effect, in fruit complexes (its tenacity is superior to that of the conventional items) and in Honey ”📖 Arctander |
Sensory Thresholds
| Odor Detection Threshold | 0.5615 ppm (n=11)📖 van Gemert |
Regulatory Status
| EU Annex III | Listed (restricted)⚖️ IFRA 51 |
| FEMA Number | FEMA 2770⚖️ FEMA GRAS |
| GRAS Status | Generally Recognized as Safe⚖️ FEMA GRAS |
| IOFI Classification | Nature Identical📖 Fenaroli |
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: DTXSID3026728
Physical Properties
| Molecular Weight | 154.253 g/mol🔬 EPA CompTox |
| Density | 3.127 g/cm^3🔬 EPA CTX |
| Boiling Point | 225.437 °C🔬 EPA CTX |
| Melting Point | 101.5 °C🔬 EPA CTX |
| Flash Point | 104.206 °C🔬 EPA CTX |
| Refractive Index | 1.471 Dimensionless📊 OPERA |
| Molar Volume | 177.941 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.098 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 3.491 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.491 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.65 Log10 unitless📊 OPERA |
| Water Solubility | 0.005 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0.383 mmHg🔬 EPA CTX |
| Viscosity | 3.178 cP📊 OPERA |
| Surface Tension | 27.866 dyn/cm📊 OPERA |
| Thermal Conductivity | 141.229 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 | 49.714 cm^3/mol📊 OPERA |
| Polarizability | 19.708 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.
