Farnesene (CAS 502-61-4) — Green Base Note Fragrance Ingredient
Farnesene
CAS 502-61-4
What Is Farnesene?
Farnesene is a naturally occurring hydrocarbon found in the essential oils of many plants, including apples, hops, and some citrus fruits. You might encounter its fresh, green aroma in perfumes, candles, or even some fruit-flavored products. This ingredient matters because it adds a crisp, slightly woody greenness to fragrances, helping create naturalistic scents that evoke gardens and fresh produce.
Safety Profile
GENERALLY SAFEWhat Does Farnesene Smell Like?
Farnesene greets the nose with a burst of green apple peel and freshly crushed stems – crisp, slightly tart, and unmistakably vegetal. As it evolves, the scent softens into a delicate woody-green character reminiscent of walking through an orchard after rain. The dry-down reveals subtle earthy undertones with a whisper of citrus rind, leaving a clean, natural impression that blends seamlessly with floral and fruity notes.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used here to enhance the crisp green opening, farnesene contributes to the fragrance’s legendary ‘just-cut grass’ effect that makes it smell like an Irish countryside after rain.
Jean-Claude Ellena employs farnesene to create the photorealistic green mango note, capturing both the fruit’s sweetness and its stem’s green bitterness.
The farnesene here works with tomato leaf to produce one of perfumery’s most convincing green garden scents – dewy, vegetal, and alive.
This classic green chypre uses farnesene to amplify its galbanum opening, creating an almost electric green freshness that defined postwar perfumery.
Farnesene’s green facets sharpen the iris and rose heart of this legendary floral-green composition, adding a modern crispness to the classic structure.
2D Molecular Structure
SMILES: CC(C)=CCC\C(C)=C\C\C=C(/C)C=C
Chemistry, Properties & Perfumer Guide
The Chemistry
Farnesene belongs to the sesquiterpene hydrocarbon class, occurring naturally as both α- and β-isomers. Plants produce it as part of their defense mechanisms against pests. Industrially, it’s synthesized through oligomerization of isoprene or from sugar fermentation using genetically modified yeast strains. The molecule’s three double bonds make it relatively reactive, contributing to its fresh green odor character while also making it prone to oxidation over time.
Physical & Chemical Properties
| Boiling Point | ~125 °C (at 10 mmHg) |
|---|---|
| Density | 0.84-0.86 g/cm³ |
| Refractive Index | 1.485-1.495 |
| Flash Point | >100 °C |
| Solubility | Insoluble in water, soluble in alcohol and oils |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-3% | Up to 5% | Green note enhancer |
| Functional Fragrance | 0.1-1% | Up to 2% | Freshness booster |
| Flavor | 10-50 ppm | Up to 100 ppm | Green apple note |
Classic Accords
Tip: Stabilize with antioxidants like BHT to prevent oxidation that can dull farnesene’s bright green character.
Alternatives & Comparisons
When a more intense ‘green banana’ note is needed, though less woody than farnesene.
For a more floral-green effect with better stability in alkaline formulations.
When a more diffusive woody-green note is required with superior longevity.
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 apply to farnesene under the 49th Amendment.
RIFM Assessment
RIFM has evaluated farnesene as safe for current use levels in fragrance applications.
Sustainability
Modern production increasingly uses biofermentation from renewable sugar sources rather than petrochemical feedstocks. Apple pomace (waste from juice production) serves as a natural source. The shift to biotech production has reduced the environmental impact by 60% compared to traditional chemical synthesis methods.
Explore Farnesene
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References
- Bicas et al. (2009). Bioflavors: Production, Composition, and Applications. Biotechnology Advances. DOI: 10.1016/j.biotechadv.2009.03.003
- Brenna et al. (2012). Biocatalytic Methods for the Synthesis of Enantiopure Odor Active Compounds. Chemistry & Biodiversity. DOI: 10.1002/cbdv.201100323
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Report a data errorIngredient Data Sheet
CAS 502-61-4Physical Properties
| Molecular Weight | 204.35 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 6.1🔬 PubChem |
| Boiling Point | 260 °C🔬 EPA CompTox |
| log Kp (skin permeability) | 0.384💻 Calculated |
| SMILES | CC(=CCCC(=CCC=C(C)C=C)C)C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
Odor & Flavor
| Primary Descriptors | appleberrycitrusgreenherbal• leffingwell |
| Functional Groups | alkene💻 RDKit |
| “Very mild, sweet and warm, rather non-descript odor of good tenacity.”📖 Arctander | |
| Farnesene has a citrus, herbaceous odor.📖 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: DTXSID4047202
Physical Properties
| Molecular Weight | 204.357 g/mol🔬 EPA CompTox |
| Density | 0.803 g/cm^3📊 OPERA |
| Boiling Point | 261 °C🔬 EPA CTX |
| Melting Point | -30.186 °C📊 OPERA |
| Flash Point | 113.826 °C📊 OPERA |
| Refractive Index | 1.476 Dimensionless📊 OPERA |
| Molar Volume | 251.478 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 6.007 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 6.007 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 6.007 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 6.9 Log10 unitless📊 OPERA |
| Water Solubility | 0 mol/L📊 OPERA |
| Henry's Law Constant | 0.624 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0.047 mmHg📊 OPERA |
| Viscosity | 1.312 cP📊 OPERA |
| Surface Tension | 24.139 dyn/cm📊 OPERA |
| Thermal Conductivity | 130.838 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 0 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 0 count💻 Computed |
| Rotatable Bonds | 6 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 70.969 cm^3/mol📊 OPERA |
| Polarizability | 28.134 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.
