Phenoxyacetaldehyde (CAS 2120-70-9) — Green Top to middle Note Fragrance Ingredient
Phenoxyacetaldehyde
CAS 2120-70-9
What Is Phenoxyacetaldehyde?
Phenoxyacetaldehyde is a synthetic fragrance ingredient used to add green, floral, and slightly herbal nuances to perfumes. It’s found in various personal care products and fine fragrances. This molecule is valued for its ability to create fresh, dewy effects in floral compositions, enhancing naturalistic impressions without being overpowering.
Safety Profile
USE WITH AWARENESSWhat Does Phenoxyacetaldehyde Smell Like?
Phenoxyacetaldehyde opens with a crisp, green burst reminiscent of crushed stems and fresh-cut grass, quickly revealing a delicate floralcy akin to lily-of-the-valley petals. The heart develops a honeyed sweetness with subtle herbal undertones, while the dry-down leaves a clean, slightly powdery trail. Its character evolves like morning dew evaporating from spring foliage – initially vibrant, then softening to a skin-hugging whisper.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to amplify the aquatic floralcy, creating the illusion of water droplets on lotus flowers. Its green freshness balances the melon notes.
Provides the dewy top note that makes the lily accord smell freshly picked, enhancing the fragrance’s ‘just rained’ quality.
2D Molecular Structure
SMILES: O=CCOC1=CC=CC=C1
Chemistry, Properties & Perfumer Guide
The Chemistry
Phenoxyacetaldehyde is an aromatic aldehyde with a benzene ring connected to an acetaldehyde group via an oxygen bridge. Industrially produced through oxidation of phenoxyethanol or via Grignard reactions. The molecule lacks chirality but exhibits moderate polarity due to the ether linkage and aldehyde functionality. Its reactivity makes it useful for creating Schiff bases in perfumery.
Physical & Chemical Properties
| Appearance | Colorless to pale yellow liquid |
|---|---|
| Boiling Point | Approx. 210-215°C (estimated) |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Green floral modifier |
| Soap | 0.1-0.5% | Up to 1% | Adds freshness |
Classic Accords
Tip: Stabilize in ethanol before adding to aqueous systems to prevent polymerization.
Alternatives & Comparisons
When a sweeter, more candied floralcy is desired without the green aspects.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No current IFRA restrictions. Listed on IFRA Transparency List.
GHS Classification
RIFM Assessment
RIFM evaluation ongoing. Preliminary data suggests moderate skin sensitization potential.
Sustainability
Synthesized from petrochemical precursors with relatively low environmental impact due to efficient production methods. Not known to bioaccumulate. No natural equivalent exists, making synthetic production the only viable route.
Explore Phenoxyacetaldehyde
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References
- Bauer et al. (2001). Common Fragrance and Flavor Materials. Wiley-VCH.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 2120-70-9Physical Properties
| Molecular Weight | 136.15 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.8🔬 PubChem |
| Boiling Point | 243 °C🔬 EPA CompTox |
| Vapor Pressure | 0.1202 mmHg @ 25°C📊 OPERA |
| Flash Point | 92.4 °C🔬 EPA CompTox |
| Involatility Index | 0.0111💻 Calculated |
| log Kp (skin permeability) | -2.253💻 Calculated |
| SMILES | C1=CC=C(C=C1)OCC=O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Heart💻 Calculated |
| Volatility Class | Slow💻 Calculated |
| Persistence Score | 1.3 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | aldehydicfloralfreshgreensweetwoody• leffingwell |
| Functional Groups | aldehydeetheraromatic💻 RDKit |
| “Powerful green, wood-sap-like, but fresh and "aldehydic"-sweet, floral-sweet odor of considerable tenacity. The terminal notes are particularly sweet and attractive.”📖 Arctander | |
Regulatory Status
| IFRA Listed | Yes — see IFRA Standards for category limits⚖️ IFRA 51 |
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: DTXSID1051858
Physical Properties
| Molecular Weight | 136.15 g/mol🔬 EPA CompTox |
| Density | 1.07 g/cm^3📊 OPERA |
| Boiling Point | 228.861 °C📊 OPERA |
| Melting Point | 28.898 °C📊 OPERA |
| Flash Point | 88.738 °C📊 OPERA |
| Refractive Index | 1.505 Dimensionless📊 OPERA |
| Molar Volume | 127.261 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 1.599 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 1.599 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 1.599 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.6 Log10 unitless📊 OPERA |
| Water Solubility | 0.029 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0.112 mmHg📊 OPERA |
| Viscosity | 2.432 cP📊 OPERA |
| Surface Tension | 36.411 dyn/cm📊 OPERA |
| Thermal Conductivity | 154.065 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 26.3 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 3 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 37.751 cm^3/mol📊 OPERA |
| Polarizability | 14.966 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.
