1-Octen-3-one (CAS 4312-99-6) — Green Top to Heart Note Fragrance Ingredient
1-Octen-3-one
CAS 4312-99-6
What Is 1-Octen-3-one?
1-Octen-3-one is a synthetic aroma compound that gives a mushroom-like, earthy scent. It’s found in trace amounts in nature but primarily used in perfumery to create realistic forest or damp soil effects. This molecule matters because it’s one of the most potent odorants known – detectable at extremely low concentrations, allowing perfumers to build complex naturalistic accords with minimal material.
Safety Profile
USE WITH AWARENESSWhat Does 1-Octen-3-one Smell Like?
1-Octen-3-one bursts with an intense, almost aggressive mushroom character – like crushing wild porcini between your fingers with damp forest duff. The initial punch evolves into a complex earthy heart with metallic undertones, recalling rusted tools in wet soil. At dilution, it reveals a surprisingly elegant dry-down: the fungal sharpness softens into a warm, slightly sweet humus note that blends beautifully with woody materials. This is the smell of autumn decay transformed into perfumery gold.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Used to create hyper-realistic damp earth effects that contrast with the fragrance’s green floralcy, making the composition feel like walking through a rainforest after heavy rain.
Provides an underground fungal nuance that deepens the vetiver’s rooty character, adding dimension to this dark woody fragrance.
2D Molecular Structure
SMILES: CCCCCC(=O)C=C
Chemistry, Properties & Perfumer Guide
The Chemistry
1-Octen-3-one is an unsaturated ketone with the molecular formula C8H14O. While it occurs naturally in mushrooms and some plants, commercial production typically involves oxidation of 1-octen-3-ol or synthesis from acetylene derivatives. The molecule’s extreme potency stems from its conjugated double bond system adjacent to the carbonyl group, creating an electrophilic center that strongly interacts with olfactory receptors. The (R)-enantiomer is significantly more odor-active than the (S)-form, with detection thresholds in the parts-per-trillion range.
Physical & Chemical Properties
| Boiling Point | 172-174 °C |
|---|---|
| Density | 0.838 g/cm³ |
| Vapor Pressure | 1.3 mmHg at 25°C |
| Refractive Index | 1.432 |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.001-0.01% | Up to 0.05% | Extremely potent – use sparingly |
| Functional Fragrance | 0.0001-0.001% | Up to 0.005% | For realistic mushroom effects |
| Flavor | 0.1-1 ppm | Up to 5 ppm | Meat/mushroom savory notes |
Classic Accords
Tip: Always pre-dilute to 0.1% or lower before incorporating into blends – undiluted material can overwhelm compositions.
Alternatives & Comparisons
For pure earthy effects without the fungal character. More stable but less complex than 1-octen-3-one.
Provides similar earthy-mushroom notes with added nutty aspects. Less metallic but also less potent.
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions. Listed on IFRA Transparency List with no usage limits specified.
GHS Classification
RIFM Assessment
RIFM evaluation complete (FEMA 3515). Considered safe at current usage levels in fragrance applications.
Sustainability
As a synthetic material, 1-octen-3-one has minimal environmental impact in production. Its extreme potency means very small quantities are needed, reducing transportation emissions. Some manufacturers are exploring bio-based production routes using fungal fermentation, which could further improve sustainability. Proper handling is crucial to prevent wastewater contamination due to its strong odor characteristics.
Explore 1-Octen-3-one
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References
- Buttery et al. (1986). Identification of 1-Octen-3-one in Mushrooms. Journal of Agricultural and Food Chemistry. DOI: 10.1021/jf00070a043
- Burdock (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781420090869
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorIngredient Data Sheet
CAS 4312-99-6Physical Properties
| Molecular Weight | 126.2 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 2.4🔬 PubChem |
| Boiling Point | 59 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -1.766💻 Calculated |
| SMILES | CCCCCC(=O)C=C🔬 PubChem |
Volatility & Performance
| Fragrance Note | Top💻 Calculated |
Odor & Flavor
| Primary Descriptors | metallicmushroom• leffingwell |
| Functional Groups | ketonealkene💻 RDKit |
| 1-Octen-3-one has a mushroom odor.📖 Fenaroli | |
Sensory Thresholds
| Odor Detection Threshold | 0.0012 ppm (n=4)📖 van Gemert |
Regulatory Status
| 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: DTXSID5047162
Physical Properties
| Molecular Weight | 126.199 g/mol🔬 EPA CompTox |
| Density | 0.816 g/cm^3🔬 EPA CTX |
| Boiling Point | 168.868 °C📊 OPERA |
| Melting Point | -33.96 °C📊 OPERA |
| Flash Point | 50.199 °C📊 OPERA |
| Refractive Index | 1.422 Dimensionless📊 OPERA |
| Molar Volume | 152.803 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.695 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 2.695 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.695 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.43 Log10 unitless📊 OPERA |
| Water Solubility | 0.034 mol/L📊 OPERA |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 1.053 mmHg📊 OPERA |
| Surface Tension | 27.654 dyn/cm📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 17.07 Ų💻 Computed |
| H-Bond Donors | 0 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 5 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 38.867 cm^3/mol📊 OPERA |
| Polarizability | 15.408 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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