Heptanal (CAS 111-71-7) — Citrus Top Note Fragrance Ingredient
Heptanal
CAS 111-71-7
What Is Heptanal?
Heptanal is a synthetic aldehyde with a sharp, green, fatty odor reminiscent of fresh-cut grass and citrus. Commonly found in perfumes, detergents, and flavorings, it adds a crisp, natural edge. This ingredient matters because it bridges fresh top notes with deeper heart accords, making fragrances more dynamic and lifelike.
Safety Profile
GENERALLY SAFEWhat Does Heptanal Smell Like?
Heptanal bursts with a vibrant, green-fatty character, like the first snap of a celery stalk or the rind of a just-peeled orange. Its initial sharpness mellows into a waxy, slightly nutty undertone, akin to candle wax blended with crushed leaves. Over time, it evolves into a softer, hay-like dryness that lingers subtly.
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Heptanal contributes to the fresh, citrus-green opening, enhancing the naturalistic feel of the classic cologne accord.
Used sparingly to amplify the crisp, leafy top notes, complementing the citrus and tea elements.
2D Molecular Structure
SMILES: CCCCCCC=O
Chemistry, Properties & Perfumer Guide
The Chemistry
Heptanal is a straight-chain aldehyde with seven carbon atoms, part of the homologous series of aldehydes. It is typically synthesized via the oxidation of heptanol or through hydroformylation of hexene. Industrially, it’s produced as a byproduct of fatty acid oxidation. Its reactivity makes it valuable for creating more complex fragrance molecules.
Physical & Chemical Properties
| Boiling Point | 153 °C |
|---|---|
| Density | 0.818 g/cm³ |
| Flash Point | 39 °C |
| Vapor Pressure | 4.5 mmHg at 25°C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Adds fresh green character |
| Functional Fragrances | 0.1-1% | Up to 3% | Enhances clean, natural notes |
Classic Accords
Tip: Use heptanal to add a natural, green edge to citrus or herbal compositions.
Alternatives & Comparisons
Safety, Regulatory & Sustainability
⚠ Regulatory Disclaimer
General reference only. Consult current IFRA Standards Library before formulating.
IFRA Status
No IFRA restrictions. Generally recognized as safe for use in fragrances.
EU Allergen Declaration
Not listed as an EU allergen.
GHS Classification
RIFM Assessment
RIFM safety assessment confirms safe use at current levels in fragrances.
Sustainability
Heptanal is typically synthesized from petrochemical sources, but efforts are underway to produce it via renewable feedstocks. Its efficient synthesis and biodegradability make it environmentally favorable.
Explore Heptanal
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References
- PubChem. (2023). Heptanal. National Library of Medicine. PubChem CID 8137
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Apr 2026.
Report a data errorPhysicochemical Properties
DTXSID: DTXSID0021597
Physical Properties
| Molecular Weight | 114.188 g/mol🔬 EPA CompTox |
| Density | 0.825 g/cm^3🔬 EPA CTX |
| Boiling Point | 153.173 °C🔬 EPA CTX |
| Melting Point | -39.026 °C🔬 EPA CTX |
| Flash Point | 40.286 °C🔬 EPA CTX |
| Refractive Index | 1.405 Dimensionless📊 OPERA |
| Molar Volume | 141.401 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.547 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 2.234 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.234 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 3.87 Log10 unitless📊 OPERA |
| Water Solubility | 0.017 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 3.66 mmHg🔬 EPA CTX |
| Viscosity | 1.259 cP📊 OPERA |
| Surface Tension | 25.42 dyn/cm📊 OPERA |
| Thermal Conductivity | 140.416 mW/(m*K)📊 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 | 34.666 cm^3/mol📊 OPERA |
| Polarizability | 13.743 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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