Nonanal (CAS 124-19-6) — Citrus Top Note Fragrance Ingredient
Nonanal
CAS 124-19-6
What Is Nonanal?
Nonanal is a synthetic fragrance ingredient that smells like fresh citrus with waxy, floral undertones. You’ll find it in cleaning products, air fresheners, and some citrus-forward perfumes. This aldehyde is prized for its ability to create bright, uplifting top notes that mimic the smell of orange peel. It adds realism to citrus accords and helps bridge floral and fruity elements in modern fragrances.
Safety Profile
GENERALLY SAFE
What Does Nonanal Smell Like?
Nonanal bursts with the crisp, zesty brightness of freshly peeled oranges, but quickly reveals a surprising depth – like citrus oil on warm candle wax. The initial aldehydic punch (think champagne bubbles) mellows into a soft floralcy reminiscent of neroli blossoms floating in a soapy bath. As it dries, a clean laundry-like musk emerges, leaving a trail that’s more sophisticated than its fruity opening suggests. This transformation from juicy to powdery makes it a perfumer’s secret weapon for adding dimension to citrus accords.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Nonanal provides the sparkling citrus lift in this classic, blending with lemon and rosemary to create its iconic fresh-chiseled character. The aldehyde’s waxy facet helps bridge to the floral heart.
Used sparingly here to amplify the Sicilian lemon top note, adding realism and extending the citrus impression before the apple and bamboo heart takes over.
2D Molecular Structure
SMILES: CCCCCCCCC=O
Chemistry, Properties & Perfumer Guide
The Chemistry
Nonanal is a straight-chain aldehyde (C9H18O) belonging to the fatty aldehyde family. Industrially produced via hydroformylation of 1-octene or oxidation of 1-nonanol. Unlike many fragrance aldehydes, it lacks the α,β-unsaturation that can cause sensitization. The molecule’s flexibility allows it to adopt conformations that interact with both citrus and floral olfactory receptors, explaining its dual character. Commercial grades typically contain traces of related aldehydes that can influence the odor profile.
Physical & Chemical Properties
| Boiling Point | 185-190 °C |
|---|---|
| Density | 0.827 g/cm³ |
| Flash Point | 71 °C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | Citrus accent |
| Functional Fragrance | 0.1-0.5% | Up to 1% | Cleaning product freshness |
Classic Accords
+ Jasmine + Orange Blossom = Floral freshness
Tip: Stabilize in ethanol before adding to water-based formulations to prevent aldol condensation.
Alternatives & Comparisons
Similar citrus-waxy profile but with more floral intensity and longer persistence. Use when more tenacity is needed.
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 on IFRA Transparency List.
GHS Classification
H319 Eye irritation
RIFM Assessment
RIFM assessment confirms safe use at current industry levels.
Sustainability
Synthesized from petrochemical feedstocks, though some green chemistry routes using bio-based octene are emerging. The short carbon chain makes it more readily biodegradable than larger aldehydes. Production waste streams require standard VOC controls.
Explore Nonanal
Browse essential oils and aroma compounds.
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Industry & Science Data
References
- Burdock, G.A. (2010). Fenaroli’s Handbook of Flavor Ingredients. CRC Press. ISBN 9781420090869
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Physicochemical Properties
DTXSID: DTXSID9021639
Physical Properties
| Molecular Weight | 142.242 g/mol🔬 EPA CompTox |
| Density | 0.834 g/cm^3🔬 EPA CTX |
| Boiling Point | 192.592 °C🔬 EPA CTX |
| Melting Point | 4.52 °C🔬 EPA CTX |
| Flash Point | 73.414 °C🔬 EPA CTX |
| Refractive Index | 1.418 Dimensionless📊 OPERA |
| Molar Volume | 174.415 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.456 Log10 unitless📊 OPERA |
| LogD (pH 5.5) | 3.456 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.456 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 4.59 Log10 unitless📊 OPERA |
| Water Solubility | 0.001 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0.001 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0.649 mmHg🔬 EPA CTX |
| Viscosity | 1.493 cP📊 OPERA |
| Surface Tension | 25.854 dyn/cm📊 OPERA |
| Thermal Conductivity | 145.44 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 | 7 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 43.932 cm^3/mol📊 OPERA |
| Polarizability | 17.416 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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