Lyral (CAS 31906-04-4) — floral heart Note Fragrance Ingredient
Lyral
CAS 31906-04-4
What Is Lyral?
Lyral is a synthetic fragrance ingredient commonly found in perfumes, soaps, and household products. It creates a fresh, lily-of-the-valley (muguet) scent that’s widely used in floral compositions. This molecule matters because it offers a clean, modern floralcy that’s more stable than natural muguet extracts, making scents last longer while maintaining a natural-smelling profile.
Safety Profile
USE WITH AWARENESSWhat Does Lyral Smell Like?
Lyral unfolds as a dewy, green floral burst reminiscent of lily-of-the-valley at dawn. The top note carries a crisp, almost metallic freshness that quickly softens into a rounded floral heart with waxy undertones. As it dries down, it reveals a clean, soapy character with subtle cucumber-like nuances. The overall effect is like walking through a sunlit garden after spring rain—bright yet tender, with remarkable tenacity for a floral note.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Lyral provides the luminous muguet core that makes Pleasures so instantly recognizable—a modern interpretation of florals that feels both clean and sophisticated.
Used here to create the watery floral illusion, Lyral’s crispness blends with lotus and melon for that iconic ‘water flower’ effect.
Lyral adds a dewy floral counterpoint to Dune’s arid amber accord, creating tension between desert heat and oasis freshness.
The synthetic purity of Lyral helps achieve the fragrance’s ‘white petals on skin’ concept—floral without being powdery or vintage.
Lyral’s green floralcy cuts through the citrus opening, bridging to the woody base while maintaining a clean, contemporary feel.
2D Molecular Structure
SMILES: CC(C)(O)CCCC1=CCC(CC1)C=O
Chemistry, Properties & Perfumer Guide
The Chemistry
Lyral (chemical name: 4-(4-hydroxy-4-methylpentyl)cyclohex-3-enecarbaldehyde) is an alicyclic aldehyde belonging to the family of lily-of-the-valley odorants. It’s synthesized via hydroformylation of myrcene derivatives followed by aldol condensation. The molecule’s conformational flexibility allows it to bind effectively to olfactory receptors. While purely synthetic in commerce, structural analogs occur naturally in some plants. The aldehyde group is crucial for its floral character, while the cyclohexene ring contributes freshness and diffusion.
Physical & Chemical Properties
| Molecular Weight | 178.14 g/mol |
|---|---|
| XLogP | -0.5 |
| Topological Polar Surface Area | 93.1 Ų |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.5-2% | Up to 5% | IFRA 49 restricts to 0.6% in leave-on products |
| Soap | 0.1-0.5% | Up to 1% | Stable in alkaline media |
| Shampoo | 0.05-0.2% | Up to 0.5% | Good water solubility |
| Laundry | 0.01-0.1% | Up to 0.3% | Provides fabric freshness |
Classic Accords
Tip: Use with antioxidants to prevent aldehyde degradation in alkaline formulations.
Alternatives & Comparisons
Softer, more citrusy muguet note with better IFRA compliance but weaker tenacity.
More metallic floral with similar diffusion but lacks Lyral’s green freshness.
Now banned in EU, was the closest structural analog with nearly identical odor profile.
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
Restricted under IFRA 49th Amendment: Maximum 0.6% in leave-on products, 1.2% in rinse-off due to sensitization potential (Category B).
EU Allergen Declaration
Must be declared when present at ≥0.001% in leave-on or ≥0.01% in rinse-off products (Annex III of EU Cosmetics Regulation).
GHS Classification
RIFM Assessment
RIFM assessment confirms skin sensitization potential at high doses but deems it safe at current IFRA limits.
Sustainability
As a synthetic molecule, Lyral’s production doesn’t deplete natural resources but requires petrochemical feedstocks. Its high potency means small quantities are needed, reducing environmental load compared to some naturals. However, its sensitization potential has led to reduced usage in favor of newer, safer muguet alternatives.
Explore Lyral
Browse essential oils and aroma compounds.
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References
- PubChem Compound Summary for CID 36052 PubChem Lyral
- IFRA Standards Library, 49th Amendment IFRA 49
- Sell CS (2006). The Chemistry of Fragrances. RSC Publishing.
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Report a data errorIngredient Data Sheet
CAS 31906-04-4Physical Properties
| Molecular Weight | 210.31 g/mol🔬 PubChem |
| LogP (Octanol-Water) | 1.7🔬 PubChem |
| Boiling Point | 274 °C🔬 EPA CompTox |
| Vapor Pressure | 0 mmHg @ 25°C📊 OPERA |
| Flash Point | 135.1 °C🔬 EPA CompTox |
| log Kp (skin permeability) | -2.776💻 Calculated |
| SMILES | CC(C)(CCCC1=CCC(CC1)C=O)O🔬 PubChem |
Volatility & Performance
| Fragrance Note | Base💻 Calculated |
| Volatility Class | Very slow💻 Calculated |
| Persistence Score | 7 / 5💻 Calculated |
Odor & Flavor
| Primary Descriptors | aldehydicfloralwoody• leffingwell |
| Functional Groups | aldehydealcoholalkene💻 RDKit |
| “Fruity odor, but less animal than that of o the n-Valerate. 4-39; 5-238 ; 809: gamma-CYCLO HOMOGERANIOL 1,1-Dimethyl-2 (bera-hydroxyethy l)-3-me- desirable “maritime” odor of Ambregris. The “seashore” type odor has often been a 2-(6,6-Dimethyl-2-methy lene)-cyclohexyl- challenge to the perfumer who wanted to ethanol.”📖 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: DTXSID1027970
Physical Properties
| Molecular Weight | 210.317 g/mol🔬 EPA CompTox |
| Density | 0.978 g/cm^3📊 OPERA |
| Boiling Point | 294.51 °C📊 OPERA |
| Melting Point | -30 °C🔬 EPA CTX |
| Flash Point | 128.247 °C📊 OPERA |
| Refractive Index | 1.528 Dimensionless📊 OPERA |
| Molar Volume | 205.469 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 2.1 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 2.975 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 2.92 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 9.3 Log10 unitless📊 OPERA |
| Water Solubility | 0.029 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole📊 OPERA |
Transport Properties
| Vapor Pressure | 0 mmHg📊 OPERA |
| Viscosity | 16.43 cP📊 OPERA |
| Surface Tension | 36.699 dyn/cm📊 OPERA |
| Thermal Conductivity | 142.466 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 37.3 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 2 count💻 Computed |
| Rotatable Bonds | 5 count💻 Computed |
| Aromatic Rings | 0 count💻 Computed |
| Molar Refractivity | 63.238 cm^3/mol📊 OPERA |
| Polarizability | 25.069 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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