Thymol (CAS 89-83-8) — Spicy Top Note Fragrance Ingredient
Thymol
CAS 89-83-8
What Is Thymol?
Thymol is a naturally occurring phenol found in thyme oil and other essential oils. People encounter it in mouthwashes, cough drops, and some perfumes for its medicinal, herbaceous scent. This aromatic compound matters because it provides both functional antimicrobial properties and a distinctive herbal character to fragrances and flavorings.
Safety Profile
USE WITH AWARENESS
What Does Thymol Smell Like?
Thymol bursts with an intensely medicinal, herbaceous aroma reminiscent of crushed thyme leaves and antiseptic tinctures. The sharp phenolic top note carries a warm, spicy undertone that evolves into a dry, woody-herbal heart. In dry-down, it leaves a clean, slightly camphoraceous trail with hints of leather and tobacco. The scent profile is assertive yet refined – like walking through a sun-baked Mediterranean herb garden with pockets of earthy warmth.
Scent Profile
In Famous Fragrances
Fragrance associations may not reflect actual formulations.
Thymol provides the aromatic backbone in this citrus-aromatic classic, contributing a crisp herbal contrast to the bright citrus top notes and grounding the composition with its medicinal warmth.
Used sparingly here to enhance the anise-lavender opening with thymol’s phenolic sharpness, adding complexity to this iconic fougère structure.
2D Molecular Structure
SMILES: CC(C)C1=CC=C(C)C=C1O
Chemistry, Properties & Perfumer Guide
The Chemistry
Thymol (C10H14O) is a monoterpene phenol, structurally related to carvacrol through the position of its hydroxyl group. It occurs naturally in thyme (Thymus vulgaris), oregano, and other Lamiaceae family plants. Industrially produced via alkylation of m-cresol with propylene or isolated from essential oils. The para-methyl group and ortho-hydroxyl configuration create its distinctive antimicrobial properties and aromatic character. No chiral centers but exhibits polymorphism in crystalline form.
Physical & Chemical Properties
| Boiling Point | 233 °C |
|---|---|
| Melting Point | 51.5 °C |
| Density | 0.969 g/cm³ |
| Flash Point | 102 °C |
Perfumer Guide
| Application | Typical % | Range | Notes |
|---|---|---|---|
| Fine Fragrance | 0.1-0.5% | Up to 1% | Used as herbal modifier |
| Functional Fragrance | 0.5-2% | Up to 3% | For antimicrobial effects |
Classic Accords
+ Oakmoss + Patchouli = Dark Fougère
Tip: Balance thymol’s sharpness with sweet vanillic or balsamic notes to prevent excessive medicinal character.
Alternatives & Comparisons
Structural isomer with similar properties but slightly sweeter, less medicinal odor profile. Preferred when a softer phenolic character is desired.
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
Not restricted under current IFRA standards (Amendment 49).
GHS Classification
H319 Eye irritation
H335 May cause respiratory irritation
RIFM Assessment
RIFM assessment confirms safe use at current industry levels with proper precautions for skin contact.
Sustainability
Most commercial thymol is synthesized from petrochemical precursors, though natural extraction from thyme oil remains viable. Synthetic production avoids agricultural land use but carries higher carbon footprint. Biocatalytic production methods are under development to improve sustainability.
Explore Thymol
Browse essential oils and aroma compounds.
Affiliate disclosure: we may earn a small commission at no extra cost to you.
Industry & Science Data
References
- PubChem Compound Summary for Thymol CID 6989
Data: PubChem (NIH), PubMed, RIFM, IFRA. Last reviewed: Mar 2026.
Physicochemical Properties
DTXSID: DTXSID6034972
Physical Properties
| Molecular Weight | 150.221 g/mol🔬 EPA CompTox |
| Density | 0.97 g/cm^3🔬 EPA CTX |
| Boiling Point | 232.831 °C🔬 EPA CTX |
| Melting Point | 50.216 °C🔬 EPA CTX |
| Flash Point | 105.014 °C🔬 EPA CTX |
| Refractive Index | 1.523 Dimensionless📊 OPERA |
| Molar Volume | 154.211 cm^3/mol📊 OPERA |
Partition & Solubility
| LogP (Octanol-Water) | 3.3 Log10 unitless🔬 EPA CTX |
| LogD (pH 5.5) | 3.192 Log10 unitless📊 OPERA |
| LogD (pH 7.4) | 3.191 Log10 unitless📊 OPERA |
| LogKoa (Octanol-Air) | 7.59 Log10 unitless📊 OPERA |
| Water Solubility | 0.006 mol/L🔬 EPA CTX |
| Henry's Law Constant | 0 atm-m3/mole🔬 EPA CTX |
Transport Properties
| Vapor Pressure | 0.012 mmHg🔬 EPA CTX |
| Viscosity | 8.566 cP📊 OPERA |
| Surface Tension | 34.439 dyn/cm📊 OPERA |
| Thermal Conductivity | 135.017 mW/(m*K)📊 OPERA |
Molecular Descriptors
| Topological Polar Surface Area | 20.23 Ų💻 Computed |
| H-Bond Donors | 1 count💻 Computed |
| H-Bond Acceptors | 1 count💻 Computed |
| Rotatable Bonds | 1 count💻 Computed |
| Aromatic Rings | 1 count💻 Computed |
| Molar Refractivity | 47.144 cm^3/mol📊 OPERA |
| Polarizability | 18.689 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.
