Thymol
[CAS# 89-83-8]

Identification

• Classification: API >> Synthetic anti-infective drugs >> Disinfectant antiseptic
• Name: Thymol
• Synonyms: 2-Isopropyl-5-methyl phenol; 5-Methyl-2-(1-methylethyl)phenol
• Molecular Formula: C₁₀H₁₄O
• Molecular Weight: 150.22
• CAS Registry Number: 89-83-8
• EC Number: 201-944-8
• FEMA: 3066
• SMILES: CC1=CC(=C(C=C1)C(C)C)O

Properties

• Density: 0.965 g/mL (Expl.)
• Melting point: 48-51 °C (Expl.)
• Index of Refraction: 1.5277 (Expl.)
• Boiling point: 232 °C (Expl.)
• Flash point: 101 °C (Expl.)
• Water solubility: 0.1 g/100 mL (20 °C) (Expl.)

Safety Data

• Hazard Symbols: GHS05;GHS07;GHS09 Danger
• Risk Statements: H302-H314-H411
• Safety Statements: P260-P264-P264+P265-P270-P273-P280-P301+P317-P301+P330+P331-P302+P361+P354-P304+P340-P305+P354+P338-P316-P317-P321-P330-P363-P391-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin corrosion	Skin Corr.	1B	H314
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1C	H314

• Transport Information: UN 3261

Discovery and Applications

Thymol, chemically known as 2-isopropyl-5-methylphenol, is a natural monoterpenoid phenol predominantly found in thyme (Thymus vulgaris) and other aromatic herbs. It is characterized by a pleasant aromatic odor and strong antiseptic properties. Thymol has been utilized since ancient times for its medicinal and aromatic properties. The ancient Egyptians used thyme for embalming, while the ancient Greeks used it in their baths and burned it as incense in their temples, believing it was a source of courage. The spread of thyme throughout Europe was thought to be due to the Romans, as they used it to purify their rooms and to "give an aromatic flavour to cheese and liqueurs". In the European Middle Ages, the herb was placed beneath pillows to aid sleep and ward off nightmares. In this period, women also often gave knights and warriors gifts that included thyme leaves, because it was believed to bring courage to the bearer. Thyme was also used as incense and placed on coffins during funerals, because it was supposed to ensure passage into the next life.

In the pharmaceutical industry, thymol is utilized for its cooling and analgesic properties. It is incorporated into topical formulations such as ointments, creams, and balms to provide relief from minor aches and pains, including muscle cramps and sprains. Additionally, thymol is used in oral care products like toothpaste and mouthwash for its refreshing taste and potential antibacterial effects.

Beyond its pharmaceutical applications, thymol is employed in the food and beverage industry as a flavoring agent, imparting a minty taste to various products. It is also used in the cosmetic industry for its fragrance and cooling effects in products such as shampoos, conditioners, and lotions. Furthermore, thymol has been explored in research for its potential to enhance the extraction of bioactive compounds from natural sources, such as capsaicinoids and carotenoids from Capsicum frutescens.

In summary, thymol is a versatile compound with a long history of use across various industries, including pharmaceuticals, food and beverages, and cosmetics. Its cooling, analgesic, and aromatic properties continue to make it a valuable ingredient in numerous applications.

References

2025. Effect of high amylose starch on the incorporation of thymol into electrospun pullulan nanofibers. Food Chemistry.
DOI: 10.1016/j.foodchem.2024.142070

2025. Protecting anthocyanins of postharvest blueberries through konjac glucomannan/low-acyl gellan gum coatings contained thymol microcapsule during low-temperature storage. Food Chemistry.
DOI: 10.1016/j.foodchem.2024.141347

2009. Powder NMR crystallography of thymol. Physical Chemistry Chemical Physics, 11(14).
DOI: 10.1039/b821018g