Chemical Treatments
Chemical Safety Data
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Thymol Safety Data

Safety information from various sources regarding thymol crystals that are use for beekeeping purposes.

There is some confusion in the application of the words 'thymol' and 'thyme oil'. I use the word 'thymol' in this document to mean a common phenol that exists as a white crystalline solid at room temperature. Formula: C10H14O and molecular structure as indicated in the diagram at right.

  Molecular Structure of Thymol

Thyme oils come from several different plants, some of which contain more than one type of essential oil.

Thymol is only very slightly soluble in water, but has a strong affinity for fats and oils (Lipids). The degree of this solubility is represented by the following Compound Partition Coefficients (P or p):-

(P or p)
Ethanol0.1Higher solubility in water than fat
n-BuOH0.65Slightly more soluble in water than fat
Acetylsalicic Acid1.13Only a tiny bit more soluble in fat than in water
Benzamide - PhC(O)NH22.50Higher solubility in fat
Thymol950Very high solubility in fat

Other names by which Thymol is known:-

CAS No:- 89-83-8
EC No:- 201-944-8

Physical data

Appearance:- White crystalline solid or powder with a pungent odour.
Melting point = 49°C
Boiling point = 233°C
Molar mass = 134.24 g/mol.
Vapour pressure = 0.04 mm Hg at 20°C
Specific gravity = 0.97
Flash point = 107°C (closed cup)
Solubility:- Soluble in most Alcohols, but only slightly soluble in water


Stable. Incompatible with strong oxidizing agents, organic materials, strong bases.


Harmful if swallowed, inhaled or absorbed through the skin. Eye, skin and respiratory irritant. Eye contact may cause serious harm.

Toxicity data

ORL-RAT LD50 980 mg per kg
IVN-MUS LD50 100 mg per kg

Transport information

UN No 2810. Hazard class 6.1. Packing group III.

Environmental information

Harmful in the environment.

Personal protection

Safety glasses, adequate ventilation, avoid contact with skin or other tissue, avoid breathing fumes.

This page of data has been collected from many sources, I cannot guarantee that it is up-to-date.

Dave Cushman.

Page created 25/04/2003

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