Substance profile
Thymol
Thymol is colorless, translucent crystals or plates from ethyl acetate with an odor of thyme.
01 · Identification
What Thymol is
Thymol is colorless, translucent crystals or plates from ethyl acetate with an odor of thyme. Its molecular formula is C10H14O and its molecular weight is 150.22 g/mol. It boils at 233 °C, melts at 49.6 °C.
Under the GHS it carries the signal word Danger.
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H302 | Harmful if swallowed. |
| H314 | Causes severe skin burns and eye damage. |
| H411 | Toxic to aquatic life with long lasting effects. |
Precautionary statements: P260, P270, P273, P280, P301, P310, P312, P330, P331, P391, P501
03 · Physical and chemical properties
Thymol properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 233 °C (451.4 °F) | HSDB | |
| 233 °C (451.4 °F) | at 760 mmHg | DOE PAC | |
| 232.5 °C (450.5 °F) | range, midpoint shown | JECFA | |
| Melting point | 49.6 °C (121.3 °F) | HSDB | |
| 51.5 °C (124.7 °F) | HMDB | ||
| Density | 0.9699 g/cm³ | at 25 °C | HSDB |
| 0.972 g/cm³ | at 25 °C | DOE PAC | |
| Solubility | In water, 900 mg/L at 20 °C | at 20 °C | HSDB |
| In water: 0.098 g in 100 g at 25 °C | at 25 °C | HSDB | |
| Vapor pressure | 0.016 mmHg | at 25 °C | HSDB |
| 0.0953 mmHg | at 40 °C | HSDB | |
| 1 mmHg | at 64 °C | HSDB | |
| Flash point | 110 °C (230 °F) | HSDB | |
| Odor threshold | 86 to 790 ppb | HSDB | |
| The olfactory threshold of thymol in water is reported as 500 ug/L. | HSDB | ||
| Odor Threshold Low: 0.001 [ppm] | Haz-Map |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Source notes
Further notes on Thymol
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Solubility
1 g dissolves in about 1000 mL water, 1 mL alcohol, 0.7 mL chloroform, 1.5 mL ether, 1.7 mL olive oil at 25 °C; soluble in glacial acetic acids, oils, fixed alkali hydroxide
Source: HSDB
05 · Handling and storage
Storing and handling Thymol
Storage conditions
Conditions for safe storage, including any incompatibilities: Keep container tightly closed in a dry and well-ventilated place.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Incompatible with acetanilide.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Thymol in the storage compatibility matrix →