Substance profile
Guaiacol
Guaiacol is faintly yellowish, limpid, oily liquid or yellow crystals with an aromatic odor.
01 · Identification
What Guaiacol is
Guaiacol is faintly yellowish, limpid, oily liquid or yellow crystals with an aromatic odor. Its molecular formula is C7H8O2 and its molecular weight is 124.14 g/mol. It boils at 205 °C, melts at 32 °C, is soluble in water.
Under the GHS it carries the signal word Warning.
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. |
| H315 | Causes skin irritation. |
| H319 | Causes serious eye irritation. |
Precautionary statements: P264, P270, P280, P301, P302, P305, P312, P313, P330, P332, P337, P338, P352
03 · Physical and chemical properties
Guaiacol 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 | 205 °C (401 °F) | HSDB | |
| 205 °C (401 °F) | range, midpoint shown, at 760 mmHg | CAMEO | |
| 204.5 °C (400.1 °F) | range, midpoint shown | JECFA | |
| Melting point | 32 °C (89.6 °F) | HSDB | |
| 28 °C (82.4 °F) | CAMEO | ||
| Density | 1.13 g/cm³ | at 21.39 °C | CAMEO |
| 1.1287 g/cm³ | at 21 °C | HSDB | |
| 1.1345 g/cm³ | range, midpoint shown | JECFA | |
| Solubility | Soluble in carbon tetrachloride | HSDB | |
| Miscible with alcohol, chloroform, ether, oils, glacial acetic acid; slightly soluble in petroleum ether; soluble in sodium hydroxide solution | HSDB | ||
| 1 g is soluble in 60-70 mL water, in 1 mL glycerol | o-methoxyphenol | HSDB | |
| Vapor pressure | 0.103 mmHg | HSDB | |
| 5 mmHg | at 78.89 °C | CAMEO | |
| 0.1 mmHg | Haz-Map | ||
| Flash point | 82.22 °C (180 °F) | HSDB | |
| Vapor density | 4.27 (air = 1) | CAMEO | |
| Odor threshold | Odor threshold = 0.001-0.002 ppm (recognition) | Haz-Map |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Guaiacol
Storage conditions
Store in tight, light-resistant container as defined in the USP-NF. This material should be handled and stored per label instructions to ensure product integrity.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
O-METHOXYPHENOL may react with oxidizing materials. It forms salts readily with bases. (NTP, 1992)
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Guaiacol in the storage compatibility matrix →