Substance profile
Thallium
Thallium is a bluish-white, very soft, inelastic, easily fusible, heavy metal.
01 · Identification
What Thallium is
Thallium is a bluish-white, very soft, inelastic, easily fusible, heavy metal. It boils at 1473 °C, melts at 304 °C, is practically insoluble in water.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
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 |
|---|---|
| H330 | Fatal if inhaled. |
| H300 | Fatal if swallowed. |
| H373 | May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H413 | May cause long lasting harmful effects to aquatic life. |
Precautionary statements: P260, P270, P271, P273, P301, P304, P310, P314, P330, P501
03 · Physical and chemical properties
Thallium 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 | 1473 °C (2683.4 °F) | HSDB | |
| 1457 °C (2654.6 °F) | ICSC | ||
| 1473 °C (2683.4 °F) | at 760 mmHg | DOE PAC | |
| Melting point | 304 °C (579.2 °F) | HSDB | |
| 150 °C (302 °F) | OSHA | ||
| Density | 11.8 g/cm³ | HSDB | |
| 11.9 g/cm³ | ICSC | ||
| 1.1 g/cm³ | OSHA | ||
| Solubility | Insoluble in water; reacts with acid | HSDB | |
| Dissolves in warm dilute mineral acids, forming thallous (+1) salts and liberating hydrogen gas | HSDB | ||
| Vapor pressure | 1.193e-7 mmHg | HSDB | |
| 0.0075 mmHg | at 609 °C | HSDB | |
| depends upon the specific compound | OSHA | ||
| Flash point | 215.56 °C (420 °F) | OSHA |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Thallium
Storage conditions
Store separated from strong acids, fluorine, other halogens food and feedstuffs
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
FLUORINE ACTS SO VIGOROUSLY ON THALLIUM THAT THE METAL BECOMES INCANDESCENT.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
THALLIUM is a reducing agent. Reacts so vigorously with fluorine that the metal becomes incandescent [Mellor 5:421 1946-47].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Thallium in the storage compatibility matrix →