Thallium(I) sulfate (Tl2SO4) or thallous sulfate is the sulfate salt of thallium in the common +1 oxidation state, as indicated by the Roman numeral I. It is often referred to as simply thallium sulfate.
Thallous sulfate, Thallium sulfate
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||504.83 g/mol|
|Appearance||white prisms or dense white powder|
|Melting point||632 °C (1,170 °F; 905 K)|
|2.70 g/100 mL (0 °C) |
4.87 g/100 mL (20 °C)
18.45 g/100 mL (100 °C)
Refractive index (nD)
|R-phrases (outdated)||R28, R38, R48/25,|
|S-phrases (outdated)||(S1/2), S13, S36/37,|
|NFPA 704 (fire diamond)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|16 mg/kg (rat, oral)|
23.5 mg/kg (mouse, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
During the last two centuries, Tl2SO4 had been used for various medical treatments but was abandoned. In the later 1900s it found use mainly for rodenticides. These applications were prohibited in 1975 in the US due to the nonselective nature of its toxicity. Thallium(I) sulfate inhibits the growth of plants by preventing germination. Tl2SO4 is mostly used today as a source of Tl+ in the research laboratory. It is a precursor to thallium(I) sulfide (Tl2S), which exhibits high electrical conductivity when exposed to infrared light.
Thallium(I) sulfate is soluble in water and its toxic effects are derived from the thallium(I) cation. The mean lethal dose of thallium(I) sulfate for an adult is about 1 gram. Since thallium(I) sulfate is a simple powder with indistinctive properties, it can easily be mistaken for more innocuous chemicals. It can enter the body by ingestion, inhalation, or through contact with the skin. The thallium(I) cation is very similar to potassium and sodium cations, which are essential for life. After the thallium ion enters the cell, many of the processes that transport potassium and sodium are disrupted. Due to its poisonous nature, many western countries have banned the use of thallium(I) sulfate in products for home use and many companies have also stopped using this compound.
A dosage in excess of 500 mg is reported as fatal. Thallium(I) sulfate, after entering the body, concentrates itself in the kidneys, liver, brain, and other tissues in the body.
- "Thallium (soluble compounds, as Tl)". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- Micke, Heinrich; Wolf, Hans Uwe (2000). "Thallium and Thallium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a26_607.
- World Health Organization Pesticide Data Sheet no.10 (1975)
- Mendelssohn, H. Ecological effects of chemical control of rodents and jackals in Israel at LPO Mission Rapaces