Thallous sulfate, Thallium sulfate
|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)
|EU classification|| T+
|R-phrases||R28, R38, R48/25,
|S-phrases||(S1/2), S13, S36/37,
LD50 (Median lethal dose)
|16 mg/kg (rat, oral)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is: / ?)(|
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, but it is more correct to add the I to specify the oxidation state, given that thallium(III) sulfate also exists and has some laboratory uses. Thallium(I) sulfate is colourless, odourless, and tasteless, but highly toxic.
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.
- 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
- International Chemical Safety Card 0336
- NIOSH Pocket Guide to Chemical Hazards
- Pesticide Data Sheet (WHO/FAO)
- Kaunas University of Technology
- University of Wisconsin-Madison Chemistry Department
- Smithsonian National Zoological Park
|Salts and the ester of the Sulfate ion|