Thallium

Product Name: Thallium
EINECS: 231-138-1
Molecular Formula: Tl
Molecular Weight: 204.38 g/mol
Melting Point: 303 °C(lit.)
Boiling Point: 1457 °C(lit.)
Density: 1.01 g/mL at 25 °C
Form: Rod
Appreance: silver-grey metal
Merck: 13,9327
Stability: stable
Water Solubility: insoluble in water
Product Categories: Metals; Inorganics; Metal and Ceramic Science; Thallium ; Catalysis and Inorganic Chemistry; Chemical Synthesis
Mol File: 7440-28-0.mol
Storage: under water
Synonyms of Thallium (CAS NO.7440-28-0): Ramor ; Thallium , elemental ; Thallium metal ; Thallium metallo-organic standard ; Thallium single element plasma standard ; Thallium single element standard ; Thallium standard ; Thallium standard solution

 Thallium (CAS NO.7440-28-0) was discovered by flame spectroscopy in 1862. Because of it's bright green spectral emission lines, people called it thallium . After the publication of the improved method of flame spectroscopy by Robert Bunsen and Gustav Kirchhoff and the discovery of caesium and rubidium in the years 1859 to 1860 flame spectroscopy became an approved method to determine the composition of minerals and chemical products. William Crookes and Claude-Auguste Lamy both started to use the new method. William Crookes used it to make spectroscopic determinations for tellurium on selenium compounds deposited in the lead chamber of a sulfuric acid production plant near Tilkerode in the Harz mountains. He had obtained the samples for his research on selenium cyanide from August Hofmann years earlier. By 1862 Crookes was able to isolate small quantities of the element and determine the properties of a few compounds. Claude-Auguste Lamy used a similar spectrometer to Crookes' to determine the composition of a selenium-containing substance which was deposited during the production of sulfuric acid from pyrite. He also noticed the new green line in the spectra and concluded that a new element was present. Lamy had received this material from the sulfuric acid plant of his friend Fréd Kuhlmann and this by-product was available in large quantities. Lamy started to isolate the new element from that source. The fact that Lamy was able to work ample quantities of thallium enabled him to determine the properties of several compounds and in addition he prepared a small ingot of metallic thallium which he prepared by remelting thallium he had obtained by electrolysis of thallium salts.

As both scientists discovered thallium independently, especially the isolation of the metallic thallium was done by Lamy, Crookes tried to secure his priority on the work. Lamy was awarded a medal at the International Exhibition in London 1862: For the discovery of a new and abundant source of thallium and after heavy protest Crookes also received a medal: thallium, for the discovery of the new element. The controversy between both scientists continued through 1862 and 1863. Most of the discussion ended after Crookes was elected Fellow of the Royal Society in June 1863.

 Thallium (CAS NO.7440-28-0) is used to refine and  make alloy and chemical reagents. It also can used in industry of instrumentation and semiconductor doping.

 Potassium cyanide --> Polyurethane foam plastic --> Zinc-copper couple --> Thallium(i) sulfate --> Thallium(i) carbonate

 Thallium (CAS NO.7440-28-0) and its compounds are on the Community Right-To-Know List. Reported in EPA TSCA Inventory.

human poison by unspecified route. human systemic effects by ingestion: nerve or sheath structural changes, extra-ocular muscle changes, sweating, and other effects. flammable in the form of dust when exposed to heat or flame. violent reaction with f₂. when heated to decomposition it emits toxic fumes of tl. used as a rodenticide and fungicide, and in lenses and prisms, in high-density liquids. see also thallium compounds and powdered metals.
analytical methods:
for occupational chemical analysis use niosh: elements (icp) 7300.
hazard codes: xn, t+
risk statements: 26/28-33-53-36/37/38-20/22-36/38 
r26/28: very toxic by inhalation and if swallowed 
r33: danger of cumulative effects 
r53: may cause long-term adverse effects in the aquatic environment
r36/37/38: irritating to eyes, respiratory system and skin 
r20/22: harmful by inhalation and if swallowed 
r36/38: irritating to eyes and skin
safety statements: 13-28-45-61-36/37/39-36/37-26 
s13: keep away from food, drink and animal foodstuffs
s28: after contact with skin, wash immediately with plenty of soap-suds 
s45: in case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible) 
s61: avoid release to the environment. refer to special instructions / safety data sheets 
s36/37/39: wear suitable protective clothing, gloves and eye/face protection
s36/37: wear suitable protective clothing and gloves 
s26: in case of contact with eyes, rinse immediately with plenty of water and seek medical advice
ridadr: un 3288 6.1/pg 2
wgk germany: 3
rtecs: xg3425000
f: 23
hazardclass: 6.1
packinggroup: ii 

OSHA PEL: TWA 0.1 mg(Tl)/m³ (skin)
ACGIH TLV: TWA 0.1 mg(Tl)/m³ (skin)
DFG MAK: 0.1 mg/m³

For occupational chemical analysis use NIOSH: Elements (ICP) 7300.

 Thallium (CAS NO.7440-28-0) is very soft and malleable and can be cut with a knife at room temperature.But it may tarnish quickly in air.It also can emit toxic fumes when heated. The Thallium (CAS NO.7440-28-0) is a reducing agent. Reacts so vigorously with fluorine that the metal becomes incandescent. It is high toxic.So the storage environment should be ventilate, low-temperature and dry.