Thallium

  • Ranir
Formula
Tl
Structure
Description
Bluish-white soft malleable metal or gray granules.
Uses
In semiconductor research. Alloyed with mercury for switches and closures which operate at subzero temperatures.

Registry Numbers and Inventories.
CAS
7440-28-0
EC (EINECS/ELINCS)
231-138-1
EC Index Number
081-001-00-3
EC Class
Very toxic; Danger of cumulative effects; Dangerous for the Environment
RTECS
XG3425000
RTECS class
Human Data
UN (DOT)
1707
Merck
12,9391
Beilstein/Gmelin
16308 (G)
RCRA
U214; U215; U216; U217; P113; P115
Swiss Giftliste 1
G-6708
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Korea ECL
Listed

Properties.
Formula
Tl
Formula mass
204.38
Melting point, °C
301
Boiling point, °C
1457
Density
11.85 g/cm3 (20 C)
Solubility in water
Insoluble
Thermal expansion
0.000128/K (302 C)
Heat of fusion
4.3 kJ/mol
Heat of vaporization
175.3 kJ/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Employees should be provided with and required to use impervious clothing, gloves, face shields (eight-inch minimum), and other appropriate protective clothing necessary to prevent skin contact with soluble thallium compounds where skin contact may occur. Employees should be provided with and required to use dust and splash proof safety goggles where soluble thallium compounds may contact the eyes. Thallium and thallium compounds.
Respirators
Use NIOSH/MSHA approved respirator appropriate for exposure of concern.
Small spills/leaks
Evacuate area and ventilate. Wear protective equipment. If required, use an inert absrobent. Sweep up and place in an appropriate container for disposal. Wash contaminated surfaces.
Stability
No data.
Incompatibilities
Strong oxidizing agents.
Decomposition
When heated to decomposition, emits toxic fumes of thallium.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use agent most appropriate to extinguish fire.
Fire potential
Moderate as dust exposed to heat or flame.

Health.
Exposure limit(s)
TLV (as Tl (soluble compounds)): ppm; 0.1 mg/m3 (as TWA) (skin) (ACGIH 994-1995). OSHA PEL: TWA 0.1 mg/m3 skin NIOSH REL: TWA 0.1 mg/m3 skin NIOSH IDLH: 15 mg/m3 (as Tl)
Poison_Class
1
Exposure effects
Early effects may include paresthesias, myalgias, peripheral burning sensation, headache, cranial nerve palsies, seizures, delirium, coma, peripheral neuropathy, severe pain, and muscle weakness/atrophy. Protracted cases may develop ataxia, choreiform movements, dementia, depression and psychosis. Neurological damage resolves slowly and may be permanent.
   Ingestion
Gi symptoms may include anorexia, salivation, diarrhea, constipation, stomatitis, severe paroxysmal abdominal pain, vomiting, and hemorrhage.
   Inhalation
Respiratory failure or ards may develop in severe cases.
   Skin
Severe acne, hair pigmentation, mees lines, and alopecia may occur.
   Eyes
Optic neuritis, decreased visual acuity and impaired color vision may occur.

First aid
 
   Ingestion
Administer charcoal as a slurry (240 ml water/30 g charcoal). Usual dose: 25 to 100 g in adults/adolescents. Consider after ingestion of a potentially life-threatening amount of poison if it can be performed soon after ingestion (generally within 1 hour). Monitor cardiac, renal and hepatic function. Prussian blue: although preferred in europe, prussian blue is not commercially available in the us and is not fda-approved. Contraindications: diethylthiocarbamate has been reported to result in dangerous redistribution of thallium to the cns and is contraindicated. Potassium chloride - has been reported to enhance elimination with equivocal results; can acutely worsen neurological symptoms.
   Inhalation
If symptoms develop, move individual away from exposure and into fresh air. If symptoms persist, seek medical attention. If breathing is difficult, administer oxygen. Keep person warm and quiet; seek immediate medical attention.
   Skin
Remove contaminated clothing and wash exposed area thoroughly with soap and water. A physician should examine the area if irritation or pain persists.
   Eyes
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.

Transport.
UN number
1707
Response guide
USCG CHRIS Code
TLX