Thorium

Formula
Th
Structure
Description
Silver to grayish radioactive metal. Twice as dense as lead.
Uses
Because the thorium atom density is higher in thorium metal than in any thorium compound, metal is the preferred form of thorium where the highest nuclear reactivity or highest density is wanted.

Registry Numbers and Inventories.
CAS
7440-29-1
EC (EINECS/ELINCS)
231-139-7
RTECS
XO6400000
UN (DOT)
2975
Merck
12,9514
Beilstein/Gmelin
16314 (G)
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed

Properties.
Formula
Th
Formula mass
232.04
Melting point, °C
1120 - 1160
Boiling point, °C
1730 - 2230
Vapor pressure, mmHg
0.1 (2431 C)
Density
12.3 g/cm3
Solubility in water
Insouluble
Thermal expansion
0.0000125/K
Heat of fusion
20.93 kJ/mol
Heat of vaporization
598 kj/mole

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
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Contact the local, state, or Department Of Energy Radiological Response Team. Do not use water. Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Keep material dry. Do not attempt to sweep up dry material.
Stability
When pure it is air-stable.
Incompatibilities
React vigorously with incandescence.

Fire.
Autoignition, °C
130
Fire fighting
Contact the local, state, or Department Of Energy Radiological Response Team. Do not use water. Use graphite, soda ash, powdered sodium chloride, or suitable dry powder.
Fire potential
May burn but does not ignite readily.
Hazards
Some of these materials may burn, but most do not ignite readily. Uranium and Thorium metal cuttings may ignite spontaneously if exposed to air. Extremely flammable; will ignite itself if exposed to air. Burns rapidly, releasing dense, white, irritating fumes. Substance may be transported in a molten form. May re-ignite after fire is extinguished. Nitrates are oxidizers and may ignite other combustibles. May explode from heat or contamination. Some may burn rapidly. Some will react explosively with hydrocarbons (fuels). May ignite combustibles (wood, paper, oil, clothing, etc.). Containers may explode when heated. Runoff may create fire or explosion hazard.

Health.
Exposure limit(s)
OEL_Russia: 0.05mg/m3
Carcinogin
I-1
Exposure effects
Supralethal radiation doses may result in headache, acute brain syndrome, alterations in mental status including coma, and (rarely) seizures within minutes of exposure. Prenatal ionizing radiation exposure may cause congenital anomalies, mental retardation, and an increased incidence of seizures.
   Ingestion
Gastrointestinal syndrome (nausea/vomiting) commonly occurs after doses of 9 to 20 gy and may occur following doses as low as 5 gy. Initial vomiting is followed by persistent diarrhea, which may be bloody.
   Inhalation
Pulmonary radiation injury may result in radiation pneumonitis and radiation pulmonary fibrosis.
   Skin
Thermonuclear burns may occur. If erythema is produced by a penetrating radiation, serious systemic injury is certain.
   Eyes
See Inhalation.

First aid
 
   Ingestion
Medical problems take priority over radiological concerns. Use first aid treatment according to the nature of the injury. Do not delay care and transport of a seriously injured person.
   Inhalation
Monitoring exposed patients for contamination and decontamination procedures should be started. All personnel involved in handling patients should wear disposable protective clothing. The patient should be completely undressed and given a soap and water bath or shower (if the patient's condition permits and if the facility exists). Acute inhalation of radionuclides presents some difficult problems.
   Skin
Immediately flush with running water for at least 20 minutes. See Ingestion.
   Eyes
Immediately flush with running water for at least 20 minutes. See Ingestion.

Transport.
UN number
2975
Response guide
Hazard class
7
Std. Transport #
4929112