Hafnium

  • Hafnium powder, dry
Formula Hf
Structure
Description Hafnium powder, dry, is a grayish metallic colored powder.
Uses Used for reactor control rods, in gas-filled & incandescent lamps, scavenger for oxygen & nitrogen.

Registry Numbers and Inventories.
CAS 7440-58-6
EC (EINECS/ELINCS) 231-166-4
RTECS MG4600000
RTECS class Other
UN (DOT) 2545
Merck 12,4618
Beilstein/Gmelin 16293 (G)
Swiss Giftliste 1 G-4689
Canada DSL/NDSL DSL
US TSCA Listed
Korea ECL Listed

Properties.
Formula Hf
Formula mass 178.49
Melting point, °C 2224
Boiling point, °C 5400
Density 13.31 g/cm3 (20 C)
Solubility in water Insoluble
Viscosity 0.052 P (2231 C)
Thermal expansion 6.01E-5/K

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 Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Apply approriate foam to diminish vapor and fire hazard. Water spill: Use natural barriers or oil spill control booms to limit spill travel.
Stability May explosively decompose on shock, friction, or concussion. May explode on heating. The substance may spontaneously ignite on contact with air and at higher temperatures.
Incompatibilities Reacts exothermically with compounds having active hydrogen atoms (such as acids and water) to form flammable hydrogen gas and caustic products May react with azo/diazo compounds to form explosive products Can react explosively with oxidizing materials.

Fire.
Fire fighting Use suitable dry powder. Use dry chemical or carbon dioxide. Use water only if flooding quantities are available.
Fire potential Flammable/combustible material.
Hazards May react violently or explosively on contact with water. Some are transported in flammable liquids. May be ignited by friction, heat, sparks or flames. Some of these materials will burn with intense heat. Dusts or fumes may form explosive mixtures in air. Containers may explode when heated. May re-ignite after fire is extinguished.
Combustion products Toxic gases and vapors (such as hydrogen chloride and carbon monoxide) may be released in a fire involving hafnium.

Health.
Exposure limit(s) OSHA PEL: TWA 0.5 mg/m3 *Note: The PEL also applies to other Hf cmpds (as Hf). NIOSH REL: TWA 0.5 mg/m3 *Note: The REL also applies to other Hf cmpds (as Hf). NIOSH IDLH: 50 mg/m3 (as Hf)
Poison_Class -
Exposure effects
   Ingestion See Inhalation.
   Inhalation Substance or decomposition products may cause severe injury or death.
   Skin Irritation of unabraded skin occurs with direct contact.
   Eyes Eye irritation may be seen.

First aid		  
   Ingestion Seek medical assistance.
   Inhalation Move victim to fresh air. Apply artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult.
   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 2545
Response guide 135
Hazard class 4.2
Packing Group I; II; III  
Std. Transport # 4916712