Hafnium

178.49

179.946503

231-166-4

X71938L1DO

0847

2545|1326

DTXSID8064698

Gray crystals|Highly lustrous metal of hexagonal crystal structure|Hard, shiny, ductile metal with a color very similar to that of stainless steel ... hafnium sponge metal is a dull powder gray|Highly lustrous, ductile, grayish solid.|Crystallizes in a...cubic system which transforms to a hexagonal close-packed system below 2033 K.

38220000

0

0.00000

Silver-gray wire

13.31 g/cm³ @ Temp: 20 °C

2227 °C

4602 °C

soluble HF; slowly reacts with conc H2SO4, aqua regia [KIR80]

Storage: Store hafnium in a fireproof area. Keep it separate from strong oxidizing agents, strong bases, halogens, phosphorus, and sulfur. Keep stored under water.

0 mmHg (approx)

(Reference) Mice-injected LD50: 76 mg/kg

Inflammable in case of fire, high temperature and oxidant

Explosive in powder form, either dry or wet with less than 25% water.

Atomic number: 72; ductile; has been successfully alloyed with iron, titanium, niobium, tantalum, and other metals; rapidly absorbs hydrogen to form HfH at 700 °C; halogens react directly to form tetrahalides; properties are considerably influenced by impurities of zirconium present|Standard molar enthalpy of formation (kJ/mol at 298.15 K): 0 (crystal), 619.2 (gas); standard molar Gibbs energy of formation (kJ/mol at 298.15 K): 576.5 (gas); standard molar entropy (J/mol-K at 298.15 K): 43.6 (crystal), 186.9 (gas); molar heat capacity at constant pressure (mol/K at 298.15 K): 25.7 (crystal), 20.8 (gas)|High thermal neutron cross-section (115 barns); high strength|Six naturally occurring isotopes: 180 (35.22%); 178 (27.1%); 177 (18.56%); 179 (13.75%); 176 (5.21%); 174 (0.163%; alpha-emitter...); artificial isotopes: 157; 158; 168-173; 175; 181-183.|For more Other Experimental Properties (Complete) data for HAFNIUM, ELEMENTAL (8 total), please visit the HSDB record page.

Highly flammable. The dry powder reacts with moisture to produce hydrogen, a flammable gas. The heat from this reaction may be sufficient to ignite the hydrogen. It does not appreciably react with large quantities of water.

Metals, Elemental and Powder, Active

Strong Reducing Agent

Metals, such as HAFNIUM METAL(reactivity similar to zirconium), are reducing agents and tend to react with oxidizing agents. Their reactivity is strongly influenced by their state of subdivision: in bulk they often resist chemical combination; in powdered form they may react very rapidly. Thus, as a bulk metal it is somewhat unreactive, but finely divided material may be pyrophoric. The metal reacts exothermically with compounds having active hydrogen atoms (such as acids and water) to form flammable hydrogen gas and caustic products. The reactions are less vigorous than the similar reactions of alkali metals, but the released heat can still ignite the released hydrogen. Materials in this group may react with azo/diazo compounds to form explosive products. These metals and the products of their corrosion by air and water can catalyze polymerization reactions in several classes of organic compounds; these polymerizations sometimes proceed rapidly or even explosively. Some metals in this group form explosive products with halogenated hydrocarbons.

20 °C for dust cloud|20 °C

Explosive in powder form (either dry or with <25% water); finely divided powder can be ignited by static electricity or even SPONTANEOUSLY.

Ignites in air when finely divided. Dust explosion possible if in powder or granular form, mixed with air.

Good corrosion resistance

III

8

UN 3178 4.1/PG 3

-

11-20/21/22-34-23/24/25

9-16-26-27-33-36-36/37/39-45-28

MG4600000

F,Xn,T

The warehouse is ventilated, low temperature and dry; stored separately from oxidants and acids

Explosive when mixed with oxidant

Stable. Incompatible with oxygen, sulfur, strong oxidizing agents, halogens, phosphorus, strong acids. Highly flammable.

P210

H228

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.|If the quantity justifies recovery, get in touch with the supplier for special instructions.|Used papers and cloths which have become contaminated with powders should be kept wet in covered Containers until they are /disposed/.

Although /hafnium/ is relatively inert, when powdered it becomes very reactive. The dry powder may react explosively at elevated temperatures with nitrogen, phosphorus, oxygen, sulfur and other non-metals. The halogens react similarly, and in contact with hot concentrated nitric acid and other oxidants it may explode (often after a delay with nitric acid). The powder is pyrophoric and readily ignitable by friction, heat or static sparks, and if dry burns fiercely. Presence of water (5-10%) slightly reduces the ease of ignition, but combustion of the damp powder proceeds explosively (the oxygen content of water, 89%, being much higher than that of air).|Strong oxidizers, chlorine.|Reacts violently with strong acids, strong oxidants, halogens causing explosion hazard. /Hafnium powder/

USEPA; Development Document for Effluent Limitations, Guidelines, & Standards for the Nonferrous Metals Manufacturing Point Source Category. Vol 9 Primary & Secondary Titanium, Primary Zirconium & Hafnium; GRA & I Issue 11 (1990) EPA 440/1-89/019.9

Excerpt from ERG Guide 135 [Substances - Spontaneously Combustible]: Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated. (ERG, 2016)|Flammable. Finely dispersed particles form explosive mixtures in air. Risk of fire and explosion. See Chemical Dangers.|Flammable - 3rd degree, Reactive - 3rd degree

|Danger|H250 (82.19%): Catches fire spontaneously if exposed to air [Danger Pyrophoric liquids; Pyrophoric solids]|P210, P222, P280, P302+P334, P370+P378, and P422|Aggregated GHS information provided by 238 companies from 9 notifications to the ECHA C&L Inventory.|Not Classified

Excerpt from ERG Guide 135 [Substances - Spontaneously Combustible]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 135 [Substances - Spontaneously Combustible]: Fully encapsulating, vapor-protective clothing should be worn for spills and leaks with no fire. ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). Do not touch or walk through spilled material. Stop leak if you can do it without risk. SMALL SPILL: EXCEPTION: For spills of Xanthates, UN3342 and for Dithionite (Hydrosulfite/Hydrosulphite), UN1384, UN1923 and UN1929, dissolve in 5 parts water and collect for proper disposal. CAUTION: UN3342 when flooded with water will continue to evolve flammable Carbon disulfide/Carbon disulphide vapors. Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Use clean, non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Skin: Wear appropriate personal protective clothing to prevent skin contact. Eyes: Wear appropriate eye protection to prevent eye contact. Wash skin: The worker should immediately wash the skin when it becomes contaminated. The worker should wash daily at the end of each work shift. Remove: Work clothing that becomes wet or significantly contaminated should be removed and replaced. Change: Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premise. Provide: Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection. Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2016)|Workmen...should be meticulous in keeping powder off their clothing. If they wear rubber or plastic aprons, these should be treated with an anti-static compound.|Outer clothing made from synthetic fibers should be prohibited unless effectively treated with anti-static materials.|Wear appropriate personal protective clothing to prevent skin contact.|Wear appropriate eye protection to prevent eye contact.|For more Personal Protective Equipment (PPE) (Complete) data for HAFNIUM, ELEMENTAL (16 total), please visit the HSDB record page.|(See protection codes)

The substance may spontaneously ignite on contact with air and at higher temperatures with nitrogen, phosphorous and sulphur. /Hafnium powder, wet or dry/|Flammability: Both dry and wet may ignite in powders.

Explosive in powder form, either dry or wet with less than 25% water.

If material on fire or involved in fire: Use suitable dry powder. ... Use dry chemical or carbon dioxide. ... Use water only if flooding quantities are available. /Hafnium powder, dry/|If material on fire or involved in fire: Use suitable dry powder. ... Use dry chemical or carbon dioxide. ... Use water only if flooding quantities are available. /Hafnium powder, wetted/

Persons not wearing protective equipment and clothing should be restricted from areas of spills until cleanup has been completed. 1. Ventilate area of spill. 2. Collect spilled material in most convenient and safe manner and deposit in sealed containers for reclamation, or for disposal in secured sanitary landfill. Liq containing hafnium...should be absorbed in vermiculite, dry sand, earth, or similar material.|Any spilled powder should be cleaned up immediately with water so that it has no chance to dry in place.|Spillage disposal: Evacuate danger area. Eliminate all sources of ignition. Do not wash away into sewer because it is flammable. Do not absorb in sawdust or other combustible absorbents. Wet the powder to prevent formation of dust or ignition; carefully collect the powder into sealable containers, and remove it to a safe place. During this procedure, use extra personal protection, e.g., a P2 filter respirator for harmful particles.|Environmental considerations: land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. ... Apply appropriate foam to diminish vapor and fire hazard. ... /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ /Hafnium powder, wetted/|Environmental considerations: water spill: Use natural barriers or oil spill control booms to limit spill travel. /Hafnium powder, wetted/

Ventilation control: ...all processes using these materials /zirconium and hafnium/ should be...ventilated to keep air-borne contaminants far below.../5 mg/cu m/.|Care should be taken when machining metal or when handling hot sponge hafnium.|All sources of ignition, including static electric charges, should be eliminated from areas in which powder is to be handled. All surfaces...should be impervious and seamless so that they can be washed down with water and kept completely free from dust. Dried powders should be disturbed and handled as little as possible and then only with non-sparking tools.|The worker should immediately wash the skin when it becomes contaminated.|For more Preventive Measures (Complete) data for HAFNIUM, ELEMENTAL (16 total), please visit the HSDB record page.

/GUIDE 135: SUBSTANCES - SPONTANEOUSLY COMBUSTIBLE/ Fire or Explosion: Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated. /Hafnium powder, dry/|/GUIDE 135: SUBSTANCES - SPONTANEOUSLY COMBUSTIBLE/ Health: Fire will produce irritating, corrosive and/or toxic gases. Inhalation of decomposition products may cause severe injury or death. Contact with substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution. /Hafnium powder, dry/|/GUIDE 135: SUBSTANCES - SPONTANEOUSLY COMBUSTIBLE/ Public Safety: CALL Emergency Response Telephone Number ... . As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Stay upwind. Keep unauthorized personnel away. Keep out of low areas. /Hafnium powder, dry/|/GUIDE 135: SUBSTANCES - SPONTANEOUSLY COMBUSTIBLE/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing will only provide limited protection. /Hafnium powder, dry/|For more DOT Emergency Guidelines (Complete) data for HAFNIUM, ELEMENTAL (16 total), please visit the HSDB record page.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Hafnium and its compounds are mild irritants of the eyes, skin, and mucous membranes. No industrial poisonings involving hafnium have been reported.|Irritant /to/ eyes.

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 0.5 mg/cu m.

Recommended Exposure Limit: 10 Hr Time-Weighted Avg: 0.5 mg/cu m.

Remove all ignition sources. Evacuate danger area! Consult an expert! Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Wet powder to prevent dusting and ignition. Sweep spilled substance into covered water-filled containers. Then store and dispose of according to local regulations. Do NOT wash away into sewer. Do NOT absorb in saw-dust or other combustible absorbents.

Fireproof. Separated from strong oxidants, strong acids and halogens. Keep under inert gas. Store only in original container.

May cause mechanical irritation to the eyes, skin and respiratory tract.

NO open flames, NO sparks and NO smoking. Do NOT expose to friction or shock. Closed system, dust explosion-proof electrical equipment and lighting. Prevent deposition of dust.

STRICT HYGIENE!

Avoid inhalation of dust. Use closed system.

Protective gloves.

Wear safety spectacles.

highly toxic

Hafnium is...never found free in nature. It is always found associated with the more plentiful zirconium.

Hafnium can be absorbed into the body by inhalation of its aerosol.|The whole body retention of 181Hf was studied in marmosets (Callithrex jacchus) and found to be closely similar to that in rats and Chinese hamsters. Limited tissue distribution studies suggest a higher uptake in liver and much lower deposition in skin and muscle in the marmoset as compared to the rat or Chinese hamster. Studies in Chinese hamsters showed that treatment with the chelating agent diethylenetriaminepentaacetic acid resulted in only a small reduction in the whole body retention of 181Hf. The absorption of orally administered 181Hf, in various chemical forms, was found to be between 0.04 and 0.13% of the ingested dose and was unaffected by age between 5 and 21 months but was increased by fasting. The measured absorption of 181Hf in Chinese hamsters and in rats was similar to that of plutonium suggesting that radiohafnium could be used as a surrogate for plutonium for selected studies in human volunteers. /Radiohafnium/

Of all elements, zirconium and hafnium are two of most difficult to separate. ... Very pure hafnium has been produced with zirconium being the major impurity.

Excerpt from ERG Guide 135 [Substances - Spontaneously Combustible]: Fire will produce irritating, corrosive and/or toxic gases. Inhalation of decomposition products may cause severe injury or death. Contact with substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution. (ERG, 2016)

Eye: If this chemical contacts the eyes, immediately wash the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Contact lenses should not be worn when working with this chemical. Skin: If this chemical contacts the skin, promptly wash the contaminated skin with soap and water. If this chemical penetrates the clothing, promptly remove the clothing and wash the skin with soap and water. Get medical attention promptly. Breathing: If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform mouth-to-mouth resuscitation. Keep the affected person warm and at rest. Get medical attention as soon as possible. Swallow: If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2016)|(See procedures)

Fresh air, rest.

Rinse contaminated clothes (fire hazard) with plenty of water. Remove contaminated clothes. Rinse and then wash skin with water and soap.

Rinse with plenty of water (remove contact lenses if easily possible).

/SIGNS AND SYMPTOMS/ Lungs may be affected by repeated or prolonged exposure. The substance may have effects on the liver.|/SIGNS AND SYMPTOMS/ Overexposure to hafnium and its compounds may cause mild irritation of the eyes, skin, and mucous membranes.

Hafnium

inhalation, ingestion, skin and/or eye contact

In Animals: irritation eyes, skin, mucous membrane; liver damage

Redness.

Eyes, skin, mucous membrane, liver

The largest use is as an alloy additive in nickel-based superalloys ... second major use is as a control-rod material in nuclear reactors|YEARLY DEMAND FOR HAFNIUM IN US IS NOW IN EXCESS OF 60,000 LB.|The yearly demand for hafnium in the US is now /1990/ in excess of 100,000 lb|Yearly demand for hafnium in US is now /2002/ in excess of 50,000 kg.

Forms available: powder; rods; single crystals|Available in sponge, iodide crystal bar, ingot, wrought products from bar to foil, and wire|Sold in chunk or particulate form /for alloying purposes/

Electrical equipment, appliance, and component manufacturing|Hafnium: ACTIVE|Price of the metal is about $2/g.|...Extensively used as shielding material & as control rods in thermal nuclear reactors, because its thermal neutron cross section, 105 barns, is nearly 1000 times that of Zr; Hf can absorb & give up heat twice as fast as Zr & Ti. It is used as construction material in space technology & in jet engines...|Although hafnium /ore/ reserves are significant, demand is low and easily met as a byproduct of the production of reactor-grade zirconium|Six naturally occurring isotopes: 180 (35.22%); 178 (27.1%); 177 (18.56%); 179 (13.75%); 176 (5.21%); 174 (0.163%; alpha-emitter...); artificial isotopes: 157; 158; 168-173; 175; 181-183.

Fire Hazards -> Flammable - 3rd degree, Reactive - 3rd degree