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Hafnium																				Related Pages
Synonyms & Trade Names
			Celtium, Elemental hafnium, Hafnium metal
CAS No.
			7440-58-6
	RTECS No.
			MG4600000
	DOT ID & Guide
			1326 170(powder, wet)2545 135(powder, dry)

FormulaHf
	Conversion
	IDLH
			50 mg/m3 (as Hf)See: 7440586

Exposure Limits
			NIOSH RELTWA 0.5 mg/m3 [*Note: The REL also applies to other hafnium compounds (as Hf).]
					OSHA PEL TWA 0.5 mg/m3 [*Note: The PEL also applies to other hafnium compounds (as Hf).]
	Measurement Methods
			**NIOSH** S194 (II-5);**OSHA** ID121
					
					See: NMAM or OSHA Methods
										
Physical Description
			Highly lustrous, ductile, grayish solid.													
										
Molecular Weight178.5	
	Boiling Point8316°F
	Melting Point4041°F
	SolubilityInsoluble
	Vapor Pressure0 mmHg (approx)
	Ionization PotentialNA											
Specific Gravity13.31	
	Flash PointNA
	Upper Explosive LimitNA
	Lower Explosive LimitNA
Explosive in powder form (either dry or with <25% water); finely divided powder can be ignited by static electricity or even SPONTANEOUSLY.
Incompatibilities & Reactivities
			Strong oxidizers, chlorine
Exposure Routes
			inhalation, ingestion, skin and/or eye contact
Symptoms
			In Animals: irritation eyes, skin, mucous membrane; liver damage
Target Organs
			Eyes, skin, mucous membrane, liver
										
Personal Protection/Sanitation
			(See protection codes) **Skin:**Prevent skin contact
							**Eyes:**Prevent eye contact
							**Wash skin:**When contaminated/Daily
							**Remove:**When wet or contaminated
							**Change:**Daily
							**Provide:**Eyewash, Quick drench
	First Aid
			(See procedures)**Eye:**Irrigate immediately
							**Skin:**Soap wash promptly
							**Breathing:**Respiratory support
							**Swallow:**Medical attention immediately
Respirator Recommendations
			**NIOSH/OSHA****Up to 2.5 mg/m3**: (APF = 5) Any quarter-mask respirator. Click here for information on selection of N, R, or P filters.**Up to 5 mg/m3**: (APF = 10) Any particulate respirator equipped with an N95, R95, or P95 filter (including N95, R95, and P95 filtering facepieces) except quarter-mask respirators. The following filters may also be used: N99, R99, P99, N100, R100, P100. Click here for information on selection of N, R, or P filters.(APF = 10) Any supplied-air respirator**Up to 12.5 mg/m3**: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode*(APF = 25) Any powered, air-purifying respirator with a high-efficiency particulate filter.***Up to 25 mg/m3**:(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters.(APF = 50) Any supplied-air respirator that has a tight-fitting facepiece and is operated in a continuous-flow mode*(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and a high-efficiency particulate filter*(APF = 50) Any self-contained breathing apparatus with a full facepiece(APF = 50) Any supplied-air respirator with a full facepiece**Up to 50 mg/m3**: (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode**Emergency or planned entry into unknown concentrations or IDLH conditions:** (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus**Escape:**(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters.Any appropriate escape-type, self-contained breathing apparatus
					Important additional information about respirator selection
See also
			INTRODUCTION
					  ICSC CARD: 0847

			
							

			Page last reviewed:  October 30, 2019						Content
							source: 	National Institute for Occupational Safety and Health NIOSH Pocket Guide to Chemical Hazards
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A – NIOSH Potential Occupational Carcinogens
B – Thirteen OSHA-Regulated Carcinogens
C – Supplementary Exposure Limits
D – Substances with No Established RELs
E – OSHA Respirator Requirements for Selected Chemicals
F – Miscellaneous Notes
G – 1989 Air Contaminants Update Project: Exposure Limits NOT in Effect
Type C & CE – Definitions for Type C and Type CE Respirators
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