Chemical Datasheet


Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 7440-25-7
none data unavailable none
NIOSH Pocket Guide International Chem Safety Card
Tantalum (metal and oxide dust, as Ta)
NFPA 704
data unavailable
General Description
Tantalum dust is a black odorless powder. mp: 2996° C, bp: approx. 5250°C. Density: 16.65 g/cm3. Insoluble in water. Tantalum oxide dust is a white, microcrystalline powder mp: 1800°C. Density: 7.6 g/cm3. Insoluble in water. The mixture is listed as a toxic inhalation hazard by OSHA.


Reactivity Alerts
Air & Water Reactions
Metal, Combustible Solid; powder ignites SPONTANEOUSLY in air. Highly flammable in Air (powdered form) No rapid reaction with water
Fire Hazard
No information available.
Health Hazard
Exposure Routes: inhalation, skin and/or eye contact

Symptoms: Irritation eyes, skin

Target Organs: Eyes, skin, respiratory system (NIOSH, 2016)
Reactivity Profile
TANTALUM dust reacts rapidly with oxidizing agents (oxygen, fluorine, chlorine). Highly flammable in air, igniting spontaneously when dry. (Lewis, 3rd Ed, 1993). Dissolves in molten bases (such as sodium hydroxide). Insoluble in aqueous bases. Insoluble in acids except hydrofluoric acid and fuming sulfuric acid. Tantalum in bulk form (bar, sheet, etc.) is much less reactive than it is in powdered form.

TANTALUM OXIDE dust is generally unreactive at room conditions. Insoluble in water and acids with the exception of hydrofluoric acid. Reacts when strongly heated with sodium carbonate.
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

Isolation and Evacuation
No information available.
No information available.
Non-Fire Response
No information available.
Protective Clothing
Skin: No recommendation is made specifying the need for personal protective equipment for the body.

Eyes: No recommendation is made specifying the need for eye protection.

Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift).

Remove: No recommendation is made specifying the need for removing clothing that becomes wet or contaminated.

Change: No recommendation is made specifying the need for the worker to change clothing after the work shift. (NIOSH, 2016)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
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.

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. (NIOSH, 2016)

Physical Properties

Chemical Formula:
  • Ta (metal)
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: data unavailable
Melting Point: 5425 ° F (NIOSH, 2016)
Vapor Pressure: 0 mm Hg (approx) (NIOSH, 2016)
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 16.65 (metal), 14.40 (powder) (NIOSH, 2016)
Boiling Point: 9797 ° F at 760 mm Hg (NIOSH, 2016)
Molecular Weight: 180.9 (NIOSH, 2016)
Water Solubility: Insoluble (NIOSH, 2016)
Ionization Potential: data unavailable
IDLH: 2500 mg/m3 (as Ta) (NIOSH, 2016)

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Tantalum (7440-25-7) 10 mg/m3 11 mg/m3 64 mg/m3
(DOE, 2016)

Regulatory Information

EPA Consolidated List of Lists

No regulatory information available.

DHS Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names