Tungsten Silicide W5Si3









ESPI Metals

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Product Name:       Tungsten Silicide

Formula:                 W5Si3

CAS Number:          12039-95-1




Hazardous Component:   Tungsten Silicide 

Percent (%):                    0-100

OSHA/PEL:                        N/E

ACGIH/TLV:                      5 mg (W)/m3

HMIS Hazard Rating:

Health:                             2

Flammability:                  0

Reactivity:                       0




Boiling Point:                  N/E

Melting Point:                 N/E

Specific Gravity:            N/E

 Solubility in H2O:           Insoluble

Appearance and Odor:  Grey powder and pieces, no odor.





Flash Point:  N/A

Flammability:  Non-flammable 

Autoignition Temp:  No data

Flammable LimitsLower:  N/A      Upper:  N/A

Extinguishing Media: Use suitable extinguishing agent for surrounding materials and type of fire.

Special Firefighting Procedures:  Firefighters must wear full face, self-contained breathing apparatus with full protective clothing to prevent contact with skin and eyes.

Unusual Fire and Explosion Hazards:  When heated to decomposition, tungsten silicide may emit toxic fumes.




Effects of Exposure:

To the best of our knowledge the chemical, physical and toxicological properties of tungsten silicide have not been thoroughly investigated and recorded.

Tungsten compounds may be irritating to the eyes and respiratory tract.  Chronic exposure may result in permanent lung damage.

Inorganic silicon compounds may be acute inhalation irritants.  Prolonged inhalation may cause pulmonary fibrosis known as silicosis.

Acute Effects:

Inhalation:  May cause irritation to the respiratory tract.

Ingestion:  No acute effects recorded.

Skin:  May cause abrasive irritation.

Eye:  May cause abrasive irritation.

Chronic Effects:

Inhalation:  No chronic effects recorded.

Ingestion:  Large doses may cause nervous system disturbances and diarrhea.

Skin:  No chronic effects recorded.

Eye:  No chronic effects recorded.


Medical Conditions Generally Aggravated by Exposure:  Pre-existing respiratory disorders.

CarcinogenicityNTP:  Yes              IARC:  Yes            OSHA:  Yes



 INHALATION:  Remove to fresh air, keep warm and quiet, give oxygen if breathing is difficult and seek medical attention if symptoms persist.

INGESTION:  Give 1-2 glasses of milk or water and induce vomiting, seek medical attention if symptoms persist.  Never induce vomiting or give anything by mouth to an unconscious person.

SKIN:  Remove contaminated clothing, brush material off skin, wash affected area with soap and water, seek medical attention if symptoms persist.

EYES:  Flush eyes with lukewarm water, lifting upper and lower eyelids, for at least 15 minutes.  Seek medical attention if symptoms persist.




 Stability:  Stable

Conditions to Avoid:  None

Incompatibility (Material to Avoid):  None recorded.

Hazardous Decomposition Products:  None recorded.

Hazardous Polymerization:  Will not occur




Steps to Be Taken in Case Material Is Released or Spilled:  Wear appropriate respiratory and protective equipment specified in section VIII.  Isolate spill area and provide ventilation.  Vacuum up spill using a high efficiency particulate absolute (HEPA) air filter and place in a closed container for proper disposal.  Take care not to raise dust.

Waste Disposal Method:  Dispose of in accordance with all State, Federal and Local regulations.




Respiratory Protection:  NIOSH approved respirator

Ventilation:  Use local exhaust to maintain concentration at low exposure levels.  General exhaust is recommended.

Protective Gloves:  Rubber gloves

Eye Protection:  Safety glasses

Other Protective Clothing or Equipment:  Protective gear suitable to prevent contamination.




Precautions to Be Taken in Handling and Storage:  Store in a cool, dry area.  Store in a tightly sealed container.  Wash thoroughly after handling.

Work Practices:  Implement engineering and work practice controls to reduce and maintain concentration of exposure at low levels.  Use good housekeeping and sanitation practices.  Do not use tobacco or food in work area.  Wash thoroughly before eating and smoking.  Do not blow dust off clothing or skin with compressed air.  Maintain eyewash capable of sustained flushing, safety drench shower and facilities for washing.

DOT Regulations:

Hazard Class:                None



The above information is believed to be correct, but does not purport to be all inclusive and shall be used only as guide.  ESPI shall not be held liable for any damage resulting from handling or from contact with the above product.


Issued by:             S. Dierks

Date:                    May 2007

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