Molybdenum Sulfide








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Product Name:     Molybdenum Sulfide

Formula:              MoS2

CAS Number:       1317-33-5




Hazardous Components:  Molybdenum Sulfide

Percent (%):                    0-100

OSHA/PEL:                        5 mg/m3 (as Mo)  

ACGIH/TLV:                      5 mg/m3 (as Mo)

HMIS Rating:

Health:                              1

Flammability:                   0

Reactivity:                        1




Boiling Point:                   N/A

Melting Point:                  1185 oC

Specific Gravity:              4.80 g/cc at 14 oC

Solubility in H2O:             Insoluble


Appearance and Odor:    Black lustrous powder, rotten-egg-like odor.





Flash Point:  N/A

Autoignition Temperature:  N/A

Explosive LimitsLower:  N/A       Upper:  N/A

Extinguishing Media:  Use suitable extinguishing media for surrounding material and type of fire.

Special Firefighting Procedures:  Wear a self-contained breathing apparatus and full protective clothing to prevent contact with skin and eyes.

Unusual Fire and Explosion Hazards:  May emit toxic fumes under fire conditions.




Effects of Exposure:

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

Molybdenum and its compounds are highly toxic based upon chemical experimentations.  But in spite of their considerable use in the industry, human industrial poisoning by molybdenum inhalation has yet to be reported.  Some studies have been made of its effects, and it is suggested that suitable precautions should be taken against human inhalation of significant amounts of the more soluble molybdenum compounds.  Molybdenum is not stored in the body to any extent because it is rapidly excreted.  All molybdenum compounds can be referred to molybdenum or to more toxic anions if present.  Molybdenum is a common air contaminant.

The sulfides have variable toxicity.  They cause softening and irritation of the skin.  If taken by mouth they are corrosive and irritating through the liberation of H2S and free alkali.  H2S is especially toxic.  Sulfides of the heavy metals are generally insoluble and hence have little toxicity action except through the liberation of H2S.

Acute Effects:

Inhalation:  A respiratory irritant.  Coughing, sneezing, difficulty breathing and pulmonary edema possible.  May cause irritation of the mucous membranes of the nose and throat.

Ingestion:  May cause acute molybdenum poisoning.

Skin:  Irritation, inflammation and redness possible.  May cause dermatitis.

Eye:  Irritation, inflammation, watering and redness possible.  Risk of serious injury.

Chronic Effects:

Inhalation:  May cause pneumoconiosis.

Ingestion:  May cause chronic molybdenum poisoning.

Skin:  No chronic health effects recorded.

Eye:  No chronic health effects recorded.

Medical Conditions Generally Aggravated by Exposure:  Respiratory disorders.

CarcinogenicityNTP:  No     IARC:  No    OSHA:  No



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 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:  Heat, excessive moisture/water, incompatible materials.

Incompatibility (Material to Avoid):  Potassium nitrate, violent reaction with H2O2.

Hazardous Decomposition Products:  Mo, MoOx, SOx, S, H2S

Hazardous Polymerization:  Will not occur




Steps to Be Taken in Case Material Is Released or Spilled:  Wear a self-contained breathing apparatus and full protective clothing.  Isolate the area where the spill occurred, ensure proper ventilation is available and that water/moisture are kept out of the area.  Vacuum up the spill using a high efficiency particulate absolute (HEPA) unit and place in a container for proper disposal.

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




Respiratory Protection:  NIOSH-approved respirator.

Ventilation:  Handle in dry, controlled atmosphere.  Use local exhaust to maintain exposure below TLV.  Mechanical (general) exhaust is recommended.

Protective Gloves:  Neoprene

Eye Protection:  Safety Glasses

Other Protective Clothing or Equipment:  Wear protective clothing to prevent contamination of skin and clothes.




Precautions to Be Taken in Handling and Storage:  Store in a cool, dry area. Store in 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 of clothing or skin with compressed air. Maintain eyewash capable of sustained flushing, safety drench shower and facilities for washing.

TSCA Listed:   Yes

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 a guide.  ESPI shall not be held liable for any damage resulting from handling or from contact with the above product.


Issued by:               S. Dierks

Revised/Verified:      July 2012

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