Molybdenum disulfide

5.06 @ 15 °C/15 °C

4.80 @ 14°C

LEAD-GRAY, LUSTROUS POWDER

Black luster, hexagonal crystals

INSOL IN WATER OR DIL ACIDS

SOL IN HOT SULFURIC ACID, AQUA REGIA, NITRIC ACID

2375 °C

1185 °C

Liquid; Other Solid; Liquid; CBI; Large Crystals; Wet Solid; Other Solid; Dry Powder

Lustrous lead-grey powder; Black and lustrous when artificially prepared; Insoluble in water; [Merck Index] Black odorless powder; Insoluble in water; [MSDSonline]

This chemical does not meet GHS hazard criteria for 82.2% (1274 of 1550) of all reports.

Warning

H332 (17.2%): Harmful if inhaled [Warning Acute toxicity, inhalation]

P261, P271, P304+P340, and P317 (click each P-code to see the statement)

Aggregated GHS information provided per 1550 reports by companies from 12 notifications to the ECHA C&L Inventory.

This chemical does not meet GHS hazard criteria for 75% (3 of 4) of all reports.

Chemical: Molybdenum sulfide (MoS2)

Molybdenum sulfide (MoS2) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Molybdenum sulfide (MoS2) are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Molybdenite (MoS2): Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

Molybdenum sulfide (MoS2): Does not have an individual approval but may be used under an appropriate group standard

Nat'l Research Council Canada; Data Sheets on Selected Toxic Elements (1982) NRCC No. 19252

USEPA, Office of Drinking Water; Criteria Document (Draft): Molybdenum (1985)

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 15 mg/cu m. /Molybdenum insoluble compounds, as Mo, total dust/

Vacated 1989 OSHA PEL TWA 10 mg/cu m is still enforced in some states. /Molybdenum insoluble compounds, as Mo/

Carc. 1B (25%)

Acute Tox. 4 (17.2%)

(FL) FLORIDA 35 ug/l /Molybdenum/

(ME) MAINE 35 ug/l /Molybdenum/

HYDROGEN PEROXIDE REACTS VIGOROUSLY WITH ... MOLYBDENUM DISULFIDE ...

Mixtures of potassium nitrate with .... molybdenum disulfide are ... detonable.

/Incompatible with/ strong oxidizers. /Molybdenum, insoluble compounds, (as Mo)/

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

10.0 [mg/m3], as Mo, inhal. fraction, 3 mg/m3, as Mo, respir. fraction (metal and insol. compds)

8 hr Time Weighted Avg (TWA): 10 mg/cu m (inhalable fraction). /Molybdenum, metal and insoluble compounds, as Mo/

8 hr Time Weighted Avg (TWA): 3 mg/cu m (respirable fraction). /Molybdenum, metal and insoluble compounds, as Mo/

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed three times the TLV-TWA for no more than a total of 30 min during a work day, and under no circumstances should they exceed five times the TLV-TWA, provided that the TLV-TWA is not exceeded. /Molybdenum, metal and insoluble compounds, as Mo/

50 [mg/m3]

550 [mg/m3]

3300 [mg/m3]

Respirators may be used when engineering and work practice controls are not technically feasible, when such controls are in the process of being installed, or when they fail and need to be supplemented. Respirators may also be used for operations which require entry into tanks or closed vessels, and in emergency situations. If the use of respirators is necessary, the only respirators permitted are those that have been approved by the Mine Safety and Health Administration (formerly Mining Enforcement and Safety Administration) or by the National Institute for Occupational Safety and Health. /Soluble Molybdenum cmpd (as Molybdenum); Molybdenum and insoluble molybdenum cmpd/

Respirator selection: Upper limit devices recommended by ACGIH: Up to 50 mg/cu m: Any dust and mist respirator; up to 100 mg/cu m: any dust and mist respirator except single-use and quarter mask respirators or any supplied air respirator or any self contained breathing apparatus; up to 250 mg/cu m: any powered air purifying respirator with a dust and mist filter or any supplied air respirator operated in a continuous flow mode; up to 500 mg/cu m: any air purifying full facepiece respirator with a high efficiency particulate filter or any powered air purifying respirator with a tight fitting facepiece and a high efficiency particulate filter or any supplied air respirator with a tight fitting facepiece operated in a continuous flow mode or any self contained breathing apparatus with a full facepiece or any supplied air respirator with a full facepiece; up to 7500 mg/cu m: any supplied air respirator with a half mask and operated in a pressure-demand or other positive pressure mode; Emergency or planned entry in unknown concentration or IDLH conditions: any self contained breathing apparatus with a full facepiece and operated in a pressure demand or other positive pressure mode or any supplied air respirator with a full facepiece and operated in a pressure demand or other positive pressure mode in combination with an auxiliary self contained breathing apparatus operated in pressure demand or other positive pressure mode; Escape: any air purifying full facepiece respirator with cartridge(s) providing protection against the compound of concern and having a high efficiency particulate filter or any appropriate escape type self contained breathing apparatus. /Molybdenum, insoluble compounds (as Mo)/

Soviet limits (1966), 4 and 6 mg/cu m for soluble and insoluble cmpd, respectively; West Germany, 5 and 15 mg/cu m for soluble and insoluble cmpd, respectively; East Germany, 10 mg/cu m for insoluble cmpd only. /Molybdenum compounds, sol and insoluble/

Humans: total body burden 9.3 mg amount in skeleton: 5 mg amount in liver: 2 mg kidney: 0.9-3.1 mg Mo/kg liver: 1.3-5.8 mg Mo/kg muscle: 0.018 mg Mo/kg bone: 0.7 mg Mo/kg hair: 0.06-0.2 mg Mo/kg nail: 0.15-16 mg Mo/kg whole blood: 0.001 mg Mo/kg.

The following medical procedures should be made available to each employee who is exposed to molybdenum and insoluble molybdenum compounds at potentially hazardous levels: Initial medical screening: Employees should be screened for history of certain medical conditions /kidney disease; chronic respiratory disease; liver disease/ which might place the employee at increased risk from molybdenum and insoluble molybdenum compounds exposure. Periodic medical exam: Any employee developing the above listed conditions should be referred for further medical examination. /Molybdenum and insoluble molybdenum compounds/

Occurs as the mineral molybdenite, which is the principal source of molybdenum.

Both suspended insoluble molybdenum sulfide and soluble molybdates are present in streams that drain areas where molybdenum ore is mined and processed, especially in Colorado and New Mexico.

CHIEF CMPD OF MOLYBDENUM ENCOUNTERED IN INDUSTRIAL EXPOSURE (ESP IN MINING) IS SULFIDE ...

EXPOSURE TO MOLYBDENUM DISULFIDE LUBRICANT SPRAY ... MAY ... PROVE HAZARDOUS TO HEALTH. INSOL MOLYBDENUM CMPD SUCH AS MOLYBDENUM DISULFIDE ... ARE CHARACTERIZED BY LOW TOXICITY ... DERMATITIS FROM CONTACT WITH MOLYBDENUM DISULFIDE IS UNKNOWN.

... MOLYBDENUM CMPD EXHIBIT A LOW ORDER OF TOXICITY, BUT ... SOME DIFFERENCES IN TOXICITY MAY BE ASCRIBED TO DIFFERENT COMPOUNDS; THE TRIOXIDE AND AMMONIUM MOLYBDATE WERE MORE TOXIC THAN THE ORE MOLYBDENITE, THE METAL OR THE DIOXIDE. /MOLYBDENUM CMPD/

MOLYBDENUM INTOXICATION DEPENDS UPON THE CHEM FORM & DOSE & IS INFLUENCED BY SULFATE, COPPER (2+), ZINC (2+), LEAD (2+), PROTEIN INTAKE, FORM & AMT OF COPPER, & ORGANIC SULFUR, SUCH AS CYSTINE & METHIONINE IN THE BODY. /MOLYBDENUM/

... THE FATE OF MOLYBDENUM IN A COAL FIRED ELECTRIC POWER PLANT IN COLORADO /WAS STUDIED/ ... RESULTS SHOWED THAT MOLYBDENUM FROM COAL IS ... ENRICHED IN FLY ASH LEAVING COAL FIRED POWER PLANT IN STACK GASES, (EVEN AFTER TREATMENT WITH ELECTROSTATIC PRECIPITATORS AND WET SCRUBBERS), BUT ... DECREASED IN BOTTOM ASH. ENRICHMENT IN FLY ASH APPEARS TO BE RELATED TO THE VOLATILITY OF MOLYBDENUM & ITS ADSORPTION ON FINE PARTICLES. MOLYBDENUM THAT ESCAPES IN PARTICULATE MATTER IN STACK GASES MAY BE EXPECTED TO SETTLE TO EARTH AND ENRICH SOIL, PLANTS, & WATER ... /MOLYBDENUM/

Molybdenum in sewage sludge was found to vary between 2 and 30 mg/kg dry weight. /Molybdenum/

Molybdenite (MoS2), by inhalative or oral routes, was found ... to be practically nontoxic; guinea pigs exposed 1 hr daily for 25 days at the extremely high level of 490 mg/cu m of molybdenite ore (230 mg Mo/cu m) showed only increased respiration; rats ingesting as much as 500 mg daily for 44 days showed no toxic signs, and all gained weight.

Inhalation of molybdenum compounds in high concn may be irritating to the upper respiratory tract. /Molybdenum/

In persons with impaired pulmonary function, especially those with obstructive airway diseases, the breathing of insoluble molybdenum compounds might cause exacerbation of symptoms due to their irritant properties. /Molybdenum and insoluble molybdenum compounds/

INDUST EXPOSURES RELATED TO PRODN & FABRICATION OF MOLYBDENUM PRODUCTS ARE TO DUSTS & FUME OF MOLYBDENUM, ITS OXIDES & SULFIDES CHIEFLY FROM ELECTRIC FURNACE OR OTHER HIGH TEMP TREATMENT. ... SPRAYING OF MOLYBDENUM MAY PROVIDE HAZARD; AND LOSS OF MOLYBDENUM CATALYSTS TO THE AIR ADDS TO THE METAL BURDEN OF CONTAMINATED ATMOSPHERES.

... Common operations in which exposure to soluble molybdenum compounds may occur ... /are/: liberation during rolling of hot billets in processing molybdenum steel; for use as electrodes; during welding operations; use as chemical reagent for lab analyses; in petroleum refining and chemical processing; as an intermediate in the manufacture of corrosion inhibitors; use as coloring agents for enamels and ceramic glazes; agricultural chemicals; use in electroplating process; use in formulation of corrosion inhibitors for aqueous systems; pigments for paints, lacquers, and coloring animal fibers and hair; use in enamel processes for adherence of vitreous coatings to ceramics and metal; use in leather and skin tanning; use as chlorination catalysts; in fire retardant resins; as a brazing flux and as an intermediate for organo metallic compunds; use in photography; ion exchange processes and formulation of plastics and adhesives; as a catalyst in desulfurization of gasoline, use as a reagent for determination of phosphorus and lead. /Soluble molybdenum compounds (as molybdenum)/

(FL) FLORIDA 35 ug/l /Molybdenum/

(ME) MAINE 35 ug/l /Molybdenum/

Determination of molybdenum in tissues (lung, liver, kidney, spleen, bone) of guinea pigs following 25 days of inhalation of subLD50 doses of the sulfide, the dust and fume of the trioxide, and calcium molybdate showed rather uniform distribution in the tissues, incl bone, for all substances at the end of the exposure. Values from 10 to 60 ug/10 g fresh tissue were common for all substances except molybdate trioxide and calcium molybdate dusts, which were higher by a two to four fold factor in the kidney, lung, spleen, and bone. Other exceptions were high lung retentions (40 and 18 times, respectively) for the sulfide and molybdate over that by other tissues according to the thiocyanate method of analysis.

... LARGE AMT /OF MOLYBDENUM/ TEND TO ACCUMULATE IN LIVER. /MOLYBDENUM/

Naturally occurs as the mineral molybdenite (main source of molybdenum); [Merck Index] Used as a lubricant in greases, oil dispersions, resin bonded films, and dry powders (especially at extreme pressures and high vacuum); Also used as a hydrogenation catalyst and in microprobe analysis of soil erosion aerosols; [HSDB]

Mining [Category: Industry]

Lubricants in greases, oil dispersions, resin bonded films, dry powders, especially at extreme pressures and high vacua

Dry lubricant, hydrogenation catalyst

MICROPROBE ANALYSIS OF SOIL EROSION AEROSOLS

2023: 25,000,000 - <40,000,000 lb

(1972) 5.1X10+10 G

Purification of molybdenite, reaction of sulfur or hydrogen sulfide on molybdenum trioxide.

Operations recovering molybdenum as a by product of copper mining produce a concentrate containing both metals. Molybdenite is separated from the copper minerals by differential flotation.

All Other Basic Inorganic Chemical Manufacturing

Molybdenum sulfide (MoS2): ACTIVE

Molybdenite concn contains about 90% molybdenum disulfide. The remainder is primarily silica. The concentrate is roasted to remove the sulfur and convert the sulfide to oxide.

LAB PREPN: BELL, HERFERT, J AM CHEM SOC 79, 3351 (1957).