モリブデン(VI)トリオキシド

4.69 at 68 °F (USCG, 1999) - Denser than water; will sink

4.69 @ 26 °C/4 °C

4.696 @25 °C

WHITE OR SLIGHTLY YELLOW TO SLIGHTLY BLUISH POWDER OR GRANULES

COLORLESS OR WHITE YELLOW RHOMBIC CRYSTALS

WHITE POWDER AT ROOM TEMP, YELLOW AT ELEVATED TEMP

less than 1 mg/mL at 75 °F (NTP, 1992)

After strong ignition it is very slightly sol in acids

0.490 g/1000 cc water @ 28 °C

Sol in concentrated mineral acids

Sol in soln of alkali hydroxides and soln of potassium bitartrate

1.066 g/l water @ 18 °C

2111 °F at 760 mmHg (Sublimes) (NTP, 1992)

1155 °C, SUBLIMES

1155 °C @760 [mm Hg]

1463 °F (NTP, 1992)

795 °C

802 °C

Molybdenum trioxide appears as colorless to white or yellow odorless solid. Sinks in water. (USCG, 1999)

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

White or slightly yellow to slightly bluish solid; [Merck Index] Light green odorless powder; Partially soluble in water (1.07 g/L at 18 deg C); [MSDSonline] A soluble compound; [ACGIH]

READILY COMBINES WITH ACIDS & BASES TO FORM A SERIES OF POLYMERIC CMPD

PENTAVALENT MOLYBDENUM COMPLEXES ARE UNSTABLE TO OXIDATION, BUT HEXAVALENT MOLYBDENUM COMPLEXES WITH OXYGEN AS THE PREFERRED LIGAND & FORMS STABLE ISOPOLY & HETEROPOLY ACIDS & SALTS ... THESE POLYACIDS CAN REACT WITH PHOSPHATES & TARTRATES IN BIOLOGIC FLUIDS & TISSUES. BECAUSE OF PREFERRED AFFINITY OF MOLYBDENUM 6+ FOR OXYGEN LIGANDS, MOLYBDENUM BINDS TO CARBOXY GROUPS, HYDROXYL GROUPS, & ALSO SULFHYDRYL GROUPS PRESENT IN MACROMOLECULES. /MOLYBDENUM/

Warning

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

P203, P261, P264+P265, P271, P280, P304+P340, P305+P351+P338, P318, P319, P337+P317, P403+P233, P405, and P501 (click each P-code to see the statement)

Warning

H319 (> 99.9%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

P203, P261, P264+P265, P271, P280, P304+P340, P305+P351+P338, P318, P319, P337+P317, P403+P233, P405, and P501 (click each P-code to see the statement)

Chemical: Molybdenum oxide (MoO3)

Hazard Traits - Carcinogenicity

Molybdenum oxide (MoO3) is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Molybdenum oxide (MoO3) 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)

Status: Active Update: 27-04-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/15499

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

An eye, mucous membrane, and upper respiratory tract irritant; [HSDB] Serious health risk by ingestion or prolonged inhalation; [eChemPortal: ESIS] Carcinogenicity in man cannot be assessed conclusively because of insufficient data (Group 3B); [MAK] An irritant; [MSDSonline] See Molybdenum.

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

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

Toxicology & Carcinogenesis Studies of Molybdenum Trioxide in F344/N Rats and B6C3F1 Mice (Inhalation Studies). Technical Report Series No. 462 (1997) NIH Publication No. 97-3378 U.S. Department of Health and Human Services, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709

MOLYBDENUM TRIOXIDE reacts violently with chlorine trifluoride, lithium, potassium and sodium. Readily combines with acids and bases to form a series of polymeric compounds. Incompatible with interhalogens and metals. A violent detonation occurs when heated with molten magnesium. (NTP, 1992)

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SMALL SPILLS AND LEAKAGE: If you spill this chemical, dampen the solid spill material with 5% ammonium hydroxide, then transfer the dampened material to a suitable container. Use absorbent paper dampened with 5% ammonium hydroxide to pick up any remaining material. Your contaminated clothing and the absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Wash all contaminated surfaces with 5% ammonium hydroxide followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

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.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

Employees should wash promptly when skin becomes contaminated. Promptly remove nonimpervious clothing that becomes contaminated. /Molybdenum, soluble compounds (as Mo)/

... A complete respiratory protection program should be instituted which incl regular training, maintenance, inspection, cleaning, and evaluation. /Sol Molybdenum compounds (as Mo); Molybdenum and insoluble molybdenum compounds/

0.5 [mg/m3], as Mo, respirable fraction

8 hr Time Weighted Avg (TWA): 0.5 mg/cu m (respirable fraction). /Molybdenum, soluble compounds, as Mo/

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded. /Molybdenum, soluble compounds, as Mo/

A3; Confirmed animal carcinogen with unknown relevance to humans. /Molybdenum, soluble compounds, as Mo/

2.3 [mg/m3]

43 [mg/m3]

260 [mg/m3]

U.S. Bu. Mines approved respirator; safety glasses or face shield; protective gloves (USCG, 1999)

US BUREAU OF MINES APPROVED RESPIRATOR; SAFETY GLASSES OR FACE SHIELD; PROTECTIVE GLOVES

Respirator selection: Upper limit devices recommended by OSHA: Up to 50 mg/cu m: any dust respirator except single-use and quarter-mask respirators or any supplied air respirator or any self-contained breathing apparatus; up to 125 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 250 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 5000 mg/cu m: any supplied-air respirator with a half-mask and operated in a pressure-demand or other positive pressure mode; up to 7500 mg/cu m: any supplied-air respirator with a full facepiece 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 a high-efficiency particulate filter or any appropriate escape-type self-contained breathing apparatus. /Molybdenum, soluble compounds, (as Mo)/

Wear appropriate equipment to prevent repeated or prolonged skin contact. Wear eye protection to prevent reasonable probability of eye contact. /Molybdenum, soluble compounds (as Mo)/

Employees should be provided with and required to use impervious clothing, gloves, face shields (eight inch minimum), and other appropriate protective clothing necessary to prevent repeated or prolonged skin contact with soluble molybdenum compounds or liquids containing soluble molybdenum compounds. ... Employees should be provided with and required to use dust and splash proof safety goggles where soluble molybdenum compounds or liquids containing soluble molybdenum compounds may contact the eyes. /Soluble molybdenum compounds (as molybdenum)/

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/

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/

1000 mg Mo/m3 (NIOSH, 2024)

1000.0 [mg/m3], as Mo

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.

METABOLISM OF MOLYBDENUM IN ANIMAL IS CLOSELY LINKED WITH THAT OF COPPER, WITH WHICH IT APPEARS TO HAVE RECIPROCAL ANTAGONISM ... /MOLYBDENUM/

THERE IS COMPLEX RELATIONSHIP BETWEEN MOLYBDENUM, COPPER & SULFATE, & PROBABLY SOME OTHER SULFUR CMPD. COPPER GENERALLY HAS BENEFICIAL EFFECT ON THE SYMPTOMS CAUSED BY EXCESSIVE MOLYBDENUM BUT THE ACTION OF THE SULFUR COMPOUNDS, ESPECIALLY SULFATE, IS NOT YET SO CLEARLY UNDERSTOOD. /MOLYBDENUM/

ANTAGONISM BETWEEN MOLYBDENUM & COPPER IS ... INFLUENCED IN A COMPLEX WAY BY DIETARY SULFATE, DEPENDING ON SPECIES: ... (1) SULFATE INTAKE CAUSES A REDISTRIBUTION OF MOLYBDENUM IN BLOOD CHARACTERIZED BY RED CELL DEPLETION; (2) SULFATE INCR ELIMINATION OF MOLYBDENUM FROM THE BODY; (3) DEPLETION OF HEPATIC COPPER WITH ASSOCIATED SIGNS OF COPPER DEFICIENCY FROM MOLYBDENUM OCCURS ONLY AT DIETARY LEVELS ABOVE SOME CRITICAL VALUE AND IS THUS AN ANTAGONISTIC EFFECT OF SULFATE ON MOLYBDENUM METABOLISM AND TOXICITY IN THE RAT ... /MOLYBDENUM/

Daily intake of molybdenum can be estimated to be between 100 and 500 ug. ... In areas where molybdenum ore is mined, considerable contamination may occur, which can cause high concentrations in drinking water leading to daily intakes of more than 1000 ug. /Molybdenum/

The amount of molybdenum in vegetable crops is greatly influenced by the molybdenum content of soil. ... The availability is dependent on pH, that is, it is greater in alkaline soils. ... The available molybdenum is of greater importance for plant nutrition than is the total amount of molybdenum. /Molybdenum/

The contents of ... molybdenum, and the copper/molybdenum ratio were determined in different native plant species from a mountain area of central southern Norway. The overall mean values and ranges (mg/kg dry mass) were ... molybdenum: 0.25, 0.01-3.57; ... copper/molybdenum: 79, 1-7955. /Molybdenum/

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical. [http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=1313-27-5]

The following medical procedures should be made available to each employee who is exposed to soluble molybdenum compounds at potentially hazardous levels: Initial medical screening: employees should be screened for history of certain medical conditions which might place the employee at increased risk from soluble molybdenum compounds exposure. Only those giving a positive history of the /following/ conditions should be referred for further medical examination: kidney disease; ... chronic respiratory disease: In persons with impaired pulmonary function ... the breathing of sol molybdenum compounds might cause exacerbation of symptoms due to their irritant properties; blood disease: ... persons with preexisting blood disorders may be more susceptible to the effects of these agents; gout: molybdenum compounds may cause gout. ... Periodic medical examination: Routine periodic exam are not considered necessary. However, anyone developing the above listed conditions should be referred for further medical examination. /Soluble molybdenum compounds (as Mo)/

Soluble molybdate ions are present in trace concn in many surface waters .. as product of natural weathering of molybdenum bearing soils. /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.

Pneumoconiosis with x-ray findings and subjective symptoms has been reported in 3 out of 19 workers exposed to metallic molybdenum and molybdenum trioxide. Exposure varied between 1 and 19 mg/cu m for 4-7 years.

A SURVEY OF A MOLYBDATE ROASTING PLANT IN COLORADO WAS MADE ... 25 MALE WORKERS WERE EXAMINED FOR BIOCHEMICAL ABNORMALITIES FROM EXPOSURE TO SOLUBLE MOLYBDENUM DUSTS. THE 8-HR TWA EXPOSURE TO SOLUBLE MOLYBDENUM (MAINLY MOLYBDENUM TRIOXIDE AND MOLYBDENUM OXIDES) WAS CALCULATED TO BE ABOUT 9.5 MG MOLYBDENUM/CU M, APPROXIMATELY DOUBLE THE RECOMMENDED TLV. THE MEAN AGE OF THE WORKERS WAS 28.3 YR (RANGE 19 TO 44 YR) AND THE MEAN DURATION OF EMPLOYMENT, 4.0 YR (RANGE 0.5 TO 20 YR). ... ONLY ADVERSE BIOCHEMICAL FINDINGS WERE LARGE ELEVATIONS IN SERUM CERULOPLASMIN (AVG 50.47 + or - 1.38 MG/100 ML VERSUS 30.50 + or - 1.33 MG/100 ML FOR CONTROLS) AND SMALLER INCREMENTS IN SERUM URIC ACID LEVELS (5.90 + or - 0.24 MG/100 VERSUS 5.01 + or - 0.25 MG/100 ML FOR CONTROLS).

ANEMIA IS CHARACTERISTIC FEATURE OF MOLYBDENUM TOXICITY, WITH LOW HEMOGLOBIN CONCN AND REDUCED RED CELL COUNTS. /MOLYBDENUM COMPOUNDS/

INCR BLOOD URIC ACID VALUES & GOUT LIKE SYMPTOMS HAVE BEEN REPORTED ... AMONG THE GENERAL POPULATION LIVING IN AREA WITH HIGH MOLYBDENUM & LOW COPPER CONTENT IN SOILS & VEGETABLES. /MOLYBDENUM/

For more Human Toxicity Excerpts (Complete) data for MOLYBDENUM TRIOXIDE (6 total), please visit the HSDB record page.

(FL) FLORIDA 35 ug/l /Molybdenum/

(ME) MAINE 35 ug/l /Molybdenum/

The mechanism of molybdenum toxicity is not yet quite understood. It is assumed that the primary factor is the formation of a copper-tetrathiomolybdate complex in the reduction medium of the gastrointestinal tract which reduces the biological utility of copper. /Molybdenum/

Molybdenum is an essential metal as a cofactor for the enzymes xanthine oxidase and aldehyde oxidase. /Molybdenum/

Data ... concerning excretion and the rapid clearance from the liver, kidney, spleen, testis, and hard tissues in animal studies show that the biological half time, at least for the most part of the absorbed molybdenum, must be in the order of hours and extending to a max of about one day in lab animals and cows. ... After a single subcutaneous injection in rats, the concentration of molybdenum in blood decr rapidly. After 24 hr, only about 1% of the max concn remained. During the next 10 days, concn in blood diminished with a half time of about 7 days. After application of doses up to 3 ug/kg to rats the biological half time was 3 hr for subcutaneous, and 6 hr for intragastric application. After single subcutaneous application of 0.02 to 1 ug molybdenum/kg to rats the biological half time in the kidneys, liver, spleen, jejunoileum, and skin varied between 2.5 and 4.7 days. /Molybdenum/

Following rapid absorption from the gastrointestinal tract /of/ guinea pigs, molybdenum trioxide was found to be deposited rather uniformly in the critical organs within 4 hr ... .

Rats stored relatively more molybdenum from ingested molybdenum trioxide than from Powellite (CaMoO4). ... Significant storage above normal of molybdenum in bone was noted in all cases.

RABBITS SHOWED ... RAPID ABSORPTION OF MOLYBDENUM /AS MOLYBDENUM TRIOXIDE/ FOLLOWING INGESTION, WITH RAPIDLY RISING BLOOD LEVELS. MOLYBDENUM IS RAPIDLY ELIMINATED BY KIDNEYS, RETURNING ... TO NORMAL VALUES IN 72 HR ... FECAL ELIMINATION, WHICH IS ABOUT 1/2 THAT OF URINARY, RETURNED TO NORMAL ... IN 72 HR.

IN BLOOD, LEVEL DEPENDS LARGELY ON CONTENT OF MOLYBDENUM AND INORGANIC SULFATE IN DIET. ... RABBITS GIVEN SINGLE DOSE OF TRIOXIDE HAVE SHOWN A RISE FROM 130 TO 200 UG PER 100 ML, EVEN AS HIGH AS 1,850-1,970 UG ... .

For more Absorption, Distribution and Excretion (Complete) data for MOLYBDENUM TRIOXIDE (21 total), please visit the HSDB record page.

Used primarily in steel production as a corrosion inhibitor (~80-90%),then catalyst for refineries (~10%), then super alloys (~5%); [IARC Monograph 118] Used as a polymerization catalyst of olefins, a reagent in chemical analysis, a corrosion inhibitor, a catalyst in the petroleum industry, and an agricultural chemical; Also used to make molybdenum metal and alloys as well as ceramics, enamels, and pigments; [HSDB]

Metal Preparation and Pouring [Category: Foundry]

Ceramics making [Category: Hobbies]

Pure molybdenum trioxide is used in chemical and catalyst manufacture and the technical product is added to steel as an alloying agent.

To catalyze the polymerization of olefins

Reagent in chem analysis

2023: 100,000,000 - <250,000,000 lb

(1972) 2.18X10+10 G

ROASTING OF MOLYBDENITE; IGNITION OF THE METAL, SULFIDES, LOWER OXIDES AND MOLYBDIC ACIDS; PURIFICATION: SUBLIMATION

PREPN FROM AMMONIUM MOLYBDATE: SCHUMB, HARTFORD, J AM CHEM SOC 56, 2613 (1934).

All Other Basic Inorganic Chemical Manufacturing

Molybdenum oxide (MoO3): ACTIVE

HYDROGEN SULFIDE GASES ARE CONTACTED WITH ABSORBENT CONTAINING MOLYBDENUM OXIDE & TITANIUM DIOXIDE IN TITANIUM/MOLYBDENUM RATIO (30-99):(1-70) @ 100-300 °C TO REMOVE THE HYDROGEN SULFIDE.

WASTE GASES CONTAINING NITROGEN OXIDES ARE TREATED WITH AMMONIA @ 200-500 °C IN THE PRESENCE OF CATALYST CONTAINING AS A COMPONENT MOLYBDENUM TRIOXIDE.