NIOSH Pocket Guide to Chemical Hazards

Molybdenum CAS 7439-98-7
Mo RTECS QA4680000
Synonyms & Trade Names
Molybdenum metal
DOT ID & Guide
Exposure
Limits
NIOSH REL*: See Appendix D [*Note: The REL also applies to other insoluble molybdenum compounds (as Mo).]
OSHA PEL*: TWA 15 mg/m3 [*Note: The PEL also applies to other insoluble molybdenum compounds (as Mo).]
IDLH 5000 mg/m3 (as Mo) Conversion
Physical Description
Dark gray or black powder with a metallic luster.
MW: 95.9
BP: 8717°F
MLT: 4752°F
Sol: Insoluble
VP: 0 mmHg (approx)
IP: NA

Sp.Gr: 10.28
Fl.P: NA
UEL: NA
LEL: NA

Combustible Solid in form of dust or powder.
Incompatibilities & Reactivities
Strong oxidizers
Measurement Methods
NIOSH 7300; OSHA ID121, ID125G
Personal Protection & Sanitation
Skin: No recommendation
Eyes: No recommendation
Wash skin: No recommendation
Remove: No recommendation
Change: No recommendation

First Aid (See procedures)
Eye: Irrigate immediately

Breathing: Respiratory support
Swallow: Medical attention immediately
Respirator Recommendations OSHA
Up to 75 mg/m3: (APF = 5) Any dust and mist respirator^
Up to 150 mg/m3: (APF = 10) Any dust and mist respirator except single-use and quarter-mask respirators^/(APF = 10) Any supplied-air respirator
Up to 375 mg/m3: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode/(APF = 25) Any powered, air-purifying respirator with a dust and mist filter^
Up to 750 mg/m3: (APF = 50) Any air-purifying, full-facepiece respirator with a high-efficiency particulate filter/(APF = 50) Any supplied-air respirator that has a tight-fitting facepiece and is operated in a continuous-flow mode/(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and a high-efficiency particulate filter/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece
Up to 5000 mg/m3: (APF = 1000) Any supplied-air respirator operated in a pressure-demand or other positive-pressure mode
Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus
Escape: (APF = 50) Any air-purifying, full-facepiece respirator with a high-efficiency particulate filter/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms In animals: irritation eyes, nose, throat; anorexia, diarrhea, weight loss; listlessness; liver, kidney damage
Target Organs Eyes, respiratory system, liver, kidneys
See also: INTRODUCTION