NIOSH logo and tagline

Molybdenum

Synonyms & Trade Names
Molybdenum metal
CAS No.
7439-98-7
RTECS No.
DOT ID & Guide
Formula
Mo
Conversion
IDLH
5000 mg/m3 (as Mo)
See: 7439987
Exposure Limits
NIOSH REL
See Appendix D
OSHA PEL
TWA 15 mg/m3 [*Note: The PEL also applies to other insoluble molybdenum compounds (as Mo).] See Appendix G
Measurement Methods
NIOSH 7300 , 7301 , 7303 , 9102;
OSHA ID121 , ID125G
See: NMAM or OSHA Methods
Physical Description
Dark gray or black powder with a metallic luster.
Molecular Weight
95.9
Boiling Point
8717°F
Melting Point
4752°F
Solubility
Insoluble
Vapor Pressure
0 mmHg (approx)
Ionization Potential
NA
Specific Gravity
10.28
Flash Point
NA
Upper Explosive Limit
NA
Lower Explosive Limit
NA
Combustible Solid in form of dust or powder.
Incompatibilities & Reactivities
Strong oxidizers
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
Personal Protection/Sanitation
(See protection codes)
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 quarter-mask respirator.
Click here for information on selection of N, R, or P filters.

Up to 150 mg/m3:
(APF = 10) Any particulate respirator equipped with an N95, R95, or P95 filter (including N95, R95, and P95 filtering facepieces) except quarter-mask respirators. The following filters may also be used: N99, R99, P99, N100, R100, P100.
Click here for information on selection of N, R, or P filters.
(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 high-efficiency particulate filter.

Up to 750 mg/m3:


(APF = 50) Any air-purifying, full-facepiece respirator with an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters. 


(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 an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters. 


Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 1003
Page last reviewed: October 30, 2019