Molybdenum

Synonyms & Trade Names

Molybdenum metal

CAS No.

7439-98-7

RTECS No.

QA4680000

DOT ID & Guide

Formula

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

Specific Gravity

10.28

Flash Point

Upper Explosive Limit

Lower Explosive Limit

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

Molybdenum

NIOSH REL

OSHA PEL

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