Molybdenum(IV) oxide

  • Molybdenum dioxide
  • Molybdenum oxide
Formula
MoO2
Structure
Description
Brown-violet tetragonal crystals.

Registry Numbers and Inventories.
CAS
18868-43-4
EC (EINECS/ELINCS)
242-637-9
20/21/22 36/37/3826 36
RTECS
QA4688000
RTECS class
Other
UN (DOT)
3288
Beilstein/Gmelin
15492 (G)
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
Korea ECL
Listed

Properties.
Formula
MoO2
Formula mass
127.94
Melting point, °C
770 - 795
Boiling point, °C
1207 - 1307
Sublimation point, °C
730
Vapor pressure, mmHg
0.01 (800 C)
Density
6.47 g/cm3 (25 C)
Solubility in water
Insoluble
Refractive index
1.52
Dielectric constant
16 - 18
Thermal expansion
4.2E-5/K
Heat of fusion
121.8 kJ/mol
Heat of vaporization
146.9 kJ/mol

Hazards and Protection.
Storage
Keep tightly closed. Store in a cool dry place. Store under nitrogen.
Protection
Wear appropriate government approved respirator, chemical-resistant gloves, safety goggles, other protective clothing.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS.
Incompatibilities
Strong oxidizing agents, Strong acids.
Decomposition
Nature of decomposition products not known.

Fire.
Fire fighting
Extinguish using Noncombustible. Use extinguishing media appropriate to surrounding fire conditions. Wear self-contained breathing apparatus and protective clothing to prevent contact with skin and eyes.
Fire potential
Non-Combustible
Hazards
Emits toxic fumes under fire conditions.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.

Health.
Exposure effects
Harmful. Harmful by inhalation, in contact with skin and if swallowed. Irritating to eyes, respiratory system and skin. Target organ(s): Liver. Kidneys.
   Inhalation
Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Effects of contact or inhalation may be delayed.
   Skin
Avoid any skin contact. See Inhalation.
   Eyes
See Inhalation.

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult.
   Skin
Remove and isolate contaminated clothing and shoes. Remove material from skin immediately. Immediately flush with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin.
   Eyes
Immediately flush with running water for at least 20 minutes.

Transport.
UN number
3288
Response guide
Hazard class
6.1