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OSMIUM TETROXIDE
ICSC: 0528
Peer-Review Status: 10.09.1997 Validated
Osmic acid anhydride
Osmium oxide
Osmium tetraoxide 
CAS #: 20816-12-0 RTECS #: RN1140000
UN #: 2471
EC #: 076-001-00-5
EINECS #: 244-058-7
    Formula: O4Os
Molecular mass: 254.2

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Not combustible but enhances combustion of other substances.  NO contact with flammables.  In case of fire in the surroundings, use appropriate extinguishing media. 
EXPLOSION Risk of fire and explosion on contact with combustible substances.     
 
EXPOSURE   AVOID ALL CONTACT!   
Inhalation Burning sensation. Cough. Headache. Wheezing. Shortness of breath. Visual disturbances. Symptoms may be delayed. See Notes.  Use local exhaust or breathing protection.  Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention. 
Skin Redness. Skin burns. Pain. Skin discoloration. Blisters.  Protective gloves. Protective clothing.  First rinse with plenty of water for at least 15 minutes, then remove contaminated clothes and rinse again. Refer for medical attention . 
Eyes Redness. Pain. Blurred vision. Loss of vision. Severe deep burns.  Wear safety goggles or eye protection in combination with breathing protection if powder.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion Abdominal cramps. Burning sensation. Shock or collapse. See Inhalation.  Do not eat, drink, or smoke during work. Wash hands before eating.  Rinse mouth. Give nothing to drink. Rest. Refer for medical attention . 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Ventilation. Do NOT let this chemical enter the environment. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Then store and dispose of according to local regulations. Do NOT absorb in saw-dust or other combustible absorbents.  Unbreakable packaging.
Put breakable packaging into closed unbreakable container.
Do not transport with food and feedstuffs.
Severe marine pollutant. 
EC Classification
Symbol: T+; R: 26/27/28-34; S: (1/2)-7/9-26-45 
UN Classification
UN Hazard Class: 6.1; UN Pack Group: I 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-61G64A.  Separated from combustible substances, reducing agents and food and feedstuffs. Ventilation along the floor. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS-TO-PALE-YELLOW SOLID IN VARIOUS FORMS WITH PUNGENT ODOUR. 

Physical dangers
 

Chemical dangers
Decomposes on heating. This produces fumes of osmium. The substance is a strong oxidant. It reacts with combustible and reducing materials. Reacts with hydrochloric acid. This produces toxic gas (chlorine - see ICSC 0126). Mixtures with alkalis are unstable. 

Occupational exposure limits
 

Routes of exposure
The substance can be absorbed into the body by inhalation of its aerosol or vapour and by ingestion. 

Inhalation risk
A harmful contamination of the air can be reached very quickly on evaporation of this substance at 20°C. 

Effects of short-term exposure
Lachrymation. The substance is corrosive to the eyes, skin and respiratory tract. Inhalation may cause lung oedema. See Notes. Exposure to high concentrations could cause death. The effects may be delayed. Medical observation is indicated. 

Effects of long-term or repeated exposure
Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the kidneys. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Boiling point: 130°C
See Notes.
Melting point: 42°C
Relative density (water = 1): 4.9
Solubility in water, g/100ml at 25°C: 6
Vapour pressure, kPa at 27°C: 1.5
Relative vapour density (air = 1): 8.8  
This substance may be hazardous to the environment. Special attention should be given to crustacea. 

NOTES
Begins to sublime and distil well below boiling point.
The symptoms of lung oedema often do not become manifest until a few hours have passed and they are aggravated by physical effort.
Rest and medical observation is therefore essential.
Immediate administration of an appropriate spray, by a doctor or a person authorized by him/her, should be considered.
The odour warning when the exposure limit value is exceeded is insufficient.
Do NOT take working clothes home.
Rinse contaminated clothes (fire hazard) with plenty of water.
Card has been partially updated in August 2007: see Occupational Exposure Limits. 

ADDITIONAL INFORMATION
 

IPCS
International
Programme on
Chemical Safety
WHO ILO EC Prepared in the context of cooperation between the International Programme on Chemical Safety and the European Commission
© IPCS 2004-2012
LEGAL NOTICE Neither the EC nor the IPCS nor any person acting on behalf of the EC or the IPCS is responsible for the use which might be made of this information.


    See Also:
       Toxicological Abbreviations