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SELENIOUS ACID
ICSC: 0945
Peer-Review Status: 10.03.2000 Validated
Monohydrated selenium dioxide
Selenous acid 
CAS #: 7783-00-8 RTECS #: VS7175000
UN #: 3283
EC #: 034-002-00-8
EINECS #: 231-974-7
    Formula: H2SeO3
Molecular mass: 129.0

TYPES OF
HAZARD /
EXPOSURE
ACUTE HAZARDS / SYMPTOMS      PREVENTION      FIRST AID / FIRE FIGHTING
FIRE Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.    In case of fire in the surroundings, use appropriate extinguishing media. 
EXPLOSION      
 
EXPOSURE   PREVENT DISPERSION OF DUST! STRICT HYGIENE!   
Inhalation Burning sensation. Cough. Laboured breathing. Sore throat. Shortness of breath. Symptoms may be delayed. See Notes.  Use ventilation, local exhaust or breathing protection.  Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention. 
Skin Redness. Pain. Blisters. Skin burns.  Protective gloves. Protective clothing.  Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention . 
Eyes Redness. Pain. Severe deep burns.  Wear face shield or eye protection in combination with breathing protection.  First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. 
Ingestion Abdominal pain. Burning sensation. Sore throat. Diarrhoea. Nausea. Vomiting. Shock or collapse.  Do not eat, drink, or smoke during work. Wash hands before eating.  Rinse mouth. Do NOT induce vomiting. Refer for medical attention . 

SPILLAGE DISPOSAL
PACKAGING & LABELLING
Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Cover the spilled material with dry lime or soda ash. Carefully collect remainder. Then store and dispose of according to local regulations.   
EC Classification
Symbol: T, N; R: 23/25-33-50/53; S: (1/2)-20/21-28-45-60-61; Note: A 
UN Classification
UN Hazard Class: 6.1; UN Pack Group: II 
GHS Classification
 

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-61S3283-II or 61GT5-II.  Separated from food and feedstuffs. Dry. Keep in a well-ventilated room. 

IMPORTANT DATA
Physical State; Appearance
COLOURLESS HYGROSCOPIC CRYSTALS. 

Physical dangers
 

Chemical dangers
Decomposes on heating. This produces toxic fumes of selenium dioxide. 

Occupational exposure limits
TLV (as Se): 0.2mg/m³ as TWA; (ACGIH 2004).
MAK (inhalable fraction): 0.05 mg/m³; Carcinogen category: 3B; Peak limitation category: II(4); Pregnancy risk group: C; (DFG 2004). 

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

Inhalation risk
Evaporation at 20°C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed. 

Effects of short-term exposure
The substance is corrosive to the eyes, skin and respiratory tract. Inhalation may cause lung oedema. See Notes. The substance may cause effects on the eyes. This may result in allergic-type reaction of the eyelids (rose eye). Medical observation is indicated. 

Effects of long-term or repeated exposure
Repeated or prolonged contact may cause skin sensitization. The substance may have effects on the respiratory tract, gastrointestinal tract, central nervous system and liver. This may result in nasal irritation, persistent garlic odour, stomach pain, nervousness and liver impairment. 


PHYSICAL PROPERTIES ENVIRONMENTAL DATA
Decomposes at 70°C
Density: 3.0 g/cm³
Solubility in water, g/100ml at 20°C: 167
Vapour pressure, Pa at 15°C: 266  
The substance is harmful to aquatic organisms. 

NOTES
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 inhalation therapy by a doctor or a person authorized by him/her, should be considered.
Card has been partly updated in April 2005.
See section 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