IPCS INCHEM Home
SELENIOUS ACIDICSC: 0945
Monohydrated selenium dioxide
Selenous acid
March 2000
CAS #: 7783-00-8
UN #: 3283
EC Number: 231-974-7

  ACUTE HAZARDS PREVENTION FIRE FIGHTING
FIRE & EXPLOSION Not combustible. Gives off irritating or toxic fumes (or gases) in a fire.        In case of fire in the surroundings, use appropriate extinguishing media.   

 PREVENT DISPERSION OF DUST! STRICT HYGIENE!  
  SYMPTOMS PREVENTION FIRST AID
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 CLASSIFICATION & 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. 

According to UN GHS Criteria

 

Transportation
UN Classification
UN Hazard Class: 6.1; UN Pack Group: II 

STORAGE
Separated from food and feedstuffs. Dry. Keep in a well-ventilated room. 
PACKAGING
 
SELENIOUS ACID ICSC: 0945
PHYSICAL & CHEMICAL INFORMATION

Physical State; Appearance
COLOURLESS HYGROSCOPIC CRYSTALS. 

Physical dangers
 

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

Formula: H2SeO3
Molecular mass: 129.0
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  


EXPOSURE & HEALTH EFFECTS

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

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. 

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

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. 


OCCUPATIONAL EXPOSURE LIMITS
TLV: 0.2 mg/m3, as TWA.
MAK: (as Se, inhalable fraction): 0.02 mg/m3; peak limitation category: II(8); carcinogen category: 3B; pregnancy risk group: C 

ENVIRONMENT
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. 

ADDITIONAL INFORMATION
  EC Classification
Symbol: T, N; R: 23/25-33-50/53; S: (1/2)-20/21-28-45-60-61; Note: A 

All rights reserved. The published material is being distributed without warranty of any kind, either expressed or implied. Neither ILO nor WHO nor the European Commission shall be responsible for the interpretation and use of the information contained in this material.
    See Also:
       Toxicological Abbreviations