IPCS INCHEM Home
SULPHUR DIOXIDEICSC: 0074
October 2006
CAS #: 7446-09-5Sulfurous oxide
Sulfurous anhydride
Sulfur oxide
UN #: 1079
EINECS #: 231-195-2

  ACUTE HAZARDS PREVENTION FIRE FIGHTING
FIRE & EXPLOSION Not combustible. Heating will cause rise in pressure with risk of bursting.        In case of fire in the surroundings, use appropriate extinguishing media.  In case of fire: keep cylinder cool by spraying with water. NO direct contact with water. Combat fire from a sheltered position. 

 STRICT HYGIENE! IN ALL CASES CONSULT A DOCTOR! 
  SYMPTOMS ACUTE HAZARDS FIRST AID
Inhalation Cough. Shortness of breath. Sore throat. Laboured breathing. See Notes.  Use ventilation, local exhaust or breathing protection.  Fresh air, rest. Artificial respiration may be needed. Refer for medical attention. 
Skin ON CONTACT WITH LIQUID: FROSTBITE.  Cold-insulating gloves.  ON FROSTBITE: rinse with plenty of water, do NOT remove clothes. Refer for medical attention . 
Eyes Redness. Pain.  Wear safety goggles, face shield or eye protection in combination with breathing protection.  Rinse with plenty of water for several minutes (remove contact lenses if easily possible). Refer for medical attention. 
Ingestion      

SPILLAGE DISPOSAL CLASSIFICATION & LABELLING
Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Ventilation. NEVER direct water jet on liquid. 

According to UN GHS Criteria

cylinder;gasskull;toxicexcl mark;warnenviro;aqua
WARNING
Contains refrigerated gas; may cause cryogenic burns or injury
Toxic if inhaled
Causes eye irritation
Causes damage to respiratory tract if inhaled
Causes damage to the respiratory tract through prolonged or repeated exposure if inhaled
Harmful to aquatic life 

Transportation
UN Classification
UN Hazard Class: 2.3; UN Subsidiary Risks: 8 

STORAGE
Ventilation along the floor. Dry. 
PACKAGING
Note: 5 
SULPHUR DIOXIDE ICSC: 0074
PHYSICAL & CHEMICAL INFORMATION

Physical State; Appearance
COLOURLESS GAS OR COMPRESSED LIQUEFIED GAS WITH PUNGENT ODOUR. 

Physical dangers
The gas is heavier than air. 

Chemical dangers
The solution in water is a medium strong acid. Reacts violently with sodium hydride. Attacks plastic. 

Formula: SO2
Molecular mass: 64.1
Boiling point: -10°C
Melting point: -75.5°C
Relative density (water = 1): 1.4 (liquid, -10°C)
Solubility in water, ml/100ml at 25°C: 8.5
Vapour pressure, kPa at 20°C: 330
Relative vapour density (air = 1): 2.25  


EXPOSURE & HEALTH EFFECTS

Routes of exposure
The substance can be absorbed into the body by inhalation. 

Effects of short-term exposure
Rapid evaporation of the liquid may cause frostbite. The substance is irritating to the eyes and respiratory tract. Inhalation may cause asthma-like reactions. The substance may cause effects on the respiratory tract. This may result in asthma-like reactions, reflex spasm of the larynx and respiratory arrest. The effects may be delayed. Medical observation is indicated. 

Inhalation risk
A harmful concentration of this gas in the air will be reached very quickly on loss of containment. 

Effects of long-term or repeated exposure
Repeated or prolonged inhalation may cause asthma. 


Occupational exposure limits
TLV: 0.25 ppm as STEL; A4 (not classifiable as a human carcinogen).
MAK: 2.7 mg/m3, 1 ppm; peak limitation category: I(1); pregnancy risk group: C.
EU-OEL: 1.3 mg/m3, 0.5 ppm as TWA; 2.7 mg/m3, 1 ppm as STEL 

ENVIRONMENT
The substance is harmful to aquatic organisms. 

NOTES
Depending on the degree of exposure, periodic medical examination is suggested.
The symptoms of asthma often do not become manifest until a few hours have passed and they are aggravated by physical effort.
Rest and medical observation are therefore essential.
Anyone who has shown symptoms of asthma due to this substance should avoid all further contact.
Do NOT spray water on leaking cylinder (to prevent corrosion of cylinder).
Turn leaking cylinder with the leak up to prevent escape of gas in liquid state. 

ADDITIONAL INFORMATION
  EC Classification
Symbol: T; R: 23-34; S: (1/2)-9-26-36/37/39-45 

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