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SULPHUR DIOXIDE ICSC: 0074
Date of Peer Review: October 1994

Sulfurous oxide
Sulfurous anhydride
Sulfur oxide
(cylinder)
CAS # 7446-09-5 SO2
RTECS # WS4550000 Molecular mass: 64.1
UN # 1079
EC # 016-011-00-9
TYPES OF HAZARD / EXPOSURE ACUTE HAZARDS / SYMPTOMS PREVENTION FIRST AID / FIRE FIGHTING
FIRE Not combustible. Heating will cause rise in pressure with risk of bursting.

In case of fire in the surroundings: use appropriate extinguishing media.
EXPLOSION

In case of fire: cool cylinder by spraying with water but avoid contact of the substance with water. Combat fire from a sheltered position.
EXPOSURE
STRICT HYGIENE!
IN ALL CASES CONSULT A DOCTOR!
Inhalation Cough. Shortness of breath. Sore throat. Symptoms may be delayed (see Notes).
Ventilation, local exhaust, or breathing protection.
Fresh air, rest. Half-upright position. Artificial respiration may be needed. Refer for medical attention. See Notes.
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. Severe deep burns.
Safety goggles 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 take to a doctor.
Ingestion


SPILLAGE DISPOSAL PACKAGING & LABELLING
Evacuate danger area! Consult an expert! Ventilation. NEVER direct water jet on liquid. Personal protection: complete protective clothing including self-contained breathing apparatus.
Do not transport with food and feedstuffs.
EU Classification
Symbol: T
R: 23-34
S: (1/2-)-9-26-36/37/39-45
UN Classification
UN Hazard Class: 2.3
UN Subsidiary Risks: 8

EMERGENCY RESPONSE SAFE STORAGE
Transport Emergency Card: TEC (R)-20S1079
NFPA Code: H 3; F 0; R 0
Fireproof if in building. Provision to contain effluent from fire extinguishing. Separated from food and feedstuffs, incompatible materials. See Chemical Dangers. Cool. Dry.
IPCS
International
Programme on
Chemical Safety
Prepared in the context of cooperation between the International Programme on Chemical Safety and the Commission of the European Communities IPCS, CEC 2004

SEE IMPORTANT INFORMATION ON BACK


SULPHUR DIOXIDE ICSC: 0074
IMPORTANT DATA
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 ammonia, acrolein, acetylene, alkali metals, chlorine, ethylene oxide, amines, butadiene. Reacts with water or steam causing corrosion hazard. Attacks many metals including aluminium, iron, steel, brass, copper and nickel in presence of water. Incompatible with halogens. Attacks plastic, rubber and coatings in liquid form.

OCCUPATIONAL EXPOSURE LIMITS:
TLV: 2 ppm as TWA, 5 ppm as STEL; A4 (not classifiable as a human carcinogen); (ACGIH 2004).
MAK: 0.5 ppm, 1.3 mg/m; Peak limitation category: I(1); Pregnancy risk group: C; (DFG 2004).
ROUTES OF EXPOSURE:
The substance can be absorbed into the body by inhalation.

INHALATION RISK:
A harmful concentration of this gas in the air will be reached very quickly on loss of containment.

EFFECTS OF SHORT-TERM EXPOSURE:
The substance is severely irritating to the eyes and the respiratory tract. Inhalation of the gas may cause lung oedema (see Notes). Rapid evaporation of the liquid may cause frostbite. The substance may cause effects on the respiratory tract, resulting in asthma-like reactions, reflex spasm of the larynx and respiratory arrest. Exposure may result in death. The effects may be delayed. Medical observation is indicated.

EFFECTS OF LONG-TERM OR REPEATED EXPOSURE:
Repeated or prolonged inhalation exposure may cause asthma.
PHYSICAL PROPERTIES
Boiling point: -10C
Melting point: -75.5C
Relative density (water = 1): 1.4 at -10C (liquid)
Solubility in water, ml/100 ml at 25C: 8.5
Vapour pressure, kPa at 20C: 330
Relative vapour density (air = 1): 2.25
ENVIRONMENTAL DATA
This substance may be hazardous in the environment; special attention should be given to air quality, water quality and plants.
NOTES
Depending on the degree of exposure, periodic medical examination is suggested. 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 are therefore essential. Immediate administration of an appropriate inhalation therapy by a doctor or a person authorized by him/her, should be considered. 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.
Card has been partly updated in April 2005. See sections Occupational Exposure Limits, EU classification.
ADDITIONAL INFORMATION


LEGAL NOTICE Neither the CEC nor the IPCS nor any person acting on behalf of the CEC or the IPCS is responsible for the use which might be made of this information
IPCS, CEC 2004
See Also:
        Sulfur dioxide (CHEMINFO)