POTASSIUM METABISULPHITE (K₂S₂O₅)

SYNONYMS
Potassium pyrosulphate.
GENERAL PRECAUTIONS
Avoid skin and eye contact.
Avoid inhalation or ingestion of the powder.
Keep away from heat.
Keep away from moisture.
Keep away from metals.
Keep the container tightly sealed.
Wash hands thoroughly after handling.
CHARACTERISTICS
White crystals or powder.
HEALTH HAZARD DATA
This substance is a strong corrosive and in the presence of moisture will liberate sulphurous acid. It will cause burns to the skin, especially if the skin is moist. It will burn the eyes causing permanent damage unless treatment is rapid. It can cause severe damage to the respiratory system and the stomach with severe pain and possible collapse in severe cases.
TREATMENTS
Skin ­ remove contaminated clothing and immediately wash the affected area with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). If irritation or pain persist or blisters develop, seek medical attention. Wash contaminated clothing before re­use.
Eyes ­ Immediately wash the affected eye with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). If burning or pain persist or vision is blurred, seek immediate medical attention.
Inhalation ­ remove from the area of exposure to fresh air. Keep warm and allow to rest. If there is any sign of discomfort seek immediate medical attention.
Ingestion ­ wash the mouth thoroughly with water and give water to drink. Seek immediate medical attention.
INCOMPATIBILITY
Heating produces toxic sulphur dioxide.
Potassium metabisulphite will corrode metals.
STORAGE
Store in a non­metal, tightly sealed container, in a cool, dry atmosphere away from heat.
HANDLING
Handle with extreme care. Use a fume hood if available to help keep the level of exposure low and to aid with protection. Wear protective clothing. A long sleeved laboratory coat or gown, rubber gloves, safety goggles and a face mask as a minimum standard. If there is a danger of a splash occurring from a solution then a full face shield should be worn.
DISPOSAL
WEAR:
Rubber gloves, safety glasses and laboratory coat. Work in a fume hood or wear a respirator.
SPILLS:
Gas leak: eliminate all sources of ignition. If the valve is leaking because it cannot be closed, the gas can be bubbled through a calcium hypochlorite solution. Be sure to include a trap in the line to prevent the solution being sucked back into the cylinder.
Solid: cover the spill with soda ash or sodium bicarbonate. Mix and spray with water. If effervescent wait until the reaction is complete. Scoop into a large beaker and cautiously add an equal volume of calcium hypochlorite (the reaction may be vigorous). Add more water, stir and allow to stand for one hour. Dilute and neutralise the oxidised solution and discharge to sewer with a large excess of water.
PACKAGE LOTS:
If a gas, bubble into a soda ash solution. if a solid, mix with an equal volume of soda and water to form a slurry, use a large container. In either case add calcium hypochlorite. Add more water if necessary and allow to stand for two hours. Neutralise the oxidised solution then discharge to the sewer with a large excess of water.
ENVIRONMENT:

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