Safety Information
Sodium Metabisulphite. 25kg Bag Food Grade
Sodium metabisulphite or sodium pyrosulfite (IUPAC spelling; Br. E. sodium metabisulphite or sodium pyrosulphite) is an inorganic compound of chemical formula Na2S2O5. The substance is sometimes referred to as disodium (metabisulphite). It is used as a disinfectant, antioxidant and preservative agent.
It is used as a preservative and antioxidant in food and is also known as E223.
It may cause allergic reactions in those who are sensitive to sulfites, including respiratory reactions in asthmatics, anaphylaxis and other allergic reactions in sensitive individuals.
Sodium metabisulphite and potassium metabisulphite are the primary ingredients in Campden tablets, used for wine and beer making.
It is commonly used in homebrewing and winemaking to sanitise equipment. It is used as a cleaning agent for potable water reverse osmosis membranes in desalination systems. It is also used to remove chloramine from drinking water after treatment.
It is used in photography.
Concentrated sodium metabisulphite can be used to remove tree stumps. 98% sodium metabisulphite causes degradation of lignin in the stumps, facilitating removal.
When mixed with water, sodium metabisulphite releases sulphur dioxide (SO2), a pungent, unpleasant smelling gas that can also cause breathing difficulties in some people. For this reason, sodium metabisulphite has fallen from common use in recent times, with agents such as hydrogen peroxide becoming more popular for effective and odorless sterilisation of equipment. Released sulphur dioxide however makes the water a strong reducing agent.