Sodium metabisulfite CAS#7681-57-4

Sodium metabisulfite (chemical formula: Na2S2O5) appears as a white crystalline or powder solid with a slight sulfur odor. It is toxic upon inhalation and can strongly irritate skin and tissue. It can be decomposed to release toxic oxide fumes of sulfur and sodium upon high temperature. It can be mixed with water to form a corrosive acid. It is generally used as disinfectant, antioxidant, and preservative agent as well as a laboratory reagent. As a kind of food additive, it can be used as a preservative and antioxidant in food. It can also be applied to the wine and beer making. Moreover, it can be used to sanitize the equipment of homebrew and winemaking as a cleaning agent. It also have various kinds of other applications, e.g. being applied to photography, as an excipients in some tablets, for water treatment, as a source of SO2 in wine, as a bactericide and as a bleaching reagent as well as reducing agent. It can be manufactured through the evaporation of a sodium bisulfite which has been saturated with sulfur dioxide. It should be warned that sodium metabisulfite has certain acute effects on the respiratory system, eyes and skin. In severe case, it can cause breathing difficulty and even pulmonary damage which finally leads to death. Therefore, effective protective measures and attention should be taken during the operation.