General description:
Sodium metabisulfite appears as a white crystalline or powder solid with a slight sulfur odor. Toxic by inhalation. Strongly irritates skin and tissue. The substance is sometimes referred to as disodium metabisulfite. It is used as a disinfectant, antioxidant, and preservative agent.
Application & Usage:
It is used to precipitate gold from auric acid
It is used in waste treatment to chemically reduce hexavalent chromium to trivalent chromium which can then be precipitated and removed from an aqueous waste stream
It is used as a cleaning agen