Sodium perborate are chemical compounds with chemical formula [Na+]2[B2O4(OH)4]2−(H2O)x. Commonly encountered salts are the anhydrous form (x = 0) and as a hexahydrate (x = 6). These two species are sometimes called, respectively, “monohydrate” or PBS-1 and “tetrahydrate” or PBS-4, after the historic assumption that NaBO3 would be the anhydrous form). Both the anhydrous and hexahydrate salts are white, odorless, water-soluble solids.Peroxyborates are widely used in laundry detergents, as one of the peroxide-based bleaches.Sodium perborate was first obtained in 1898, independently, by Sebastian Tanatar and by P. Melikoff and L. Pissadewsky; the researchers prepared sodium perborate by treating sodium borate with a solution of hydrogen peroxide and sodium hydroxide, but Tanatar also obtained sodium perborate by electrolysis of a solution of sodium borate.