Also known as Perboric Acid Sodium Salt Monohydrate, this odorless compound presents as a white, crystalline a powder. The monohydrate form of Sodium Perborate dissolves better than the tetrahydrate and has higher heat stability. Initiating contact between this substance and combustible material may cause fire and it is harmful if swallowed as well as irritating to the eyes. Sodium Perborate Monahydrate is hygroscopic and should be stored at ambient temperatures.