Sodium perborate (PBS) is a white, odorless, water-soluble chemical compound with chemical formula NaBO3. It crystallizes as the monohydrate, NaBO3·H2O, tetrahydrate, NaBO3·4H2O and trihydrate, NaBO3·3H2O. [1]The monohydrate and tetrahydrate are the commercially important forms.[1]