Sodium bisulfate is used primarily to lower pH. For technical grade applications it is used in metal finishing, cleaning products, and to lower the pH of water for effective chlorination, including swimming pools.
 
Sodium bisulfate, also known as sodium hydrogen sulfate (NaHSO4), is an acid salt. It is a dry granular product that can be safely shipped and stored. The anhydrous form is hygroscopic. Solutions of sodium bisulfate are acidic, with a 1M solution having a pH of < 1.
 
Sodium bisulfate is used primarily to lower pH. For technical grade applications it is used in metal finishing, cleaning products, and to lower the pH of water for effective chlorination, including swimming pools.
 
Sodium bisulfate is also AAFCO approved as a general use feed additive, including companion animal food. It is used as a urine acidifier to reduce urinary stones in cats. Sodium bisulfate is considered GRAS by FDA and meets their definition of a natural product. The food grade product meets the requirements set out in the Food Chemicals Codex (FCC). It is denoted by E number E514ii in the EU. Food Grade sodium bisulfate is used in a variety of food products, including beverages, dressings, sauces, and fillings. It is also widely used in meat and poultry processing and most recently in browning prevention of fresh cut produce.