The chemical name for K2HPO4 is dipotassium monohydrogen phosphate. This chemical compound is also called by other names, including dipotassium phosphate; dipotassium salt; phosphoric acid; and potassium phosphate, dibasic. It is used to adjust pH and to control fungi, growth of weeds and other plants, and harmful microorganisms.
K2HPO4 is a pesticide that is registered for legal use in the United States by the U.S. Environmental Protection Agency. Although the EPA has determined that K2HPO4 use doesn't harm humans, it has toxic effects on fish, and it reduces phytoplankton populations, according to the Pesticide Action Network. Phytoplankton provide food for many aquatic animals and release oxygen from carbon dioxide.