Potassium iodide is used with silver nitrate to make silver iodide an important chemical in film photography. Medicinally it is used for thyroid blockade, thyroid storm and also as an expectorant. It is a component in some hair treatment chemicals. It is also used as a fluorescence quenching agent in biomedical research, an application that takes advantage of collisional quenching of fluorescent substances by the iodide ion.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.