Na3PO3, also known as sodium phosphite, is an inorganic compound composed of sodium, phosphorus, and oxygen. It typically appears as a white crystalline solid and is soluble in water. Sodium phosphite is often used in agriculture as a fungicide and as a nutrient source for plants. In addition to its agricultural applications, Na3PO3 is utilized in various industrial processes, including the production of phosphite esters and as a reducing agent in chemical reactions. Its properties make it valuable in both environmental and manufacturing contexts, contributing to its importance in multiple fields.