It is widely used as a fertilizer supplying nitrogen (13%) and potassium (38% KO) in pyrotechnics and gunpowder (75% content historically) food preservation (e.g. cured meats as E252) and toothpaste for dentinal hypersensitivity.

Its primary purpose is as a strong oxidizer providing oxygen for combustion reactions in explosives and fireworks and delivering essential nutrients to plants while acting as a nitrate preservative.

Potassium nitrate (KNO3) is a white crystalline ionic salt composed of potassium cations and nitrate anions in an orthorhombic crystal structure at room temperature odorless with density 2.11 gcm melting at 334C and decomposing above 400C.