Household items that contain potassium nitrate include toothpaste made for sensitive teeth, tree stump remover solutions and some brands of fertilizers. Potassium nitrate is also present in the brine used to preserve meat, such as corned beef.
A non-household use for potassium nitrate is as an oxidizer for fireworks and some gun powders. The chemical compound can be found naturally as crystallized deposits in caves and in accumulations of bat dung as well.
Potassium nitrate can be synthesized by combining potassium hydroxide and ammonium nitrate, creating ammonia as a by-product. Sodium nitrate and potassium chloride can also be combined to create potassium nitrate through a double displacement reaction.