Organic acids (and their salts), such as formic, citric, acetic, propionic, and butyric acid, among others, are already used as acidifiers where they act by reducing pH and destroying common germs. Of these acids, potassium Diformate (KH(HCOO)2; CAS 20642-05-1) is a double-salt of formic acid and potassium formate which has received attention as an alternative to formic acid because of its easiness to handle as a crystalline powder, thermal stability, no odor, as well as its non-corrosive behavior. It is acidic because it consists of 35% formic acid moiety that is tightly bound to potassium formate in a 1:1 ratio. Potassium diformate has a good anti-mildew effect, and its anti-mildew performance is better than the common anti-mold agent sodium diacetate.