The combination of copper and zinc in the media allows the chemical reaction of Oxidation-Reduction (redox) to take place when water passes through. This involves the transfer of electrons between two molecules, changing these molecules into entirely different elements. In the KDF® process, electrons are taken from harmful contaminants like chlorine and microorganisms. This loss of electrons changes contaminants into far less harmful, or even harmless, elements. For example, chlorine, when it loses an electron in a redox reaction, is changed into the harmless, water-soluble chemical chloride.