It involves deionized water, mainly a system wherein water is purified by removing the ions of the dissolved minerals in an attempt to result in very highly purified water that would be suitable for sensitive applications. The common base is the ion exchange resins where water passes through resin beds replacing unwanted cations with hydrogen ions, while replacing unwanted anions with hydroxide ions to produce DI water eventually. Such industries as the manufacture of electronics, pharmaceuticals, laboratories, and cosmetics all require deionized water because even traces of minerals interfere with processes or quality. These systems are valued for their consistency and assurance of high-purity water delivery at low conductivity with minimal dissolved solids for optimum performance in critical applications.