Kester 2331-ZX is an innovation in organic acid water-soluble flux chemistry for soldering circuit board assemblies. This unique, neutral pH chemistry flux provides the best ionic cleanliness of any organic water-soluble flux available to the electronics industry. This popular flux has been used for soldering critical assemblies in the computer, telecommunications and other industries. No offensive odors will be emitted during soldering. 2331-ZX will not create excessive foaming in standard water cleaning systems. 2331-ZX has good soldering properties for improved productivity without sacrificing reliability of the assembly. This flux does not attack properly cured solder masks or FR-4 epoxy-glass laminate. 2331-ZX is not detrimental to the surface insulation resistance of the soldered assembly. Use of this flux minimizes cleaning costs while complying with environmental regulations. 2331-ZX is classified as ORH1