1.1 ,This specification covers rigid plastic PVC and CPVC Exterior compounds composed of poly(vinyl chloride), chlorinated poly(vinyl chloride), vinyl chloride copolymers or vinyl chloride blends, and the necessary compound ingredients intended for use in making building products. The compounding ingredients are permitted to consist of lubricants, stabilizers, nonpoly(vinyl chloride) resin modifiers, colorants or pigments, or both, and inorganic fillers.