Chlorinated polyvinyl chloride, or CPVC, is a thermoplastic which is produced by the post-chlorination of polyvinyl chloride (PVC) resin. CPVC typically contains 65-67% chlorine, compared to 55-57% for standard PVC. Its importance as an engineering thermoplastic is due to its relatively high glass transition temperature, high heat distortion temperature and chemical inertness; it also has outstanding mechanical, dielectric, and flame and smoke properties.
Many CPVC compounds conform to potable water regulations. It is compliant with most international standards and is approved by international agencies including NSF International. It also has excellent resistance to the formation of biofilms. Products made from or including CPVC offer outstanding heat resistance, flame and smoke performance, and weatherability. CPVC can be both downcycled and recycled, and many local recycling protocols allow for CPVC to be integrated into recovery and recycling systems intended for PVC.