Most rigid and semi rigid PVC compounds have impact performance requirements that can be met only through the use of impact modifiers. Generally, in order to improve the impact resistance of PVC products, impact modifiers (toughening agents) are being used.

Impact modifiers are used for long term use of PVC/C-PVC products especially under cold conditions and outdoor exposure. C-PVC pipes used for conveying hot water from solar heaters or geysers are usually exposed to solar radiation and weathering. Therefore, impact modifiers shall be judiciously selected for C-PVC pipes for indoor and outdoor use.