Are uPVC windows toxic or harmful to evironment?

uPVC was literally invented to reduce the pollutions caused by PVC, which mainly consists of lead & dioxides. This has greatly contributed to the betterment of the environment in terms of air quality. They are also a type of thermoplastic that could be recycled into another product. This has cut down on the tons of landfill could have polluted the land & stopped rain water from entering the underground water table. So uPVC is anything but bad for the environment.