Fire retardancy
PVC-U windows are safe in fires and do not accelerate the spread of flames like other materials.
This is because the chlorine, i.e. salt, content of the PVC acts as a fire retardant. The frames do not melt as some may be led to believe by the behaviour of similar materials. Instead they char and self-extinguish if the source of the flame is removed.
PVC has such a good safety record that it is used to protect electric cabling.
For more information, please download this document published by The British Plastics Federation.
