What are the limitations of recycled polyester?

Recycling of garments made from blends of polyester and other materials are not possible and it is only pure polyester that can be recycled. Also, certain fabric finishes can prevent the garment from being recycled.
When coloured/dyed PET bottles are used to produce polyester fabric chlorine-based bleaches are used to whiten the bottles to achieve the desired colour of polyester fabric.

Some studies suggest that PET bottles leach antimony oxide which is known to cause cancer. Antimony oxide is used as a catalyst while producing PET bottles and polyester. Though it is used extremely less i.e500 mg/kg PET and is still a cause of concern.

Washing recycled polyester or virgin polyester releases microplastics which end up polluting the environment and water bodies. As per Plymouth University, more than 700,00 plastic fibers are released in each washing cycle.