Comparable to polyester, recycled polyester is a sustainable fabric choice because it is made from recycled plastic bottles. This helps to reduce the amount of plastic that ends up in landfills and incinerators. Recycled polyester also requires less energy and water to produce than virgin polyester (and is just as durable), which helps to reduce the environmental impact of the fashion industry.
Recycled polyester is still a synthetic fabric, and does not biodegrade like a natural fiber would. It will also still shed microplastics. Aside from that, it's considered to be safe, and may be safer than virgin polyester because it's made from recycled materials, which have already been through a manufacturing process. This means that recycled polyester is less likely to contain any harmful chemicals or toxins that may have been used in the original manufacturing process.