copper vs pvc compressor lines?

67Dart/Cuda is correct about OSHA and PVC. In the event it fails it can shatter like glass and the manufacturers of PVC pipe put the note in their literature, "Not to be used for compressed air or gas". There are plastic systems designed for compressed air, one being called "Air Pro" that is rated at 230psi and is heat fused together. Even though iron and copper can easily handle high pressures, if I was going metal I would look at copper since it's cleaner than iron pipe with regards to moisture and compressor oils affecting it, if not using a filter and dryer.