The metal will not react with the PVC. Some codes prohibit the use of metal hangers for non-metallic piping. The code in my state has no such prohibition. It is important that the non-metallic piping not have movement at/against any sharp edge. The non-metallic piping does move as the temperature changes-- a law of nature that is immutable. So design accordingly.

Thank you. I see straight pipes hanging straight up and down from straight hangers (no bends or twists), so, whoever did it, they did a nice job. I don't see any scratch marks at all and this plumbing is 10+ years old, so I'm going to say it doesn't look like it will be a problem.

Thanks again for the answer!