Brian was very clear in one of the video interviews that they would not be rubber but a plastic formulation, that they would be designed not to disintegrate. He knows better. You may want to wait till folks get them in hand and post reviews but I think this is going to be a non-issue for you if that was your only concern. Me, I am coming to accept I have no where to display the thing, it came out much bigger than I was imagining. So I'm passing at this point.