Don; There is another Susan (Susan Maltby of Canada) who has well-respected credentials as a chemist and has written several articles for Coin World on the hazards of PVC flips. Here is a reference link to her.
http://www.pcgs.com/News/Coin-Preservation

NON-PVC are flips and pages that contain NO PVC. They are hard and brittle, not soft and pliable. I collected coins for 20 years before I started collecting chips. I am VERY familiar with the damage that PVC flips can do to coins & chips.