But finding a vendor that can handle the different safety challenges posed by just one book can also be taxing. A vinyl book is one such product that presents several manufacturing hurdles. She warns, "You have to know what types and levels of chemicals are acceptable and have product tested with various safety regulations and recommendations. We avoid using PVCs, so an alternate to the material had to be found. We have been using PEVA, which is non-toxic and passes safety tests, but it wasn't previously used because the vendor equipment couldn't effectively heat-seal PEVA around the foam it must enclose in a bath book. If a seal was to open and expose the foam, the foam then has the potential of becoming a choking hazard. You can't print on the heat-sealed area because it needs to be free from ink in order to seal to proper strength. So, it was hard to find a vendor."