ok, so here's what i heard back in response to my inquiry about what the gyms are made from :

Regarding the materials used; what I can basically tell you is that PVC is initially incorporated...but that is just the beginning, much like rubber is the beginning stage of making tires for your car. Please note that these gyms are 'species specifically designed and computer balanced,' and goes through a time-consuming 3 stage molecular process.

Dr. Sowards created these 100% non-toxic branches without the use of any dye's, stains, or artifical coloring to give these gyms their beautiful wood-grain appearance, which is created 'naturally' during the molecular process...and the paint used on the base {with the floor models} is 100% child/pet safe.

i get the impression they have some sort of "secret formula" that they don't want to divulge. but it sounds pretty safe.