Post a pic of the bamboo and maybe someone on here will know exactly what kind it is and if it is safe or not. If it's one of the kinds that you buy for decoration that grow in swirly shapes instead of straight up, then I don't think it's the same kind of bamboo I used.
As for dried bamboo, the only way you'll know for sure is if you post a pic of what kind of bamboo it is, and if someone on here can identify it as toxic or not.
With all that said, I have a hypothesis that if it has any toxicity at all, it could be that if by breaking off any foilage from it could cause a type of toxic/irritant sap, or if your cham was to consume any part of the bamboo.