Question about Beads

I did lots of searching and didn't find this specific question/answer anywhere.

Is it safe to have the Heartfelt beads on direct contact with the wood, or do I need to have it in a plastic container?

I'm drawing plans for my humidor I'm going to build soon, and I'm wondering if I should have a cedar box just for beads, or if I should design a section of the humidor to hold a container.

I don't want to trash the wood if it's not safe to have the beads in direct contact.