I've been looking everywhere in care sheets and through books and theres only one thing I can't seem to find.

For a Kenyan Sand Boa, what is the humidity range? I know that they are supposed to have a very low humidity but I haven't been able to find what is safe, dangerous, or ok. I'm guessing less than 50% but I want to be sure.
I know your supposed to provide a humidity box for their shedding schedule, but this still tells me nothing..

What is the maximum humidity that is safe for a KSB? Is it ok for it to be almost, completely dry in the tank?
Thanks everyone.