So… currently it is unfinished… though the Proofgrade may have some kind of finish on it… @dan can comment on that if he likes.
I recognize the dangers of introducing chemicals to the food, but I’m not really worried about bacteria at all. This is used on raw dough only, which is then cooked in boiling water or baked in an oven with temps high enough to get rid of any bacterial organisms. The wood itself isn’t being used in the actual cooking process, so there are no worries there. There is minimal contact between the burnt edges and the food, and even less contact between the finished sides and the food. I think the wooden rolling pin in my drawer is a bigger risk.
That said, I do plan to maybe sand down the char a bit, and probably treat with mineral oil or beeswax. I just haven’t gotten there yet.