Here is a listing:
viewtopic.php?f=8&t=12521 The list begins on the second page of this topic, it includes foods that are safe and toxic, plants that are safe and toxic as well as trees and woods and household items. As far as I am aware of if a wood is listed as toxic there is nothing that you can do to change this as that would require changing the nature of the tree that the wood came from and we don't have any way of doing that.