There are some very poisonous woods. Untreated Pine is regarded as safe. Maple also, but do NOT use spalted wood for tips, they carry a form of mold to cause the spalting. If you are not familiar with wood and its safety, dont make them. Treated woods are not good. I am using a non-toxic varnish on mine. Its water based. You can see in my pics the difference. I coat the inside of the tip as well. I still have to use them to find out how safe I think they are. But since we inhale pine, maple and a bunch of others via wood stove fumes, I cant imagine these would be any different.