Your table crackers say they may contain traces of tree nuts. What are your preventions on cross contamination? And what amount of tree nuts may this contain. So far this is the only table crackers I have been able to find that my son can have. He is allergic to wheat, dairy, eggs, peanuts, almonds, cashews, hazelnuts and Brazil nuts. I would like to make sure that these are safe as well. Since they are gluten and lactose free.