I wouldn't worry too much about using it. I have used it before. Most are labeled non-toxic as that is a "selling" feature. Don't get any with the glitter in them. I had alot of problems with the glue letting one rock or the other loose from the bond and a I got frustrated with using it. Aquarium safe silicon is another option. Stainless steel screws and bolts are good for driftwood and super glue works really well attaching plants.