For Dry Ice sending of Biological Substances you need on the outside of a box specific labels. labels must meet set sizes and must be clearly visible on the outside of the box be stuck. When transport a package, with Dry Ice, mark with UN number (UN 1845) + the net weight and proper shipping name. Nearby, affixed on the same surface, the hazard warning label for Class 9- miscellaneous dangerous goods, must be added.