Cardboard also known as fiberboard is a common material used to make boxes for shipping things. When shipping hazardous materials the United Nations designates boxes is either “4G” or “4GV.”
4G Packaging
The designation “4G” is a dangerous goods packaging code used to alert shipping personnel that inside the cardboard container there is packaging which contains dangerous goods. While the fiberboard does provide limited protection for the inner packaging, its main use is simplify the ease of handling small containers such as cans, bottles, and jars.