For ease of identification of dangerous goods, the international community has created a classification system. All dangerous goods are included in one of nine primary classes. In some cases it has also been necessary to sub-divide some of the classes into divisions in order to adequately provide for the dangers of the individual goods.
There is a label for each class/division to categorize the nature of the hazard. These labels must be affixed to the outside of the package when it is offered for transport and must remain on the package while it is in transit. Some examples of these are illustrated below: