For safety reasons ! There are restrictions on the carriage of goods when they are likely to:
- impair the physical integrity of a person
- harm the environment in case of contact or spill during transport.
It is thus a question of preventing the risks, as well for the people as for the goods and the environment. Precautions concerning packing, marking or labeling, documentation, prohibitions ... the regulation in force makes it possible to identify the dangerous goods and to organize their transport, especially between countries.
Other prohibitions also exist because of the value, rarity or unique nature of the property, which can not be replaced in the event of loss or damage (identity papers, invitations to tender, precious jewels, etc.)