There are exact regulations concerning dangerous goods which must be followed for sea freight transport. Did you actually know that common PR gifts, like filled gas lighters, matches, glues etc., can be dangerous goods? Moreover, there are often dangerous devices in the finished appliance - e.g. devices with batteries, gas cartridges etc.
If you are not the manufacturer yourself you should be well-informed about your goods. Since in the event of an accident (due to undeclared or falsely declared dangerous goods) the sender or the client is exclusively liable for the consequent damage.
All dangerous goods must be declared as such and be correspondingly packaged.
The stipulated dangerous goods signs must be enclosed.