Sailing With Dangerous Cargo.
Crew members and Officers who want to join ships specially the tankers must know what type of cargo will be carried by the ship that they are going to sign contract to work. Because some ship owners and ship crewing agents used to hide the truth about the dangerous cargo and the hazardous cargo that the ship is going to carry. So that they can profit from paying the required higher salary and the bonus money to the seaman those who are going to work there while endangering their life during the time of carrying those cargos from one port to other.
Some ship owners get lucrative contract to carry inflammable cargos like airline fuel, gasoline or kerosene through war zone waters with their tankers. Usually they load the cargo with one country crew and once the cargo is fully loaded, the ship owner will bring onboard new crew members from another country and they will not know what cargo that they are carrying in side the tanker ship as cargo and the destination of the tanker ship's cargo.
The next day the captain will get orders from the company to sail to some destination point. The master may get some Idea of the cargo and the destination that they are going to discharge their cargo. On the final moment they may get the destination of the cargo mean while their recruiting agent too will send a telex saying "Don't worry; we have made all the necessary safety arrangements for you tanker ship's safe passage".
This is a fake message and the crew and the officers will have to believe this message as they are afraid to take the ship back to another country as there will be more legal procedures against them may take there. So most of them will agree to take the vessel through the war zone for just a small salary where they may end their lives too if any conflicts involved with their danger cargo.
In the past years these events happened to many hundreds of innocent seaman who wanted to earn money for their loving families.
So, make sure that you will not have any surprise cargo or surprise destination with a dangerous cargo.
Also as a merchant officer or ship crew member you must know working longer months onboard chemical tanker which carries Hazardous cargo can damage your health. Like wise working onboard gas tankers for longer months can reduce your food carving.
Read here about dangerous goods. The information is provided by the International Maritime Organization.