I entered into force in 1983, followed by the other Annexes at later dates. Annex IV has not yet entered into force. I, II, and V deal with technical matters concerning, e.g., details of ship construction, tank design etc. Ships are not allowed to discharge oily sludge from the combustion of heavy fuel oil into the sea. Oily mixtures and residues normally have to be discharged to port reception facilities.
Similar regulations apply to residues from the cargoes of chemical tankers.
Chemical residues which do not have to be discharged to reception facilities may be discharged into the sea subject to severe restrictions and only in very small quantities, depending on the hazard which the particular chemical poses to the marine environment. In Special Areas like the North Sea and Baltic Sea, no ship's garbage except food wastes is allowed to be discharged into the sea.