The handling of ship generated waste, including slops, is
regulated by the international convention MARPOL 73/78, which is
the International Convention for the Prevention of Pollution From
Ships, 1973 as modified by the Protocol of 1978. (‘MARPOL’ is short
for ‘marine pollution’ and 73/78 short for the years 1973 and
1978).
MARPOL 73/78 is one of the most important international marine
environmental conventions and it was designed to minimise pollution
of the seas, including dumping of oil and exhaust pollution.
Its stated object is: ‘to preserve the marine environment through
the complete elimination of pollution by oil and other harmful
substances and the minimisation of accidental discharge of such
substances’.
The original MARPOL Convention was signed on 17th February 1973,
but did not come into force. The current Convention is a
combination of the 1973 Convention and the 1978 Protocol. It
entered into force on 2nd October 1983. As of 30th
September 2007, 145 countries, representing an estimated 98.34% of
the world's shipping tonnage, were parties to MARPOL 73/78 (Annex
I/II). These countries include The Netherlands and the Ivory Coast.
In 2011 this figure had reached 150 countries and more than 99% of
the world’s shipping tonnage.
Under the MARPOL Convention, each state has the obligation to
ensure that it has the necessary facilities to handle ships’ waste
efficiently and safely and each vessel has to maintain an oil log
book detailing movements in its oil cargoes.