The London Convention, with its amendments of 1978, 1980 and 1993, controls marine pollution from dumping and incineration at sea. It prohibits the dumping of some substances including plastics and mercury and allows the regulated dumping of other substances. It does not cover operational discharges from ships, for example, ballast water and oily bilge water. Proposals to amend the Convention include replacing the existing list of banned substances with a severely restricted list of substances which may be dumped at sea.