The IMO has enhanced its 2020 regulation on sulphur with the entry into force of a rule to ban the carriage of non-compliant fuel oil.

The IMO 2020 regulation limits sulphur in ships' fuel oil to a maximum 0.50%. The regulation has been in force globally since 1 January 2020, under IMO's MARPOL treaty, with benefits for the environment and human health from a reduction in sulphur oxides in the air.

The complementary International Convention for the Prevention of Pollution form ships (MARPOL) amendment prohibits the carriage of non-compliant fuel oil for combustion purposes for propulsion or operation on board a ship - unless the ship has an approved exhaust gas cleaning system ("scrubber") fitted.

The amendment does not change in any way the 0.50% limit which has been in force since 1 January 2020. It is intended as an additional measure to support consistent implementation and compliance and provide a means for effective enforcement by States, particularly port State control.

In designated emission control areas, the maximum sulphur limit in fuel oil is 0.10 % (the four ECAs are: the Baltic Sea area; the North Sea area; the North American area (covering designated coastal areas off the United States and Canada); and the United States Caribbean Sea area (around Puerto Rico and the United States Virgin Islands)).