The long-awaited deadline for the International Maritime Organization (IMO) global sulfur cap arrived on Jan. 1, 2020. The sulfur cap reduces the amount of sulfur in fuels from 3.5% m/m (mass by mass) to 0.5% m/m. The drastic reduction is in line with IMO goals for emissions reductions by 2050 and is expected to cost the shipping industry — and its sprawling supply chain — billions of U.S. dollars in compliance costs.
The announcement of a new sulfur cap in 2016 came after decades of study and several additions made to Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL), which went into force in 2005. Annex VI calls for IMO member states to create regulations to reduce polluting airborne emissions from ships, including sulfur oxides, nitrogen oxides, ozone-depleting substances and volatile organic compounds. The dramatic reduction in sulfur is part of an ongoing tightening of emissions rules beginning with Annex VI.