PM (Particulate Matter)

Particulate matter from marine engines is the fine carbonaceous and sulphate aerosol in exhaust, controlled indirectly through the fuel sulphur limits of MARPOL Annex VI Regulation 14 rather than by a direct PM limit. Cutting fuel sulphur from 3.50% to 0.50% globally in 2020, and to 0.10% in ECAs, sharply lowers sulphate PM, the largest component for residual fuels. The IMO has studied black carbon, the strongly warming fraction of PM relevant to the Arctic, through the PPR Sub-Committee, but no mandatory black carbon limit is yet in force. Exhaust gas cleaning systems and distillate fuels also reduce PM.