Emission control area

An Emission Control Area is a sea region designated under MARPOL Annex VI where stricter air-pollution limits apply: a 0.10 percent sulphur cap (against 0.50 percent globally) in SOx-ECAs, and NOx Tier III for engines on ships built from the area’s effective date in NOx-ECAs. Existing ECAs cover the Baltic, North Sea, North America, the US Caribbean, and the Mediterranean from 1 May 2025. Ships entering switch to compliant distillate fuel or run a scrubber, logging the fuel changeover for port state inspection.