NOx Emission Compliance

Northern Hemisphere

Interested in Learning More About NOx Tier III Compliance?

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1 January 2016 is another important date for a regulatory change where the MARPOL Annex VI, Regulation 13 for Tier III emission standards for ships constructed on or after 1 January 2016 and operating within the existing IMO Emission Control Areas (ECAs) will be enforced. Currently there are two NOx ECAs, the North American and the US Caribbean Sea, whereas there are four Sulphur Oxides (SOx) ECAs including the Baltic Sea and the North Sea.

The NOx Tier III standards will be applicable to marine diesel engines installed:

  • on ships constructed on or after 1 January 2016 and which will operate in existing NOx ECA’s (i.e., North American ECA or the US Caribbean Sea ECA); and
  • on ships constructed on or after the date of adoption of a new ECA, or a later date as may be specified in the amendment designating the new ECA, whichever is later and which will operate in the new ECA. (Note: ships constructed means ships the keels of which are laid or that are at a similar stage of construction.

Exemptions are provided for marine diesel engines installed:

  • on purely recreational ships with a length < 24 m
  • on a ship with a combined propulsion power < 750 kW if it is demonstrated that the ship cannot comply with Tier III because of design or construction limitations of the ship; and
  • on purely recreational ships constructed prior to 1 January 2021 of less than 500 GT and with a length ≥ 24m

Dominican Republic and Puerto Rico


To learn more about NOx Tier III compliance, download our latest advisory.