In Resolution MEPC.190(60), the IMO Marine Environment Protection Committee (MEPC) adopted amendments to MARPOL Annex VI that designate a North American Emission Control Area (ECA). This is intended to ensure more stringent control of emissions of sulphur oxides (SOx), nitrogen oxides (NOx) and particulate matter (PM) than the limits that apply globally.

Compliance with the emissions regulations is mandatory as from 1 August 2012.

The new appendix VII to MARPOL Annex VI contains the definition and boundaries (with full coordinates) of the North American Emission Control Area (ECA), which is based on the North American Datum of 1983/World Geodetic System 1984 (NAD83/WGS84) (reference to MEPC.1/Circ.723). The US Caribbean ECA does not come into force until 2014.

Fuel sulphur limit
When vessels are operating within the North American ECA established for SOx and particulate matter control, the sulphur content of fuel oil used on board must not exceed the following limits:

  • 1.00% on or after 1 August 2012;
  • 0.10% on or after 1 January 2015; or
  • an equivalent method as approved (MARPOL Annex VI, Regulation 4).

Fuel change-over procedure
Vessels continuously operating on low sulphur fuel oil and those that in the future will be equipped with exhaust cleaning systems are not subject to changeover requirements.

All ships using separate fuel oils when operating within an ECA are to carry a written fuel oil change-over procedure, developed specifically for that vessel, containing:

  1. A step-by-step procedure for carrying out the fuel oil change-over;
  2. The date, time and position of the vessel; and
  3. Methods for calculating the time necessary to ensure the fuel oil service system is fully flushed of all fuel oils exceeding the applicable sulphur content limit prior to entering the ECA.

Ships provided with redundant service and settling tanks may experience a minor challenge as the change-over time is related to the dilution of existing high sulphur fuel oil (HSFO) in the fuel oil service system.

DNV Petroleum Services considers the engine room log book to be the most suitable place in which to record the change-over.

For further information about fuel oil transfer, please contact DNV Petroleum Services at

Exhaust gas cleaning systems
An exhaust gas scrubber can be installed to remove sulphur from the engine exhaust gas as an equivalent to a fuel sulphur limit.

The Ratio Emission allowed in the North American ECA from 1 August 2012 is 43.3 SO2 (ppm)/CO2.

For further information about exhaust gas cleaning systems (EGCS), please contact DNV Advisory Services or read more here.

Previous newsletters
DNV Technical eNewsletter 7 Sept. 2010:
Change-over to low sulphur fuel – a practical example to consider.

DNV Technical eNewsletter 15 Nov. 2011:
Amended clean fuel requirements – for owners and operators of ocean-going vessels visiting California ports.

Date: 2012-05-07

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DNV Classification Support