Oceangoing Vessels

Diesel engines on oceangoing vessels such as container ships, tankers, bunk carriers, and cruise ships are significant contributors to air pollution in many of our nation’s cities and ports. As trade with other countries increases, these emissions will represent an even larger share of our national emission inventories.

On October 9, 2008, the Member States of the International Maritime Organization adopted new international standards for marine diesel engines and their fuels. This important new program matches closely the program that the United States Government first advanced at the IMO in February 2007 and that was reflected in our Advance Notice of Proposed Rulemaking in December 2007.

The IMO program, contained in amendments to Annex VI to the International Convention for the Prevention of Pollution from Ships (also called MARPOL), consists of engine and fuel sulfur standards. The program is geographically-based, meaning that ships that operate in designated Emission Control Areas (ECAs) will be required to use the most advanced technology-forcing engines, and the sulfur content of the fuel used in those areas cannot exceed 1,000 ppm. In all other areas of the world, including on the high seas, engine emissions will be also be reduced, and the global fuel sulfur cap outside ECAs will drop to 5,000 ppm in 2020 (pending an availability review in 2018).

Due to the contribution of international marine transportation to U. S. air quality, the new international program will provide important benefits to our national air quality. Obtaining ECA status for United States coasts will be an important step in securing the benefits of these standards. We will also take these international standards into account as we continue to develop our Category 3 marine diesel engine rulemaking.

This page provides general and technical information on EPA’s Category 3 marine diesel engine rulemaking and the U.S. government's efforts at the IMO to reduce air pollution from oceangoing vessels. Category 3 marine diesel engines are those with per-cylinder displacement at or above 30 liters. Information about EPA's other marine engine programs is available on Diesel Boats and Ships and Gasoline Boats and Personal Watercrafts.

Press Release

President signs the Maritime Pollution Protection Act of 2008. (July 22, 2008)

Regulations

There are two types of diesel engines used on oceangoing vessels. The main propulsion engines on most oceangoing vessels are very large Category 3 marine diesel engines. Category 3 engines are currently subject to "Tier 1" emission standards that rely on engine-based technologies to reduce emissions. These Tier 1 standards -- which were adopted by EPA in 2003 and went into effect in 2004 (see 68 FR 9746; Feb. 28, 2003) -- are equivalent to the rules adopted by the International Maritime Organization in Annex VI to the International Convention for the Prevention of Pollution from Ships (a treaty called "MARPOL").

Auxiliary engines on oceangoing vessels typically range in size from small portable generators to locomotive-size engines with power of 4,000 kilowatts or more. Engines of this type on U.S.-flagged oceangoing vessels are subject to EPA’s marine diesel engine standards for engines with per-cylinder displacement up to 30 liters per cylinder.

New Standards

Advance Notice of Proposed Rulemaking: Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder (published December 7, 2007)
- Fact Sheet | PDF Version (3 pp, 102K, EPA420-F-07-050, November 2007)
- Advance Notice of Proposed Rulemaking | PDF Version (32 pp, 1MB)
- Supporting Documentation: Information related to the development of this proposal can be found on the electronic docket at www.regulations.gov. NOTE: To access the docket, select "Advanced Search," then Docket Search, and type "OAR-2007-0121" as the Docket ID.

Change in Regulatory Deadline for Rulemaking to Address the Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder (published December 5, 2007)
- Fact Sheet | PDF Version (2 pp, 91K, EPA420-F-07-067, November 2007)
- Final Rule | PDF Version (8 pp, 155K)
- Proposed Rule Fact Sheet | PDF Version (2 pp, 91K, EPA420-F07-024, April 2007)
- Notice of Proposed Rule Change | PDF Version (4 pp, 98K)
- Proposed Direct Final Rule | PDF Version (5 pp, 119K) The direct final rule was withdrawn as a result of adverse comments.

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Existing Standards

See the electronic Code of Federal Regulations for the full text of current regulations that apply to marine compression-ignition engines. The documents that established these provisions are available below.

Final Emission Standards: Tier 1 Marine Diesel Engines (published February 28, 2003)
- Fact Sheet (PDF) (7 pp, 427K, EPA420-F-03-001, January 2003)
- Federal Register Notice | PDF Version (45 pp, 301K)
- Summary and Analysis of Comments: Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder (PDF) (121 pp, 337K, EPA420-R-03-003, January 2003)
- Final Regulatory Support Document: Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder (PDF) (153 pp, 647K, EPA420-R-03-004, January 2003)
- Final Index for Docket A-2001-11 (PDF) (35 pp, 231K)
- See Proposed Emission Standards for the proposed rule, fact sheet and regulatory support documents.
Final Rule Tier 2 Emission Standards for Commercial Marine Diesel Engines (EPA’s original rule to establish marine diesel engine standards, published December 29, 1999)

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IMO MARPOL Annex VI Amendments

On October 9, 2008, the Member States of the International Maritime Organization adopted new international standards for marine diesel engines and their fuels. This new program will dramatically reduce air pollution from ships by establishing a new tier of performance-based standards for marine diesel engines and their fuels and by establishing additional, more stringent emission requirements for ships that operate in specially-designated coastal areas where air-quality problems are acute.

Amendments to Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL)