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. There is an opportunity to gain large additional public-health benefits from Category 3 marine diesel engines through the application of advanced technology emission controls including high-efficiency catalytic aftertreatment.
Under the Clean Air Act, we are working on an additional tier of federal emission standards for Category 3 marine diesel engines (those with per-cylinder displacement of 30 liters or greater). We issued an Advance Notice of Proposed Rulemaking in November 2007. In addition to engine and aftertreatment technologies, we will also consider the role of fuel quality in achieving future emission reductions and the impact of emissions from foreign vessels that enter U.S. ports. EPA also provides support to the U.S. delegation to the International Maritime Organization as it considers a new tier of international consensus standards for marine engines and fuels.
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 Gasoline Boats and Personal Watercrafts and Diesel Boats and Ships.
Related Topics
NOTE: You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.
- Press Release
- EPA Regulations
- IMO MARPOL Annex VI Amendments
- Guidance and Publications
- Related Links
Press Release
President signs the Maritime Pollution Protection Act of 2008. (July 22, 2008)
EPA 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.
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)
IMO MARPOL Annex VI Amendments
The United States in February 2007 formally proposed a series of amendments to Annex VI of the MARPOL treaty. The emission program described in that proposal would dramatically reduce air pollution from ships by establishing a new tier of performance-based standards for marine diesel engines on all vessels and by establishing stringent emission requirements for ships that operate in coastal areas where air-quality problems are acute.
Negotiations for amended standards are continuing and are expected to be completed in 2008.
U.S. Submittals to Amendment Process:
- U.S.Government Submittal to the 11th Session of the IMO's Subcommittee on Bulk Liquids and Gases: Development of Standards for NOx, PM, and SOx (PDF) (6 pp, 153K, BLG 11/5/15, February 9, 2007)
- U.S. Government Submittal to the 11th Session of the IMO's Subcommittee on Bulk Liquids and Gases: Air-Quality Concerns from Particulate Matter and Oxides of Sulphur (PDF) (4 pp, 151K, BLG 11/5/27, February 23, 2007)
- Statement from the United States to the BLG 11 Meeting: Introduction of US Paper BLG 11/5/15 - Proposal for new NOx Limits (PDF) (3 pp, 15K, BLG 11/5/15, April 16, 2007)
- Statement from the United States to the BLG 11 Meeting: Introduction of US Paper BLG 11/5/15 - Proposal for new PM and SOx Limits (PDF) (3 pp, 17K, BLG 11/5/15, April 16, 2007)
- Revision of the NOx Technical Code Tiers 2 emission limits for diesel marine engines at or above 130kW (PDF) (7pp, 68K, December 1999)
Other Documents Relevant to the Amendment Process:
- Estimation of Health Benefits of South Coast Air Basin 2007 AQMP/SIP Oceangoing Marine Vessel Control Measures (PDF) (7 pp, 224K, October 2007)
- MARPOL Annex VI: Proposal to Initiate a Revision Process (PDF) Submitted by Finland, Germany, Italy, the Netherlands, Norway, Sweden and the United Kingdom (12 pp, 204K, April 2005)
- In June 2007, the World Shipping Council endorsed the two U.S. proposals to amend MARPOL Annex VI.
MARPOL Annex VI was adopted September 1997 and took effect May 2005.
- Fact Sheet: Emission Standards for New Marine Diesel Engines: Relationship Between EPA's Control Program and MARPOL Annex VI (PDF) (6 pp, 216K, EPA420-F-02-004, April 2002)
- MARPOL 73/78 Annex VI Marine Diesel Engine Requirements - FAQs (PDF) (8 pp, 32K, EPA420-F-99-038, October 1999)
- IMO's MARPOL Annex VI Requirements (PDF) (59 pp, 164K)
- MARPOL NOx Technical Code (PDF) (100 pp, 476K)
- Guidance for Certifying to MARPOL Annex VI (PDF) (4 pp, 17K)
Guidance and Publications
- Draft Report: Global Trade and Fuels Assessment -- Future Trends and Effects of Designating Requiring Clean Fuels in the Marine Sector: Task Order No. 1, Industry Characterization (PDF) (72 pp, 1.8MB, April 2006)
- AER Report: Modeling Sulfur Oxides Emissions Transport From Ships at Sea (PDF) (154 pp, 2.4MB, EPA420-R-07-009, July 2007)
- Overview of EPA's Emission Standards for Marine Engines (PDF) (9 pp, 184K, EPA420-F-04-031, August 2004)
- Analysis of Commercial Marine Vessels Emissions and Fuel Consumption Data (PDF) (158 pp, 2.6MB, EPA420-R-00-002, February 2000)
- Commercial Marine Activity in the United States Final Reports
- Commercial Marine Activity for Great Lake and Inland River Ports in the United States (PDF) (84 pp, 360K, EPA420-R-99-019, September 1999)
- Commercial Marine Activity for Deep Sea Ports in the United States (PDF) (214 pp, 1MB, EPA420-R-99-020, September 1999)
- Both reports in WordPerfect format and tables as Excel 5 spreadsheets: 590K ZIP file
Related Links
- International Maritime Organization (the United Nations agency that facilitates international shipping regulations through treaties such as MARPOL)
- Nonroad Diesel Equipment (which includes marine diesel engines under 37kW)
- Diesel Boats and Ships
- Gasoline Boats and Personal Watercraft
- Engine Certification Information Center
- Compliance Fees
- Marinas & Boating (from EPA Office of Water)
- Importing Vehicles and Engines
- Clean Diesel Programs
- Nonroad Diesel Equipment
- Diesel Fuel
For more information, contact EPA's Assessment and Standards Division at asdinfo@epa.gov or 734-214-4636.