Oceangoing Vessels
Diesel engines on oceangoing vessels such as container ships, tankers, bulk carriers, and cruise ships are significant contributors to air pollution in many of our nation’s cities and ports. Their emissions are expected to increase even more in the future, as our trade with other countries increases, and ship emissions will represent a larger share of our national emission inventories.
This page provides general and technical information on EPA’s Clean Air Act regulations for the largest marine diesel engines as well as the U.S. government's international efforts to reduce air pollution from oceangoing vessels.
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 (those with per-cylinder displacement at or above 30 liters). 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. Auxiliary engines 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. More information about EPA's programs for smaller marine engines is available on Diesel Boats and Ships and Gasoline Boats and Personal Watercraft.
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.
- EPA Regulations
- Emission Control Area Designation
- International Standards
- Press Releases
- Guidance and Publications
- Related Links
EPA Regulations
Category 3 engines on U.S.-flagged oceangoing vessels 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 standards adopted by the International Maritime Organization (IMO) in Annex VI to the International Convention for the Prevention of Pollution from Ships (a treaty called "MARPOL". )
EPA is developing a rule for additional tiers of emission standards for new marine compression-ignition engines at or above 30 liters per-cylinder displacement. These new tiers will be based on the application of high efficiency after treatment, and will closely match 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.
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 regulations are available below.
- 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.
- 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.
Emission Control Area Designation
One component of EPA’s coordinated strategy for addressing emissions from oceangoing vessels is the designation of an Emission Control Area (ECA). The United States submitted a joint proposal with Canada to the IMO on March 27, 2009, to designate specific areas of our coastal waters as an ECA. By 2020, an ECA designation with tough geographic-based emissions standards that apply to large ships would prevent between 3,700 and 8,300 premature deaths annually, and avoid approximately 3.4 million instances of respiratory ailments, such as asthma.
Compared to fuels used in ships today, ECA standards will lead to a 96 percent reduction in sulfur in ships’ fuels, as well as a cut in emissions of PM by 85 percent and NOx by 80 percent. To achieve these reductions, ships must use fuel with no more than 1,000 parts per million (ppm) sulfur beginning in 2015, and new ships will have to use advanced emission control technologies beginning in 2016.
Designation of this ECA will deliver substantial public health benefits to many people living in the U.S. and Canada, as well as to marine and terrestrial ecosystems. Air pollution from large engines on ships affects not just U.S. and Canadian ports and coastlines, but is also carried hundreds of miles inland. When people breathe this polluted air, their health is adversely affected leading to lost productivity due to increased illnesses, hospitalizations and even premature deaths. As of early this decade, more than 100 million people in the U.S. and Canada were living in areas with air pollution at levels exceeding our respective national ambient air quality standards. Moreover, scientists have not identified any safe ambient threshold for particulate matter, thus the health of people in areas currently attaining our standards can be enhanced by improving air quality. In addition, the gains that have been made by extensive domestic regulations to control emissions from land-based sources over the last four decades could be eroded or even reversed by expected growth in human and economic activity, including shipping. To maintain and improve air quality, public health and the environment, decisive action must be taken to realize the benefits that can be gained from additional emissions reductions.
The documents that describe and support the ECA proposal are available below.
- Fact Sheet: Proposal of Emission Control Area Designation for Geographic Control of Emissions from Ships | PDF Version (6 pp, 1.6M, EPA-420-F-09-015, March 2009)
- Proposal to the IMO: The proposal includes an Executive Summary with four annexes. Also submitted to the IMO is an Information Document that provides a synopsis of a comprehensive Technical Support Document (TSD).
- Entire Document (PDF) (66 pp, 1.6M)
- Executive Summary (PDF) (7 pp, 76K)
- Annex 1: Justification for ECA (PDF) (54 pp, 1.5M)
- Annex 2: Description of Area (PDF) (1 pp, 40K)
- Annex 3: Chart of Area (PDF) (1 pp, 96K)
- Annex 4: Draft Reg Text (PDF) (2 pp, 40K)
- Information Document (PDF) (11 pp, 65K)
- Technical Support Document (Entire Document (PDF)) (329 pp, 8.9M)
- Table of Contents (PDF) (3 pp, 132K)
- Chapter 1: Executive Summary (PDF) (4 pp, 175K)
- Chapter 2: Emission Inventory (PDF) (88 pp, 2.3B)
- Chapter 3: Impacts of Shipping Emissions on Air Quality, Health and the Environment (PDF) (130 pp, 3.8M)
- Chapter 4: Quantified Health Impacts Analysis (PDF) (36 pp, 520K)
- Chapter 5: Costs (PDF) (40 pp, 997K)
- Chapter 6: Economic Impacts (PDF) (37 pp, 576K)
- Entire Document (PDF) (66 pp, 1.6M)
- For more information about the process for applying to designate the coastal areas of the U.S. as an Emission Control Area under Annex VI, see Frequently Asked Questions about the Emission Control Area Application Process | PDF Version (7 pp, 750K, EPA420-F-09-001, January 2009)
International Standards
The International Maritime Organization (IMO) facilitates development of standards to control air exhaust emissions from the engines that power ships. The IMO is the United Nations agency concerned with maritime safety and security and the prevention of marine pollution from ships. The international standards are found in Annex VI to the International Convention on the Prevention of Pollution from Ships (MARPOL).
The effective date for the current Annex VI Tier 1 NOx limits was January 1, 2000. Now that the Annex has entered into force for the United States (as of January 8, 2009), vessel owners will be required to comply with these standards, although most have voluntarily complied in the interim.
Current Annex VI Tier 1 NOx Standards
- Fact Sheet: Frequently Asked Questions about how to obtain an Engine International Air Pollution Prevention (EIAPP) Certificate | PDF Version (6 pp, 274K, EPA420-F-09-006, February 2009)
IMO MARPOL Annex VI Amendments
In October 2008, Member States of the International Maritime Organization adopted new international standards for marine diesel engines and their fuels (2008 Amendments to MARPOL Annex VI) that apply globally, and establishes additional, more stringent emission requirements for ships that operate in specially-designated coastal areas where air quality problems are acute. These new global and geographic standards will dramatically reduce air pollution from ships, and will provide important benefits to our national air quality. We will also take these international standards into account as we continue to develop our Category 3 marine diesel engine rulemaking.
Under the new global standards, NOx emissions will be reduced, and the fuel sulfur cap will drop to 5,000 ppm in 2020 (pending a fuel availability review in 2018). Under the new geographic standards, ships operating in designated areas will be required to use engines that meet the most advanced technology-forcing standards for NOx emissions, and to use fuel with sulfur content at or below 1,000 ppm. To obtain the full benefits of the program, the United States has proposed designation of an Emission Control Area off our coasts.
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.
- Fact Sheet: International Maritime Organization Adopts Program to Control Air Emissions from Oceangoing Vessels | PDF Version (4 pp, 183K, EPA420-F-08-033, October 2008)
- Amendments to MARPOL Annex VI: Annexes 13 and 14 to the Report of the 58th Session of the Marine Environment Protection Committee (149 pp, 906K, MEPC 58/23/Add.1, October 17, 2008)
Main 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 U.S. Submittals to the Amendment Process:
- Guidelines for Certification of Tier III Engines Utilizing Exhaust Gas After-Treatment (PDF) (3 pp, 137K, October 2008)
- Regulation 13(7) Existing Engines (PDF) (3 pp, 150K, October 2008)
- Control of NOx Emissions from Existing Marine Diesel Engines (PDF) (5 pp, 142K, October 2008)
- Compliance and Testing Issues for Tier III Engines (PDF) (6 pp, 82K, October 2008)
- Simplified Certification and Relaxed Technical File Considerations -- A Proposal to Amend the NOx Technical Code (PDF) (5 pp, 129K, October 2008)
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.
Original MARPOL Annex VI (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)
Press Releases
March 2009 Press Release announcing ECA proposal. (March 30, 2009)
President signs the Maritime Pollution Protection Act of 2008. (July 22, 2008)
Guidance and Publications
- Coast Guard Policy Letter (CG-543 Policy Letter 09-01), Guidelines for Ensuring Compliance With Annex VI to the International Convention for the Prevention of Pollution from Ships (MARPOL) 73/78; Prevention of Air Pollution from Ships (PDF)
(43 pp, 1MB, February 2009)
and related Coast Guard information - Report: Global Trade and Fuels Assessment - Future Trends and Effects of Requiring Clean Fuels in the Marine Sector (PDF) (197 pp, 2MB, EPA420-R-08-021, November 2008)
- 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.