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 coordinated strategy to address emissions from oceangoing vessels. This strategy includes EPA’s Clean Air Act (CAA) regulations for the largest marine diesel engines as well as the U.S. government's international efforts to reduce air pollution from oceangoing vessels through the designation of an Emission Control Area and new international standards for marine diesel engines.

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.

EPA Regulations

EPA is proposing emission standards for new marine diesel engines with per cylinder displacement at or above 30 liters (called Category 3 marine diesel engines) installed on U.S.-flagged vessels. The proposed engine standards are equivalent to the nitrogen oxides (NOx) limits recently adopted in amendments to Annex VI to the International Convention for the Prevention of Pollution from Ships (a treaty called "MARPOL") and are based on the position advanced by the United States Government as part of international negotiations. The near-term standards for newly-built engines would apply beginning in 2011. Long-term standards would begin in 2016, and are based on the application of high-efficiency after-treatment technology.

EPA is also proposing a change to the diesel fuel program that would forbid the production and sale of marine fuel oil above 1,000 ppm sulfur for use in the waters within the proposed U.S. ECA and internal U.S. waters and allow for the production and sale of 1,000 ppm sulfur fuel for use in Category 3 marine vessels.

This proposal is part of a coordinated strategy to ensure that all ships that affect U.S. air quality meet stringent NOx and fuel sulfur requirements. When taken together, the elements of the coordinated strategy are expected to result in significant improvements in U.S. air quality and public health.

See the electronic Code of Federal Regulations for the full text of current regulations that apply to marine compression-ignition engines. The documents that describe and support the 2009 proposal plus documents that established EPA’s current Tier 1 standards are available below.

Notice of Proposed Rulemaking: Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder (signed June 26, 2009)
- Fact Sheet | PDF Version (5 pp, 186K, EPA420-F-09-029, June 2009)
- Pre-publication Preamble (PDF) (160 pp, 1.4MB, June 2009)
- Pre-publication Regulations (PDF) (160 pp, 3.2MB, June 2009)
- Notice of Public Hearings | PDF Version (2 pp, 72K, published July 8, 2009)
- Draft Regulatory Impact Analysis (PDF) (500 pp, 12.4MB, EPA420-D-09-002, June 2009)
  Instead of downloading the entire document, you can access individual chapters.
- Memo: Proposed Technical Amendments to EPA Regulations (PDF) (147 pp, 2.3MB, June 2009)
- ANPRM Fact Sheet | PDF Version (3 pp, 102K, EPA420-F-07-050, November 2007)
- Supporting Documentation: Information related to the development of this proposal can be found on the electronic docket at www.regulations.gov. See Docket ID EPA-HQ-OAR-2007-0121.
- NOTE: The proposed rule is scheduled for publication in the Federal Register on August 28. As a result of the delayed publication, we will be extending the comment period to September 28, 2009.
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-F-07-024, 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)
- Final Tier 1 Rule | 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.

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Emission Control Area Designation

On July 17, 2009, the joint proposal from the United States and Canada to amend MARPOL Annex VI to designate specific areas of our coastal waters as an Emission Control Area (ECA), was accepted in principle at the International Maritime Organization (IMO). In addition, France has joined the ECA proposal on behalf of its island territories of Saint-Pierre and Miquelon, which form an archipelago off the coast of Newfoundland. The proposal will circulate among member states for six months. In March 2010, member states who are parties to MARPOL Annex VI will vote to adopt an amendment designating the North American ECA.

Designation of this ECA will deliver substantial public health benefits to many people living in the U.S., Canada and French territories, as well as to marine and terrestrial ecosystems.

In practice, implementation of the ECA would mean that ships entering designated areas would need to use compliant fuel for the duration of their voyage that is within that area, including time in port as well as voyages whose routes pass through the area without calling on a port. The quality of fuel that complies with the ECA regulation will change over time. The North American ECA could go into force as early as 2012. From the effective date until 2015, fuel used by all vessels operating in designated areas cannot exceed 1.0 percent sulfur (10,000 ppm). Beginning in 2015, fuel used by all vessels operating in these areas cannot exceed 0.1 percent sulfur (1,000 ppm). Beginning in 2016, NOx after-treatment requirements become applicable.

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) (74 pp, 1.79M)
  - Executive Summary (PDF) (8 pp, 77K)
  - Annex 1: Justification for ECA (PDF) (60 pp, 1.65M)
  - Annex 2: Description of Area (PDF) (2 pp, 36K)
  - Annex 3: Chart of Area (PDF) (1 pp, 77K)
  - Annex 4: Draft Reg Text (PDF) (2 pp, 37K)
- Information Document (PDF) (13 pp, 93K)
- Technical Support Document (Entire Document (PDF) (329 pp, 8.9M, EPA-420-R-09-007, April 2009)
  - 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)
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)

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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 air pollution standards are found in Annex VI to the International Convention on the Prevention of Pollution from Ships (MARPOL). Committees of the IMO meet periodically to consider and adopt revisions to the various annexes of MARPOL. This page describes both the currently applicable international air pollution standards as well as amendments that have been recently adopted but have not yet become enforceable.

Current Annex VI Tier 1 NOx Standards

Globally, the effective date for the current MARPOL Annex VI Tier 1 NOx limits was January 1, 2000. Annex VI entered into force for the United States on January 8, 2009. Vessel owners are now required to comply with these standards, although most voluntarily complied in the interim since 2000. Documents describing these currently applicable international standards are available below under “Original MARPOL Annex VI.”

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 IMO adopted new international standards for marine diesel engines and their fuels (2008 Amendments to MARPOL Annex VI) that will apply globally, once the amended treaty is ratified by enough parties. The amendments establish additional, more stringent emission requirements for ships that operate in designated coastal areas where air quality problems are acute. These new global and geographic standards have the potential to significantly reduce air pollution from ships, and provide important benefits to our national air quality.

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. Documents describing the amendments and the amendment process are available below.