United States               Air and Radiation          EPA420-F-02-004
 Environmental Protection                             April 2002

 Office of Transportation and Air Quality


                                  EPA's Control
 Program  and MARPOL Annex VI
The U. S. Environmental Protection Agency (EPA) is proposing emission
standards for large marine diesel engines used on ocean-going vessels.
These emission standards, along with EPA's other emission standards
for smaller marine diesel engines, are separate from but are
comparable to emission standards adopted by the International
Maritime Organization (IMO) in Annex VI to the International Convention
on the Prevention of Pollution from Ships. This fact sheet summarizes
the main provisions of these two regulatory programs and describes
how the two programs fit together.
       Is            Annex VI?
The IMO, which was set up in 1948 under the United Nations to address
safety, navigation, and pollution prevention for ships engaged in interna-
tional trade, was responsible for drafting MARPOL: the International
Convention on the Prevention of Pollution from Ships, 1973, as Modi-
fied by the Protocol of 1978 Relating Thereto. There are six annexes that
address different kinds of pollution from ships: oil, noxious substances,
                                              > Printed on Recycled Paper

garbage, sewage, and air emissions. Annex VI addresses air emissions:
ozone depleting substances, incinerators, and emissions from tanker
operations, as well as NOx (oxides of nitrogen) and SOx (oxides of
sulfur) emissions from ship engines. Although Annex VI was adopted by
the IMO in 1997, it will not go into force internationally until 15 coun-
tries representing 50 percent of world merchant tonnage ratify it. So far,
six countries representing  16 percent have ratified it.
What is the         of U.S. ratification of Annex VI?
The U.S. government is preparing the appropriate documents for the
President to submit Annex VI to the Senate for its advice and consent to
ratification. In transmitting Annex VI to the Senate, the Administration
will work with Congress on new legislation to implement the Annex. At
the same time, the United States government supports a revision of the
Annex VI standards for NOx emissions, taking into account the emission
reduction potential of new control technologies. By ratifying the Annex,
the United States will continue to promote environmentally responsible
international emission standards at the IMO and recognize the role the
IMO plays in protecting the world's marine environment from pollution.
The U.S. government has already requested the Marine Environment
Protection Committee of the IMO to begin consideration of more strin-
gent NOx emission limits for marine diesel engines. Once the Annex
goes into force, amendment of NOx standards will be made easier
through the tacit amendment process that would then  apply.
What is the EPA program for marine        engines?
EPA has set marine diesel engine standards under Section 213 of the
Clean Air Act, which directs EPA to set emission standards for classes or
categories of new nonroad engines and vehicles. The standards are to
achieve the greatest degree of emission reduction achievable through the
use of technology that is expected to be available when the emission
limits go into effect, taking into account the cost of the technology and
noise, energy, safety factors, and lead time.

EPA set standards for marine diesel engines below 30 liters per cylinder
in 1999. The Tier 1 standards are equivalent to the Annex VI limits for
these engines and are voluntary until the Tier 2 standards go into effect.
The Tier 2 standards, which phase in between 2004 and 2007, reflect
additional reductions that can be achieved through engine-based con-
trols. These standards apply only to engines on US-flag vessels.

              We are now proposing standards for marine diesel engines at or above 30
              liters per cylinder. The Tier 1 standards are equivalent to the Annex VI
              NOx limits for these engines, for engines built in 2004 and later. We are
              considering a second tier of standards that would reflect additional
              reductions that can be achieved through engine-based controls and would
              apply to new engines built after 2006 or later. The proposed  standards
              would apply only to engines on US-flag vessels; we are seeking com-
              ment on applying them to engines on foreign flag vessels as  well.
              What is the relationship            IV1ARPOL and EPA
              In general, MARPOL does not prevent a country from setting standards
              for its ships. Annex VI specifically allows a country to set alternative
              standards that would apply to engines on ships that operate solely in
              waters under its jurisdiction. To meet its obligations under the Clean Air
              Act to set standards for these engines, the U.S. is exercising these
              MARPOL provisions. Because engines on these vessels will be subject
              to both programs, it is important to understand the relationship between
              them. Ship owners and operators as well as engine manufacturers should
              be familiar with these two programs because each program has require-
              ments for both groups.
Liability for
What would be the most significant differences
           the two programs?

    We require that the engine manufacturer be responsible for ensuring
    compliance with the emission standards for the full useful life of the
    engine, while the Annex VI program makes the ship operators fully
    responsible for ensuring in-use compliance.

    We require that the engine manufacturer demonstrate prior to
    production that they comply with the emission standards for the full
    useful life of the engine. The Annex VI program would only require
    that the manufacturer demonstrate that the engine meets the stan-
    dards when it is installed in the vessel; there is no Annex VI dura-
    bility demonstration.

    We allow, but do not require, witness testing for U.S. compliance.

Test fuel
date for

We are proposing to certify Category 3 marine engines using the
Annex VI test procedures for diesel marine engines with modifica-
tion. The modifications are required to ensure that the test data used
for certification are representative of in-use operation. We expect
that manufacturers would be able to use data from certification tests
conducted according to the modified EPA procedures for Annex VI

We are proposing that the official test fuel specification for C3
engines be a residual fuel. Annex VI specifies using distillate test
fuels and uses distillate testing as the basis of its standards. We are
proposing to allow certification testing on marine distillate fuel to
be consistent with Annex VI. However, we would correct the NOx
emissions, based on fuel nitrogen content, before the test results are
compared to our residual fuel based standards.

We are proposing to apply the standards based on the date of final
assembly of the engine, while Annex VI generally applies the
standards based on the start-date of the manufacture of the vessel.

We are proposing a simple production testing program to ensure
that certification designs would be  translated into production en-
gines that meet applicable standards. Annex VI also requires verifi-
cation that engines are properly installed, but allows this to be
demonstrated by either a parameter check or by testing.

Annex VI requires that engine manufacturers provide operators
with a Technical File that contains  maintenance instructions, test
data, and other compliance information. We are proposing only to
require the manufacturer to provide maintenance instructions
necessary to ensure that the engine would continue to meet the
emission standards in use.

To ensure that an engine in-use  continues to meet the standards, we
are proposing that operators be required to perform  a simple field
measurement test to confirm emissions after a parameter adjustment
or maintenance operation. The Annex VI program would require
only periodic surveys of the engine, which can take the form of a
simplified onboard test or, more frequently, a parameter check.

 Parameter       We are proposing to allow manufacturers to specify in their applica-
 adjustment      tions for certification the range of adjustment across which the
                  engine is certified to comply with the applicable emission standards.
                  Operators would be prohibited by the anti-tampering provisions
                  from adjusting engines to a calibration different from the calibration
                  specified by the manufacturer when they are within 175 miles of the
                  U.S. coast. We are also proposing to require all new Category 3
                  engines be equipped with emission measurement systems and with
                  automatic electronic-logging equipment that automatically records
                  all adjustments to the engine and the results of the required verifica-
                  tion tests.  Annex VI would prohibit operators from adjusting en-
                  gines to a calibration different from the calibration specified by the
                  manufacturer under any circumstances.

Onboard         We are proposing that simplified onboard measurements be used to
measurement     confirm proper adjustment of in-use engines. Annex VI allows such
                  systems, but does not require them.
              Could a manufacturer comply with both the EPA
              requirements and the Annex VI requirements at the
              A manufacturer that complied with the proposed EPA requirements
              would need to do very little additional work to meet the Annex VI
              requirements. First, the engine manufacturer would need to provide the
              operator with a Technical File that contains more information than would
              be required by EPA. The manufacturer may also need to ensure that the
              relevant emission testing is witnessed appropriately.

              For manufacturers that have already complied with the Annex VI, the
              amount of additional work that would be required to comply with the
              proposed EPA requirements would be dependent on how the manufac-
              turer conducted its emission testing. Additional requirements include:

               Demonstrate prior to production that the engines would comply with
                the emission standards for the useful life of the engine.

               Warrant to the purchasers that the engines would comply with the EPA
                requirements for the useful life of the engine.

               Perform a simple production test after installation.

  Install an onboard measurement system.

  Specify how the operator should adjust the engine in use and how
  proper adjustment should be verified through testing.
How can I obtain additional information about
You can find additional information about the EPA marine diesel engine
program at www.epa.gov/otaq/marine.htm.

You can find additional information about the IMO program on the IMO
Web site at www.imo.org. Please note that the IMO does not provide
copies of its programs on its Web site. You may obtain a copy from your
local library, or purchase a copy of Annex VI ofMARPOL 73/78: Regu-
lations for the Prevention of Air Pollution from Ships andNOx Technical
Code from the IMO (ISBN 92-801-6089-3) (IMO Sales Number IMO-