United States Air and Radiation EPA420-F-97-002
Environmental Protection January 1997
Agency
Office of Mobile Sources
v>EPA Environmental
Fact Sheet
Statement of Principles for Small
Nonhandheld Spark-ignited Engines
The U.S. Environmental Protection Agency (EPA) and manufacturers of small
nonroad nonhandheld engines have agreed to the structure for a Phase 2
program to be proposed for small nonhandheld spark-ignited (SI) engines.
These engines contribute approximately seven percent of the ozone-forming
HC emissions from mobile sources. The program would achieve substantial
reductions in ozone-forming pollutants in all parts of the country. It would
include standards that are expected to achieve a reduction of about 40 percent
in hydrocarbon (HC) + oxides of nitrogen (NOx) exhaust emissions from these
engines below Phase 1 levels.
Current Standards
In July 1995, EPA finalized the first national regulations affecting small SI
engines used primarily in lawn and garden equipment. The regulations,
commonly known as "Phase 1," take effect for new handheld and
nonhandheld engines beginning in model year 1997. The Phase 1 stan-
dards are expected to result in a 32 percent reduction in HC emissions
from these engines.
Statement of Principles
In December 1996, EPA and manufacturers of small nonhandheld nonroad
engines signed a Statement of Principles (SOP) which describes areas of
agreement between the Signatories on many issues for the nonhandheld
side of the industry. The SOP lays out a framework for a Phase 2 proposal
that will lead to substantially reduced emissions from two classes of new SI
engines below 19 kilowatts (25 horsepower) for use in nonhandheld appli-
cations.
i Printed on Recycled Paper
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Class 1 engines, which have displacement of less than 225 cubic centimeters (cc),
are small engines used primarily in residential applications such as walk behind
mowers and edgers. Class 2 engines, with displacement greater than or equal to
225 cc, are larger engines often used in riding mowers and lawn tractors and also
in more expensive, commercial applications.
Elements of the Statement of Principles
The provisions discussed in the SOP are expected to result in a shift of engines to
cleaner, more durable technology (such as over-head valve (OHV) technology),
and to ensure that emission reductions are achieved for the useful life of the
equipment. Highlights of this SOP that will be reflected in a future notice of
proposed rulemaking include:
«• Emission standards (in grams per kilowatt-hour) for HC + NOx, and carbon
monoxide (CO), to be met over the lifetime of the engines:
• In-use HC+NOx standard of 25 g/kW-hr for Class 1 engines effective in
2001.
• In-use HC+NOx standard of 12.1 g/kW-hr for Class 2 engines to be phased-
in between 2001-2005 which would shift these engines completely to OHV
or comparably clean and durable technology by 2005.
• In-use CO standard of 610 g/kW-hr for Class 1 and 2 engines, effective in
2001.
«• Memoranda of Understanding (MOUs) between EPA and engine manufactur-
ers for OHV Demonstration Programs to explore the feasibility and consumer
acceptance of applying OHV technology to Class 1 engines.
«• A compliance program including certification, production line testing, and a
field durability and in-use emission performance demonstration program for OHV
engines.
«• An agreement by the Signatories to work cooperatively on a voluntary Fuel
Spillage Reduction Program to educate consumers about the significant contribu-
tion to air pollution from spillage, and to encourage the development and use of
technology that will reduce or eliminate spills by users.
«• Flexibilities for manufacturers during transition to OHV technology, and
provisions for relief for engine families with less than 1000 units produced for sale
in the United States.
California has unique air quality needs for emission reductions that go beyond
the substantial reductions expected to be achieved by this program. Towards that
end, EPA is committed to working cooperatively with the California Air Resources
Board to help meet the needs of its State Implementation Plan while harmonizing
regulatory programs for these engines to the greatest extent possible.
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Next Steps
EPA plans to issue an Advance Notice of Proposed Rulemaking in early
1997 that will seek comment from all interested parties on the elements in
this SOP. EPA will then develop the provisions of the proposed Phase 2
regulations to be issued in the Fall of 1997, based in part on the SOP and
public comments on the ANPRM. The proposed rule will also include
provisions for small nonroad handheld engines. Final Phase 2 regulations,
following a public comment period on the proposal, will be issued in the
Fall of 1998.
For More Information
The text of this SOP and other nonroad engine documents may be accessed
via the EPA Internet server (http://www.epa.gov/OMSWWW) or via dial-up
modem on the Technology Transfer Network electronic bulletin board
system (TTN BBS: 919-541-5742 (1200-14400 bps, no parity, 8 data bits, 1
stop bit.)) Information is also available by calling the Office of Mobile
Sources, 313-668-4333, or by writing to:
U.S. Environmental Protection Agency
National Vehicle and Fuel Emissions Laboratory
2565 Plymouth Road
Ann Arbor, Michigan 48105
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