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Regulatory

Announcement

 Printed on Recycled Paper

United States

Environmental Protection

Agency

Air and Radiation EPA420-F-00-046

November 2000

Office of Transportation and Air Quality

Emission Standards for New Nonroad

Engines and Highway Motorcycles

Overview

Since 1994, EPA has established emissions control programs under the

Clean Air Act for various classes and categories of nonroad engines,

including those used in farm and construction, marine, locomotive, and

lawn and garden applications. With the Advance Notice being released

today, the Agency is seeking early input on our plan to propose a national program to control emissions from engines used in nonroad

applications that remain unregulated. These include:

• industrial spark-ignition engines rated above 19 kW (25 hp) (e.g.,

forklifts and generators);

• recreational gasoline engines (e.g., snowmobiles and off-road

motorcycles);

• and recreational marine diesel engines and all sterndrive and inboard gasoline engines.

The U.S. Environmental Protection Agency (EPA) is publishing an

Advance Notice of Proposed Rulemaking concerning emissions from

new nonroad vehicles and engines that are currently unregulated, and

highway motorcycles. Control of emissions from these engines will help

reduce the harmful health effects of ozone, carbon monoxide, and

particulate matter from these nonroad and highway engines.
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In addition, we are requesting comment on possible emission reductions

from highway motorcycles as part of this rulemaking. We are raising

these questions because there may be opportunities to reduce emissions

from these vehicles. There are also potential issues of consistency in

standards between nonroad and highway motorcycles. Current EPA

emission standards for highway motorcycles were established more than

20 years ago.

We are also announcing a final finding that nonroad spark-ignition (SI)

engines (engines powered by gasoline, natural gas or liquified petroleum

gas) rated above 19 kW and land-based recreational engines contribute to

air pollution in more than one nonattainment area in the U.S. With this

Final Finding, we are obligated under the Clean Air Act to set emission

standards requiring the greatest degree of emission reduction achievable,

considering several factors.

Health and Environmental Benefits

Emissions from these engines together account for about 11 percent of

hydrocarbon (HC) emissions, 9 percent of carbon monoxide (CO) emissions, and 3 percent of oxides of nitrogen (NOx) emissions from mobile

sources. The anticipated emission standards would significantly reduce

emissions from engines that contribute to ozone formation and potentially expose people to high concentrations of poisonous CO exhaust and

air toxics. Emission reductions will provide much-needed assistance to

states facing ozone, CO, and particulate matter air quality problems that

are causing a range of health problems for their citizens, especially

respiratory impairment and related illnesses. In addition, personal exposure to high levels of CO, particulate matter (PM), and air toxics raises

health concerns for many individuals.

Emission Standards for New Land-Based

Recreational Engines and Highway Motorcycles

Recreational vehicles include snowmobiles, off-road motorcycles (dirt

bikes), and all-terrain vehicles (ATVs). The program could also affect

some motorized scooters, mini-bikes, and mopeds. The Advance Notice

focuses on potential reductions in HC and CO. Many recreational vehicles are equipped with 2-stroke engines and have very high emissions

of HC and CO. Recreational vehicles currently contribute about 8 percent

of HC emissions and 5 percent of CO emissions from mobile sources. In

addition, we expect some reduction in PM and air toxics emissions.
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We are also interested in opportunities to reduce emissions from highway motorcycles along with off-road motorcycles. California’s emission

standards for highway motorcycles, which are more stringent than

federal standards, are being considered internationally. There may be

opportunities to harmonize with such programs to effectively reduce

emissions nationwide.

In the Advance Notice, we request comment on several issues and areas

of information, including:

• technologies that may be available to reduce emissions and the cost

of those technologies

• the timing and level of new emission standards

• test procedures for measuring emissions from vehicles and engines

• compliance programs, including production-line and in-use testing

by manufacturers

Emission Standards for New Recreational Marine

Engines

We plan to propose a national program to control emissions from unregulated marine propulsion engines. Emission standards for recreational

marine diesel engines will focus on NOx and PM. For sterndrive and

inboard gasoline engines, we anticipate a significant reduction in NOx,

CO, and HC emissions.

This Advance Notice anticipates a proposal containing three important

sets of provisions. First, emission standards will establish the level of

stringency that manufacturers must achieve when designing their engines. Emission-control technologies we will be evaluating for recreational marine diesel engines include established engine technologies

such as seawater aftercooling, and high-pressure fuel injection, perhaps

with electronic controls. For sterndrive and inboard engines we are

considering emission standards based on the use of three-way catalytic

converters, electronic fuel injection, and exhaust gas recirculation, all of

which have become commonplace in automotive engines.

Second, we are seeking comment on testing provisions that would

require engine manufacturers to show they can meet emission standards

over a variety of operating conditions. These testing requirements may

be very similar to those already adopted for commercial marine diesel

engines.
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Finally, we discuss certification and compliance provisions to help us

ensure that each engine is able to control emissions over its full lifetime.

Much of this will follow from other programs for similar engines, but it

will also reflect the unique characteristics of these engines.

Emission Standards for New, Large Spark-ignition

Nonroad Engines

We intend to propose a national program to control emissions of CO,

NOx, and HC from large nonroad spark-ignition engines, which may

operate on gasoline, natural gas or liquified petroleum gas. These engines

are used in a variety of industrial equipment, including forklifts, airport

ground-service equipment, generators, and compressors.

Even though these engines are very similar to, or are built from, base

automotive engines, nonroad engine designs have changed little over the

years. Adopting basic automotive emission-control technologies allows

for dramatic improvements to engine performance and fuel economy in

addition to the expected emission reductions.

Under the anticipated control program, manufacturers would use electronic fuel injection and catalytic converters to meet emission standards.

The California Air Resources Board (California ARB) adopted emission

standards for Large SI engines in October 1998. Further engine testing

and a concern for off-cycle emissions has led us to consider several

provisions not adopted by California ARB, most notably:

• A more stringent emission standard to more accurately reflect the

in-use deterioration of emission controls

• A duty cycle that includes transient engine operation

• Not-to-exceed testing and emission standards

• Basic engine diagnostic requirements

• Measures to reduce evaporative emissions from gasoline-fueled

equipment

Public Participation Opportunities

We are releasing the Advance Notice to encourage full public participation in the rulemaking development process. We especially encourage

commenters to provide specific suggestions and data in the areas we

identify.
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For instructions on submitting written comments, please see the Federal

Register notice, which is available from the EPA Air and Radiation

Docket by calling 202-260-7548 (refer to Docket A-2000-01). We are

also accepting comments via e-mail at “nranprm@epa.gov”. In addition,

you can access the Advance Notice and related documents electronically

on the Office of Transportation and Air Quality (OTAQ) Web site at:

 www.epa.gov/otaq

There will also be an opportunity for oral and written comment when we

later publish a Notice of Proposed Rulemaking.

For More Information

You can access documents on this rulemaking electronically on the

OTAQ Web site given above, or by contacting Margaret Borushko at:

U.S. Environmental Protection Agency

Office of Transportation and Air Quality

2000 Traverwood Drive

Ann Arbor, MI 48105

borushko.margaret@epa.gov

734-214-4334