RESPONSE TO COMMENTS ON THE NPRM 

Emission Standards for New Nonroad Spark.IgnitionEngines 

at or Below 19 Kilowatts 

DRAFT ~ _3o~'1 May 27,1995 

EPAAlR~E.l 

u.s. Environmental Protection Agency 

Office of Air and Radiation 

Office of Mobile Sources 

Certification Division 
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TABLE OF CONTENTS 

SECTION 1: INTRODUCTION ........................................................................... 3 


SECTION 2: STATUTORY AUTHORITy............................................................... 6 


SECTION 3: EFFECTIVE DATE, APPLICABll.JTY, AND DEFINITIONS ....................... 7 


3. 1 	 Model Year and Effective Date ................................................................. 7 


3.2 	 Nonroad Engine and Vehicle Definitions .................................................... 11 


3.3 	 Definition of Handheld Equipment, Snowthrowers, and Two-stroke Lawnmowers ... 12 


3.4 	 Lawnmowers.................................................................................... 17 


3.5 	 Snowthrowers...................................................................................22 


3.6 	 Use of Power Rating as Cutoff for Applicability ...........................................25 


3.7 	 Non-Coverage of Compression-ignition Engines...........................................26 


3.8 	 Non-Coverage of Recreational Propulsion Engines ........................................27 


3.9 Non-coverage of Marine Propulsion Engines ...............................................28 


SECTION 4: CERTIFICATION REQUIREMENTS AND EMISSION STANDARDS ...........29 


4.1 	 Equipment and Vehicle Manufacturer Requirements .......................................29 


4.2 	 Engine Family Definition ......................................................................31 


4.3 	 Labeling ..........................................................................................32 


4.4 	 Cap on Noise .................. ~ .................................................................33 


4.5 	 Safety Implications .............................................................................35 


4.6 	 Retention ofCertification Engine ............................................................ .36 


4.7 	 CO Standard .....................................................................................36 


4.8. 	 Class V Compliance Margin Language.......................................................39 


4.9 	 HC. +. NOx Standard............................................................................40 


4.10 	 Stringency of Standards....................................................................... .40 


4.11 Regulating HC vs. VOC ...................................................................... .42 


SECTION 5: TEST PROCEDURES AND EQUIPMENT ............................................ .42 


5.1 	 Certification Test Fuels.........................................................................42 


5.2 	 Service Accumulation Fuel (or Break-In Fuel) ............................................. .43 


5.3 	 Power Measured During the Idle Mode ..................................................... .44 


5.4 	 Differences between the proposed Federal test procedure and the Society of Automotive 


Engineers (SAE) Recommended Procedure 11088.........................................45 


5.5 	 Unconditioned Air Supply, Humidity Measurement ...................................... .46 


5.6. 	 Test Conditions, Test Engine Orientation ....................................................46 


5.7. 	 Ambient Test Conditions and f-parameter Specifications ................................. .47 


5.8 	 Oxygen Interference Check - Frequency ofCheck ........................................ .48 


5.9 	 Carbon Monoxide Analyzer Interference Check ........................................... .48 


5.10 	 Calibration Frequency ..........................................................................49 


5.11 	 Test Procedure Overview, Dynamometer Requirement ....................................50 


5.12 	 Recorded Information, Explanation of Terms...............................................50 


5.13 	 Humidity and temperature measurement of engine intake air..............................50 


5. 14. 	 Engine service accumulation time determination ........................................... .51 


5.15 	 Effect of emission measuring equipment on engine performance .........................52 


5.16 	 The use of observed vs. corrected torque in power calculations ..........................52 


5.17 	 Engine stabilization - thennal stability requirement .........................................53 


5.18 	 Data Sampling Period and Frequency ........................................................53 


5.19 	 Averaging of speed and torque data for power calculation .................................54 


5.20 	 Emission Bench Calibration Information .............................................. " ....55 


5.21 	 Automatic Data Collection Of Continuous Analyzer Response ............................55 


5.22 	 Engine Cooling Fan For Air BlowerslPumps .............................................. .56 


5.23. 	 Analytical Gases - Pure Gases ................................................................56 


5.24. 	 Analytical Gases - Diluent for Hc-Fid Zero, Span and Calibration Gases ...............57 


5.25. 	 Analyzer Calibration - Step Calibration Requirement.. ..................................... 57 


5.26. 	 Oxides of Nitrogen Measurement, Accuracy and Instrumentation ........................58 


Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
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5.27. Testing Mode Intervals .........................................................................59 


5.28. Mixing Chamber Requirements - Helmholtz Frequency Requirement ...................59 


5.29. Acceptance of the Micro-Dilution Tunnel Testing Method .................................60 


5.30. Air Flow Measurement for Two-Stroke Engines ...........................................60 


5.31 Catalyst Durability Cycle: Change to Test Requirements ..................................61 


5.32 Exhaust Gas Composition for Testing of Three-Way Catalysts ...........................62 


5.33 Deterioration Limits.............................................................................62 


5.34 Purpose ofCatalyst Durability Cycle .........................................................63 


5.35 Worst Case Emitter .............................................................................65 


SECTION 6: SELECTIVE ENFORCEMENT AUDITING ...........................................66 


6.1 Attached Equipment During An SEA.........................................................66 


6.2 Additional Parts Necessary For An SEA .....................................................67 


6.3 Annual Limit Of SEAs .........................................................................68 


6.4 Number Of SEAs Per Day .....................................................................69 


6.5 Sampling Plans..................................................................................70 


6.6 SEA Self-Auditing ..............................................................................71 


6.7 Audit from Engine Family or Configuration? ...............................................72 


6.8 SEAs and Manufacturer Production Schedules ................ ,............................73 


6.9 Port Selection for Imported Engine SEA Testing ...........................................74 


6.10 In-Use Testing For Phase 2 Versus Sea Auditing ..........................................75 


6.11 Designating Official Data.......................................................................75 


6.12 EPA May Specify SEA Governor Set Speeds ...............................................76 


6. 13 Duration ofthe SEA ............................................................................76 


6.14 Dealers Involved in SEAslRecordkeeping ...................................................77 


SECTION 7: IN-USE TESTING .........................................................................77 


SECTION 8: DEFECT REPORTING AND VOLUNTARY RECALL ..............................80 


8.1 Definition of Emissions-related Defect .......................................................80 


8.2 The 25 Engine Trigger .........................................................................82 


8.3 Appropriateness of Voluntary Recalls ........................................................83 


8.4 Description of Method for Notifying Owners ...............................................84 


8.5 The Five Year Reporting Period ..............................................................85 


8.6 Extension of 15 Day Reporting Deadline ....................................................86 


8.7 Usefulness of Warranty Data ..................................................................86 


8.8 Dealer Concerns.................................................................................88 


8.9 Emission Defect Warranty Requirements ...................................................89 


8.10 Independent Commercial Importer (ICI) Program ..........................................93 


8.11 Tampering ..................................................................................... '..93 


SECTION 9: ECONOMIC EFFECTS ....................................................................93 


SECTION 1 0: ADMINISTRATIVE REQUIREMENTS ...............................................98 


10.1 Small Entities ....................................................................................98 


10.2 Reporting Burden ...............................................................................99 


10.5 Health Effects! Air Toxins.................................................................... 100 


10.6 Modeling ....................................................................................... 101 


10.7 Estimate of Use of Fixed Jet Carburetors for Class V .................................... 101 


SECTION 11: ADDmONAL ISSUES ................................................................ 102 


11.1 Absence of Averaging, Banking and Trading Programs ....... ,......................... 102 


11.2 Administrative Procedure Act ............................................................... 106 


11.3 SIP Credits .................................................................................... 107 


11.4 Metric ........................................................................................... 108 


11.5 Service Information........................................................................... 109 


11.6 Consumer/Commercial Terminology ....................................................... 109 


Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
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SECTION 1: INTRODUCTION 


On May 16, 1994, the Environmental Protection Agency (EPA) published in the Federal 

Register a Notice of Proposed Rulemaking (NPRM) for emission standards for new nonroad 

spark-ignition (SI) engines at or below t9 kilowatts (kW) (hereafter, "small SI engines"). The 

purpose of the small SI engines NPRM, as required by Congress in section 213(a)(3) of the 

amended Clean Air Act, is to regulate emissions from a category of new nonroad engines and 

vehicles that, in EPA's judgment, cause or contribute to air pollution in areas that failed to attain the 

National Ambient Air Quality Standards (NAAQS) for ozone or carbon monoxide (CO). 

The Agency held a public hearing on this proposal on June 21, 1994, in Ann Arbor, 

Michigan. Six individuals, representing engine, equipment, and emission controls manufacturers . 

and associations, presented prepared statements and answered questions. A transcript of the public 

hearing is available in the docket for this rulemaking. The public comment period during which the 

Agency accepted written comments on the proposal was originally slated to close on July 15, 

1994, but was extended until August 5, 1994. The Agency received submissions regarding the 

NPRM from 33 commenters, including 16 engine or equipment manufacturers or manufacturer 

associations, one emission controls manufacturer association, one environmental consulting 

company, one environmental organization, one equipment dealer association, one private citizen, 

one state farm bureau, one professional association, and 10 state or local government agencies or 

associations. 

How to use this document 

The purpose of this document is to summarize and respond to the comments submitted by 

the public. Included in the document are responses to the issues raised at the public hearing and in 

the written and oral comments received by EPA. Each of the remaining sections of this document 

is structured by topic, rather than by individual commenter. Sections begin with a brief description 

of the approach taken in the May 16, 1994 NPRM, followed by a summary of the relevant 

comments and finally by EPA's response to those comments. All of the written comments 

submitted to EPA, as well as records of all oral comments received during the comment period, are 

contained in EPA's Nonroad Engines and Vehicles Small Spark Ignition Engine Docket (EPA Air 

and Radiation Docket, Docket Number A-93-25). 

Table 1 lists those commenters who expressed their views to EPA regarding this 

rulemaking. 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5121195 
Table 1: List of Commenters on the Small SI Engines NPRM 

Ardisam, Inc. 


Association of Local Air Pollution Control Officials (ALAPCO) 


Auger and Power Equipment Manufacturers Association (APEMA) 


The Black & Decker Corporation (BDC) 


Briggs & Stratton Corporation 


California Air Resources Board (CARB) 


California Bureau of Automotive Repair (BAR) 


City of Chicago, Department of Law 


ECHO, Incorporated 


Engine Manufacturers Association (EMA) 


General Equipment Company 


Holliday Environmental Services, Inc. 


Honda, American Honda Motor, Co. 


Ralph Hovnanian, private citizen 


lllinois Farm Bureau 


Kohler Co. 


Kubota Corporation 


Machinery and Electrical Products (MEP) 


Manufacturers of Emission Controls Association (MECA) 


National ArOOrist Association (NAA) 


Natural Resources Defense Council (NRDC) 


North American Equipment Dealers Association (NAEDA) 


Northeast States for Coordinated Air Use Management (NESCAUM) 


Onan Corporation 


Outdoor Power Equipment Institute (OPEl) 


Portable Power Equipment Manufacturers Association (PPEMA) 

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State and Territorial Air Pollution Program Administrators (STAPPA) 


State of Louisiana, Department of Environmental Quality 


State of New York, Department of Environmental Conservation 


State of Tennessee, Department of Environment and Conservation 


State of Wisconsin, Department of Natural Resources 


Tecumseh Products Company 


The Toro Company 


In summary, EPA received a range of comments; generally the industry and their 

associations found aspects of the proposal too burdensome while the states and environmentalists 

expressed concern that the NPRM was too lenient on several issues. The most frequently 

addressed issue in the comments was the proposed August 1, 1996 effective date. States, with 

their concerns about emission credits, suggested effective dates ranging from January 1, 1996 to 

no later than the proposed August 1, 1996 date. Industry, on the other hand, prefers a delay in the 

effective date, and thus supported options ranging from January 1, 1997 to January 1, 1999. 

Many other comments addressed the handheld definition, the proposed emission standards, and 

details of the test procedure. Industry also expressed concern about certification and in-use testing 

requirements, and believed EPA to have underestimated the economic costs of the proposal. In 

addition, many industry entities raised concerns about post-certification issues such as Selective 

Enforcement Audits (SEA), defect reporting and voluntary recall, and emission defect warranties. 

After reviewing the comments and the data submitted by some of the commenters, EPA 

developed a final rule that incorporates many of the ideas raised. 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5127/95 
SEC1"ION 2: STATUTORY AUTHORITY 

Summary ofthe Proposal 

In the proposal, EPA cited those sections of the Clean Air Act that provide authority for the 

requirements contained in the proposal, and discussed the mandate ofCAA section 213. The 

emission contribution of the subject engines as indicated in the Nonroad Study l was presented, 

and the background of the rulemaking was detailed. 

Summary of the Comments 

The Portable Power Equipment Manufacturers Association (PPEMA) commented that EPA 

failed to make an affInnative significance determination that small engines contribute significantly 

to ozone or CO in nonattainment areas; without such a determination, according to PPEMA, EPA's 

emission standards lack statutory authority. 2 

EPA's Response to the Comments 

EPA does not agree. In the proposal's statutory authority discussion, EPA stated its 

finding that small engines are a class or category of nonroad engines that contribute to air pollution. 

See 59 FR 25399 at 25400 (May 16, 1994). EPA also cited section 213(a)(3)'s requirement that 

EPA regulate those classes or categories of new nonroad engines that, in EPA's judgment, cause 

or contribute to ozone or CO in nonattainment areas. EPA did not make a finding under section 

213(a)(4) with respect to other pollutants, as it did in the large CI proposal, because EPA did not 

propose to regulate small engine emissions other than VOCs, CO, or NOx. 

The statutory authority discussion specifically incorporates by reference the significance 

determination for nonroad engines proposed on May 17, 1993 (58 FR 28809), which was 

finalized as proposed at 59 FR 31306 (June 17, 1994). In the proposal's background discussion, 

EPA states that small SI engines are the source of five percent of summer VOCs in the 19 ozone 

non attainment areas included in the Nonroad Study, and five percent of winter CO emissions in the 

16 CO nonattainment areas included in the study. See 59 FR 25399 at 25400 (May 16, 1994). 

EP A does not agree that a finding of significant contribution must be made for each class or 

category of nonroad engine regulated under section 213(a)(3). Paragraphs (1) and (2) of section 

213(a) make it clear that EPA's significance determination should be based on whether emissions 

from all new .and existing nonroad engines are significant contributors to ozone or CO 

concentrations. There is no indication that the significance determination should be based on 

contributions from various subcategories of nonroad engines. By contrast, if the Administrator 

makes an affmnative decision regarding aggregate significance, then section 213(a)(3) requires the 

Administrator to promulgate regulations for those claSses and categories of nonroad engines and 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5127/95 
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vehicles "which in the Administrator's judgment cause, or contribute to, such air pollution." This 

mandate does not include any reference to a determination of significance for classes or categories. 

Moreover, EPA's interpretation is supported by the legislative history of the Act. See S. Rep. No. 

228, WIst Cong., 1st sess. 103-105 (1989); H. Rep. No. 490, WIst Cong., 2nds sess. 309-310 

(1990); CHAFFEE-BAUCUS STATEMENT OF SENATE MANAGER, 136 Congo Rec. at 

S16938 (daily ed., Oct. 27, 1990). EPA notes that the requirement in the Senate bill that would 

have mandated EPA to make individual significance determinations for each class or category 

regulated was deleted from the Clean Air Act as it was finally passed by Congress. Thus, the 

Agency believes Congress did not intend a showing of significant contribution to be required for 

regulation of classes or categories of nonroad engines and vehicles. This issue is discussed in 

further detail in the large CI final rule at 59 FR 31306, 31309 (June 17, 1994). 

SECTION 3: EFFECTIVE DATE. APPLICABILITY. AND DEFINITIONS 

3. 1 Model Year and Effective Date 

3.1.1 Summary o/the Proposal 

This rule will become effective beginning with the 1997 model year. EPA proposed an 

effective date of August 1, 1996 for implementation of this rulemaking; engines manufactured on 

or after August 1. 1996 for use within the U.S. would have been subject to the standards and 

requirements of the rule. On model year, EPA proposed in the alternative: (1) a model year 

beginning August 1 and ending July 31 of the succeeding year, (2) a model year like that in the onhighway program, and (3) a model year like that in the on-highway program but running from 

August to July rather than January to December. 

3.1.2 Summary o/the Comm~nts 

EPA received comment on the proposed effective date from manufacturers and industry 

associations, states and state and local air officials, and an environmental association. Several 

states, state and local air officials, and an environmental association supported an effective date of 

January 1, 1996.3 They argued that delayed implementation decreases the value of a phased 

approach to small engine regulation by eroding the near-tenn benefits of a program intended largely 

to provide near-tenn benefits.4 A state, an environmental association, and associations of state and 

local air officials that are participants in the negotiated rulemaking for the second phase of small 

engine regulation stated that their agreement to participate in the negotiated rulemaking was based 

partly on a January 1, 1996 effective date for the Phase 1 rulemaking.5 

Emission Standards for New-Nonroad Spark.-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5127/95 
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Several states and a manufacturer supported the proposed effective date of August 1, 

1996.6 One state argued that industry has had ample notice, and that to delay would reward parties 

that have not devoted resources in good faith to develop cleaner engines'? Another state 

commented that it would have to adopt California's regulation for SI engines under 25 horsepower 

to get the SIP credits it needs if the federal effective date is delayed.8 

Several manufacturers and industry associations supported an August I, 1997 effective 

date, citing lead time considerations.9 An association pointed out that, from the promulgation of 

the final rule in May 1995 to the effective date of August I, 1996 would provide only one year of 

lead time prior to implementation. 10 The association stated that one year of lead time is insufficient 

for engine manufacturers to retool to achieve emission compliance for implementation of 

. nationwide standards, or for equipment manufacturers and component suppliers to modify their 

products to accommodate new or redesigned engines. I I 

Another industry association and a manufacturer pointed out that an August effective date 

does not coincide with the production cycle for all engines covered by this rule; many operate on a 

calendar year basis. 12 That association supported an effective date for products that are not 

preempted in California two years after California's regulations become effective (e.g., January I, 

1997), and an effective date for products that are preempted in California two years after this Phase 

I rule takes effect (e.g., January 1, 1999).13 The association cited lead time concerns, particularly 

in regard to products that are preempted from regulation in California. 14 One manufacturer 

supported a January 1998 effective date for engines used in products that are preempted from 

regulation in California, arguing that the additional lead time is critical to prevent disruptions in 

supply since most attention has been focused on engine development for nonpreempted 

products. 15 Other dates supported by manufacturers or industry associations include November 1, 

1996,16 November I, 1997,17 and January 1, 1998.18 

On model year, comments were received from manufacturers and industry, state and local 

air officials', and environmental associations. All comments supported the on-highway model year 

definition. 19 An industry association stated that the on-highway model year definition would 

provide needed flexibility in certifying seasonal products.20 Another industry association 

commented that because the on-highway model year definition allows two frrsts of August, 

manufacturers would have the greatest flexibility during the period of the year they are most likely 

to introduce new models.21 

3.1.3 EPA IS Response to the Comments 

EPA is finalizing a model year 1997 effective date and adopting the on-highway model year 

definition. The 1997 model year will run from January 2, 1996 to December 31, 1997. 

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EPA acknowledges industry's need for sufficient lead time. EPA also acknowledges the 

need of states to realize reductions of air pollutant emissions, and to adhere to schedules mandated 

in the CAA for reasonable further progress toward VOC reductions from 1990 levels and for 

attainment of the ozone National Ambient Air Quality Standard. The model year 1997 effective 

date provides additional lead time for those manufacturers that take advantage of the flexibility 

allowed by the model year definition; it also allows early introduction of complying products by 

manufacturers that are in a position to produce complying products earlier in the model year rather 

than later. 

EPA is allowing . additional lead time for Class V engines covered by this rule that are used 

in farm and construction equipment or vehicles which CAA section 209(e)( l)(A) preempts from 

state regulation. The effective date for such Class V engines is January 1, 1998. Although one 

association commented that even more additional lead time is necessary for preempted products,22 

EPA is not persuaded that more additional lead time is essential since manufacturers have already 

gained increased knowledge of and experience with the technologies and calibrations that are 

available for their engines to meet the standards. 

Under the final rule, the model year includes January 1 of the calendar year for which it is 

designated and does not include a January 1 of any other calendar year. The maximum duration of 

a model year is one calendar year plus 364 days. A certificate of conformity is issued for each 

engine family introduced into commerce for a single model year. The annual production period 

within a model year for any specific model within an engine family begins either: (1) when such 

engine is first produced, or (2) on January 2 of the calendar year preceding the year for which the 

model year is designated, whichever date is later. The annual production period ends either: (1) 

when the last such engine is produced, or (2) on December 31 of the calendar year for which the 

model year is named, whichever date is sooner. 

It is a prohibited act to introduce a specific model year engine into commerce prior to or 

after the model year for which the certificate is issued and in effect. However, in recognition of the 

fact that some manufacturers will be in a position to ship certified engines prior to January 2, 1996, 

EPA is making an exception for engine families that are certified by EPA prior to January 2, 1996; 

such engine families may enter commerce prior to January 2, 1996 once a certificate of conformity 

has been issued. 

Engines produced after December 31 of the calendar year for which the model year is 

named are not covered by the certificate of conformity for that model year. A new certificate of 

conformity demonstrating compliance with applicable standards must be obtained for such engines, 

even if they are identical to engines built before December 31. 

To provide maximum flexibility in the start-up of this program. the Agency is interpreting 

the Phase 1 model year definition somewhat differently than in the on-highway program. For the 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
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1997 model year only, manufacturers may choose to produce both certified and uncertified engine 

families during annual production periods that begin prior to September 1, 1996. All engines 

manufactured during annual production periods that begin on or after September 1, 1996 must be 

certified. In addition, annual production periods that begin prior to September 1, 1996 may not 

exceed 12 months in length, to ensure that all engines are certified no later than calendar year 1997. 

EPA has determined that flexibility in the interpretation of the model year definition for program 

start-up is necessary in fairness to manufacturers both to provide necessary lead time and to 

account for the variability in production periods of the small SI engine industry. 

For example, a manufacturer of lawnmower engines with an annual production period from 

July 1996 to June 1997 might choose to certify two-thirds of its engine families by July 1996, with 

the remainder of its production being uncertified. Normally, the manufacturer must certify all its 

engines in every annual production period; the enhanced flexibility provided by this special 

interpretation, which allows manufacturers to choose when to begin certifying in production 

periods beginning before September 1, 1996, is for the start-up of this program only. 

The lawnmower manufacturer in the above example may call the engine families certified in 

calendar year 1996 ~ither model year 1996 or model year 1997 engines; the advantage to calling 

them model year 1997 engines is that they can then be built past December 31, 1996. Similarly, 

the lawnmower engine families certified in calendar year 1997 may be called model year 1997 or 

model year 1998 engines, but only model year 1998 engines may be built beyond December 31, 

1997. 

Another example is a string trimmer engine manufacturer that operates on a January to 

December production period. The manufacturer may choose to certify any portion of its engine 

families in January 1996, and must certify all its engine families in January 1997. 

EPA expects that manufacturers will federally certify a substantial number of engine 

families in calendar year 1996 to take maximum advantage of "green" marketing strategies. Most 

of the engine families covered by this regulation will already have been certified to California 

standards prior to model year 1997. No data are available for EPA to accurately predict the 

percentage of small engine families that will be certified in calendar year 1996. For purposes of 

state implementation plan submittals, EPA is estimating that half will be certified in calendar year 

1996. 

The model year definition, with a maximum duration of one calendar year plus 364 days, is 

primarily intended to allow flexibility in the introduction of new models. Under no circumstances 

should the model year definition be interpreted to allow existing models to "skip" annual 

certification by pulling ahead the production of every other model year. While this situation, to the 

Agency's knowledge, has not occurred in the past, a practice of producing engines for a two year 

period would violate the Congressional intent of annual certification based upon an annual 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5127/95 
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production period. The Agency is not currently setting forth rules for how to determine when 

abuse has occurred, since this has not been a problem to date. However, the Agency is requiring 

that engine manufacturers certify annually based on an annual production period. 

3.2 Nonroad Engine and Vehicle Definitions 

3.2.1 Summary ofthe Proposal 

EPA proposed to incorporate the nonroad engine definition proposed and finalized in the 

large CI rule. EPA also proposed to amend the definition of nonroad vehicle proposed in the large 

CI rule by including nonroad equipment within the definition of nonroad vehicle. EPA is finalizing 

these definitions as proposed. 

3.2.2 Summary of the Comments 

EMA, OPEl, and PPEMA object to the definitions. EMA and OPEl object to the nonroad 

engine definition, and to the definition of the term "new," and incorporate by reference their 

comments on the laJ"ge CI rule (EPA Air Docket A-91-24) and the waiver of preemption to 

California for nonroad engine and vehicle standards (EPA Air Docket A-91-18).23 

PPEMA objects to both the nonroad engine and nonroad vehicle definitions because the 

definitions are expressed in terms of engine applications; according to PPEMA, EPA is not 

authorized to regulate engine applications other than vehicles.24 PPEMA comments that including 

equipment within the category of vehicles is a strained interpretation, beyond judicial tolerance. 25 

PPEMA accuses EPA of equating engines with engine applications in an unsuccessful attempt to 

remain within the authority granted by the CAA.26 PPEMA rejects EPA's responses to its 

comments on the large CI rule.27 PPEMA also requests an explanation of why the nonroad 

vehicle definition in the proposal is unlike that in the large CI rule, where nonroad vehicle and 

nonroad equipment are defined separately.28 

STAPPA and ALAPCO support EPA's view that Congress used the terms "engine" and 

"vehicle" in a generally inclusive manner and support adding equipment to the nonroad vehicle 

definition. 29 

3.2.3 EPA's Response to the Comments 

In regard to the objections of EMA and OPEl to the nonroad engine definition, and to the 

definition of "new," EPA incorporates by reference its previous response to those comments. See 

59 FR 31306,31310-31313 and 31328-31331 (June 17,1994). 

EPA also stands by its previous response to PPEMA's comments on the nonroad engine 

definition in the large CI rule (see, e.g., 59 Fed. Reg. 31306,31313-31314). In summary, EPA 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
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is authorized by CAA sections 213 and 301 to regulate both nonroad equipment and particular 

applications of nonroad engines, as well as nonroad engines and nonroad vehicles. The final large 

CI rule includes a definition for nonroad equipment. 

In Phase 1, the definition of nonroad equipment is incorporated into the definition of 

nonroad vehicle. EPA does not agree that including equipment with vehicles in a definition for the 

purposes of nonroad engine regulation is an interpretation beyond judicial tolerance. Rather, EPA 

is refining a term of art for the purposes of these regulations; it is simply more efficient as well as 

convenient to refer to nonroad engines and vehicles than to nonroad engines, vehicles, and 

equipment. Moreover, EPA notes that Congress clearly intended for nonroad equipment to be 

included within the regulatory scope of this rule, as is shown by the legislative history. See S. 

Rep. No. 228, 10ist Cong., 1st sess. 104 (1989). 

3.3 Definition of Handheld Equipment, Snowthrowers, and Two-stroke 

Lawnmowers 

3.3.1 Summary ofthe Proposal 

The Agency proposed that small SI engines be categorized as either handheld or 

nonhandheld, depending on the usage of the equipment in which the engine is installed. To qualify 

as handheld, it was proposed that the engine be required to meet at least one of the following three 

criteria: 

(1) the engine must be used in a piece of equipment that is carried by the operator 

throughout the performance of the intended function( s); 

(2) the engine must be used in a piece of equipment that must operate multipositionally, 

such as upside-down or sideways, to meet its intended function(s); or 

(3) the engine must be used in a piece of equipment for which the combined engine and 

equipment dry weight is under 14 kg, no more than two wheels are present, and at least one of the 

following attributes is also present: (a) the operator must alternately provide support or carry the 

equipment throughout the performance of its intended function(s); (b) the operator must provide 

support or attitudinal control for the equipment throughout the performance of its intended 

function(s); or (c) the engine is used exclusively in a hand portable generator or pump. 

3.3.2 Summary of the Comments 

Comments on this issue were submitted by several engine and equipment manufacturers 

and their respective associations, as well as by environmental and state organizations. In general, 

state and environmental organizations suggested that EPA tighten the definition to further limit the 

extent of the handheld category and prevent abuse of the classifications, while manufacturers and 

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their organizations suggested loosening the definition to allow the equipment of concern to their 

group to fall into the handheld category. 

Specific suggestions for tightening the handheld definition included adopting CARB's 

defmition with perhaps a list of additional equipment that the EPA wished to define as 

handheld,30,31,32 revising the weight limit for handheld equipment downward,33,34 revising the 

definition to include only equipment for which the operator bears the entire weight during all nonidle operation,35 tightening the use of the tenns "support" and "attitudinal control,"36,37 removing 

all products with any wheels from the handheld category ,38 and removing lightweight 

snowthrowers,39,40 pumps and generators41 ,42,43 from the definition of handheld. Specific 

suggestions for loosening the definition included revising the weight limit upward,44 removing the 

weight limit completely ,45,46 ,47 allowing augers,48 two-stroke lawnmowers,49 and two-stroke 

snowthrowers50,51,52,53 into the handheld category, and clarifying whether certain pieces of 

marginal equipment met the definition of handheld (specifically, cart-attached cut-off saws, twostroke three-wheeled edgers up to 30 cc,54 hover trimmers,55 and all pumps and generators under 

14 kg regardless of the usage of the same engines in other products56). 

3.3.3 EPA's Response to the Comments 

The Agency is retaining its handheld equipment definition largely as proposed, with the 

only changes being the addition of a fourth category for one-person augers under 20 kg and the 

elimination of the tenn "exclusively" from the category for pumps and generators. Based on an 

extensive review of product literature, the Agency believes that this revised definition adequately 

describes those types of equipment that are legitimately handheld while excluding nonhandheld 

applications. 

As described more fully in the preamble to the proposed rule, the necessity for a distinction 

between handheld and nonhandheld equipment is based in part on the substantial difference 

between emissions from current four-stroke and two-stroke engines, which is an inherent result of 

their design differences. Although two-stroke engines have significantly higher emissions, their 

use is necessary in some applications because they are generally lighter for the same rated power 

and can be used in any orientation, unlike their four-stroke counterparts. As a result. applications 

requiring that the user carry the device or use it in multiple positions generally need two-stroke 

engines at the current time. Conversely, nonhandheld applications do not require two-stroke 

technology, as they are ground-supported and not multipositional, and hence can and should use 

the inherently cleaner four-stroke engines. 

It is not feasible at this time, given the timing of this rulemaking and the currently available 

technology, to require all engines to meet the four-stroke standards. However, the emission 

reductions being required by this rule are, on a percentage basis, of the same magnitude for the 

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two-stroke and four-stroke engines. Of course, the Agency is not requiring the use of either twostroke or four-stroke engines in any particular type of equipment. If technological advances are 

such that two-stroke engines can meet the nonhandheld standards, manufacturers are free to utilize 

that technology or any other technology that can meet the standards. The distinction between 

handheld and nonhandheld is not to specifically limit the use of any type of engine but, rather, to 

limit emissions as much as is achievable while recognizing the unique needs of handheld 

applications. 

The Agency is sympathetic to comments that it should coordinate its handheld definition 

with CARB. Nevertheless, it believes that its definition clarifies and expands on the CARB 

definition in important ways. An investigation into the types of equipment each definition would 

cover reveals that there is a very high degree of overlap. Only a few categories were identified that 

would be covered by one but not both definitions. Given the different mandates of the two 

organizations and the specific air quality problems of the State of California, EPA believes it is not 

inappropriate for the definitions to be slightly different. 

Many types of equipment are counted by both EPA and CARB as handheld, by virtue of 

the general segments of the definitions (criteria (1) and (2) above): being carried by the operator 

throughout their use and/or being used in multiple orientations. While CARB requires equipment 

to meet both of these criteria to be considered handheld, EPA considers only one to be sufficient. 

Nevertheless, the majority of equipment that consumers would consider handheld are considered to 

be so by both organizations. This includes string trimmers, hedge clippers, brush cutters, clearing 

saws, leaf blowers, chain saws, and zero- and one-wheeled edgers. Additionally, both CARB and 

EPA are exempting two-stroke engines used in snowthrowers from the non handheld standards. 

CARB is instead requiring two-stroke engines used in snowthrowers to meet the handheld 

standards; EPA is requiring them to meet the handheld CO standard but will not require them to 

meet the HC standards, either handheld or nonhandheld, unless manufacturers of these engines opt 

to certify to those HC standards. 

The two organizations are aware of only a few pieces of equipment which do not overlap. 

These differences arise from the non-general segments of the definitions (criterion (3) above). 

Specifically, CARB does not consider to be handheld the following items that EPA would allow to 

be included in the handheld category: zero- to two-wheeled tillers under 14 kg, two-wheeled 

edgers under 14 kg, and zero- to two-wheeled pumps and generators under 14 kg. Additionally, 

EPA is revising its handheld definition to include one-person ice and earth augers under 20 kg.57 

Certain other engines -- specifically, those under 175 hp used in farm and construction 

equipment -- are covered solely by EPA regulations. ThIs is because section 209 of the CAA 

preempts engines under 175 hp used in farm and construction equipment from separate coverage 

by any State or political subdivision. The following is a partial list of farm and construction 

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equipment: earth augers, brush cutters and clearing saws 40 cc and above, chain saws 45 cc and 

above, chippers, compressors, continuous diggers, cultivators, agricultural mowing equipment, 

pumps 40 cc and above, concrete, masonry, and cutoff saws, and trenchers.58 Spark-ignited 

engines at or below 19 kW used in these pieces of equipment are therefore subject only to EPA 

regulation. Of these pieces of equipment, brush cutters, clearing saws, chain saws, and concrete, 

masonry, and concrete/cutoff saws59 meet EPA's general definition of handheld equipment, while 

pumps, cultivators, continuous diggers, and trenchers must be under 14 kg and have no more than 

two wheels to be considered handheld, and augers must be under 20 kg and be intended for oneperson use to be considered handheld. Chippers, compressors, and agricultural mowing 

equipment would fall under the nonhandheld category. 

Some commenters suggested that equipment weighing 14 kg is too heavy to be handheld, 

but did not suggest an acceptable alternative weight. Although the Agency agrees that 14 kg is 

indeed heavy for some uses and some consumers, it believes that certain pieces of equipment at 

that weight would be used in a handheld manner (such as lightweight edgers and tillers). It is 

likely that market forces would limit the manufacture and sale of "handheld" equipment that is too 

heavy for the typicaJ consumer of such products. Indeed, a review of product literature indicates 

that 14 kg appears to be the break point that the market has chosen between equipment types 

powered with two-stroke engines and those powered by four-stroke.60,61 

Additionally, for products not falling into the general handheld definitioru), a product 

weight of less than 14 kg is not, in and of itself, sufficient to qualify as handheld. Such products 

are also limited to no more than two wheels and must require some degree of operator carrying, 

support or attitudinal control in order to qualify as handheld; that is, they must not be completely 

ground-supported. The Agency believes that these additional constraints will prevent true 

nonhandheld equipment from inadvertently falling into the handheld category. 

On the other hand, the mere fact of some degree of ground support should not disqualify a 

piece of equipment from the handheld category. Some lightweight products requiring some level 

of ground support, including products with one or two wheels, would typically be considered 

handheld by the general pUblic. Equipment such as tillers and edgers with up to two wheels would 

require some carrying. support or attitudinal control; lawnmowers and three- and four-wheeled 

edgers. conversely, would be completely ground-supported and thus not handheld.62 The term 

"carry" means that the entire weight of the equipment is borne by the operator. The term 

"attitudinal control" is meant to apply to situations where the equipment is partially groundsupported but the operator must regulate its horizontal or vertical position in order to prevent it 

from falling over. Similarly, the term "support" is meant to apply to some operator control to 

prevent the equipment from falling. slipping or sinking; the entire weight of the equipment does not 

have to be supported or carried by the operator. However, if such equipment is over 14 kg. the 

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Agency continues to believe, based on its review of product literature, that it is not intended for use 

in a handheld manner. The Agency does not concur with one commenter that a tiller meeting the 

above attributes of having no more than two wheels and requiring some operator support should be 

considered handheld even though it weighs 33 kg.63 Such a weight is clearly beyond the bounds 

of what the marketplace has considered handheld and, for such a product, the weight increment 

between a two-stroke and a four-stroke engine is relatively insignificant. 

Some commenters stated that pumps and generators under 14 kg should not qualify as 

handheld, as the incremental weight of a four-stroke engine should not be an issue in transport 

from, say, a truck to a construction site. Although the EPA agrees with this assessment for the 

example cited, the categorization was intended primarily for small pumps and generators that 

would be transported into remote areas for emergency work or for operation of household 

equipment in a remote cabin. Transportation in such instances would be much further than to a 

construction site, and the weight would therefore become more of an issue. The State of California 

has a special provision allowing such equipment with non-certified engines to be purchased by 

emergency response organizations. The Agency is taking a somewhat different route toward a 

similar end, while ~aking these pieces of equipment more widely available. 

The Agency wishes to clarify that all pumps and generators under 14 kg with no more than 

two wheels will be categorized as handheld equipment. The phrase "the engine is used exclusively 

in a generator or pump" in the definition was not meant to preclude handheld status for pumps and 

generators with engine models that are also used in other pieces of handheld equipment. Rather, 

the provision was meant to prevent equipment manufacturers from installing an engine certified for 

use in a handheld pump or generator in a piece of nonhandheld equipment. Equipment 

manufacturers and importers are prohibited from utilizing engine families certified to the handheld 

standards in equipment not meeting the handheld definition, and are liable for civil penalties if they 

do so. Thus, the term "exclusively" in the handheld definition is superfluous and has been 

removed. 

The Agency also wishes to clarify that only earth and ice augers that are under 20 kg 

(including a bit of typical size for that model) and are sold for use primarily by one person will be 

considered handheld. Two person augers, and any auger of 20 kg or more (including the bit) must 

meet the nonhandheld standards. The Agency believes that this slight broadening of the definition 

reasonably responds to the needs of auger manufacturers to continue to provide a lightweight, 

high-strength, high-powered product during the time frame of the Phase 1 regulations. The 

Agency does not believe that there is a need for two-person augers to be included as handheld, as 

weight is much less of a concern in that case. Additionally, several four-stroke two-person augers 

are already on the market, demonstrating the availabi~ity of four-stroke technology, its utility to the 

. consumer, and its marketability. Finally, concerns that the two-stroke engine models used by 

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auger manufacturers will be discontinued appear to be unfounded, since these engines are also 

used in snowthrowers. Thus, their market demand would be sufficient for the engine 

manufacturers to invest in their redesign so they may meet the handheld standards and continue to 

be offered for sale. 

The Agency was only partially convinced by auger manufacturer comments of the 

technological necessity for two-stroke engines in their products. To the extent that the Agency sees 

a need for two-stroke technology on augers at the current time, it is for one-person augers only. 

Such equipment may legitimately have a need to retain as light a weight as possible in order for one 

person to be able to counter the torque generated by the drilling operation, retain the auger in a 

vertical position, lift it from the hole, and transport it to and from the drilling location. 

Additionally, in contrast to truly nonhandheld equipment, which is fully ground-supported, augers 

have no frame, wheels, or other supporting devices and, thus, require operator contact for 

attitudinal control during use. In contrast to other equipment that is clearly handheld, however, 

augers tend to be of a heavier construction in order to withstand the significant forces they 

encounter during use, so that the 14 kg weight limitation may not be as relevant to augers as to 

other types of equip~ent. A review of product literature and manufacturer comments indicate that 

an upper limit of 20 kg would include most or all one-person augers currently on the market. 

Auger manufacturers are predominantly small companies, and therefore are somewhat 

constrained in their ability to quickly reengineer their product, acquire a new engine source, and 

absorb the costs of a four-stroke engine. It is for this reason, coupled with the technological 

reasons cited above, that the Agency is allowing one-person augers under 20 kg to meet the 

handheld definition for this Phase 1 regulation of small SI engines. However, this definition will 

not necessarily be carried into future regulation of small SI engines, such as in the Phase 2 

negotiated rulemaking activities currently underway. 

Comments from auger manufacturers on this rulemaking dwelled largely on the need to 

retain the current product, presumably due to cost implications. The Agency believes that relief is 

necessary in order for these manufacturers to continue to function in the short term and that the 

special attributes of augers set them apart from other equipment that is clearly either handheld or 

nonhandheld. However, further clarification of the technological need for two-stroke engines in 

augers would be necessary for the Agency to continue to include them in the same category as 

equipment more obviously in need of light weight and/or multi positional use. 

3.4 Lawnmowers 

3.4.1 Summary ofthe Proposal 

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Under EPA's proposal, alilawnmowers would be classified as nonhandheld equipment. 

EPA requested comment on the ability of two-stroke lawn mower engine manufacturers to meet 

nonhandheld standards, the impact such a requirement would have on such manufacturers, the 

need for relief for such manufacturers, and the impact such relief might have on the environmental 

benefits of the proposal. EPA requested comment on four options for providing relief for twostroke lawnmower engine manufacturers. 

3.4.2 Summary of the Comments 

Two industry associations and one manufacturer recommended that EPA allow two-stroke 

lawnrnower engine manufacturers to meet handheld standards.64 They commented that two-stroke 

lawnmower engines would effectively be eliminated from the market under the proposal.65 

One manufacturing company will be particularly impacted by the requirement that 

lawnrnower engines meet non handheld standards because it is the largest producer of two-stroke 

lawnrnower engines.66 It commented that the definition of handheld and nonhandheld should not 

be used to discriminate against engines according to their application;67 to bypass the requirement 

of technological feasibility;68 to distort the competitive balance of the industry by banning major 

products;69 and to place disproportionate burdens on one company as the price of maintaining an 

important product line -- all with no commensurate air quality benefit. 70 

The company commissioned a report (Heiden Associates, Inc., April 20, 19~3) that 

estimated emissions from two-stroke lawnmowers in the nonattainrnent areas included in the 

Nonroad Study.7 1 According to the company, the study found that two-stroke lawnmower 

emissions account for 3.9 percent of nonroad VOC emissions in those nonattainment areas.72 The 

contribution to CO was one half or one third of the VOC contribution, and the NOx contribution 

was calculated at zero.73 Eliminating two-stroke mowers would not accomplish even a .2 percent 

nationwide VOC reduction, since four-stroke units would replace the two-stroke units, according 

to that comment.74 

The company originally favored the option for relief of meeting handheld standards until 

Phase 2. It commented that this option would reduce the disparate impact it would face compared 

to the rest of the industry, and would provide it with the incentive to continue emissions 

development work.75 Later, supplemental comments favored the declining production cap 

option.76 

An industry association commented that lawnmowers with two-stroke engines are 

important to equipment users who have to contend with steep inclines.77 If it is not 

technologically feasible for two-stroke lawnrnower engines to meet nonhandheld standards, an 

undue burden could be placed on landscapers and other users, according to this comment.78 

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A state commented that it sees no reason to grant special concessions to some 

manufacturers because their current product line uses a more polluting technology than their 

competitors; such a policy would penalize those manufacturers that hav.e pursued cleaner 

technologies.79 The state argued that complying engines are available and a sufficient number of 

manufacturers participate in the market to ensure competition.80 None of the options for relief 

presented seems wise because none prevents continued use of higher polluting machines when 

complying engines are available, according to the state.81 

Environmental and state and local air officials' associations expressed strong opposition to 

the options for relief for two-stroke lawnmowers; given that 90 percent of lawnmowers sold in the 

U.S. already rely on four-stroke technology, it can't be argued that four-stroke engines are not 

available technology for alllawnmowers.82 The state and local air officials commented that the 

expected difference between a two-stroke and four-stroke lawnmower is equivalent to 

approximately 300 grams of HC per hour of operation, or 7,500 grams per year for a typical 

homeowner.83 A new automobile emits roughly 0.7 grams of HC per mile driven, which means 

that the difference between a two-stroke and four-stroke during one hour of grass cutting is 

approximately equi!,alent to the emissions associated with an entire month of commuting for a 

typical driver.84 For many households, the difference for a single season's mowing could be 

comparable to nearly an entire year of driving, according to the comment. 85 

Environmental and state and local air officials' associations commented that manufacturers 

have had ample opportunity to react to requirements that might reasonably have been expected.86 

These manufacturers participated in the process that led to the December 1990 adoption ofCARB's 

standards and have already enjoyed a four year period in which to take appropriate action.87 The 

state and local air officials commented that regulatory relief for these manufacturers would fail to 

provide appropriate market stimulus in a global marketplace that is increasingly sensitive to 

environmental performance and fuel economy. 88 Those associations also commented that such 

regulatory relief would compromise the effectiveness of Phase 1, and thereby undermine their 

acceptance of the phased approach to regulation of small engines.89 

3.4.3 EPA's Response to the Comments 

EPA is finalizing its proposal that lawnmowers be classified as nonhandheld equipment. 

However, in response to industry comments, EPA is providing an exception to the nonhandheld 

standard to allow two-stroke lawnmower engine manufacturers to produce a declining percentage 

of two-stroke lawnmower engines that meet handheld standards until model year 2003. This relief 

for two-stroke lawnmower engine manufacturers is justified by the economic hardship that would 

result if two-stroke lawnmower engines were required to meet nonhandheld standards upon the 

effective date of Phase 1, and by the need for additional lead time for two-stroke engines used in 

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lawnmowers to meet nonhandheld standards; EPA has concluded that handheld standards are the 

most stringent standards achievable for two-stroke lawnmower engines in the near tenn given these 

economic hardship and lead time considerations. 

Economic hardship that would result if two-stroke lawnmower engines were required to 

meet nonhandheld standards is documented in two sets of comments from one engine 

manufacturer.90 It stated that it would be forced to close a manufacturing plant that employs 230 

people unless some fonn of relief from the requirement that two-stroke lawnmower engines 

comply with nonhandheld standards is granted.91 The plant is devoted to two-stroke engine 

operations, according to the comments.92 The manufacturer commented that the declining 

production option would avoid closure of the plant and maintain a minimally necessary market 

presence for its two-stroke lawnmowers during Phase 1.93 The manufacturer stated that its 

principal goal and long-tenn strategy is to develop technology that will enable two-stroke 

lawnmower engines to meet Phase 2 nonhandheld standards.94 Reducing sales below 50 percent 

would destroy the market for the product before Phase 2 technology could be implemented, and 

reduce plant utilization to unacceptable levels, according to the manufacturer.95 

The need for additional lead time was a common theme among industry commenters, 

although only one two-stroke lawnmower engine manufacturer addressed the difficulty, if not 

impossibility, of two-stroke lawnmower engines meeting non handheld standards by the effective 

date of Phase 1.96 According to the manufacturer, it is not technologically feasible for two-stroke 

engines to meet nonhandheld standards at this time.97 The manufacturer stated in its comments 

that more engineering effort is required for two-stroke lawnmower engines to meet handheld 

standards than for four-stroke engines to meet nonhandheld standards, partly due to the difference 

in duty cycles for handheld and nonhandheld engines, with handheld engines having the advantage 

of a higher horsepower divisor than is obtained under the variable nonhandheld load 

specifications.98 The manufacturer stated that it is an engineering uncertainty whether and how 

valve-control techniques developed in the past, to enhance power output for smaller two-stroke 

engines used in products such as chain saws, might be used to reduce emissions in 

lawnmowers.99 Finally, the manufacturer stated that while it is conceivable that its technology 

development could permit the introduction of engines meeting the Phase I nonhandheld standards 

during Phase 1, the prospect of this occurring before the year 2001 is remote. 100 

CAA section 213(a)(3) specifies that nonroad emission standards must achieve the greatest 

degree of emission reduction achievable through the application of available technology, giving 

appropriate consideration to cost, lead time, noise, energy, and safety. Taking into account the 

economic hardship and lead time considerations discussed above, EPA has determined that 

handheld standards subject to a declining production cap are the most stringent emission standards 

achievable for two-stroke lawnmower engines at this time. 

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Under the declining production cap, two-stroke lawnmower engine manufacturers that 

wish to continue producing two-stroke lawn mower engines must establish a production baseline. 

The production baseline is the highest number of two-stroke lawnmower engines produced in a 

single annual production period from 1992 through 1994. Documentation verifying the production 

baseline must be submitted to EPA with the application for certification. In model year 1997, twostroke lawnmower engine manufacturers may produce 100 percent of their production baseline, 

which must be certified to handheld standards. In model year 1998, two-stroke lawnmower 

engine manufacturers may produce 75 percent of their production baseline. From model year 1999 

until model year 2003, two-stroke lawnmower engine manufacturers may produce 50 percent of 

their production baseline in each annual production period. In model year 2003, two-stroke 

lawnmower engine manufacturers must meet either Phase 1 nonhandheld standards or Phase 2 

nonhandheld standards, whichever are applicable. 

Although EPA's approach is not consistent with CARB regulations, which require all 

lawnmowers to meet nonhandheld standards with no exceptions, EPA believes there are two valid 

reasons for the distinction. First, Congress has recognized the need for California to maintain its 

own mobile source ~mission control program (see section 209 of the CAA) because it faces 

difficult and distinct air pollution problems and, as a result, may adopt measures more stringent 

than those that apply in the nation as a whole. Second, EPA's nonroad emission standards are not 

allowed to be more stringent than is achievable after consideration of cost and lead time according 

to section 213(a)(3) of the CAA Although California is constrained by similar criteria per the 

authorization criteria of section 209 (e), consideration of such criteria is limited to the State of 

California. EPA must consider cost and lead time when nonroad emission regulations affect the 

nation as a whole. EPA has concluded that in order for the Agancy to meet the section 213(a)(3) 

requirements to consider cost and lead time in setting its nationally applicable standard, it is 

reasonable to provide for this limited relief for manufacturers of lawnmowers that use two-stroke 

engines. This conclusion in no way prejudges whether California should grant similar relief. 

EPA agrees with commenters that four-stroke technology is generally available for 

lawnmowers, and that two-stroke engines are more polluting than four-stroke engines. Unlike 

EPA's treatment of two-stroke versus four-stroke snowthrowers, EPA is not distinguishing twostroke and four-stroke lawnmowers as separate products, but rather is recognizing the 

technological infeasibility of two-stroke engines used in lawnmowers meeting the nonhandheld 

standards by the effective date. Still, although four-stroke technology is theoretically available for 

alilawnmowers, it is not immediately available for manufacturers of two-stroke lawnmower 

engines, due to the cost and lead time concerns discussed above. In light of these concerns, EPA 

is providing a reasonable opportunity for two-stroke l,:\wnmower engine manufacturers to come 

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into compliance with nonhandheld standards over the period in time during which these standards 

will apply. 

3.5 Snowthrowers 

3.5.1 Summary a/the Proposal 

EPA proposed that snowthrowers meeting the handheld definition be considered handheld 

equipment; all other snowthrowers would be considered nonhandheld. 

3.5.2 Summary a/the Comments 

EPA received comments from environmental, industry, and state and local air pollution 

officials' associations, and from manufacturers. In general, industry eitheropposed regulating 

snowthrowers for HC emissions or favored relaxed emission standards for two-stroke 

snowthI'owers, while environmental and state and local air officials' associations favored more 

stringent standards. 

One industry commenter argued that EPA should at a minimum exempt snowthrowers from . 

the hydrocarbon standards, since emissions from snow throwers do not demonstrably contribute to 

summertime ozone nonattainment concentrations. 101 According to the commenter, Phase 1 

accomplishes no demonstrable purpose by regulating snowthrower hydrocarbon emissions, as 

snowthrowers are used exclusively during the winter and reductions achieved by regulating 

snowthrowers would have no benefit for areas seeking reductions in order to attain the ozone 

NAAQS during the high ozone season. 

Industry commented that there are no snowthrowers with spark-ignited engines that weigh 

under 14 kg; 102 only electric versions are available under 14 kg. As a result, all snow throwers . 

covered by the proposal would be subject to nonhandheld standards. According to industry, if 

snowthrowers with two-stroke engines must comply with nonhandheld standards, EPA would 

effectively be banning such equipment and placing an unreasonable hardship on that segment of 

industry.103 One manufacturer stated that it is technically infeasible to meet nonhandheld 

standards. 104 Another manufacturer commented that EPA should increase the weight limit in the 

handheld definition to 30 kg, to include snowthrowers with two-stroke engines. 105 The Nonroad 

Study indicates that 26 percent of snowthrowers have two-stroke engines. 106 

Industry offered three main lines of reasoning for the position that all two-stroke 

snowthrowers should be considered handheld: (1) Snowthrower manufacturers assumed that 

Phase 1 standards would mirror CARB's standards, including its special exceptions. 1 07 (2) 

Snowthrowers do not contribute to summer ozone non attainment, 108 In addition, because all 

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snowthrowers exceed 50 cc and the CO standard for nonhandheld and handheld in the over 50 cc 

class is the same, there would be no additional air quality benefit provided by the application of 

nonhandheld standards to snowthrowers. 109 (3) Two-stroke snowthrowers have design, 

perfonnance, and operational characteristics that fill a unique market niche, and have many of the 

attributes of handheld equipment. 1 1 0 

The unique design, perfonnance, and operational characteristics cited by industry include 

size, weight, maneuverability, and ease of storage and transport. 1 11 Two-stroke snowthrowers 

have only two wheels (neither of which touch the ground during operation), and operators must 

provide continual support and attitudinal control by raising and tilting the equipment in order for it 

to perfonn. 112 

Commenters noted that two-stroke snowthrowers use a 5.4 kg (12 pound) engine arid a 

single belt-drive system, eliminating the weight of additional belts and pulleys. I 13 Moreover, 

almost all two-stroke snowthrowers are 'single-stage,' according to comments, meaning that they 

use an auger to gather snow and expel it from a single chamber. 1 14 By contrast, almost all fourstroke snow throwers are two-stage units that use an auger to gather snow.into one chamber and a 

separate impeller to.discharge it from a second chamber, according to comments. I 15 The engines 

in four-stroke snowthrowers weigh between 11 and 27 kg (25 and 60 pounds). 1 16 

Environmental and state and local air officials' associations opposed handheld status for 

two-stroke snowthrowers. 117 They expressed concern about the high levels of unburned air 

toxies emitted by two-stroke engines, given operator prox.imity .118 The associations pointed out 

that for larger snowthrowers, four-stroke models are available, and for the small two-wheeled 

version, electric models are available. 1 19 

3.5.3 EPA's Response to the Comments 

Since EPA agreed to undertake a phased approach to small engine regulation in March 1993 

(see 59 FR 25399 at 25400-25401 for a detailed explanation), EPA has maintained that its Phase I 

program would be based on CARB's and incorporate the same emission standards, where it is 

appropriate to do so in a nationally, rather than regionally, applicable regulation. EPA is not 

persuaded that it was appropriate for manufacturers to assume that by adopting CARB's standards,· 

EPA would also adopt CARB's exceptions to those standards. Under the commenter's approach, 

EPA would not be able to regulate farm and construction equipment, solely because CARB is 

prohibited from regulating such equipment under the Act. However, as discussed below, EPA 

will treat 2-stroke snowthrowers consistent with CARR 

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The corrunent that it makes no difference whether snowthrowers are considered handheld 

or nonhandheld, because the CO standard is the same, is moot in light of the fact that industry 

requested and is being granted various relaxations of the class I, II, and V CO standards. 

After considering the corrunents, the Agency has concluded that the HC standard will be 

optional for snowthrowers. This is because, as discussed in the preamble to the proposed rule (see 

59 FR at 25416) and by industry corrunents, snow throwers are operated only in the winter, which 

means that they do not measurably impact ozone nonattainment concentrations and thus need not be 

subject to stringent control requirements aimed at controlling ozone nonattainment. On a national 

level, ozone nonattainment is primarily a seasonal problem that occurs during warm, sunny 

weather. Regulating HC emissions from products used exclusively in the winter, such as 

snowthrowers, will not advance the Agency's mission to correct this seasonal problem. EPA 

recognizes that California will be regulating HC emissions from snowthrowers, and today's 

decision should in no way prejudice California's efforts. The Agency notes that California faces a 

uniquely difficult problem in that its ozone nonattainment season is year round, and that Congress 

has recognized California's potential need to adopt measures that are more stringent than those that 

apply in the nation a whole. EPA, instead, must promulgate regulations that apply nationally in 

scope and that address the air quality problems that face the nation generally. 

Under today's rule, while manufacturers of snowthrowers will still be required to certify to 

and comply with applicable CO standards, they will be required to certify to the HC standards only 

where they opt to become subject to those standards. The Agency expects that many 

snowthrowers will in fact be certified to meet the HC standards, since the technology necessary to 

meet those standards will be readily available to snowthrower manufacturers and since 

manufacturers may wish to be able to take advantage of "green marketing" opportunities. 

However, the Agency does not believe it is appropriate at this time to absolutely require all 

snowthrowers to be certified to meet a standard that is meant to address ambient air quality 

problems that do not exist when these products are in use. This decision in no way affects 

snowthrower manufacturer responsibilities with respect to CO standards. Moreover, if an engine 

manufacturer produces an engine that is used in snowthrowers and in other products that are not 

used exclusively in the winter, that engine must be certified to the applicable HC standard. 

According to information submitted by industry, the weights of two-stroke snowthrowers 

range from 16.3 kg (36 pounds) to 39.9 kg (88 pounds); the average weight of the two-stroke 

models listed was 29.5 kg (65 pounds).1 20 In EPA's opinion, a product line ranging in weight 

from 16.3 to 39.9 kg cannot fairly be considered light in weight (except in relation to something 

heavier), or specifically designed to be lifted or carried, and EPA is not inclined to raise the weight 

limit in the handheld definition to 30 kg to accorrunodate such equipment. 

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EPA is persuaded by comments describing the design, perfonnance, and operational 

characteristics of two-stroke snowthrowers that two-stroke snowthrowers fonn a distinct product 

class from four-stroke snowthrowers. As two-stroke snowthrowers are a distinct product class 

that depends on a relatively lighter-weight product, EPA does not consider four-stroke technology 

to be generally available technology for the relatively light-weight two-stroke snowthrowers. 

EPA shares the concerns raised by commenters about operator proximity to high levels of 

unburned air toxics emitted by two-stroke engines. However, EPA lacks sufficient data to address 

those concerns at this time. 

EP A agrees with comments that two-stroke snowthrowers would meet the third prong of 

the handheld definition but for the weight criterion. Rather than amend the weight criterion in the 

handheld definition to include two-stroke snowthrowers, however, EPA is providing an exception 

to the nonhandheld standards that will require two-stroke snowthrower engines to comply with the 

handheld CO standard but not require them to meet the HC standards, either non handheld or 

handheld, unless they opt to certify to those HC standards. 

3.6 Use of Power Rating as Cutoff for Applicability 

3.6.1 Summary o/the Proposal 

The Agency has limited the applicability of this action to engines at or below 19 kW (25 

horsepower) rated power. While the Age,ncy considered limiting the regulation's applicability 

based instead on a total displacement, it chose to propose and adopt a power-based cutoff for 

consistency with CARB's 25 horsepower limit. Manufacturers have generally encouraged 

consistency with the nonroad regulations being implemented in California, and EPA has tried to 

achieve this whenever it believes that it is harmonious with the Agency's mission and directives. 

3.6.2 Summary o/the Comments: 

The Agency is aware of the concern raised by STAPP AIALAPCO that the measurement of 

rated power is subject to engine configuration and test conditions, and that a cutoff based on power 

might create an incentive for manufacturers with engines just below the cutoff to change engine 

and/or test procedure parameters to result in a higher measured power in order to escape the scope 

of this regulation. In their comments, STAPP AIALAPCO supported the one liter displacement 

cutoff that EPA identified as an alternative in its examination of data from Power Systems 

Research.121 In that study, the relationship between total displacement and rated power suggests 

that a one-liter total displacement cutoff would affect nearly an identical group of engines as a 19 

kW cutoff. 

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3.6.3 EPA's Response to the Comments 

Using a displacement-based cutoff would cause a limited number of engines to be included 

that would not be included using a 19 kW cutoff (that is, engines above 19 kW but less than one 

liter displacement), such as some of the larger two-stroke engines. On the other hand, a limited 

number of engines that would have been covered under the provisions of the proposal would go 

unregulated under this scenario (that is, engines under 19 kW but greater than one liter); examples 

would include some of the larger industrial four-stroke engines. The Agency believes that the 

number of engines potentially involved is small enough to make this a marginal issue for this 

interim rule. Many of the larger two-stroke engines that would have fallen within a I-liter 

displacement limit would have been exempted from coverage in this rule because of their use in 

recreational vehicles. 

For this reason, and because EPA believes that consistency with the proposed CARB 

regulations is appropriate in this case, EPA has chosen to leave the 19 kW cutoff in place. The . 

Agency will take the matter up for consideration in the Phase 2 negotiated rulemaking, currently 

underway. 

3.7 Non-Coverage of Compression-ignition Engines 

3. 7.1 Summary ofthe Proposal 

The Agency did not propose to regulate small CI engines in this action for the reasons 

discussed in the preamble to the proposed rule. The Agency sought comment on this issue in its 

proposal because of the potential that unregulated CI engines could be substituted for post-control 

SI engines. In EPA's view, while this may occur in some cases (for example, small agricultural 

tractors), the most price-sensitive products, such as string trimmers and lawnmowers, are unlikely 

to shift significantly toward CI engines due to technological limitations, consumer preference, or 

both. 

3.7.2 Summary ofthe Comments: 

Both CARB and NRDC commented that EPA should include coverage for small CI engines 

in this rulemaking. Expressing its concern that applying a combined HC+NOx standard only to SI 

engines might cause a market shift to CI engines, CARB supported regulating both SI and CI 

engines in this rulemaking to effectively control emissions. I22 

The NRDC comments reiterated concerns about the effect of delaying standards for this 

group of engines. Delaying the regulations, NRDC argued, will result in their having little 

beneficial impact on achieving deadlines for attainment, even in severe nonattainment areas. Since 

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the states are specifically precluded from regulating farm and construction equipment, some of 

which employ small CI engines, NRDC has urged EPA to move quickly to establish standards for 

small CI engines. In addition, NRDC pointed out that small CI engines are addressed in the 

CARB proposal, and says that they should be included in EPA's rule for the sake of consistency. 

3.7.3 EPA's Response to the Comments 

The Agency has elected not to include small CI engines as a part of this rulemaking. As 

part of the Sierra Club v. Browner settlement. EPA must determine by November 1996 whether to 

undertake a rulemaking which targets emissions from small CI engines. 

Small CI engines have different emission characteristics from the engines addressed by this 

proposal, emitting much lower levels of HC and considerably higher levels of NOx than small SI 

engines. In contrast with its approach to this rulemaking. which is focused on achieving 

reductions in emissions of HC. EPA would be more likely to focus on NOx in a regulation 

addressing CI engines. Presently EPA lacks sufficient data regarding baseline emissions and 

control technologies for nonroad CI engines in this power range to determine appropriate 

standards. To devise appropriate standards and test procedures would require that EPA undertake 

a supplementary proposal. If EPA were to go through the process before finally promulgating a 

small SI rule. it would cause EPA to miss its court-ordered deadline for the final small SI rule and 

would delay promulgation of regulations already developed for small SI engines. Therefore EPA 

has chosen not to include small CI engines from this rule while working to address the issue of 

regulating small CI engines in a separate rulemaking. 

3.8 Non-Coverage of Recreational Pr9Puision Engines 

3.8.1 Summary o/the Proposal 

The Agency did not propose to apply the provisions of this rule to engines used in 

recreational vehicles, examples of which include snowmobiles. off-road motorcycles, ultralight 

planes, and all-terrain vehicles. Engines used in recreational vehicles that are not regulated in this 

rule are defined by the following characteristics: use of a continuously variable throttle (as 

opposed to a governor), rated engine speeds in excess of 5,000 RPM, and wide variations in both 

engine load and speed. Because they do not qualify as recreational vehicles under the criteria of 

this rule. golf carts and similar vehicles that have the characteristics identified above are subject to 

the emission standards set forth in this action. 

The Agency's primary reason for not applying this rule to engines used in recreational 

vehicles is the extremely transient operation of the products in which these engines are used. Their 

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characteristically transient operation limits the ability of the proposed steady state test procedure to 

adequately represent exhaust emissions. This decision is not based on any determination that these 

engines do not contribute to air pollution and therefore need not be controlled. The Agency has 

chosen not to apply this rule to engines used in recreational vehicles in order that it may proceed 

quickly with a program for other small SI engines. Developing new test procedures and standards 

appropriate for recreational vehicles would significantly delay implementation of standards forthe 

other small engines, delaying air quality benefits, as well as causing EPA to violate the deadline for 

promulgation of this rule agreed to in the Sierra Club consent decree. 

The Agency solicited comment on the non-inclusion of engines used in recreational 

vehicles, on the criteria used to identify such engines, and on the appropriate test procedure and 

emission standards if EPA were to include such engines in this rulemaking. 

3.8.2 Summary o/the Comments: 

NRDC stated that by omitting nonroad recreational engines from this rulemaking, EPA will 

not fulfill the requirements of the Clean Air Act Amendments of 1990 or the consent decree. 

The City of Chicago likewise was concerned with EPA's decision not to include nonroad 

recreational engines· in the rule. It points out that a great many vehicles with these engines are used 

throughout the ozone nonattainment areas surrounding southern Lake Michigan. Therefore it 

recommends that EPA speedily move forward on regulations to address such engines. 

While CARB was of the opinion that such engines would not have been appropriately 

controlled in this rulemaking, it encouraged EPA to continue studying recreational engines for 

future regulation. 

However, the Illinois Farm Bureau took the position that EPA was correct in not including 

recreational engines in this rule and that it should not consider regulating them in any future rule. 

The Illinois Farm Bureau's rationale is that many recreational vehicles are employed for nonrecreational purposes in agriculture. 

3.8.3 EPA's Response to the Comments 

As part of the Sierra Club v. Browner settlement, EPA will determine whether to undertake 

a rule making which targets emissions from engines used in recreational vehicles. The Agency will 

announce its intentions regarding such a rulemaking in the future. 

3.9 Non-coverage of Marine Propulsion Engines 

3.9.1 Summary o/the Proposal 

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In the proposal, EPA stated that the rule would explicitly exclude from regulation small SI 

engines used to propel marine vessels. 

3.9.2 Summary ofthe Comments 

The only comment EPA received on this matter (from CARB) was in support of EPA's 

decision. 

3.9.3 EPA's Response to the Comments 

The Agency is not applying this rule to marine propulsion engines (examples of which, in 

this power range, include outboard marine engines) because it is developing emission standards for 

such engines in a separate action. The proposal for this action, published November 9, 1994,123 

is also under court order and is currently due to be promulgated in November 1995. However, 

small SI engines used on marine vessels for purposes other than propulsion, such as generators 

and pumps, are subject to the provisions of this rule. 

SECTION 4: CERTIFICATION REQUIREMENTS AND EMISSION 

STANDARDS 

4.1 Equipment and Vehicle Manufacturer Requirements 

4.1.1 Summary ofthe Proposal 

EPA proposed that equipment and vehicle manufacturers using small nonroad engines must 

use appropriate handheld or nonhandheld certified engines, and prohibited the introduction into 

commerce of nonroad equipment and vehicles lacking appropriate certified engines after August 1, 

1996. EPA also proposed that equipment and vehicle manufacturers apply a supplemental label to 

the equipment or vehicle if the engine label is obscured by the equipment or vehicle. EPA 

requested comment on a separate effective date for equipment and vehicle manufacturers, due to 

concern about inventories of noncertified engines that could not be incorporated into equipment or 

vehicles by the effective date. Finally, EPA proposed that new replacement engines manufactured 

after the effective date ofthis rule be subject to this rule. EPA is finalizing these requirements. 

4.1.2 Summary ofthe Comments 

EPA received comments both supporting and questioning its authority to require the use of 

certified engines. One industry association commented that EPA has no authority to require the use 

of certified engines. 124 A manufacturer and an industry association commented that EPA's 

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authority under CAA section 213 does not extend to equipment, 125 A state, state and local air 

officials, and an environmental association supported the requirement that equipment 

manufacturers use complying engines. 126 

Several industry associations commented that the prohibition on introducing into commerce 

equipment and vehicles lacking appropriate certified engines after the effective date could impose a 

substantial hardship on industry, and is unnecessary to prevent stockpiling;127 equipment 

manufacturers now minimize the period they store engines to avoid the substantial costs associated 

with financing and warehousing inventoried engines, according to comments. 128 Two 

associations asked EPA to clarify that neither equipment manufacturers nor dealers have any 

special obligation to convert their inventories to use certified engines. 129 A manufacturer asked 

EPA to clarify whether existing inventories may be used following the effective date. 130 

In regard to supplemental labels, two industry associations requested that EPA clarify the 

meaning of the word "obscured," and allow the supplemental label to be less comprehensive than 

the engine label, consistent with California. 131 One engine manufacturer supported the 

requirements as proposed. 132 

Most comm~nts did not support a separate effective date for equipment and vehicle 

manufacturers. I33 An industry association commented that establishing no separate effective date 

is also consistent with California. 134 A state commented that a separate effective date should be 

based on the date of equipment manufacture, rather than the date of introduction into 

commerce. 135 Separate effective dates recommended by a manufacturer and an industry 

association included six months after the effective date, 136 and February 1, 1998. 137 

On replacement engines, an environmental association and state and local air officials 

support the requirement that new replacement engines for pre-1996 equipment meet certification 

standards.138 One manufacturer expressed concern that there may be products for which a 

complying engine does not exist; such products would have to be replaced in total at a much higher 

cost. 139 An industry association commented that it may be unreasonable to assume that only a 

small percentage of equipment will need replacement engines; it recommended that surveys be 

conducted. 140 

4.1.3 EPA's Response to the Comments 

EPA is finalizing the requirement that nonroad equipment and vehicle manufacturers use 

appropriate handheld or nonhandheld certified engines, effective with the 1997 model year. In 

EPA's view, the most effective way to ensure that certified engines are used in nonroad equipment 

and vehicles is to require such engines to be used. CAA sections 213, 216, and 301 provide 

authority for this requirement, since EPA is required to establish standards that apply to nonroad 

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engines and the vehicles in which they are used, including nonroad equipment. The definition of 

non road vehicle, which includes nonroad equipment, is discussed elsewhere in this document. 

EPA is finalizing the requirement that equipment and vehicle manufacturers apply 

supplemental labels to their equipment and vehicles if the engine label becomes obscured by the 

equipment or vehicle. Comments in regard to supplemental labels are discussed elsewhere in this 

document. 

EPA is not establishing a separate effective date for nonroad equipment and vehicle 

manufacturers. EPA recognizes that certified engines are not likely to be available in the numbers 

needed by nonroad equipment and vehicle manufacturers on the effective date, and that equipment 

and vehicle manufacturers will continue to use noncertified engines built prior to the effective date 

until noncertified engine inventories are used up and certified engines are available. As long as 

equipment and vehicle manufacturers do not inventory engines outside of normal business 

practices (that is, as long as they do not stockpile noncertified engines), equipment and vehicle 

manufacturers will be considered in compliance. EPA is adding language to 40 CPR 

9O.1003(b)(4) to this effect Dealers have no obligation under this regulation to convert their 

inventories to equip~ent and vehicles with certified engines. 

In proposing that new replacement engines manufactured after the effective date of this rule 

be subject to this rule, EPA requested comment on the need for manufacturers to produce 

replacement engines for use in pre-1996 equipment, and the extent of such a need, if any . EPA 

received no information directly on point, leading EPA to deduce that manufacturers do not see any 

significant problems with this requirement. As a result, EPA does not believe a survey is 

necessary. Ifthere are pre-1996 equipment or vehicles for which a complying engine does not 

exist in the future, the option of rebuilding the original engine is still available. EPA is finalizing 

this requirement as proposed. 

4.2 Engine Family Definition 

4.2.1 Summary ofthe Proposal 

The Agency proposed using the criteria for determining engine families as are currently 

used for on-highway motorcycles: combustion cycle, cooling mechanism, cylinder configuration, 

number of cylinders, engine class, and the number, location, type, and thermal reaction 

characteristics of catalytic converters. Comment was solicited on adding governed RPM range as a 

criterion for determining engine family, because of a concern that a wide-governed range in the 

same engine family may result in unrepresentative emission test results. 

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labeling requirements so that a single label could meet the requirements of both programs. 145 

Industry commenters expressed general concern that the labeling requirements are excessive, and 

that the cost burden would not be justified on the basis of need. Other comments centered on the 

requirement that equipment manufacturers attach a supplemental label identical to the original if the 

original is obscured. 146 Several commenters also stated specifically that the unique engine 

identification number requirement was costly and unnecessary.l47 

4.3.3 EPA's Response to the Comments 

The Agency has decided to retain the provision requiring equipment and vehicle 

manufacturers to apply a supplemental label to the equipment or vehicle if the original label is 

obscured. This provision is compatible with CARB, and ensures that owners, dealers, and fepair 

. personnel will have access to necessary engine information without disassembling the original 

vehicle or equipment. 

After considering the comments, the Agency has decided to provide manufacturers with 

additional flexibility in the labeling requirement. To reduce manufacturer burden and provide 

compatibility with CARB, EPA will accept a label that has been approved by CARB that contains 

language indicating-that federal standards have also been met. The Agency will accept the 

following: 1) a harmonized CARBIEP A label for 50-state engine families, 2) a CARB label with 

additional language saying it meets federal standards for the 49-state label, and 3) the EPAproposed labeL 

In addition, the Agency has dropped, the unique engine identification number requirement. 

Based on information supplied by engine manufacturers and their associations, 148 EPA determined 

that the information to be gained by requiring the unique number did not justify the additional 

capital and administrative costs to the manufacturers. Because no useful life time period or in-use 

standard is being established, the Agency has decided to allow in-use testing and recall on a 

voluntary basis for Phase 1 and, as a result, there is no need for EPA to require the unique engine 

identification number. 

4.4 Cap on Noise 

4.4.1 Summary ofthe Proposal 

The Agency proposed that noise levels of small SI engines not be allowed to increase as a 

result of the new emission standards. In proposing the small SI engine regulations, EPA did not 

expect that engine noise levels would be affected by the type of engine changes it anticipated to be 

necessary to meet the proposed gaseous exhaust emission standards. The primary source of noise 

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from nonroad small engines originates from combustion and the moving parts in the engine, such 

as the piston, valve train, and so forth. Noise from combustion is controlled primarily through the 

engine muffler. The Agency believes the principal method that will be used by all engine 

manufacturers to meet the proposed emission regulation will be leaner air/fuel ratios. Therefore, it 

proposed that noise levels in future engines which meet the new standards must not exceed that of 

current production engines. 

The Agency requested comment on the possible impact of the proposed regulation on 

engine noise. 

4.4.2 Summary of the Comments 

A concerned citizen stated that EPA should control noise emissions from small engines, 

arguing that the noise such engines generate can cause stress. That commenter specifically urged 

EPA to use its authority to regulate noise under section 213(a)(3) of the Clean Air Act and under 

the Noise Control Act of 1972, 42 U.S.c. 4901-4918. 149,150 

In jointly prepared comments, ST APPA and ALAPCO stated that they are not convinced 

that the noise cap is necessary, because they do not believe there is any significant likelihood that 

noise levels will be affected. Indeed, no commenter submitted any information supporting the 

contention that noise levels could increase as a result of the Phase 1 regulations. However, were 

EPA to go ahead with its proposal to control noise. STAPPA and ALAPCO were concerned that 

EPA had not proposed requirements by which it could determine compliance with a noise cap. 

Onan, EMA, OPEl, and Tecumseh stated that EPA should drop the requirement that noise 

not increase. ECHO requested that EPA modify its proposed requirement on noise to read that 

"sound levels shall not increase over the current allowable standards (if applicable) for the 

equipment types."151 PPEMA questioned EPA's authority to impose noise caps and 

recommended that EPA delete this requirement. 

Tecumseh stated that engine and equipment manufacturers already adhere to voluntary 

noise standards associated with specific test procedures. 152 They said they do so because the 

public demands it, and they believe that their desire to be responsive to the public will assure that 

noise levels do not become problematic after this rulemaking becomes effective. 

4.4.3 EPA's Response to the Comments 

While EPA does believe that engine noise should be controlled, it has not promulgated 

noise control regulations in this rule making for three reasons: (1) it needs more information 

concerning noise impacts from small SI engines before imposing noise standards, (2) it did not 

propose a test procedure to be used for determining compliance with any noise standards it might 

set, and (3) as noted previously, the industry is already self-regulating to a degree. 

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While it is aware that some noise standards for specific equipment exist such as the 

European Economic Community's noise standards for lawnmowers. EPA lacks the necessary 

information to determine whether it is reasonable at this time to impose engine noise regulations 

without regard to the type of equipment in which the engines will eventually be used. For 

example, the fact that Europe is regulating lawnmowers rather than engines indicates that noise 

may be mostly equipment-specific. Continuing with the example of lawnmowers, it appears that 

the majority of the noise may be from the blade and other non-engine components of the 

equipment. 

Moreover, EPA has recognized that it would not be sufficient for it to simply establish a 

requirement that noise not increase without providing some standardized procedure for making 

such a demonstration. The Agency did not provide a test procedure for assessing noise in the 

NPRM. Because no opportunity for comment on a specific test procedure for noise was given, 

EPA recognizes that promulgating a regulation requiring such a test would not be appropriate in the 

Phase 1 rule. 

Nevertheless, EPA strongly supports engine and equipment noise controls. It commends 

the efforts at self-regulation already undertaken by manufacturers; however, if EPA becomes aware 

of noise increases in conjunction with the entry of Phase I engines into use, it may address this 

issue in a future regulatory action. 

4.5 Safety Implications 

4.5.1 Summary ofthe Proposal 

The Agency made no proposal regarding safety (except as related to noise control, 

discussed above). 

4.5.2 Summary ofthe Comments 

ECHO commented that the impact of the proposed regulations on product safety was not 

yet clearl53. PPEMA pointed out that several safety standards apply to many handheld 

productsl54 and asked EPA to consider the safety implications of the Phase 1 regulations before 

promulgating them. 

4.5.3 EPA IS Response to the Comments 

The Agency encountered no information in its investigations that indicate to it that negative 

implications for safety will arise as a result of promulgating these regulations. No comments 

offered any substantiation supporting the idea that there may be problems related to safety arising 

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from this rulemaking. If EPA finds evidence that safety may be compromised by this action, it will 

reopen the issue. 

4.6 Retention of Certification Engine 

4.6.1 Summary ofthe Proposal 

The proposal was silent regarding the manufacturer's responsibility to maintain any test 

engine used for data submittal after the certification process has been completed. 

4.6.2 Summary of the Comments 

PPEMA requested that EPA allow manufacturers to retain the original certification engine 

for running change testing. 155 

4.6.3 EPA's Response to the Comments 

The Agency does not require engine manufacturers to maintain test engines after a 

certificate has been granted. However, EPA agrees that the manufacturer may find it useful to 

retain certification engines for future data showings to EPA, especially in back-to-back testing to 

support approval of running changes. 

4.7 CO Standard 

4.7.1 Summary ofthe Proposal 

EPA proposed the CO emission level of 402 glkWh for Classes I, II and V. 

4.7.2 Summary ofthe Comments 

The CO emission levels for Classes 1, II and V were objected to by several associations due 

to technical feasibility for some classes of engines to meet the proposed standards. 

EMAlOPEI recommended that the CO levels for Classes I and IT be raised from 402 glkWh 

to 469 glkWh based on the argument that it is not technologically feasible for a significant 

percentage of the market to meet the more stringent standard. Air to fuel ratios required cause inuse performance problems, according to the comments; EMAlOPEI supplied a lengthy rationale for 

raising the CO standard for engines marketed to the mass merchant (see Preamble discussion). 

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PPEMA requested that the CO level for class V engines be changed from 402 glkWh to 603 

glkWh based on technical feasibility of reaching the standard without excessive temperatures that 

create product durability problems. 

4.7.3 EPA'S Response to the Comments 

In response to EMNOPEI's recommendation, EPA has changed the CO level from 402 

glkWh to 469 glkWh for Class I and Class II. EPA chose to change the CO level from 402 glkWh 

for Class IT even though the only available data in the RIAlRSD for Class II (Table 1-15) showed 

that the engines in Class II currently are below the proposed CO level. This is based on 

confidential information from one engine manufacturer which illustrated that there is a wide spread 

of emission results due to engine to engine variability. Their experience, from a much larger 

number of tests, showed that there are still a large number of emission results above the CO 

standard. Research is underway to optimize cylinder cooling designs and to improve fuel 

distribution which could allow further CO reduction without overheating engines in the future. 

However, based on the amount of work shown to have been done on improvements to date, EPA 

has determined that insufficient time is available to advance fuel system and cooling system 

technologies to achi~ve the proposed CO emission levels. An increase in the CO emission standard 

will not impact the feasibility of the HC+NOx standard. This is based on the fact that changes in 

CO emission levels are directly related to the operating NF ratio of the engine alone. There are a 

number of HC and NOx emission control strategies available, such as optimized combustion 

chamber design, which are independent of CO emission levels. 

For Class V handheld engines, EPA has published data in Table 1-19 in the RINRSD 

which shows that approximately 20 to 30 percent of these engines (Class V) meet the 402 glkWh 

CO standard through enleanment of the engine. However, four pieces of information (out of the . 

eight that showed emission levels below 402 for CO) are from four production engines of the same 

engine design from one manufacturer. EPA has considered submitted comments from PPEMA and 

reviewed the information in Tables '1-16 and 1-17 in the Phase I RIAlRSD. 

EP A has no data to support the required higher reduction in per engine CO emission levels 

proposed for Class V engines than for Classes III and IV. The present CO standard of 804 glkWh 

for Class IV engines results in a reduction of 3.7 percent from the average of baseline Class IV 

engine emission levels in Table 1-16 (Data from the one Class ill engine already meets the CO 

standard). The proposed CO level of 402 glkWh for Class V engines results in a 42 percent 

reduction from the average of baseline emission levels in Table 1-17, much higher than the 3.7 

percent reduction required from Class IV engines. By changing the CO level to 603 glkWh, EPA 

would bring the Class V reduction (now 13 percent) in line with the CO reductions in Class IV 

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engines. This change provides a more level playing field, by providing similar reductions across 

Class IV and V engines. The adjusted CO levels provide reasonable emission standards which the 

manufacturers can achieve and thereby minimize the concerns with operation at much leaner levels 

at this time. Phase II emission standards will address the possibilities of further enleaned engines 

across all engine classes. PPEMA has not requested the same change in CO level from CARB due 

to the fact that nearly all of the equipment in this class of engines is exempted from CARB 

regulations due to the definition of farm and construction equipment. 

The impact on the decreased CO emission benefits, based on alterations in the CO levels for 

Classes I and V, are included in the table below. (Additional changes to the model have been made 

and therefore the emission benefits cannot be directly related to those values published in the RIA 

for the Phase I NPRM.) The total change in CO emission inventory from baseline is 2.3 percent 

with changes to Class I and Class V. The difference in emission benefits for Class V is small 

compared to the change from Class I due to the fact that the sales volume in Class V is significantly 

less than the sales in Class I. Therefore, the 201 glkWh increase for Class V is less of an impact 

than the 67 glkWh increase for Class I. 

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CO EMISSION INVENTORY CHANGE (yr 2020) 

NPRM ANAL RULE 

BASELINE WI CONTROL % BENEFIT BASELINE WI CONTROL %BE1~EAT 

CLASS I only 12,995,551 11,168,720 14.4 12,995.551 11,405,697 12.2 

CLASS II only 12,995,551 11,168,720 14.4 12,995,551 11,850,062 8.8 

CLASS V only 12,995,551 11,168.720 14.4 12,995.551 11,212,098 13.7 

CLASS I,ll & 12,995,551 11,168,720 14.4 12,995,551 12,130,398 6.66 

V 

4.8. Class V Compliance Margin Language 

4,8.1 Summary ofthe Proposal 

EPA proposed that the 402 glkWh CO standard is feasible for Class V because test data 

indicates that approximately 20 to 30 percent of Class V engines already achieve average CO levels 

of eight percent below the standard. (see Table 1-19 in the RINRSD for Phase I Small SI Engine 

Reg~lation). 

4.8.2 Summary ofthe Comments 

PPEMA states that the 8 percent compliance margin suggested by EPA does not provide 

adequate statistical assurance that all engines will meet the standard. The variability inherent in the 

production process requires an average compliance margin that is substantially higher than 8 

percent, according to PPEMA. PPEMA argues that EPA underestimates the number of engine 

models that must be brought into compliance. 

4.8.3 EPA'S Response to the Comments 

No additional data was supplied by PPEMA to change the compliance margin from that 

calculated from the available data. Since EPA's NPRM was published, a large number of 

California engine models have been certified. Although Class V engines are largely exempted in 

California, the new Class ill and IV emissions data provide important information on just how 

large a safety margin manufacturers are certifying to in order to ensure the entire engine model will 

stay below the CO standards in production. These data would suggest a larger margin than the 8 

percent provided by the proposed CO standard is needed. EPA's action to change the proposed 

CO standard from 402 glkWh to 603 glkWh for Class V engines will result in a higher compliance 

margin. 

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4.9 He + NOx Standard 

4.9.1 Summary of the Proposal 

The Agency requested comment on two proposals for setting Class I and II HC and NOx 

standards. Option I consists of setting a combined standard for emissions of HC and NOx for 

Class I and II engines. Under option 2, EPA would set separate HC and NOx emission levels for 

Class I and II engines. 

4.9.2 Summary of the Comments 

CARB stated that if EPA sets separate standards, CARB encourages the choice of 

standards to reflect CARB standards of 12 glbhph and 10 glbhph for Class I and II engines 

respectively, thus allowing manufacturers to market a single engine family nationwide. 

Onan is opposed to separate standards. If separate standards are promulgated, a substantial 

amount of testing will need to go into determining the appropriate levels of the two exhaust 

constituents. 

NRDC supports separate standards and at a minimum requests a requirement of separate 

reporting. 

Wisconsin accepts the combined standard with reservations for Phase I only, and wants 

separate reporting of HC and NOx emissions in all Phase I testing and compliance programs. 

Tecumseh supports combined standards. 

STAPP A supports a combined standard for Phase I only and requests a separate reporting 

of HC and NOx. STAPPA saw an environmental benefit of separate standards since such a 

structure would limit interpollutant trading with a separate NOx standard. 

4.9.3 EPA'S Response to the Comments 

EPA has considered all of the comments and has decided to keep the HC+NOx standard 

and add the requirement of separate emission value reporting for HC .and NOx. This will serve 

two purposes in allowing the manufacturers the flexibility in using technologies to reduce 

emissions from small engines and provide states with the detailed information needed for modeling 

of pollutants and SIP planning. 

The combined HC+NOx standard for Phase I is in harmony with CARB. EPA does not 

consider the combined HC+NOx standard a precedent for use in Phase II small SI engine 

regulations. In addition, this measure is only effective for a short number of model years before 

Phase II would come into effect. 

4. 1 0 Stringency of Standards 

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4.10.1 Summary ofthe Proposal 

EPA believes that the proposed Phase 1 emission standards are the lowest standards for 

Class I-V engines achievable by the 1996 model year. 

4.10.2 Summary of the Comments 

Onan stated that if the proposed Phase I emission standards are the lowest standards for 

Class I-V engines by the 1996 model year, then the emissions limits should be higher than those 

proposed by 20 percent or so. Manufacturers will set their production emission limits well below 

the standard to assure that their products meet the standard, given manufacturing tolerances. 

NRDC stated that the statutory requirements and language for nonroad engine standards at 

section 213(a)(3) of the Act are comparable in stringency to the section 202(a)(3)(A) motor vehicle 

emissions standards, which also require standards that achieve "the greatest degree of emissions 

reduction achievable." Thus the Act requires EPA to determine the"degree of reduction" for 

nonroad engines based on its comparable standards for onroad motor vehicles, and to consider the 

stringency and lead -time of onroad standards as the basis for establishing standards under section 

213. 

4.10.3 EPA'S Response to the Comments 

In response to manufacturer comments with respect to production tolerances and their 

impact on emission standards, EPA is well aware of the need for what has come to be known as 

"headroom." This is the level the standards must be set at to allow engine models to be built 

reliably in compliance. EPA has proposed an appropriate effective date that would allow engine 

manufacturers to make the technical changes that allow their engines sufficient headroom to meet 

the emission standards. 

EPA acknowledges that automobile engines have been made to achieve greater degrees of 

emission reductions than are presently required by this rulemaking. However, since this is the first 

requirement for small engine manufacturers to reduce emission levels, EPA has split the emission 

reductions required into two phases with the second phase of emission regulations to come after 

the first phase. The first phase of regulations will require moderate to extensive improvements in 

engine designs with some catalyst usage possible. The second phase of regulations may require 

more advanced technologies which are currently under development for application on a majority 

of these classes of engines. 

EPA has decided to adopt most of the standards as proposed with changes to only the CO 

standards for Classes land V (see response to comments on this issue). 

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4.11 Regulating HC vs. VOC 

4.11.1 Summary ofthe Proposal 

The Phase I NPRM stated that volatile organic compounds (VOCs) are compounds 

containing carbon and hydrogen in combination with any other element with a vapor pressure equal 

to or greater than 1.5 pounds per square inch under actual storage conditions. HCs therefore, are a 

subset of VOCs. Based on the testing indicating that HC emissions represent VOCs from small SI 

engines that cause or contribute to ozone nonattainment concentrations, EPA proposed an HC, 

rather than a VOC standard. 

4.11.2 Summary of the Comments 

Onan statedthat it supports regulating HC based on the fact that present emission 

measuring equipment is not capable of measuring VOC and appropriate equipment is a sizeable 

cost to small engine manufacturers. SwRI has shown that 99 percent of VOCs emitted from 

engines covered by this NPRM are HCs and CARB regulates HC (harmonization). 

EMA and OPEl support this aspect of EPA's proposal. EMA stated that HCs make up 

more than 99 percent of the VOCs emitted from small engines. Inasmuch as the types of controls 

used to reduce HC emissions likewise will reduce emissions of other VOCs, setting emission 

limits for HC emissions should essentially accomplish the same reduction in VOC emissions as 

would be achieved by setting limits for VOCs. 

4.11.3 EPA'S Response to the Comments 

EPA is setting standards for HC regulation. 

SECTION 5: TEST PROCEDURES AND EQUIPMENT 

5. 1 Certification Test Fuels 

5.1.1. Summary of the Proposal 

The proposed rule allowed for the use of one test fuel for certification, the parameter 

specifications and tolerance levels were specified in an Appendix to Subpart D. 

5.1.2. Summary of the Comments 

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The Kohler Company stated concerns that the proposed fuel specifications were too tight 

and the fuel would not be readily available. Kohler suggested that the Agency relax the tolerances 

so that recognized certification fuels such as Indolene Clear would be acceptable. 

Qnan Corporation questioned what fuel was being specified. Qnan suggested that the 

Agency add language that would allow future California and Federal on-highway certification fuels 

be used for small engine certification. 

The Portable Power Equipment Manufactures Association (PPEMA) stated that the 

proposed fuel tolerances were too stringent. They voiced concerns regarding fuel availability, 

particularly in foreign countries. PPEMA suggested the Agency's rule be consistent with CARB 

and SAE J1088, and asked that EPA allow the use of Indolene Clear. PPEMA also suggested that 

. EPA allow the use of comparable, commercially available fuels in foreign countries where the 

engine is manufactured and tested for certification. 

5.1.3. EPA's Response to the Comments 

The fuel specified in the proposed rule was meant to represent typical commercially 

available gasoline available in the U.S.A. After publishing the proposal the Agency discovered the 

fuel tolerances specified in fact were too stringent. The tolerances have been increased and the 

Agency believes the fuel can be purchased from many refineries in the U.S. Because of the 

importance of fuel parameters to emissions testing, the Agency does not believe commercially 

available fuels in foreign countries are acceptable for certification testing unless the fuel meets the 

specifications in the regulation. In addition,- the Agency has added an additional fuel as a possible 

certification fueL The Agency has added the specifications for the certification fuel used for onhighway gasoline fueled light-duty vehicles, specified in 40CFR 86. 1313-94(a). This fuel is 

commonly referred to as Indolene Clear. 

5.2 - Service Accumulation Fuel (or Break-In Fuel) 

5.2.1. Summary ofthe Proposal 

The proposal specifies that the Service Accumulation Fuel must be representative of 

commercially available fuel. The proposal also states that the Reid Vapor Pressure of the fuel be 

typical of fuel in use for the time of year the engine is tested. 

5.2.2. Summary ofthe Comments 

The Kohler Company and Qnan Corporation requested that certification fuel be allowed for 

use as the service accumulation fuel as an alternative to commercially available fuel. 

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Onan also commented that it would be more appropriate for the RVP of the fuel to be 

typical of a summertime grade fuel, since most small engines are used in the summertime. 

Echo Corporation suggested that the service accumulation fuel ~quirements be altered to 

include fuel which is characteristic of the country's motor fuel because U.S. fuel is difficult to 

import into foreign countries. 

5.2.3. EPA's Response to the Comments 

The Agency specified a commercially available fuel as an alternative to the certification fuel 

as a method of lowering manufacturers cost due to the generally high cost of certification fuel. 

However, the regulation has been changed to include the certification fuel as an option for the 

service accumulation fuel. The RVP specifications have also been altered to allow the use of a 

summertime fueL For foreign manufacturers, the Agency is not proposing that the service 

accumulation fuel must be from a U.S. refinery, only that the fuel be representative of fuel 

commercially available in the U.S. 

5.3 Power Measured During the Idle Mode 

5.3.1. Summary ofthe Proposal 

The proposal required that power measured during the idle mode of the proposed test 

cycles should not be included in the calculation of the weighted brake-specific emission rate. 

5.3.2. Summary ofthe Comments 

Onan Corporation suggested that the Agency should include the windage power measured 

during the idle mode. Onan stated that to not include the windage power would be to unjustifiably 

increase the mode weighted emission values. 

The Echo Corporation proposed that the Agency should allow the use of idle power in the 

weighted calculations only if the piece of equipment the engine is used in produces work while 

idling. 

PPEMA requested that the Agency remove the idle mode completely from Cycle C, the 

handheld test cycle. Ifthe Agency decides to leave the idle mode, manufactures should be allowed 

to include the power measured during the idle mode in the emission calculations. 

5.3.3. EPA's Response to the Comments 

The Agency has based the form of the emission standards for this rule and other engine 

rules in terms of brake-specific emission rates, ie. mass of emissions per unit time per unit power. 

The rationale behind this is to base the standard in terms of the amount of useful work performed 

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by the engine. During the idle mode an engine is producing the amount of work necessary to 

maintain idle speed, therefore no external work is generated. For this reason, any power measured 

during the idle mode portion of the test is a result of a load applied to the engine from the power 

measuring device and should not be included in the calculations of the weighted brake-specific 

emission rates. The manufacturer always has the option of disconnecting the engine from the 

dynamometer for the idle mode. For these reasons the Agency will not be altering the final rule in 

response to this comment. The Agency will not be removing the idle mode from test Cycle C. 

5.4 Differences between the proposed Federal test procedure and the 

Society of Automotive Engineers (SAE) Recommended Procedure J1088. 

5.4.1. Summary ofthe Proposal 

The proposed test procedure is based primarily on the heavy-duty gasoline engine test 

procedure detailed in Title 40 of the Code of Federal Regulations, Part 86, Subpart D. 4OCFR86 

Subpart D is a certification test procedure for heavy-duty diesel and gasoline on-highway engines. 

5.4.2. Summary ofthe Comments 

The Qnan Corporation stated that the Agency must demonstrate a lack of uniformity 

between test laboratories or the proposed changes from established test practices should be 

considered arbitrary and capricious. Qnan mentioned an industry sponsored correlation program 

run by the Engine Manufacture Association (EMA) which showed good correlation between four 

engine manufactures, one component manufacture, EPA, and the University of Michigan. 

PPEMA stated that the Agency's proposed modifications to SAE 11088 do not 

meaningfully increase the measurement precision or confidence in the prediction of emission 

reductions. Furthermore, PPEMA contends that given the demonstrable accuracy of the SAE 

11088 procedure, the Agency's proposed changes only increase the cost to manufactures and are 

not justified. 

5.4.3. EPA's Response to the Comments 

The Agency has very little data with which to compare small engine manufacturer test 

laboratories. There are over thirty engine manufacturers who sell engines in the U.S. who may 

want to certify engines to this rule if they wish to continue selling engines. To use the data from a 

single round-robin test program which only included four out of at least thirty engine 

manufactures does not appear responsible to the Agency. 

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No engine manufacturer submitted data or information on the "demonstrable accuracy" of 

the J1 088 procedure, or on the incremental costs to manufacturers which may be attributed to the 

differences between the SAE J1 088 procedure and the proposed rule. 

The burden is not on the Agency to disprove a recommended test procedure. EPA did not 

use the J1088 procedure as a starting point for the proposed test procedure. The test procedure is 

based primarily on existing EPA certification test procedures for other engines which are currently 

regulated, primarily heavy duty diesel and gasoline on-highway engines. The SAE J1088 is a 

recommended test procedure which by itself the Agency does not feel is appropriate for 

certification testing. 

5.5 Unconditioned Air Supply, Humidity Measurement 

5.5.1. Summary ofthe Proposal 

In §90.310 of the proposal, there is a requirement that engines with humidity conditioned 

air supplies must measure the humidity of the air in the engine's intake air system. 

5.5.2. Summary ofthe Comments 

The Onan Corporation suggested the paragraph be revised to allow the measurement of the 

test cell humidity for those engines which don't have humidity conditioned air supplies. 

Echo Corporation suggested the paragraph be deleted, since small engine manufactures 

don't pre-condition the intake air going into the engine. 

5.5.3. EPA's Response to the Comments 

The final rule has been altered to allow the measurement of test cell humidity for engines 

which do not use humidity conditioned air supplies. 

5.6. Test Conditions, Test Engine Orientation 

5.6.1 . 	 Summary ofthe Proposal 

. The proposal required that Class I and II engines must be level during the emission test. 

5.6.2. Summary of the Comments 

Onan Corporation suggested changing the requirement so that all engines must be tested at 

their design angle. 

5.6.3. EPA's Response to the Comments 

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The suggestion made by Onan is appropriate for small engines, since many small engines 

are not designed to operate in a level position. The fmal rule has been modified accordingly. 

5.7. Ambient Test Conditions and f-parameter Specifications 

5.7.1. Summary ofthe Proposal 

The proposed regulations require that the test cell temperature (T) and dry barometric 

pressure (Ps) are used in the calculation of a "f-parameter" according to the following formula 

= 101.3 (-1:....)0.7 f P. x 298 

In order for a test to be valid the value of the f-parameter must fall between the values of 0.98 and 

1.02. In addition, the regulations require that the ambient test cell temperature be maintained 

between 20° and 30° C. 

5.7.2. Summary ofthe Comments 

Onan Corporation commented that Ix>th the formula and the limits for the f-parameter are 

too restrictive and the dry barometric pressure standard of 101.3 kPa in the formula for "f' is too 

high. Upon request, Onan submitted additional data containing daily dry barometric pressure 

minimum and maximum values for their lalx>ratory from September 1991 to December 1993. This 

data shows that if the standard pressure is set at 101.3 kPa, Onan would be unable to perform a 

valid test approximately 85% ofthe year, if the standard pressure is set at 99 kPa Onan would be 

unable to test on approximately. 10% of the year, and if the standard pressure were changed to 97 

kPa, Onan would be able to test every day. These calculations assume test cell temperature can be 

varied between the proposed limits of 20° and 30° C. Onan requested that the Agency either 

eliminate the f-parameter requirement or change the limits or the standard pressure to allow 

manufactures to test on the majority of the year. 

PPEMA requested an ambient test cell range of 15-30 C. PPEMA stated that the fparameter serves only as a correction factor for potentially different test conditions. Temperature 

and barometric pressure are considered in engine power corrections. PPEMA requested the 

proposed f-parameter restrictions be removed. 

5.7.3. EPA's Response to the Comments 

In a preliminary draft of the test procedure, for which EPA requested a technical review by 

the SAE Small Engine and Powered Equipment Committee in July of 1993, the f-parameter 

standard pressure was 99kPa, not 10 1.3kPa. In the comments from one of the SAE reviewers, 

EPA was requested to change the standard pressure to 101.3kPa to be consistent with the standard 

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pressure used for volumetric flow rate calculations in the regulations. Since that time the Agency 

has received verbal comment from the SAE reviewer stating that they made an error in their review 

and would prefer that the standard pressure for the f-parameter calculation be set to 99k.Pa. This 

correction has been made to the final rule. 

The purpose of the f-parameter for this rulemaking is to insure that all manufacturers 

perfonn the certification test under a set of restrained ambient conditions. The Agency does not 

have any infonnation at this time regarding the effects of barometric pressure and temperature on 

small engine emission perfonnance. If in the future scientific data are produced which show the 

relationship between ambient cell temperature, barometric pressure and emission perfonnance, the 

Agency would consider issuing a technical amendment to the regulations altering the f-parameter 

and ambient cell temperature limits appropriately. The Agency is also aware of the burden placed 

on manufacturers by what may be unnecessarily stringent f-parameter tolerances. The proposed 

allowable tolerance band was ±two percent, the Agency has increased the allowable tolerance band 

for the final rule to ± four percent, from 0.96 to 1.04. 

5.8 Oxygen I~terference Check - Frequency of Check 

5.8.1. Summary ofthe Proposal 

The proposal states that an oxygen interference check must be perfonned as part of the 

hydrocarbon analyzer calibration in §90.316. The calibration frequency for the oxygen 

interference check is not spelled out. 

5.8.2. Summary of the Comments 

Onan Corporation requested infonnation on when and how often the oxygen interference 

check must be perfonned. 

5.8.3. EPA's Response to the Comments 

In Table 2 of Appendix A of Subpart D, the calibration frequency for the hydrocarbon 

analyzer, which includes the oxygen interference check, is monthly. The regulation has been 

changed to explicitly spell out this requirement in §90.316( d). 

5.9 Carbon Monoxide Analyzer Interference Check. 

5.9.1. Summary ofthe Proposal 

The proposal requires that manufacturers periodically (within one month prior to the 

certification test) perfonn a check on the response of the carbon dioxide NDIR analyzer to water 

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vapor and carbon dioxide. The method was described in the proposal, and it involves bubbling a 

mixture of C02 and nitrogen gases through water which is then read by the analyzer. 

5.9.2. Summary of the Comments 

Onan Corporation requested that manufacturers be allowed to perform a dry carbon dioxide 

interference check, or at the very least, allow the mixture to be introduced into the sample prior to 

the water trap. 

5.9.3. EPA's Response to the Comments 

The purpose of this interference check is to examine the analyzers response to both carbon 

dioxide and to water vapor. The Agency's experience led to the development of the procedure 

described in the proposal, and this language was not altered for the final rule. 

5.10 Calibration Frequency 

5.10.1. Sum'!"lry ofthe Proposal 

The proposal states that calibrations for several instruments must be performed monthly. 

5.10.2. Summary of the Comments 

Onan Corporation suggests that EPA should only require calibration intervals with respect 

to certification or audit equipment. In addition, Onan suggested that instead of requiring monthly 

calibrations on instruments, the requirement should be that the instrument must have been 

calibrated within one month prior to the certification test. 

5.10.3. EPA's Response to the Comments 

The Agency agrees with Onan's suggestion regarding calibration frequency. The proposed 

language was taken from on-highway certification test procedure documentation where 

manufacturers are performing certification tests routinely throughout the year. If a manufacturer 

does not run certification tests throughout the year, for instance the tests are run during a six month 

period, it would not be necessary for the manufacturer to perform monthly calibration on 

instruments which are not used for the remaining six months of the year. This would place a 

burden on the manufacturer which has no technical benefit. The regulation language has been 

changed from requiring a monthly calibration frequency to requiring calibration within one month 

of the certification test. 

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5.11 Test Procedure Overview, Dynamometer Requirement 

5.11.1. Summary of the Proposal 

The proposal requires a dynamometer be used as the engine loading device for the 

certification test. 

5.11.2. Summary of the Comments 

Onan Corporation requested that EPA change the requirement that a "dynamometer" must 

be used as the engine loading device for the engine test cycle to an "engine load measuring device." 

5.11.3. EPA's Response to the Comments 

The Agency agrees with OQan's suggestion. It is not necessary to use a dynamometer if 

another instrument which can perform the same function is available. The final rule has been 

changed to allow the use of an engine load measuring device to perform the engine test cycle, as 

long as the alternative device meets the necessary speed and torque accuracies specified in the rule. 

5.12 Recorded Information, Explanation of Terms 

5.12.1. Summary ofthe Proposal 

The proposed rule requires manufacturers to record the "date of most recent analytical 

assembly calibration" under the general test records section. 

5.12.2. Summary of the Comments 

Onan Corporation requested that EPA give a definition of what the "date of most recent 

analytical assembly calibration" refers to. 

5.12.3. EPA's Response to the Comments 

The proposed language was not clear on what the analytical assembly referred to; the final 

rule has been changed to read "date of most recent analyzer bench calibration." 

5.13 Humidity and temperature measurement of engine intake air 

5.13.1. Summary ofthe Proposal 

The proposal requires the measurement of engine intake air temperature, and the 

measurement of intake air humidity for those engines whose intake air humidity is pre-conditioned. 

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5.13.2. Summary of the Comments 

Onan Corporation suggested that intake air humidity and temperature measurements should 

not be required. Onan suggested that ambient test cell conditions should be allowed instead, 

particularly for humidity. 

5.13.3. EPA's Response to the Comments 

The Agency believes that engine intake air temperature should be a simple measurement for 

manufacturers to make. Measurement of engine intake air humidity is only required for engines 

with pre-conditioned intake air, otherwise the ambient test cell humidity measurement is sufficient. 

5.14. Engine service accumulation time determination 

5.14.1. Summary ofthe Proposal" 

In §90AOS, the proposal provides the manufacturer with two options regarding service 

accumulation on the certification engine. First, the manufacturer can make a determination, for each 

engine family, the appropriate service accumulation time necessary for the stabilization of 

emissions, but this time may not exceed 12 hours. As an alternative, the manufacturer can use 12 

hours as the service accumulation duration without conducting an engineering determination. 

However, in §90.11S, the second option is not mentioned. 

5.14.2. Summary of the Comments 

Onan Corporation stated that the engine manufacture should be allowed to choose any 

break-in procedure they choose. PPEMA believes the Agency's proposed 12 hour break in time is 

unnecessarily long. Echo Corporation requested that if a manufacturer can demonstrate that an 

engine emissions are not stable but are decreasing; the manufacturer should be allowed to test the 

engine at that point. 

5.14.3. EPA's Response to the Comments 

EPA believes that at least part of the misunderstanding regarding this subject was the 

discrepancy between §90AOS and §90.11S. Section §90.1IS has been changed to match §90.40S. 

A manufacturer can choose to make the service accumulation time determination or they may use 

12 hours as a.default, but the self determination time may not exceed 12 hours. The final rule has 

also been modified to accept the suggestion by the Echo Corporation regarding engines with 

decreasing emissions. If a manufacturer can demonstrate that an engine family's emissions, 

including all regulated pollutants, are decreasing from some initial time (greater than zero but less 

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than 12 hours) out to 12 hours, the manufacturer will be allowed to stop the service accumulation 

at the time where emissions begin to decrease. 

5.1 5 Effect of emission measuring equipment on engine performance 

5.15.1. Summary of the Proposal 

The proposal requires the manufacturer to run the test engine at a single speed and torque 

point both before and after the emission sampling equipment is installed. The engine's power, and 

for raw gas sampling, fuel consumption, are measured in both instances and should agree within 

approximately five percent. 

5.15.2. Summary of the Comments 

Onan Corporation requested that manufacturers should be allowed to perform this check 

after the certification test, if at all. Manufacturers should not have to perform this on every 

certification test; demonstration on similar or worst case setups should be adequate. 

5.15.3. EPA's Response to the Comments 

Manufacturers are required to perform this check prior to the certification test so that if a 

problem is found it can be corrected before the certification test is run. This test should not be 

confused with the service accumulation and should be done after the service accumulation is 

complete. The Agency does not believe it is a significant burden for manufacturers to run this 

simple, two mode test, one prior to and one after the emission sampling equipment is installed. 

This test only requires the measurement of at most three parameters, engine speed, torque and fuel 

consumption. 

5. 1 6 The use of observed vs. corrected torque in power calculations 

5.16.1. Summary ofthe Proposal 

The proposal requires manufacturers to use observed torque in the calculation of engine 

power. 

5.16.2. Summary of the Comments 

Onan Corporation requested that EPA use corrected torque, not observed. 

5.16.3. EPA's Response to the Comments 

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It has been the Agency's practice to require the use of observed torque in the calculation of 

break-specific emissions in several past engine emission regulations, see for example §86.340­

79(c)(3)(ii), §86.341-79(d)(7), §89.407-96(c)(8). At this time the Agency is not considering 

dropping this practice. 

5.1 7 Engine stabilization - thermal stability requirement 

5.17.1. Summary ofthe Proposal 

The proposal required manufacturers to run the test engine at each mode speed and torque 

set point for a sufficient amount of time to achieve thermal stability, with a minimum requirement 

that engine cylinder head temperature remain constant for three minutes at ± 5° Celsius. 

5.17.2. Summary ofthe Comments 

Onan Corporation requested that manufacturers be allowed to make their own determination 

of how long an engine needs to run before it is stabilized. PPEMA stated that a three minute 

stabilization time may be too long a time period for the wide open throttle mode for some Class ill, 

IV, and V engines without possible engine damage. PPEMA requested that manufacturers be 

allowed to make their own determination of stabilization time. Kubota requested that oil 

temperature measured in the oil pan be an alternative to cylinder head temperature. 

5.17.3. EPA's Response to the Comments 

The final rule has been modified from the proposal to take into consideration the comments 

on this topic. The Agency agrees that more than one criterion can be used to determine thermal 

stability for the purposes of emission measurement, including, but not limited to, cylinder head 

temperature and oil temperature. The tester now has two options, one is to determine and 

document the appropriate criterion for thermal stability for each engine family. Ifthe manufacturer 

does not want to make this determination, they can use the requirement that cylinder head 

temperature must remain within a lOoC bandwidth for three minutes. 

5.18 Data Sampling Period and Frequency 

5.1B.l. Summary ofthe Proposal 

The proposal requires manufacturers to record the emissions and engine data for at least 

four minutes once the engine is stabilized, and to sample the data at a minimum rate of 1Hz. 

5.1B.2. Summary ofthe Comments 

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The Agency received essentially the same comment from Onan Corporation, Echo 

Incorporated, Kubota, and PPEMA. In every case the comments did not mention the 1Hz 

sampling rate as a problem, but each commenter requested the Agency decrease the sampling time. 

Manufacturers requested a two minute sampling time for two reasons, to harmonize with the 

CARB Utility, Lawn and Garden engine regulation, and because two minutes should be a 

sufficient sampling time because thermal stability has already been achieved. 

5.18.3. EPA's Response to the Comments 

The Agency agrees with the comments received. An examination of several sets of EPA 

small engine test data showed that once thermal stability is achieved, doubling the sampling period 

from two to four minutes resulted in less than a one percent change in the average values of engine 

speed, torque, total hydrocarbon concentration, and oxides of nitrogen concentration. Based on 

this information and the comments received from manufacturers the Agency has changed the fmal 

rule to require a minimum sampling period of two minutes for each mode. 

5.19 Averaging of speed and torque data for power calculation 

5.19.1. Summary ofthe Proposal 

The proposal required that a manufacturer calculate the power for each mode by averaging 

the individually calculated power values during the mode. 

5.19.2. Summary ofthe Comments 

Onan Corporation suggested that a manufacturer be allowed to calculate the average power 

for each mode from the average speed and the average torque. 

5.19.3. EPA's Response to the Comments 

The correct formula for calculating the average power during a mode is 

l'.0 2 1'C x speedj x tarquftj 1=1. 60,000 Average Modal Power • .tf.-;;;::"'-~---ll-----""'-

Onan's suggestion would change the formula to be 

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Average Modal Power. 2x x average speed. x average torque 60,000 

These two equations are not identical and would not produce the same result. For this reason, the 

Agency willl~ave the calculation as proposed; average power must be calculated from the average 

of each individually calculated power value. 

5.20 Emission Bench Calibration Information 

5.20.1. Summary ofthe Proposal 

The proposal contained a paragraph under the data logging section stating "For purposes of 

this section, calibration data includes calibration curves, linearity curves, span-gas responses, and 

zero-gas responses'." 

5.20.2. Summary of the Comments 

The Onan Corporation corrunented that this paragraph required that infonnation be logged 

during the test that is' typically not recorded as part of the actual test data logging information. 

Onan suggested that this paragraph does not belong in this section. 

5.20.3. EPA's Response to the Comments 

The Agency agrees with Onan's comment. This paragraph does not deal with the subject 

of this section, which is data logging during the test. This paragraph has been removed from the 

final rule. 

5.21 Automatic Data Collection Of Continuous Analyzer Response 

5.21.1. Summary ofthe Proposal 

The proposal required manufacturers to maintain for long term storage the average value of 

the continuous analyzer response. 

5.21.2. Summary ofthe Comments 

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The Onan Corporation requested that manufacturers be allowed to maintain for long term 

storage the individual data points from a continuous analyzer which could be averaged as 

necessary. 

5.21.3. EPA's Response to the Comments 

The Agency agrees with the comment. If a manufacturer wanted to maintain individual data 

points from a continuous analyzer response instead of storing the average value this would not 

affect the Agency's ability to request the average response value. The final rule has been modified 

to allow for this option. 

5.22 Engine Cooling Fan For Air Blowers/Pumps 

5.22.1. Summary ofthe Proposal 

The proposal required that all engines be tested with the cooling fan installed. 

5.22.2. Sum:nary of the Comments 

PPEMA and Echo Inc. commented that for certain engine types, suct) as engines used in air 

blowers, the engine's cooling fan absorbs 90-98 percent of the engine's power, so the engine 

would not be capable of performing the engine test cycle with the cooling fan installed. Both 

comments stated that the Agency must give some consideration for these types of engines. 

5.22.3. EPA's Response to the Comments 

The Agency agrees that special provisions must be made for these types of engines. The 

engine test cycle would not be performed if the engine cooling fan absorbs such a large portion of 

the engine's power. The final rule has been altered to allow for the removal of the original cooling 

fan and the addition of an external cooling fan for engines whose cooling fan serves a dual 

purpose. 

5.23. Analytical Gases - Pure Gases 

5.23.1. Summary ofthe Proposal 

. The proposed rule requires that manufacturers use "pure" gases, defined by specific 

tolerances stated in the proposal, for use as zero gases, calibration and span gas diluents, and FID 

fuel. 

5.23.2. Summary of the Comments 

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PPEMA commented that pure gases are not necessary for raw gas sampling if the fuel flow 

method is used. 

5.23.3. EPA's Response to the Comments 

The Agency disagrees with PPEMA regarding this item. Regardless of which testing 

method a manufacturer uses, raw gas or constant volume sampling, manufacturers must use pure 

gases for the zeroing of analyzers, the Fill fuel, and the diluent for gas dividers. The final rule has 

no changes in it from the proposal regarding this topic. 

5.24. Analytical Gases - Diluent for Hc-Fid Zero, Span and 

Calibration Gases 

5.24.1. Summary ofthe Proposal 

The proposal had language under the calibration and span gas section listing 

propane/nitrogen mixture as well as a propane/zero air mixture, but the language did not have an 

explanation of when it would be appropriate to use the two different mixtures as Fill span and 

calibration gases. 

5.24.2. Summary ofthe Comments 

PPEMA stated that purified nitrogen should be the zero gas and the diluent for the HC-Fill 

analyzer span and calibration gases to avoid potentially explosive mixtures of very high propane 

concentrations with synthetic air. 

5.24.3. EPA's Response to the Comments 

It was the Agency's intent to allow the manufacturers to choose what zero gas and diluent 

to use for the HC-Fill analyzer in the proposal. Additional language has been added to the final 

rule to clarify this point, as well as to make manufacturers aware of the possible dangers of mixing 

high propane concentrations with synthetic air. 

5.25. Analyzer Calibration - Step Calibration Requirement 

5.25.1. Summary ofthe Proposal 

The proposal requires manufacturers to calibrate each analyzer on each range used by 

performing a multi-point step calibration procedure. 

5.25.2. Summary of the Comments 

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PPEMA commented that the step calibrations are unnecessary because analyzer calibrations 

are perfonned by the instrument manufacturer and should not be the responsibility of the engine 

manufacturer. 

5.25.3. EPA's Response to the Comments 

The Agency disagrees with PPEMA's comment. The Agency has found that analyzer 

calibration curves are not static and do change overtime. The stability of analyzer calibration 

curves varies between analyzer manufacturers as well as between the different types of analyzers 

(HC, CO, C02, NOx). Currently, the only method known to the Agency to be certain that analyzer 

calibration curves have not changed is to perfonn periodic multi-step calibrations. The final rule 

has not been changed as a result of this comment. 

5.26. Oxides of Nitrogen Measurement, Accuracy and 

Instrumentation 

5.26.1. Summary ofthe Proposal 

The proposal requires that engine manufacturers use a chemiluminescent oxides of nitrogen 

(NOx) analyzer with a measurement accuracy of two percent. 

5.26.2. Summary of the Comments 

PPEMA commented that a two percent accuracy requirement on NOx was unnecessarily 

stringent for two-stroke engines, because two-stroke engines emit NOx levels well below the 

standard. In addition, PPEMA asked the Agency whether or not a UV -NDIR NOx analyzer would 

be acceptable for testing. 

5.)6.3. EPA's Response to the Comments 

The Agency does not believe the accuracy requirements of the test procedure should be 

dependent on how close to an emission standard a particular type of engine is and the fmal rule was 

not altered regarding that comment. 

In the past EPA has had some experience with UV -NDIR NOx analyzers and has not found 

them to be as accurate as the chemiluminescence type. However, the proposed regulations do 

allow for the use of other analyzers, as long as the manufacturer can show the analyzer shows 

equivalent results to the required type, and this language remains in the fmal rule. Section 

9O.313(b) of the fmal rule states that "Other types of analyzers and equipment may be used if 

shown to yield equivalent results and if approved in advance by the Administrator." 

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5.27. Testing Mode Intervals 

5.27.1. Summary ofthe Proposal 

The proposal requires that a delay of more than one hour between the end of one mode and 

the start of a second mode would void a test. 

5.27.2. Summary of the Comments 

PPEMA commented that EPA should not limit the duration between one test mode and the 

next. 

5.27.3. EPA's Response to the Comments 

The Agency believes that the certification test should be a single test performed on a single 

day with as few interruptions as possible. The Agency is concerned that allowing manufacturers to 

run the different test modes on different days or with large gaps of time between modes would 

pose questions of repeatability and possible gaming by the engine manufacturer. The test cycle 

which most PPEMA. members will be responsible for performing is Cycle C, the two-mode cycle. 

Once the first mode is completed, the amount of time necessary to complete the second mode, 

including stabilization and sampling time, should not be more than 10 or 15 minutes. The Agency 

does not believe this will impose any significant burden on the engine manufacturers and the final 

rule will not be altered because of this comment. 

5.28. Mixing Chamber Requirements - Helmholtz Frequency 

Requirement 

5.28.1. Summary ofthe Proposal 

The proposal's description of the optional mixing chamber was taken from the SAE 11088 

recommended procedure. 

5.28.2. Summary of the Comments 

PPEMA requested that an additional requirement be added to the language regarding the 

mixing chamber, specifically, that the Helmholtz frequency of the mixing chamber not exceed 1110 

of the engine's firing frequency. 

5.28.3. EPA's Response to the Comments 

The Agency used the language from the SAE 11088 recommended procedure to describe 

the optional mixing chamber. Without further explanation of why the description of the mixing 

chamber should be different from the SAE description, EPA will not alter the proposed language. 

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If PPEMA can demonstrate that a technical error has been made, the Agency would consider 

making a Technical Amendment to the final rule at that time. 

5.29. Acceptance of the Micro-Dilution Tunnel Testing Method 

5.29.1. Summary o/the Proposal 

The proposal described three acceptable emission testing methods, raw gas sampling with 

air and fuel flow measurement, raw gas sampling with fuel flow measurement, and constant 

volume sampling. 

5.29.2. Summary o/the Comments 

PPEMA requested that the Micro-Dilution Tunnel (MDT) testing method developed by one 

of its members be included as an acceptable method of emission sampling. 

5.29.3. EPA's Response to the Comments 

Due to time ,and resource constraints. the Agency has not been able to perform a complete 

analysis of the MDT method. The final rule has not been altered to include the MDT method. 

However. as proposed. the final rule does allow for manufacturers to propose alternative test 

methods which could be deemed acceptable by the Administrator. 

5.30. Air Flow Measurement for Two-Stroke Engines 

5.30.1. Summary o/the Proposal 

The proposal described three acceptable emission testing methods: raw gas sampling with 

air and fuel flow measurement, raw gas sampling with fuel flow measurement, and constant 

volume sampling (CVS). 

5.30.2. Summary o/the Comments 

PPEMA commented that air flow measurement should not be required for two-stroke 

engines. 

5.30.3. EPA's Response to the Comments 

The Agency does not specify which of the three sampling methods a manufacturer must use 

to comply with the rule. No manufacturer is forced to use the raw gas method (RGM) with air and 

fuel flow measurement; both the RGM with only fuel flow or the CVS method are acceptable. In 

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addition, as in the proposal, the final rule allows manufacturers to propose alternative test methods 

which could be deemed acceptable by the Administrator. 

5.31 Catalyst Durability Cycle: Change to Test Requirements 

5.31.1. Summary ofthe Proposal 

The notice proposes the evaluation of catalyst durability by means of thennal stress testing. 

Such testing involves the use of heated air for preconditioning and aging catalysts and the use of 

synthetic exhaust gas for detennining catalyst conversion efficiency. 

5.31.2 	 Summary of the Comments 

The comments that were submitted by the Manufacturers of Emission Control Association 

(MECA) proposed the adoption of an optional hydrothennal stress test and recommended an 

increase in the concentration of C02 in the synthetic exhaust gas. 

5.31.3 EPA's Response to the Comments 

The MECA comments noted that the proposed hydrothennal stress test, which involves 

exposure in a 90 percent nitrogen/to percent steam environment at a temperature in excess of 

850°C, has been adopted by the industry for evaluating catalyst washcoat durability. This 

procedure is based on infonnation which shows that water is the component of actual exhaust gas 

which can cause an undesirable reduction in the surface area of a washcoat that does not have 

adequate stability. In response to the MECA proposal, the use of a 90 percent nitrogen/to percent 

water vapor environment has been adopted as an alternative to an air environment during catalyst 

preconditioning and aging. The resultant availability of alternative procedures, thennal stress 

testing with air and hydrothennal stress testing with the nitrogen/water mixture, will allow the 

optional use of the catalyst durability evaluation procedure that is most appropriate for specific 

engine applications. 

Prior to the publication of the NPRM, MECA had recommended the use of a synthetic 

exhaust mixture which contains 3.8 volume percent C02. The recommendation in the MECA 

comments for an increase in this value to 9 percent or 10 percent is based on information which 

shows that the concentration of C02 in the exhaust gases emitted by small nonroad engine ranges 

from 9 percent to 12 percent for 4-stoke engines and 2 percent to 10 percent for 2-stoke engines. 

In response to the MECA recommendation, the C02 concentration has been raised from 3.8 

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percent to 9 percent to make the synthetic exhaust gas mixture more representative of actual exhaust 

gas mixtures that are emitted by the kinds of engines that are covered by the Part 90 regulations. 

5.32 Exhaust Gas Composition for Testing of Three-Way Catalysts 

5.32.1 Summary ofthe Proposal 

The composition of the synthetic exhaust gas mixture that is specified in the proposal is 

comparable to compositions of synthetic exhaust gas mixtures currently used by catalyst 

manufacturers for testing related to the kinds of engines covered by the proposal. 

5.32.2 Summary of Comments 

MECA commented that if the catalyst manufacturer specifies that a catalyst is designed for 

three-way control, the manufacturer should have the options of using HC+NOx combined 

conversion as a basis for detennining durability and of using a rich synthetic exhaust evaluation 

gas with either 4650 ppm HC or 1.2 percent CO rather than 4000 ppm He and 1 percent CO 

which are parameters for a stoichiometric mixture. 

5.32.3 EPA'S Response to the Comments 

EPA allows the use of HC+NOx combined conversion as a basis for detennining durability 

where the standard is also expressed as HC+NOx (for Classes I and II only). NOx conversion 

requires that a slightly rich exhaust mixture be present. We expect engines designed to meet Phase 

1 emission standards to operate on the rich side of the stoichiometric mixture. Therefore, using a 

stoichiometric gas mixture would not be representative of the exhaust gas the three way catalyst 

will see in actual use. Therefore, EPA has changed the final rule to allow manufacturers to utilize 

4650 ppm HC or 1.2 percent CO. 

5.33 Deterioration Limits 

5.33.1 Summary ofthe Proposal 

The agency proposed a fixed catalyst efficiency loss limit of 20 percent for HC, CO and 

NOx. This was proposed based on EPA's on-highway experience and the absence of information 

at the time regarding the conversion efficiencies that will be used with small engines. 

5.33.2 Summary of Comments 

MECA submitted the following comments: 

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1. Require only demonstration of hydrocarbon conversion durability. 

2. If demonstrations of CO and NOx conversion durability are also required, the following 

options are recommended: 

a. The catalyst manufacturer can designate catalysts as two-way (He and CO control) or 

three-way (He, CO and NOx control). 

b. A two-way designation would eliminate the need for the demonstration of NOx conversion 

durability. 

3 . Failure to comply with the CO conversion deterioration limit would not preclude the 

certification of a two-way catalyst that is intended for use on engines with low engine-out CO 

emissions. 

5.33.3 EPA'S Response to the Comments 

The Agency has decided that catalysts should not be accountable for pollutants which they 

were not designed to reduce/oxidize. Therefore, the engine manufacturer must specify the 

pollutants that the catalyst will be converting and submit data on only that pollutant. 

For catalysts that convert CO on an already low CO emitting engine (ie: CO levels are 

below the standards-enough such that if the catalyst is removed or deteriorates to 0% efficiency on 

conversion of CO, then the engine will still emit CO emissions below the CO standards), the 

catalyst manufacturer of the two way catalyst will not have to meet the CO conversion deterioration 

limit. 

5.34 Purpose of Catalyst Durability Cycle 

5.34.1 Summary ofthe Proposal 

While the conversion efficiency for catalysts for small engines are expected to be less than 

those for on-highway, EPA is concerned that durable catalysts are utilized on the small engines. 

The purpose of the durability cycle for catalysts is to "ensure that durable catalysts are used on 

small engines while avoiding excessive requirements that could discourage the development of 

very promising catalyst technology." 

5.34.2 	 Summary of Comments 


Three sets of comments were received on this proposal. 


EMAlOPEI stated that the requirement for durability demonstration by the catalyst 


manufacturer should not be included in the final rule because of disharmonization with eARB and 

federal regs and because EPA's cost estimates regarding the use of catalysts did not take into 

account the additional costs the industry would incur if such catalyst must first be certified for 

durability . 

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EMNOPEI stated that the issue of whether the engine or catalyst manufacturer should be 

responsible for the durability demonstration should be addressed through the Phase II Regulatory 

Negotiation. 

The comments that were submitted by the Portable Power Equipment Manufacturers 

Association (PPEMA) expressed uncertainty about whether the proposed durability testing of low 

efficiency catalysts would be sufficient to ensure emissions compliance. 

PPEMA also stated that EPA should specify that catalysts manufacturers will be 

responsible for any noncompliance with applicable emissions standards due to design or 

manufacturing defects in catalysts. 

ST APPA stated that such a requirement is merely a screening tool designed to identify 

those profoundly inadequate catalysts and that it does not necessarily constitute a thorough 

demonstration of expected catalyst efficiency durability. Nor does such a requirement provide 

information related to the in-use emissions of the overall engine-aftertreatment system. 

5.34.3 Response to the Comments 

The catalyst"durability requirement in this rule is compatible with CARR since California 

does not preclude use of catalysts demonstrated by the catalyst manufacturer on the proposed 

durability demonstration procedure. In addition. CARR requires a two year warranty on all 

emission related components and the durability procedure provides a mechanism for engine 

manufacturers to assure they are receiving components which will be in compliance. EPA desires 

also to assure that a catalysts used on a small engine will be durable for a significant portion of the 

engine's useful life and not just for the dynamometer certification test. 

EPA would consider including the cost estimates for catalyst certification if it was thought 

to be a significant cost overall to the use of catalysts. Catalyst manufacturers have recognized the 

importance of such a requirement to ensure that all catalysts used in the marketplace are of at least a 

baseline qUality. This provides a level playing field in the marketplace. The demonstration 

procedure focuses only on thermal aging thus allowing lower cost oven aging and less complexity 

over an engine aging procedure. However, no cost information has been given to EPA by engine 

and catalyst manufacturers. EPA believes the costs of catalyst certification for small engines will 

be small. 

The issue of whether the engine or catalyst manufacturer should be responsible for the 

durability demonstration will be addressed in application to Phase II standards during the Phase II 

Regulatory Negotiation. The amount of reduction expected by the Phase II small engine catalysts 

will likely be significantly more than that expected for Phase I and greater definition of what would 

constitute adequate durability will be warranted. 

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PPEMA's uncertainty regarding the adequacy of the proposed catalyst durability evaluation 

procedure for ensuring emissions compliance is based primarily on the expectation that Phase I 

catalysts will have low efficiencies. PPEMA has provided no data or engineering rationale as to 

why low efficiency catalysts would be more poorly represented on the proposed durability 

procedures than other catalysts. EPA's technical judgment is that both low and high efficiency 

catalysts that survive the proposed durability procedures and meet certification test requirements 

will perfOl1D:-; as expected for a reasonable period in-use. 

The PPEMA comment emphasizes the need for clarification of the purpose of the required 

catalyst durability evaluation. The purpose of such testing is to identify catalysts which are so 

inadequately designed and fabricated that they fail to meet the minimum standards that are 

recognized within the industry. The durability evaluation procedure is not intended to guarantee 

compliance with the applicable emission standards for the full useful life of the affected engines. 

Such compliance is dependent on a number of variables, some of which, such as the engine-out 

emissions, are not directly related to the condition of the catalyst. Such variables will be more" 

effectively evaluated by considering the overall emission control system durability. This will be at 

issue in the Phase II regulations. 

Finally, PPEMA commented that EPA should specify that catalyst manufacturers will be 

responsible for any noncompliance with applicable emissions standards due to design or 

manufacturing defects in catalysts. EPA holds the engine manufacturer responsible for the final 

engine system it tests. It is not the Agency's intent, nor its responsibility, to determine the actual 

cause of noncompliance should it occur. That responsibility remains with the engine manufacturer 

even when it chooses to use a catalytic converter as part of its emission control system. 

5.35 Worst Case Emitter 

5.35.1 Summary ofthe Proposal 

EPA proposed to use the criteria of highest weighted brake-specific fuel consumption 

(BSFC) over the appropriate engine test cycle to determine that engine configuration within an 

engine family which will be selected as the certification test engine. EPA believes that an engine 

configuration with high BSFC will generally emit higher levels of hydrocarbons and carbon 

monoxide than a second configuration in the same engine family which has a lower BSFC. EPA 

solicited comments on the appropriateness of weighted BSFC as the criteria to be used for selecting 

the worst case emitter. 

EPA considered leaving the selection of the worst case emitter up to the engine 

manufacturer with the guideline that the engine manufacturer must test that engine configuration 

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within an engine family which is most likely to exceed any emission standard. EPA solicited 

comment on the appropriateness of this approach for selection the worst case emitter. 

5.35.2 Summary of the Comments 

Onan recommended that the method for selecting the specific engine in a family that will be 

certified should be that which is used in CARB's Tier I rule. Onan questioned the ability to 

establish a relationship between BSFC and weighted exhaust emissions by the EPA. Onan stated 

that EPA should leave the selection of the worst case emitter up to the engine manufacturer. This 

would essentially be the same as the CARB Tier I rule which would promote harmonization as 

well as provide representative emission certification data. 

5.35.3 EPA'S Response to the Comments 

EPA has decided that the manufacturer should make the selection based on its technical 

judgment or evaluation of the emission performance of the vehicles remaining in the engine family. 

EPA does not expect manufacturers to conduct an extensive program to determine worst-case 

engines, nor does EPA intend to challenge manufacturers' selections unless EPA suspects that a 

manufacturer is purposefully subverting the intent of these regulations. If suspected, then the 

engine manufacturer will be requested to provide justification for the choice of worst case emitter to 

the Administrator. The Administrator will then have the opportunity to review the documents and 

require additional documentation or changes in the choice of the engine chosen. 

SEC"nON 6: SELECTIVE ENFORCEMENT AUDITING 

6. 1 Attached Equipment. During An SEA 

6.1.1 Summary ofthe Proposal 

As described in the proposal, EPA typically would select SEA engines from a point of final 

engine assembly, from a storage or shipping facility, or in the case of imported engines, at a port 

of entry. Most often, this selection point would be at the end of the engine assembly line, where no 

further quality control procedures happen and where no additional parts would be installed on the 

engines. SEA engines could not receive any additional inspections or quality control other than 

that of normal production engines and pre-test safety checks. Engines would be tested in the same 

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order as they were selected. In the NPRM. EPA requested comment on the feasibility of selecting 

equipment, then removing the engine for audit testing. 

6.1.2 Summary of Comments 

PPEMA stated that some handheld products, such as string trimmers, blowers and pumps, 

incorporate a built-in load. 1S6 For purposes of minimizing audit costs, PPEMA believes that 

manufacturers should have the option of conducting emissions testing on the equipment itself, 

using rated power and rated speed as specified in the certification application, rather than removing 

the engine and conducting dynamometer testing. 

In response to EPA's request for comments, Kohler expressed objections to the possibility 

of including equipment as part of the audit process, stating that this would be an unnecessary 

. burden on engine and equipment manufacturers. IS7 Kohler explained that it manufacturers engines 

which are sold to equipment manufacturers through a distribution system, so it does not have ready 

access to production equipment. Kohler objected to EPA's proposed program, saying that it would 

either require a customer to remove engines or to ship the equipment to Kohler to have the engine 

removed, test and reinstalled, a program which would be time consuming, costly, and without 

justification. 

6.1.3 EPA's Response to the Comments 

Because SEA testing is an enforcement tool used to verify that production engines comply 

with emissions standards and that production engines are assembled in all material respects as 

described in the manufacturers application for certification, EPA will not grant broad permission 

for manufacturers to use such alternative test methods. EPA is not prepared to permit SEA 

emission testing of equipment. Equipment may contribute to the load experienced by the engine 

which could affect emissions. In addition, this rule specifically regulates engines, not equipment. 

Manufacturers' voluntary assembly line testing programs (ALT) may utilize alternative test 

methods to provide whatever level of confidence the manufacturer so desires,and manufacturers 

have the opportunity to propose alternative test programs for phase two regulations for small SI 

engines. Manufacturers may individually propose alternative test methods and provide data to 

demonstrate that the alternative test method generates emission levels representative of the 

prescribed test procedures. 

6.2 Additional Parts Necessary For An SEA 

6.2.1 Summary ofthe Proposal 

The Agency's proposed rule states that SEA engines would typically be selected from a 

point of final engine assembly or from a storage or shipping facility. Most often, this selection 

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point would be at the end of the engine assembly line, where no further quality control procedures 

happen or parts would be installed on the engines. 

6.2.2 Summary of the Comments 

ONAN and EMA explained that many small engine manufacturers ship their engines 

without mufflers and/or air cleaners. IS8 The SEA test procedure would have to allow these and 

other OEM/customer supplied parts to be added to the engine prior to SEA testing. 

6.2.3 EPA's Response to the Comments 

EPA has experienced similar situations conducting SEAs of on-highway engine 

manufacturers. Certain manufacturers ship engines without "dress parts" to their facilities in 

distant locations. During an SEA, EPA allows time for manufacturers to make provisions to have 

the necessary parts shipped from other facilities. This liberty will be extended to manufacturers 

covered under this regulation. It may be necessary for EPA to oversee the selection of additional 

parts, depending on the part. 

6.3 Annual Limit Of SEAs 

6.3.1 Summary ofthe Proposal 

EPA proposed an annuallirnit of two SEAs for each manufacturer with projected annual 

production of less than 100,000 engines. For manufacturers with annual production of 100,000 or 

more engines the proposed annual limit would be the greater of either two or the number 

determined by dividing the number of engine families certified in that model year by five, and 

rounding to the nearest whole number. 

6.3.2 Summary of the Comments 

Onan stated that the number of SEAs allowed per year would be burdensome. 1S9 Due to 

the complexity of its product line, Onan projects it would be forced to run three or more SEAs in a 

given model year. Although Onan would prefer dividing the number of families by eight rather 

than five, it feels that limiting the number of SEAs to one or two per year is best, especially given 

the fact that the EPA could run as many SEAs as it deemed necessary if EPA decided that noncompliance was occurring. 

Onan commented that the Administrator should not have the authority to exceed the annuallirnit of 

SEAs without good cause. 

NRDC opposed EPA's proposal to set an annual limit on the number of SEAs per 

manufacturer and emphasized that in the early stages of the program, special enforcement efforts 

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will be needed to ensure compliance by small engine manufacturers that may be confronting an 

EPA air emissions regulation for the first time. 100 NRDC believes that a self-imposed limit of four 

audits annually does not further the objectives of the SEA program - to ensure that manufacturers 

take steps necessary to ensure that all engines rolling off the assembly line are built to the same 

standards as the certification engine. 

In its comments, EMA stated that EPA should revise its basis for determining the number 

of SEAs each manufacturer could receive annually. 161 EMA believes that the proposed annual 

limits would impose an undue burden on all small SI engine manufacturers and therefore 

encourages EPA to limit to no more than two the number of SEAs each manufacturer could receive 

annually in the absence of exceptional circumstances. 

6.3.3 EPA's Response to the Comments 

EPA believes that it is reasonable to assure manufacturers that they will not be 

overburdened by SEAs by providing annual limits. However, with respect to manufacturers with 

projected annual sales of over 100,000 engines and a large variety of engine families, each SEA 

can only check a small portion of the manufacturers' production. EPA believes that relating the 

annual limit to the number of engine families as proposed will allow EPA to check a reasonable 

portion of a manufacturer's production. With respect to manufacturers with projected annual sales 

of less than 100,000 engines, an annual limit of one would not allow EPA to have the flexibility to 

return to a manufacturer that had passed an SEA early in the model year and subsequently 

implemented changes in its production process that could increase engine emissions. Therefore, 

EPA believes that the proposed annual limit system is appropriate for Phase I regulations for small 

SI engines. 

6.4 Number 01 SEAs Per Day 

6.4.1 Summary a/the Proposal 

EPA proposed that engine manufacturers with projected United States annual sales of 

7,500 or greater must complete a minimum of two engine tests per day during an SEA. Engine 

manufacturers with projected United States annual sales of less than 7,500 would be required to 

complete a minimum of one engine test per day during an SEA. 

6.4.2 Summary a/the Comments 

Gnan believes that the requirement that manufacturers complete two tests per day is 

onerous.162 Gnan explained that if the engine selected for audit has a service accumulation period 

of more than a few hours and the manufacturer does the service accumulation and SEA test on the 

same dynamometer (not an unusual practice; it saves set up and removal time), then only a single 

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SEA test could be perfonned per day unless more than one test cell/dynamometer was used. 

Making two test cells available during an SEA could be a tremendous burden on manufacturers 

who may only have a few cells that are capable of measuring emissions. Onan suggested that the 

EPA waive any requirement for a minimum number of SEA tests per day and instead require that 

the manufacturer make a good faith effort to complete as many tests as possible per day. At worst, 

Onan believes, a minimum of one test per day should be required of all manufacturers. 

6.4.3 EPA IS Response to the Comments 

EPA may permit fewer tests per day if a manufacturer is making a good faith effort to 

complete testing expeditiously. Because manufacturers have indicated a preference for self auditing 

EPA expects that manufacturers will have several test cells for new engine compliance testing, 

either for voluntary testing or for ARB compliance testing. Consequently, EPA expects that test 

cells will be available for occasional SEA testing. 

6.5 Sampling Plans 

6.5.1 Summary o/the Proposal 

The total number of engines tested in an SEA would be dictated by the statistically 

acceptable pass/fail decision within the sampling plan applied, as described. EPA proposed a 

sequential sampling plan for small SI engine SEAs. These sampling plans were designed to meet a 

40 Acceptable QUality Limit (AQL) and to ensure low statistical risks of incorrect pass/fail 

determinations. The maximum theoretical percentage of failing engines for passing an SEA was 

proposed to be 40 percent AQL for the small SI engine SEA program. 

6.5.2 Summary o/the Comments 

EMA believes that EPA should allow manufacturers to submit alternative sampling 

plans.l 63 In its comments, EMA recommended that EPA make alternative sampling plans available 

for use at the manufacturer's discretion as optional methods for audit testing at any level of engine 

family production volume. EMA requested that alternative sampling plans be structured so that 

manufacturers are required to run fewer tests, but face a somewhat increased risk of false failure. 

EMA would also like EPA to allow engine manufacturers to choose whether to accept the increased 

risk -- weighed against the cost savings -- from reduced sampling. 

According to EMA's comments, the California regulations allow manufacturers to propose 

and rely on alternative sampling plans provided they demonstrate that the alternative procedure will 

provide an equivalent assurance of compliance. EMA suggests that this same approach should be 

taken by EPA in allowing manufacturers to conduct reduced sampling with increased risk. 

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6.5.3 EPA's Response to the Comments 

EPA has found that the sampling plans offered under the current on-highway program 

adequately balance manufacturer burden with both manufacturer and EPA risk. EPA has not had 

sufficient discussions with manufacturers and therefore is not prepared to offer an alternate 

sampling plan at this time. However, EPA may consider requests by manufacturers to terminate 

testing early during SEAs of low production families when the audit results are significantly and 

consistently below each applicable standard, and selection of additional engines would be difficult 

or cause a delay in shipment of customer-ordered engines, or the manufacturer's test facility does 

not have sufficient capacity to expeditiously conclude the SEA. An alternate sampling plan may be 

offered under Phase 2. 

6.6 SEA Self-Auditing 

6.6.1 Summary ofthe Proposal 

The SEA program described in the NPRM strives to encourage manufacturers to perform 

self-auditing and promptly remedy the emission noncompliance it discovers. As proposed, EPA 

would consider reducing the number of audits conducted by the Agency, minimizing audits of 

engine families which are unusually burdensome to audit, or both options, if the manufacturer 

provided substantial data to demonstrate conformity of actual production engines with the 

applicable emission standards. 

6.6.2 Summary ofthe Comments 

EMA's comments encouraged EPA to adopt a voluntary self-audit program in lieu of SEA 

testing. 164 

EMA expressed concern that nowhere in the proposed regulation itself did any language 

appear that would assure credit would be given to manufacturers for self-audits. 

Internal audit programs conducted by manufacturers should be relied on by EPA as a 

legitimate substitute for the use of SEAs, according to EMA, and not just as an alternative that may 

prompt EPA to consider reducing or minimizing a manufacturer's annual SEA limit. 

It is EMA's belief that the consequences of failure to pass an SEA audit are sufficient 

incentive for engine manufacturers to develop thorough and reliable internal audit procedures to 

ensure that engines will be designed to pass a possible SEA audit. 

Under EMA's described voluntary self-audit program, manufacturers would be required to 

submit their audit data to EPA. If EPA questioned the credibility or reliability of a manufacturer's 

audit data or procedures, EPA could focus on the particular questionable aspect of the 

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manufacturer's self-audit program and impose SEAs where the data provided were insufficient or 

evidenced an uncorrected failure. 

EMA and Onan both argued that EPA should allow manufacturers to submit the data 

generated to meet their obligations to CARB under its quality-audit test procedures as an alternative 

to SEA testing. 165 

As an option, EMA and Onan expressed interest in submitting ISO-9000 series registration 

data in lieu of SEA testing. 166 Registration under 900I, 9002 would demonstrate that a 

manufacturer has a quality system in place that would assure products are made as intended. Such 

registration is recognized worldwide as a quality indicator and should be a reliable basis for 

reducing or eliminating SEA liability. 

In addition, EMA did not support EPA's proposal to conduct spot checks of manufacturer 

self-audits as discussed in the NPRM, and if EPA were to perform such spot checks, such checks. 

must be credited to an engine manufacturer's annual SEA limit. 

PPEMA's understanding from the proposal was that EPA may reduce the number of SEAs 

to which a manufacturer may be subject based upon the manufacturer's self-audit system. 167 

PPEMA requested c:larification as to whether engine manufacturers are obligated to conduct or 

report on self-audits. 

6.6,3 EPA's Response to the Comments 

EPA has discovered cases where a manufacturer submits assembly line test data that is in 

compliance with the applicable emission standards, however an SEA on the same configuration 

shows noncompliance. Sometimes this discrepancy is caused by manufacturers who opt to 

truncate parts of the Federal Test Procedure to expedite the self-auditing process. Therefore it is 

necessary to have the SEA program in addition to self-auditing. It is not a requirement of this rule 

for manufacturers to conduct assembly line test or submit the test data, however, EPA strongly 

recommends a self-auditing program and may reduce the number of SEAs to which a manufacturer 

may be subject. 

6.7 Audit from Engine Family or Configuration? 

6.7.1 Summary ofthe Proposal 

EPA proposed that nonroad SEAs be conducted by sampling engines from within an 

engine family. 

6.7.2 Summary ofthe Comments 

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EMA stated that EPA should select only a single engine configuration from an engine 

family for audit testing. 168 

EMA and OPEl objected to EPA's plan to make an entire engine family subject to an audit 

by reserving the option to select all engine configurations within an engine family for an SEA. 169 

Instead, they believe the final rule should provide that only a single engine configuration from an 

engine family may be selected for audit testing, as is currently done for on-highway engine 

auditing. 

To facilitate testing, EMA and OPEl recommended that EPA evaluate a single engine 

configuration in each compliance test, or at most a single cylinder number and arrangement. 

6.7.3 EPA's Response to the Comments 

EPA believes that making an entire small engine family subject to an audit would lead 

manufacturers to use extra care when grouping engines in a family. 

6.8 SEAs and Manufacturer Production Schedules 

6.8.1 Summary ofthe Proposal 

To minimize the burden on manufacturers, EPA's proposal stated that the Agency would 

consider requests by manufacturers to exclude particular engines or engine configurations from a 

test sample. Justification for such requests could be to avoid a delay in shipment of urgent 

customer-ordered engines or to minimize test cell set-up time by selecting engines of similar 

physical configurations. 

6.8.2 Summary of the Comments 

Onan offered the following additional justifications for excluding particular engines or 

configurations from a test sample: no such engines or configurations in stock or committed for 

customer delivery before they are again scheduled for production. 170 Onan believes that the 

regulation should contain explicit language making it clear that a manufacturer would not be 

required to modify its production or delivery schedule in order to accommodate SEA. 

6.8.3 EPA's response to the Comments 

As with the on-highway program, EPA will do its best not to disrupt a manufacturer's 

production schedule while conducting an SEA. EPA, however, will not add specific language 

which states that a manufacturer does not have to modify its production to accommodate an SEA. 

EPA believes that it may be necessary, at certain times, for a manufacturer to alter its production to 

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accommodate an SEA. If the regulation specifically stated that a manufacturer does not have to 

alter its production, then it would be possible for a manufacturer to postpone an SEA indefinitely. 

6.9 Port Selection for Imported Engine SEA Testing 

6.9.1 Summary ofthe Proposal 

EPA proposed to include ports of entry or storage locations in the United States as 

locations for EPA selection of foreign-produced small SI engines for SEA emission testing at 

laboratories in the United States. The location of these selections could be designated by the 

manufacturer to minimize disruption and shipping costs. 

6.9.2 Summary of the Comments 

Honda objected to EPA's intention to adopt the port-of-entry as the SEA selection point for 

foreign produced small SI engines,I71 and noted that it had spoken to this issue previously with 

regard to automobiles. In that correspondence, Honda maintained that such a method would result 

in a significant increase in the cost and administrative burden on manufacturers. In its comments 

on this proposal, Honda continued to maintain this position for reasons it explained in more detail 

under the following topics: 1. Availability of Emissions Test Laboratory, 2. Cost Estimate, 3. 

List of Potential Port Problems, 4. Diagnosis and Repair, 5. Consequences of a Testing Failure. 

EMA stated that EPA should allow, but not mandate, port of entry selection of foreignproduced engines. In EMA explained that EPA's proposed port-of-entry selection for foreignproduced small SI engines for SEA emission testing at U.S. laboratories presents problems of 

considerable potential expense to engine manufacturers. Engines produced overseas may enter the 

U.S. as loose engines, crated with other engines, or already installed in equipment required to have 

certified engines. Those engines that arrive already installed in equipment must not be subject to 

removal by EPA for testing at ports of entry. If EPA wishes to test such engines, it must do so 

before they are installed in equipment. Any other method would expose engine and equipment 

manufacturers to unnecessary additional costs and delays. 

EMA also expressed concern that even testing so-called "loose engines" may create similar 

disruptions. Because engines are often crated together in amounts of 10-20 engines in a single 

shipping container, removing one engine from a multi-engine shipping container for testing would 

create substantial additional charges. EMA and OPEl recommended that EPA not mandate but 

allow engine manufacturers the option to choose port-of-entry selection of foreign-produced 

engines for testing at port facilities. 173 

6.9.3 EPA's response to the Comments 

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Port selection would result in less expensive audits for EPA, and a more even distribution 

of audits among non-domestic and domestic vehicles and engines each year. It would enable EPA 

to respond more quickly to reports of nonconformity and, since the selection and testing would 

take place in the U.S., audits would not be affected by outside interference and would not require 

the prolonged absence of EPA personnel necessary for overseas audits. EPA's quick response to 

a report of nonconformity benefits manufacturers in the long term because if an SEA failure 

occurs, the manufacturer would have introduced less engines into commerce and therefore will be 

required to recall fewer engines. As with the on-highway SEA program, EPA will consider a 

manufacturer's concerns about shipping disruptions and the removal of superfluous equipment 

before engine testing. EPA will try to minimize disruptions while upholding the integrity of the 

SEA program. In addition, manufacturers could designate selection location in order to minimize 

disruption and shipping costs. 

6.10 In-Use Testing For Phase 2 Versus Sea Auditing 

6.10.1 Summary ofthe Proposal 

In the NPRM, EPA acknowledged its responsibility to achieve enforceable reductions of 

in-use emissions and plans to develop such measures in its long-term Phase 2 program. 

6.10.2 Summary ofthe Comments 

Onan stated that "since no in-use enforcement program is being proposed for small SI 

engines, SEA provides the only opportunity for EPA to determine the compliance of production 

engines." 174 Onan wondered what this would mean if in-use enforcement is used in Phase 2. 

Would EPA support the discontinuation of the SEA requirement or would the Agency demonstrate 

why the two are not redundant, but are actually both necessary for enforcement? 

6.10.3 EPA IS Response to the Comments 

EPA believes that SEA and in-use are different and separate programs both of which are 

necessary for the most effective enforcement program. SEA is a new engine compliance program 

which helps identify and encourages manufacturers to identify and correct noncomplying and 

marginally complying engines prior to their introduction into commerce. In-use enforcement helps 

to identify noncomplying engines in-use and provides incentive to manufacturers to build more 

durable engines. EPA will further address this issue in the context of developing the Phase 2 rule. 

6.11 ,Designating Official Data 

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6.11.1 Summary ofthe Proposal 

Whenever the Administrator conducts a test on a test engine or the Administrator and 

manufacturer each conduct a test on the same test engine, the results of the Administrator's test will 

comprise the official data for that engine. 

6.11.2 Summary of the Comments 

Onan expressed confusion about the wording "designating official data," and found the 

wording of this section to be vague and ambiguous or, at the very least, confusing. 175 

6.11.3 EPA IS Response to the Comments 

This statement means that the Administrator has the option to test an SEA engine at the 

Administrator's facility. The results of the Administrator's test would comprise the official data for 

the SEA, even if the manufacturer conducted its own test on the same engines. Generally, SEAs 

are conducted at the manufacturer's facility with EPA monitoring, so this provision is rarely 

applicable. 

6.12 EPA May Specify SEA Governor Set Speeds 

6.12.1 Summary ofthe Proposal 

Small engines equipped with adjustable parameters must comply with all requirements of 

this subpart for any specification within the physically available range. 

6.12.2 Summary of the Comments 

Onan pointed out what it believed to be a section reference error. Onan also stated that the 

governor of an engine should not be considered an adjustable parameter under the defmition of 

section 90.112, and therefore, the Administrator should not be allowed to specify the governor set 

speeds during an SEA.176 

6.12.3 EPA's Response to the Comments 

The regulatory provision cited in this section should have been section 9O.112( c). If the 

governor cannot be easily adjusted by the customer then the Administrator will not consider it an 

adjustable parameter. However, if the customer can adjust the governor then the Administrator will 

consider it an adjustable parameter and can specify the set speeds during an SEA. 

6. 1 3 Duration of the SEA 

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6.13.1 Summary ofthe Proposal 

As described in the NPRM, the total number of engines tested in an SEA would be dictated 

by the statistically acceptable pass/fail decision within the sampling plan applied. A test engine's 

pass or fail determination would be made by comparing final test results to the applicable federal 

emission standard. 

6.13.2 Summary of the Comments 

PPEMA requested clarification of the potential duration of any selective enforcement 

audit. 177 

6.13.3 EPA's Response to the Comments 

It is difficult to state the duration of an SEA, since the duration of an SEA is determined by 

many factors. Some of those factors include the number of failures, test lab availability, and the 

sampling plan used. 

6.1 4 Dealers I.nvolved in SEAs/Recordkeeping 

6.14.1 Summary ofthe Proposal 

As stated in the preamble, the manufacturer of any new nonroad engine subject to any of 

the provisions of this subpart shall establish, maintain, and retain the following adequately 

organized and indexed records: (1) General records. and (2) individual records. 

6.14.2 Summary of the Comments 

NAEDA expressed concern that wording of the NPRM regulatory text indicated that dealers 

might be expected to meet as-of-yet unspecified EPA record keeping and information gathering 

requirements. 178 

6.14.3 EPA's Response to the Comments 

Under section 90.505(d) only manufacturers would be responsible for complying with the 

recordkeeping requirements. 

SECTION 7: IN-USE TESTING 

Summary ofthe Proposal 

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The Agency proposed a program to assure that manufacturers build engines that continue to 

emit below the emission standards they are certified to after such engines are introduced into 

commerce. EPA did not, however, propose an in-use emissions standqrd that engines would be 

required to meet over their useful life. Section 213( d) authorizes EPA to enforce emission 

standards in-use; however EPA proposed to decide upon a useful life period and an in-use 

enforcement program in the Phase 2 regulations. For Phase 1, EPA proposed only a program for 

requiring manufacturers to test engines in-use without a mandatory recall program to enforce such 

testing or enforce compliance with emissions standards in-use. 

Within this proposed program, a manufacturer would be encouraged to evaluate in-use 

emissions deterioration and durability for purposes of refining its Phase I technology and by 

gathering the in-use testing data better prepare themselves for an in-use program which may exist 

under the Phase 2 regulations. Specifically, the proposed program included the following: (a) A 

conditional certification concept in which the manufacturer would propose an in-use test program at 

the time of its new engine certification by EPA, with subsequent manufacturer perfonnance of the 

in-use testing and reporting fulftlling the condition on the certificate; (b) Specific criteria would be 

applied to the manu.facturer's proposed in-use test program, including what number of engines 

would need testing, criteria for selecting test engines, and required elements in collecting and 

testing in-use engines (including appropriate maintenance history, age of engine, and specifications 

for the actual testing); and (c) An annual in-use test program reporting requirement to insure 

adequate fulfillment of the above requirements. 

Summary of the Comments 

Comments on the in-use testing program were varied. Several commenters suggested that 

EPA would be foregoing its legal obligation under the Clean Air Act if it did not promulgate, at 

minimum, the program proposed. Several commenters suggested revisions to the program to 

make it less burdensome on manufacturers. The remainder of comments focused on the alleged 

inappropriateness of any in-use program during Phase I of the regulations and argued that 

conditional certificates were unjustified. 

Those commenters that supported EPA's proposed program included the Natural 

Resources Defense Council (NRDC) which argued that without any in-use compliance obligations, 

emission standards for new engines at the time of certification would not have much value in the 

real world of actual use. 179 NRDC also argued that both section 213 and section 207 of the Clean 

Air Act required an in-use program in Phase 1 and that such a program would be critical to the 

success of a more complete in-use program under Phase 2.180 NRDC and STAPPNALAPCO 

supported the concept of manufacturer self-testing, as opposed to joint testing by manufacturers or 

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manufacturers with EPA, as a necessary step towards improving emission performance and 

gaining knowledge of engine performance in a wide variety of in-use conditions. 181 NRDC also 

supported EPA's proposal to make a certificate of conformity conditional on manufacturer in-use 

testing. One commenter proposed an option whereby a collective gathering of in-use engines could 

be conducted but individual manufacturers would still be responsible for self-testing. 

Several comments received either suggested revisions to the proposed program or opposed 

the program and suggested revisions as a second option. Tecumseh proposed an alternative in-use 

program whereby the manufacturer would conduct the testing in-house but the engines and 

equipment would remain the property of the engine manufacturer and thus avoid the burden of 

collecting equipment from consumers. 182 PPEMA proposed to allow manufacturers to use test 

camps to procure equipment or to perform bench testing after accumulating engine use at an 

accelerated rate. 183 STAPPN ALAPCO suggested that two distinct types of in-use testing be 

conducted by manufacturers, an up-front accelerated service bench testing and a testing of engines 

in actual use to determine any correlation and to determine real life in-use performance. 184 

Finally, several commenters either opposed the in-use program as a first option or were not 

in favor of it at all. .Because the proposal for the Phase 2 regulations would soon follow the 

proposed effective date of Phase 1, these commenters felt that no in-use data from Phase 1 could 

be used to determine the useful life of engines for Phase 2 and therefore was not a reasonable 

justification for the collection of in-use data. 185 Additionally, some commenters suggested that 

the Phase I regulations were intended to mirror California's tier I regulations and exclude 

immediate implementation of any federal enforcement programs. In contrast to those commenters 

who argued that an in-use program was necessary to insure emission performance throughout 

useful life, commenters opposed to the program noted that, absent a stated useful life, mandatory 

in-use testing is not justified.186 EMA argues that there is no justification for conditioning 

certificates on the completion of in-use testing. 187 Several commenters were concerned that an inuse testing requirement would impose unnecessary administrative and economic burdens on 

manufacturers. 188 One commenter suggested that a voluntary cooperative program between 

industry and EPA should be developed in place of a mandatory program to develop meaningful 

data. 

EPA's Response to the Comments 

EPA has decided to allow a voluntary in-use testing program modeled on the testing 

program it proposed in the NPRM. EPA is not requiring an in-use testing program to be conducted 

by manufacturers. However, EPA anticipates that such testing and data gathering will be 

beneficial for EPA's Phase 2 program. Should a manufacturer choose to run an in-use testing 

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program, it may do so without EPA approval and set up its program as it chooses and may use the 

testing program described in the NPRM as a model. 

EP A agrees with the commenters that noted that an in-use testing program is necessary to 

insure that new engines continue to meet emission standards for new engines at time of 

certification. Assuring that manufacturers build engines that continue to meet emission standards 

beyond the certification and production stages is important. However, EPA is not establishing a 

useful life time period or an in-use standard that engines must comply with within this phase 1 

rulemaking. Because no useful life time period or in-use standard has been established, EPA 

believes, as argued by some commenters, that conditional certificates and mandatory in-use testing 

are unjustified at this time. 

EPA agrees with the one commenter that suggested that a voluntary in-use testing program 

be established. The purpose of the voluntary in-use compliance testing program allowed for by 

this rule making is not to establish a mandatory in-use recall requirement based on an engine's 

useful life and in-use standard. Instead of a mandatory in-use testing recall requirement, EPA 

hopes that any voluntary in-use testing will allow manufacturers to take appropriate steps to avoid 

or remedy in-use en:Ussion problems discovered and establish a database to utilize for phase 2 

testing. 

Should a manufacturer chose to conduct a voluntary phase 1 in-use testing program, such 

program may pennit issues associated with a variety of maintenance and use conditions, testing or 

other issues to be identified and resolved prior to any phase 2 testing which may occur. 

Therefore, EPA has decided to make manufacturer in-use testing voluntary and no annual 

reporting will be required. 

As noted in the preamble to today's final rule, EPA is suggesting that those manufacturers 

who voluntarily choose to conduct in-use testing use the model proposed by EPA within the 

NPRM as a model. Manufacturers may choose to conduct testing on accelerated-aged engines or 

make other modifications as they find appropriate and may choose to follow the suggestions made 

by STAPP AIALAPCO in its comments. EPA will be available for any suggestions or guidance. 

SECTION 8: DEFECT REPORTING AND VOLUNTARY RECALL 


8. 1 Definition of Emissions-related Defect 

8.1.1 Summary ofthe Proposal 

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The rule defines an emission-related defect as a defect in design, materials, or 

workmanship in a device. system, or assembly described in the approved Application for 

Certification. Emission-related defects are to be determined by using procedures established by the 

manufacturer to determine safety or performance-related defects. 

8.1.2 Summary o/the Comments 

The Portable Power Equipment Manufacturers Association (PPEMA) stated that the 

proposed definition of an emission-related defect was unclear and suggested a revised definition 

which limited the reporting scope to those defects which result in an emissions nonconformity. 

PPEMA requested clarification on the meaning of a performance defect. Kohler requested a listing 

of emission-related components affected by this rule. 

8.1.3 EPA's Response to the Comments 

Defect reporting regulations serve as an element of the Agency's in-use surveillance 

network. The purpose of the defect reporting regulations is to determine those defects which have 

a high probability of affecting emissions. EPA does not want to overburden the manufacturers 

with reporting on defects which are not likely to affect emissions. Therefore, the definition of an 

emissions-related defect will be expanded to include conditions which indicate a high probability of 

the defect affecting the emission performance of an engine. The Agency believes that such 

conditions are met when the defect affects any parameter or specification enumerated in Appendix 

VIII of 40 CFR Part 85. This additional language should screen out those defects which are not 

likely to affect emissions. 

The definition provided in the proposed regulation has been expanded to read as follows: 

emissions-related defect means a defect in design, materials, or workmanship in a device, system, 

or assembly described in the approved Application for Certification which affects any applicable 

parameter or specification enumerated in 40 CFR Part 85, Appendix Vill. Appendix vm may 

eventually be revised to include a section dedicated to small nonroad spark-ignition engines. 

The components described in the approved Application for Certification will serve as a 

dynamic listing of components affected by this rule. Using an emission-component listing based 

on the Application for Certification will provide the flexibility necessary to handle yearly changes 

in components that are due to technology advances for example. It is for these reasons that the 

Agency does not compile a generic yet static listing of emission components affected by this rule. 

While the manufacturers retain the determining function of emissions-related defects, EPA 

must be given an opportunity to assess the emissions impact of these defects. As a result, 

PPEMA's proposal for submitting defect reports based solely on the manufacturers' determination 

of an emission exceedence cannot be accepted. 

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The Agency is further attempting to minimize the burden placed on manufacturers by 

having manufacturers use existing methods and procedures for determining defects. Two 

examples of existing methods currently in place are those for tracking safety and performance 

defects. In the Agency's view a performance defect would be a defect which adversely affects 

engine performance to a level discernible to the owner, and as such would result in an owner 

complaint or service request. Other comments received from the industry suggest that other types 

of customer feedback as well as engineering performance tests may also be valuable sources of 

information that can be used to determine the presence of defective components. 

8.2 The 25 Engine Trigger 

8.2.1 Summary oj Proposal 

Manufacturers are required to submit a defect report when an emissions-related defect is 

confIrmed to exist in 25 or more engines of a given engine family manufactured in the same 

certificate or model "year. 

8.2.2 Summary oj Comments 

Many manufacturers commented that the trigger of 25 engines is too low for requiring a 

defect report. Manufacturers were concerned that the engines affected by the defect could often 

represent a percentage of the whole engine family that was too small to demonstrate the existence 

of a true defect within the family. Manufacturers have suggested that the minimum trigger be 

raised to at least 75 engines, or the greater of 25 engines or two percent of the engine family's 

production. In addition, some manufacturers have requested the searching scope be reduced from 

engine families to engine models. 

8.2.3 EPA Response to Comments 

From experience with the on-highway program, most defects involve signifIcantly more 

than the 25 engines required to trigger a defect. If a defect is confIrmed in 25 engines, a signifIcant 

portion of the engine families involved are probably affected as well, except in the case of 

misbuilds which often affect only a small portion of production. 

It is expected that an emissions-related defect would cut across engine models. By 

definition, engines categorized and certified as engine families have similar emission performance 

and durability characteristics. The same emission components will most likely be used within the 

various models that comprise an engine family. Furthermore, in certifying an engine family, the . 

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manufacturer assumes responsibility for integrity of the family's emission components as well as 

its emission performance. 

The reporting scope of the current on-highway defect reporting regulations are broader than 

this rule in that a defect report is required when 25 engines (or vehicles) for a given model year, 

not engine family, are affected. Based on the Information Collection Request (lCR) document 

which supports this regulation and uses the broader on-highway scope, it is estimated that each 

manufacturer of nonroad engines, 19 kW and below, will file two defect reports per calendar year. 

The Agency does not believe such a reporting rate is excessively burdensome to the manufacturers. 

However, the Agency is willing to revisit the number 25 in the future, if warranted by information 

developed during practical application. 

8.3 Appropriateness of Voluntary Recalls 

8.3.1 Summary ofthe Proposal 

The proposed rule requires that manufacturers submit a voluntary emission recall report to 

the Agency when a manufacturer initiates a campaign to remedy an emissions-related defect. This 

proposed defect reporting rule defines a voluntary emission recall as a repair, adjustment, or 

modification program voluntarily initiated and conducted by a manufacturer to remedy any 

emission-related defect for which notification of engine owners has been provided. The preamble 

refers to this portion of the rule by stating that EPA is proposing that individual manufacturers 

establish, when appropriate, voluntary emission recall programs. 

The preamble requested comments on how such a voluntary program might be effectively 

structured. 

8.3.2 Summary of Comments 

Some manufacturers stated that no recall program, even voluntary, should be included in 

the phase 1 rule, while others commented that a voluntary program is acceptable as long as it does 

not serve as the basis for a mandatory program in the phase 2 requirements. The Agency was 

requested to clarify when a voluntary recall program is considered appropriate. 

8.3.3 EPA Response to Comments 

This rule does not require manufacturers to conduct voluntary emission recalls but only 

specifies the reporting requirements when a manufacijJ.rer chooses to do so. 

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The intent of the voluntary emission recall reporting (VERR) requirements is to have 

manufacturers send EPA specific information on repair campaigns conducted voluntarily by 

manufacturers to remedy emissions related defects. Specifically, when a manufacturer determines 

that a defect exists, decides that the defect needs to be remedied, and chooses to contact the owners 

of the affected engines to notify them of the need for the remedy, then and only then are 

manufacturers required to submit a VERR under this rule. However, it is the practice of onhighway manufacturers to send the Agency a VERR when a manufacturer decides for any reason 

to conduct a voluntary emission recall program. 

The Agency recognizes that under this rule the manufacturers may have the option of 

choosing other remedial methods in lieu of recall campaigns and it is recognized that these methods 

may also be acceptable in the case of voluntary recalls conducted to remedy emission-related 

defects. 

The notice of final rulemaking provides that when a manufacturer chooses to notify engine 

owners of a manufacturer initiated campaign to remedy an emissions-related defect, that 

manufacturer must submit a Voluntary Emissions Recall Report. 

8.4 Description of Method for Notifying Owners 

8.4.1 Summary ofthe Proposal 

Manufacturers, when conducting a voluntary emissions recall as defined by the defect 

reporting requirements, must provide a description of the method by which the manufacturers will 

notify engine owners. 

8.4.2 Summary of Comments 

Manufacturers commented that this requirement should be eliminated because, unlike the 

on-highway industry, the small spark-ignition segment of the nonroad industry does not have an 

owner registration infrastructure. Furthermore, registration as a condition of warranty is not 

permitted under Magnuson-Moss Act. 

As a result, the manufacturers contend that it is extremely difficult to locate the end users of their 

products. 

8.4.3 EPA's Response to Comments 

This rule does not specify the method a manufacturer must use to notify owners, only that 

the manufacturer provide a description of the notification method chosen by the manufacturer. The 

Agency recognizes that, in general, manufacturers affected by this rule do not presently have in 

place an extensive owner registration infrastructure. 

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However, the Agency trusts that the manufacturers can devise creative, viable alternatives 

to the owner registration process for notifying owners affected by manufacturer initiated recalls 

designed to remedy emission-related defects. As examples, the manufacturers could use their 

dealer networks as a resource in locating owners or manufacturers could advertise through the 

mass media as is currently done with safety related recalls. 

While the Agency understands that owner regi~tration a~ a condition of warranty is not 

permitted under the Magnuson-Moss Act. manufacturers could provide incentives for owners to 

register their engines with the manufacturers. Streamlin1ng the current regislratiun processtG be 

less burdensome to the engine owner may improve the percentage of 0'WDel:s \lIbo return their 

registration cards. 

Finally, manufacturers, as mentioned earlier. may have the option of choosing other· 

remedial methods in lieu of voJuntary recaH carnpaigns COOOlict.ed to renllXly emi$;$lon-rdakd 

defects. Obviously, there would be no need for owner notification in these situations. 

8.5 The Five. Year Reporting Period 

8.5.1 Summary ofthe Proposal 

The proposal states that manufacturers are required to report emission-related defects 

affecting a class or category of engines for five years from the end of the calendar year in which the 

engines were manufactured. 

8.5.2 Summary of Comments 

General concern was expressed that the five year reporting requirement was too long and 

should be reduced to no longer than the two year warranty period. 

8.5.3 EPA's Response to Comments 

The Agency understands that after the required two year warranty period expires, 

manufacturers will no longer be able to rely on warranty claim data as a method for detecting 

emission related defects. However, the Agency believes there are viable alternatives for detecting 

defects after the warranty period does expire, such as tracking data on part returns for safety andlor 

performance concerns. While these alternatives may not yield the volume or quality of data 

compared to warranty claims, the data should be sufficient in detecting egregious defects occurring 

outside of the engine's warranted life. 

Furthermore comments received from the Engine Manufacturers Association and the 

Outdoor Power Equipment Association indicated that component, field, engineering performance 

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and emission testing programs conducted by manufacturers. could provide valuable information 

for detecting emission-related defects outside the emission warranty period. 

8.6 Extension of 15 Day Reporting Deadline 

8.6.1 Summary ofProposal 

Manufacturers are required to submit defect reports to the Agency not more than 15 

working days after a confirmed emissions-related defect is found to affect 25 or more engines of a 

given engine family manufactured in the same certificate or model year. 

8.6.2 Summary of the Comments 

Manufacturers have requested the submittal period be extended from 15 days. to 20 or 30 

days, to allow the manufacturers to properly confirm and process defect information. and prepare 

and transmit the reports. 

8.6.3 EPA. Response to the Comments 

The period for submitting a defect report starts once the manufacturer has confmned that a 

defect exists. Therefore. the activities performed during this period should be limited to 

transforming existing information into the form required by this regulation and mailing out the 

report. 

The activities to be performed by the non-road manufacturers during this proposed 15 day 

submittal period should not differ significantly from those undertaken by the on-highway 

manufacturers. The on-highway manufacturers have not expressed concern with this reporting 

period over the nearly 20 years that they have been subject to defect reporting requirements. The 

Agency has not been made aware of any requirements unique to this industry which warrant an 

extension of the submittal period. As such. the submittal period will not be extended beyond the 

15 day proposal. 

8.7 Usefulness of Warranty Data 

8.7.1 Summary ofthe Proposal 

Manufacturers are required to submit a defect report when an emissions-related defect is 

confmned to exist in 25 or more engines of a given engine family manufactured in the same 

certificate or model year. 

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8.7.2 Summary of Comments 

The Engine Manufacturers Association (EMA) and the Outdoor Power Equipment 

Association (OPEl) stated that defect reporting regulations are not necessary because, even in the 

absence of these requirements, manufacturers are motivated to search for defects. Customer 

satisfaction requirements as well as the requirements of other Agency programs provide this 

motivation. 

It was stated by EMA and OPEl that manufacturers will be able to determine defects, in the 

absence of defect reporting regulations, based on customer feedback, component testing, field test 

programs, EPA Selective Enforcement Audits, engineering performance and emission tests as well 

as a number of other information sources. Furthermore, EMA and OPEl state that these sources 

will be much more likely to detect true defects than warranty data alone, that warranty data is 

inaccurate, and that the process of screening the data to be more reliable is burdensome and not 

cost effective. EMA and OPEl doubt EPA can provide guidelines to help ease this screening 

burden. 

Defects caught by the manufacturers will be repaired as early in the life of the engine as 

possible, long befor:.e any emission recall would be instituted. 

Finally, the EMA and OPEl contend that many emission-related defects which cause an 

increase in emissions are not perceivable to the owner, and therefore will not be caught by 

warranty. 

8.7.3 EPA's Response to the Comments 

As stated previously, the manufacturers retain the defect determining function, not EPA. 

The Agency is not requiring that warranty data be used as the sole means for identifying defects, 

and encourages methods which have served the manufacturers well in the past. This is the reason 

why the rule provides for manufacturers to determine defects by using procedures previously 

developed for safety and performance related-defects. 

The Agency encourages the use of as many methods as possible for determining the 

existence of emission-related defects. The Agency only requires that when a manufacturer 

confirms the existence of an emission-related defect through one of these procedures, that the 

manufacturer provide the Agency with a defect report. Based on the comments received, the defect 

report should merely be a compilation and formatting of information generated through normal 

business practices. 

Manufacturers are encouraged to use warranty data to the extent possible; EPA believes 

there are other valuable uses for the data besides filing defect reports. The Agency would expect 

that manufacturers currently perform some sort of screening of warranty claims, once they reach a 

certain level, to verify the validity of the claims, determine the cause of the problem, and feed this 

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information into the product development cycle. Additionally, screening warranty data can be 

made less burdensome by using sampling plans for determining the existence of defects. Sampling 

plans minimize the scope of the warranty data that needs to be screened. 

The Agency advocates the detection and repair of emission-related defects as early as 

possible in the engine life-cycle. Furthermore, the agency wishes to promote manufacturer initiated 

remedial campaigns. For this reason, the Agency concentrates its attention on those emissionrelated defects for which a manufacturer remedy has not been initiated. The Agency only requires 

that when the manufacturer, in accordance with this rule's definition of an emission-related defect, 

determines that a defect exists and chooses to remedy the problem through direct owner 

notification, that the Agency receive a defect report and voluntary emission recall report. 

The Agency recognizes that some emission related-defects are not discernible to the owner 

and therefore are less likely to be detected through warranty claim data. In these instances, the 

previously mentioned component, field, engineering performance and emission testing programs 

conducted by manufacturers, will provide valuable information for such detecting defects. 

8.8 Dealer Concerns 

8.8.1 Summary ofthe Proposal 

The rule requires that, at a minimum, manufacturers determine the existence of emissionrelated defects using procedures established by the manufacturer to determine either safety or 

performance-related defects. 

8.8.2 Summary of Comments 

The North American Equipment Dealers Association (NAEDA) stated that dealers are well 

positioned to identify defects in equipment in the field, but are concerned that the defect reporting 

regulations could be interpreted to transfer liability to the dealers if they do not report such defects. 

Dealers need instructions on how to release defective equipment for which owners refuse to pay 

for repairs. NAEDA also stated that if dealers are to be used for tracking and reporting defects, 

recall and tracking systems must be in place before the regulations take effect. 

8.8.3 EPA Response to the Comments 

The uSe of dealers in determining and remedying defects would be a business agreement 

between the manufacturers and the dealers, as would the development of any tracking, reporting, 

or repair systems. The Agency would generally support such an alliance and may provide advice if 

requested. 

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However, the manufacturer, as the holder of the certificate of confonnity, is solely liable 

under the defect reporting regulations for detennining and remedying any emission-related defects. 

During the first two years of the defect reporting period, any emission-related defect would 

also be covered by the two-year emission warranty requirements. Therefore, any repairs to 

remedy an emission-related defect would be performed free of charge to the owner. Owners 

would be unlikely to refuse such repairs. 

Since engines will be outside of the emission warranty for the final three years of the defect 

reporting period, owners will be required to pay for any repairs performed to correct emissionrelated defects. Owners do have the right to refuse repairs, and if then choose to do so, the dealer 

will not be held liable for releasing the product without the repairs being performed. 

When a manufacturer decides to remedy an emissions-related defect through a voluntary 

recall program, the Agency will assure, through the voluntary emission recall report, that the 

remedy corrects the defect and any emission nonconfonnity it causes, that the remedy does not 

result in engine performance problems, and that the remedy is easily performed by technicians in 

the field. Requiring such conditions helps to avoid service-related returns and develops long term 

consumer confidence that corrective repairs, in general, do not adversely affect engine 

performance. This in tum should reduce the percentage of engine owners who are motivated to 

refuse such repairs. 

8.9 Emission Defect Warranty Requirements 

8.9.1 Summary ofthe Proposal 

The NPRM proposed that the emission defect warranty would be provided by engine 

manufacturers for the first two years of engine use. EPA proposed to adopt the two year warranty 

period from California's lawn and garden regulations to reduce the burden of manufacturers having 

to administer two different warran,ty programs. EPA solicited comments on the option for basing 

the warranty period on hours of engine use instead of years. Employing such an option would 

require testing to detennine the equivalency of hours to years and would require the installation of a 

metering device to track the hours of engine use. 

8.9.2 Summary of the Comments 

Comments were received from EMA, OPEl, Kubota, Kohler, and ECHO suggesting that 

the warranty period begin from the date of first sale to the ultimate purchaser, rather than from the 

date the engine is first put into use. EPA understands that the date of first purchase by an ultimate 

consumer is not necessarily synonymous with the date the engine is first put to use. Hence, it was 

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EPA's intention that the warranty period would begin on the date of first sale to the ultimate 

purchaser, not from the date the engine is first put into use, and extend for two years from the date 

of such purchase. 

Comments were also received from EMA and OPEl in favor of basing the warranty on 

hours of use for equipment where it would be most practical. EMA and OPEl submitted data on 

two surveys conducted to determine the annual average hours of operation of walk behind and ride 

mowers, and their average lifespan. The results of the OPEl study conducted in 1990 show that 

walk behind mowers were operated on an average of 22.4 hours per year with an average product 

lifespan of six years. In addition, ride mowers were operated on an average of 39.8 hours per year 

with art average product lifespan of seven years. The results of the second survey, conducted in 

1993 by another industry group, show that walk behind mowers were operated on an average of 

20 hours per year with an average product lifespan of five years. Ride mowers were operated on 

an average of 34.5 hours per year with an average product lifespan of six years. 

EPA feels that these studies alone do not provide enough data to determine the equivalency 

between years from purchase and hours of use. In addition, it does not appear that the hours of 

operation for comm~rcial use equipment were taken into consideration when determining these 

numbers. Since, at this time, there is no readily available method for distinguishing residential use 

equipment from commercial use equipment, EPA's decision for Phase 1 of these regulations is to 

base the warranty period on years from date of purchase by the ultimate consumer, and not on 

hours of use. This matter will be researched further in Phase 2. 

PPEMA feels that a two year warranty period is too long for commercial equipment and 

recommended a six month warranty period. As mentioned above, the two year warranty period 

was adopted from California's lawn and garden regulations. CARB had determined the average 

product lifespan of residential and commercial utility equipment and, from that data, determined 

that two years is an appropriate warranty period for both types of equipment since two years is 

well below the average lifespan of most utility equipment. Once again, since there is no readily 

available method for distinguishing residential use equipment from commercial use equipment, 

EPA's final decision for Phase 1 is to employ only one warranty period for both types of 

equipment. 

Other comments received from PPEMA and ECHO suggest that the owner of a small SI 

engine, subject to these regulations, be required to show proof of purchase when making a 

warranty claim, that warranty claims arising from use of non-OEM replacement parts or equipment 

abuse should be excluded, and that engine manufacturers should be able to indicate acceptable 

replacement parts. PPEMA, Kubota, Kohler, and ECHO commented that warranty repairs should 

be performed by authorized dealers only. Finally, PPEMA requested that EPA te publish a list of 

parts subject to warranty in the final rule. 

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8.9.3 EPA's Response to the Comments 

All of the issues raised by the commenters are addressed in EPA's existing warranty policy 

for on-highway vehicles and apply to small nonroad engines accordingly as discussed below. 

EPA understands that, given the distribution system of small nonroad equipment, it is 

difficult to track the purchase dates of such equipment. However, EPA does not agree that, under 

every circumstance, owners should be required to show proof of purchase when making a 

warranty claim. As a means of resolving this issue, we encourage manufacturers to stress the 

importance of filling out and submitting warranty/registration cards that are provided at the time of 

purchase. If, when making a warranty claim, the owner does not have proof of purchase, and a 

warranty/registration card was not submitted by the owner, the manufacturer should use the 

equipment manufacture date to reasonably determine if the engine could still be within the warranty 

period. 

The manufacturer may not require the use of any specific brand of parts in the maintenapce 

of a nonroad engine. However, if the owner of a nonroad engine uses replacement parts that are 

not of equal quality to the original parts, and the replacement part causes another emission control 

or emission related part to fail, the manufacturer would have a reasonable basis for denying 

emission warranty coverage. In addition, a manufacturer may deny warranty coverage if there is 

evidence that the failure resulted from engine abuse, tampering or improper maintenance. 

Warranty coverage may not be denied on the pasis that add-on parts have been used, unless the 

add-on parts caused the failure. 

When seeking repairs under the emissions warranty, owners of a nonroad engine must take 

the engine to an authorized dealer. If the owner has a valid warranty claim, he or she may not be 

charged for any costs associated with the repair or replacement of the parts, including diagnosis of 

the problem, labor charges, parts and miscellaneous items that are necessary to perform the repair. 

If the owner is denied warranty coverage by an authorized dealer, but still believes he or 

she has a valid warranty claim, he or she may take the engine to an independent facility to have the 

repairs performed. In turn, the owner may seek reimbursement from the manufacturer if he or she 

did in fact have a valid warranty claim. 

Consistent with emission control and emission related parts on EPA's July 15, 1991, parts 

list for motor vehicle warranty coverage, and CARB's warranty parts list for utility and lawn and 

garden equipment, EPA provides the following parts list for design and defect warranty coverage: 

(1) Fuel Metering System 

(i) Carburetor and internal parts (or fuel injection system). 

(ii) Air/fuel ratio feedback and control system. 

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(iii) Cold start enrichment system. 

(2) Air Induction System 

(i) Controlled hot air intake system. 


Oi) Intake manifold. 


(3) Ignition System 

(i) Spark Plugs. 

(ii) Magneto or electronic ignition system. 

(iii) Spark advance/retard system. 

(4) Exhaust Gas Recirculation (EGR) System 

(i) EGR valve body and carburetor spacer if applicable. 

(ii) EGR rate feedback and control system. 

(5) Air Injection System 

(i) Air pump or pulse valve .. 

(ii) Valves affecting distribution of flow. 

(iii) Distribution manifold. 

(6) Catalyst of Thermal Reactor System 

(i) Catalytic converter. 

(ii) Thermal reactor. 

(iii) Exhaust manifold. 

(7) Particulate controls 

(i) Traps, filters, precipitators, and any other device used to capture particulate emissions. 

(8) Miscellaneous items used in the above systems 

(i) Vacuum, temperature, and time sensitive valves and switches. 

(ii) Electronic controls. 

(iii) Hoses, belts, connectors, and assemblies. 

Each manufacturer shall provide a copy of the above parts list to the ultimate consumer, using 

those portions of the list applicable to the engine. 

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8.10 Independent Commercial Importer (ICI) Program 

8.10.1 Summary ofthe Proposal 

The Agency proposed options of having an ICI program paralleling that of the on-highway 

program, and having no ICI program in the final rule. 

8.10.2 Summary of the Comments 

The Agency received comments from three parties: PPEMA, ECHO and CARB. All 

commenters supported EPA's second option of not including an ICI program in the final rule, and 

no comments were received suggesting that an ICI program be promulgated. 

8.10.3 EPA's Response to the Comments 

EPA is therefore not promulgating an ICI program in the final rule. 

8.11 Tampering 

8.11.1 Summary ofthe Proposal 

EPA believes that an engine is more likely to continue to meet the applicable emissions 

standards in use if the engine maintains its certified configuration. Therefore, the NPRM proposed 

anti-tampering provisions which would make. it illegal for any person to tamper with any emission 

control or emission related component, or system, installed on or in a small 81 engine subject to 

these regulations. 

8.11.2 Summary of the Comments 

Comments were received from EMA and OPEl which suggested that EPA adopt CARB's . 

approach with regard to making adjustable engine parameters tamper resistant. 

8.11.3 EPA's Response to the Comments 

EPA agrees that emission control components, emission related components, and 

adjustable engine parameters should be made tamper resistant to the extent possible. This will help 

ensure that engines meet the applicable emissions standards in use. 

SECTION 9: ECONOMIC EFFECTS 


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Summary ofthe Proposal 

The proposal estimated that, on average. the cost to engine manufacturers to install the 

necessary emission control technology would be approximately $0.80 to $1.13 per engine for 

nonhandheld equipment and approximately $2.05 to $2.20 per engine for handheld equipment, 

assuming catalysts were not required. Should catalysts actually be used on some portion of 

production. EPA estimated that the additional variable hardware costs would be $1.09 per 

nonhandheld engine and $0.10 per handheld engine, with an additional $0.24 per engine for 

equipment modifications and $0.20 per engine for potential heat shielding. These additional costs 

are averaged across the entire production of either handheld or nonhandheld engines, including 

those not needing catalysts. 

The increase in retail price was estimated to be $2.35 for nonhandheld equipment and 

$4.04 for handheld equipment. assuming no use of catalysts. When fuel reductions and lowered 

maintenance costs were considered, the lifetime consumer cost impact was estimated to be even 

less, with nonhandheld equipment actually realizing a net lifetime savings for the consumer. 

Summary of the Comments 

Comments were received from engine and equipment manufacturers, dealers, and their 

organizations, as well as one City government. Manufacturers and their organizations generally 

felt that the estimates were too low or that some costs had been overlooked. In general, however, 

these commenters did not supply their own estimates for the questioned values. Chicago 

commented on the impact of the costs rather than the costs themselves, indicating that the costs 

could unduly burden local government entities that must purchase large quantities of equipment for 

city maintenance. 189 

Specifically, PPEMA commented that the $4.04 consumer cost increase for handheld 

equipment was extremely optimistic, and ignored redesign and production realities. They also 

commented that CARB's projection was higher. 190 OPEl also commented that retooling costs and 

supplemental label costs were not considered. 191 Onan agreed that some costs were overlooked. 

commenting that, "The EPA must also consider the development costs (both labor and 

infrastructure), the costs of retooling, changing software, changing product literature, testing, and 

reporting as required by the regulations." 192 EMA also felt that the projected costs were too low, 

as did NAEDA, Tecumseh, and ECHO.193,194,195,196 Tecumseh and Onan felt that the catalyst 

costs were especially off the mark. NAEDA argued that the cost estimates should include changes 

to lifestyle prompted by equipment changes. Like Chicago, they commented that the cost impact of 

the regulations on governmental agencies that must purchase and use large quantities of lawn, 

garden and utility equipment should be considered. 

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EPA's Response to the Comments 

The cost estimates, which are provided below and in more detail in the RSD, have been 

slightly revised since publication of the proposal. Revisions were made to include supplemental 

label costs, which were indeed overlooked, and to reflect changes in the final rule that affect 

average costs, such as the added flexibility in the implementation date and the loosening of 

standards applicable to two-stroke lawnmowers and two-stroke snowthrowers. In general, 

however, the Agency has retained its cost estimates, largely because they were based on industry 

submittals of the net cost increases industry expected to incur due to this regulation, for which 

commenters did not provide alternative estimates in their later comments on the proposal. 

Commenters are mistaken that certain costs, such as those for retooling, were not included 

in the estimates. In fact, as detailed in the RSD, the Agency has considered all of the costs 

mentioned by commenters, except for supplemental label costs, which have now been added, and 

changes in product literature and software. The EPA sees no reason that product literature and 

software would incur net increases in cost, as these are regularly updated. Additionally, these 

categories were not included in the confidential cost submissions from manufacturers used in 

developing EPA's estimates, and EPA is not in a better position than the manufacturers to estimate 

them or claim that they would be net increases. For other costs, commenters stated that EPA's 

estimates were too low but, unfortunately, did not provide revised estimates. Since EPA's values 

in the proposal were based on cost estimates submitted by the industry itself prior to the proposal, 

and since no revised estimates were later provided, the EPA is not in a position to revise its 

estimates. Please refer to the RIA for a detailed listing of all costs considered in analysis of the 

emission standard levels. 

The Agency does not agree with NAEDA that this rule would cause negative consequences 

to lifestyle that should be assigned a cost value. The Agency does not expect product utility to be 

decreased by this regulation, nor are consumers required to make any changes whatsoever to their 

current equipment, to replace equipment, or to reduce their use of these products. In fact, there 

should be some lifestyle improvements for the equipment user, as fuel use and equipment 

maintenance needs are expected to improve as a result of the technology changes prompted by this . 

rule. The public as a whole is also expected to enjoy lifestyle improvements rather than detriments 

due to air quality improvements. The only lifestyle impact the Agency can envision NAEDA as 

referring to is the change from two-stroke to four-stroke engines in some types of equipment. 

While some would view this as an overall negative, others would view it as positive, even 

regardless of the air quality improvements of such a change, so that the net result on lifestyle is 

unclear; in any case, the Agency has no information with which to place a dollar value on the 

effects of such a change. 

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The Agency is sympathetic to comments from Chicago and NAEDA that the impacts of 

such changes on governmental entities should be considered. In fact, the Agency considered the 

monetary effects on all users when setting standards and developing the provisions of the rule. It 

was clearly necessary, given the mandates of the CAA and the results of the Nonroad Study, to 

regulate the emissions from these engines. The Agency has done so in this Phase 1 rule very costeffectively. In fact, the cost -effectiveness of this rule is significantly better than that of many other 

mobile source programs, such as additional requirements on automobiles, which are also 

purchased by governmental entities. The Agency continues to believe that the requirements of this 

rule are very cost-effective, with the gains to the public worth the very small marginal cost to 

governmental units and other consumers of small engines. Finally, as described below, the fuel 

use and equipment maintenance improvements engendered by this rule should be of significant 

benefit to governmental entities using large quantities of such equipment. 

The total national average annual.cost of this rule is estimated to be approximately $70 

million. If catalysts become necessary, the average annual cost is estimated to be approximately 

$87 million. The net present value of pollution control capital costs is estimated by EPA to be 

approximately $28 million. Energy impacts are expected to be positive, freeing up approximately 

$8 million for other uses in the economy. 

The following summary presents aggregate costs broken down by engines used in 

nonhandheld and those used in handheld equipment. For greater detail of expected cost impacts, 

see the RSD. 

Industry will bear pollution control costs that are moderate: roughly six percent for 

handheld and two percent for nonhandheld equipment relative to current production costs. The 

level of pollution control costs is largely due to the high levels of pollution emitted by these 

engines, especially two-stroke engines, and the relatively outdated state of the technology 

compared to on-highway engines. However, the costs are still small in absolute terms, and it is 

anticipated that these costs will be passed through to consumers in higher product prices. 

The Agency estimates that there will be no long run negative impacts on employment as a 

result of this rule, as costs can be recovered through increased prices. Any potential decreases in 

employment that might occur due to obsolescence of product line should be offset by increased 

production of engines meeting emission standards. Total demand for these products has 

traditionally been relatively inelastic and, thus, industry sales volume is not expected to decrease. 

On average, the cost to the engine manufacturer to install the necessary emission control 

technology will be approximately $2 per engine used in nonhandheld equipment and $3.50 per 

engine used in handheld equipment. This includes variable hardware and production costs, 

assuming that catalytic converters will not be needed to comply with proposed standards. 

However, engine manufacturers may voluntarily decide to use catalysts on a percentage of engines 

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at risk of only marginally complying. Should this occur, EPA estimates that the additional variable 

hardware costs will be about $4 per catalyst-equipped engine used in nonhandheld equipment and 

$3 per catalyst-equipped engine used in handheld equipment. Since catalysts are not expected to be 

used much, the overall sales-weighted average increase due to catalyst usage is estimated to be 

about $1 for engines used in nonhandheld equipment and marginal for engines used in handheld 

equipment. It should be noted that the costs between manufacturers will likely vary. 

Consumers will find small increases in retail prices for most equipment powered by these 

engines. The initial purchase price to the consumer will, however, be partially or, in some cases, 

completely offset by savings in fuel and maintenance costs. Thus, over time, environmentally 

friendly equipment will become less costly to consumers. 

The retail price of equipment that uses nonhandheld engines ranges from $90 to $9,000, 

and the retail price of equipment that uses handheld engines ranges from $60 to $ I ,000. The salesweighted average increase in retail cost to the consumer due to the rule in 2003 is estimated to be 

about $5 for nonhandheld equipment and $7 for handheld equipment. If catalysts are necessary, 

the values in 2003 are about $7 for both nonhandheld and handheld equipment. The retail price 

effects for a specific engine will likely be more or less these values, depending on the technology 

of the engine; these are average, sales-weighted costs, not indicative of the price increase specific 

to any particular manufacturer's engine or equipment. 

This rule is expected to decrease fuel consumption significantly. The average salesweighted engine is expected to experience a 26 percent decrease in fuel consumption for 

nonhandheld equipment and a 13 percent decrease in fuel consumption for handheld equipment. 

These decreases are translated into small discounted lifetime sales-weighted fuel savings of 

approximately $3 for nonhandheld equipment and marginal for handheld equipment. 

EPA expects that the engines produced to meet the proposed emission standards will be of 

higher quality than current engines: the parts and raw materials will be more durable and less likely 

to malfunction, as discussed in the RSD. This will result in equipment that is operational a higher 

percentage of the time and that lasts longer, although EPA is unable to quantify the attendant 

decrease in consumer cost or increase in useful life at this time. EPA requested comments on the 

potential decrease in maintenance costs and increase in useful life, but none were received that shed 

light on this topic. 

Considering that the fuel savings offset the average increase in retail price per engine, the 

average sales-weighted lifetime increase in cost will be about $6.50 per handheld engine, while 

nonhandheld engines will realize a lifetime savings of about $2.50 per engine. This does not 

include the lifetime savings in maintenance costs, which will further benefit the consumer. 

Based upon the costs and benefits described above, EPA has prepared a cost-effectiveness 

analysis and has performed a Regulatory Impact Analysis (RIA) for this proposal, which is 

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contained in the RSD. Presented here is a summary of the cost-effectiveness of the small SI engine 

Phase 1 program, assuming catalysts are not used. In addition, these cost-effectiveness numbers 

are based on the assumption that manufacturers of engines used in snowthrowers and ice augers 

will opt to certify such engines to meet the applicable HC standards. To the extent that this does 

not occur, estimated cost impacts to both industry and conumers would be slightly reduced, and 

the cost-effectiveness of the program as a whole would not be significantly changed, if at all. 

If all program costs are allocated to HC, this rule has a cost-effectiveness of $266 per ton 

of HC reduced. Alternatively, if all program costs are allocated to CO, the cost-effectiveness is 

$107 per ton of CO reduced. If the costs of the program are equally split between HC and CO, the 

cost-effectiveness is $133 per ton of HC reduced and $54 per ton of CO reduced. These cost­

. effectiveness numbers are significantly lower than costs per ton of other available control 

strategies. The cost-effectiveness estimates, underlying quantitative methodology, and 

comparisons to other available control strategies are explained further in the RSD. 

In summary, the cost-effectiveness of the rule is favorable relative to the cost-effectiveness 

of several other control measures required under the Clean Air Act. To the extent that costeffective nationwid~ controls are applied to small SI engines, the need to apply more expensive 

additional controls to other mobile and stationary sources of air pollution may be reduced in the 

future. 

SECTION 10: ADMINISTRATIVE REQUIREMENTS 

1 O. 1 Small Entities 

10.1.1 Summary ofthe Proposal 

In its proposal, EPA determined that this rule will have an impact on small entities and, 

therefore, tailored this rule to minimize cost burdens on smaller engine manufacturers by 

minimizing their certification, SEA, and in-use testing requirements. 197 The Agency also 

dramatically limited the requirements on equipment manufacturers utilizing small SI engines by 

making the use of non-certified engines a prohibited act (with its attendant penalties) rather than 

requiring equipment manufacturers to report to EPA that they are using certified engines. 

The Agency considered, but rejected, the notion of exempting small manufacturers from 

enforcement programs or from the regulation entirely. It determined that a more proportionate 

sharing of cost burden is more appropriate. The pollution emitted by each of these engines not 

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only contributes to ambient air quality problems, but also has health impacts on the user of the 

equipment who is in close proximity to the exhaust emissions. (See the Regulatory Support 

Document for a discussion of the health impacts of the related exhaust pollutants.) 

10.1.2 Summary ofthe Comments 

Certain manufacturers of equipment incorporating small engines of the types regulated in 

this action described themselves in their comments as "captives" of the small engine manufacturers, 

since the equipment manufacturers buy engines from the small engine manufacturers to build their 

equipment. These commenters argued that, as captives of the regulated industry and as small 

businesses, the options analysis should be extended to cover their needs, including consideration 

for exemption from the rule. Their primary concern was the potential for the elimination of their 

two-stroke engine source. In particular, they feared that the engine manufacturer would choose to 

not invest in upgrading the two-stroke engines used in augers to meet the emission standards, since 

they are produced at low volume. 

10.1.3 EPA's Response to the Comments 

The Agency- rejected the interpretation of the small entities provisions as extending to 

buyers of the covered engines as "captives," since in most cases the equipment manufacturers have 

the option of switching to engines which can comply with the new standards; nevertheless, EPA 

did consider their position in its deliberations concerning the final rule. The two-stroke auger 

engines are also used in two-stroke snowthrowers. Given that EPA is allowing both two-stroke 

snowthrowers and one-person augers to use engines that meet the handheld CO standards, these 

engines will continue to be produced in sufficient volume to make them economically viable. 

Moreover, the Agency is extending the exemption for snowthrowers from the requirement to 

certify to HC standards to ice augers, since both of these products are used exclusively during the 

winter when ozone concentrations do not present as much of an environmental concern. EPA 

expects, however, that manufacturers of engines used in snowthrowers and ice augers will 

generally opt to certify to HC standards, due to the availability of complying technology and the 

market advantages of "green marketing." The Agency believes that the revisions to the rule 

allowing two-stroke snow throwers and one-person augers to meet the handheld CO standards and 

not requiring snow throwers and ice augers to certify to HC standards adequately address the 

concerns of the commenters. 

10.2 Reporting Burden 

10.2.1 Summary ofthe Proposal 

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In the Information Collection Requests developed to support the NPRM, the Agency 

estimated that a typical manufacturer may expect to spend 6,100 hours annually to comply with the 

testing, record keeping, and reporting requirements proposed in the rulemaking. This estimate of 

the hours spent by a manufacturer on information collection activities in any given year is highly 

dependent upon manufacturer specific variables, such as the number of engine families, production 

changes, and emission defects. 

10.2.2 Summary ofthe Comments 

Some manufacturers commented that the estimated public reporting burden of 6,100 hours 

per year is a large burden for a "typical" manufacturer. They argued that if the defect reporting, 

production quality audit reporting and in-use test reporting remain as proposed the impact will be 

greater than estimated. These manufacturers suggested that harmonization with CARB should 

minimize the burden. [Tecumseh Products Co., 8/5/94, Docket No. A-93-25, IV-D-28 and Onan, 

8116/94, Docket No. A-93-25, IV-D-34] 

10.2.3 EPA's Response to the Comments 

The Agency_ shares the commenters' concerns and recognizes that the burden associated 

with the testing, record keeping, and reporting requirements is not trivial. In developing this 

rulemaking, the Agency drew on more than twenty years of experience with the on-highway 

programs to identify the most critical items for inclusion in these requirements. The Agency made 

every effort to minimize the burden while assuring that the resulting regulatory program will be 

implementable, overseeable, and enforceable. With respect to the burden estimates, as a general 

rule where there was uncertainty the Agency tried to over estimate the burden so the analytical 

results represent the upper range of the potential burden. Finally, the Agency concurs with the 

comment regarding harmonization with CARB and to the extent practical, the Agency has done so. 

10.5 Health Effects/Air Toxins 

10.5.1 Summary ofthe Proposal 

The Agency requested additional information on the effects of air toxics and CO exposure 

associated with the use of small SI engines. 

10.5.2 Summary ofthe Comments 

In its comments, PPEMA argued that no existing studies show that operation of handheld 

products has resulted in negative health effects. STAPPA requested that EPA devote time to study 

the health effects and in the meantime to err in the direction of increased operator health protection. 

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10.5.3 EPA's Response to the Comments 

The Agency appreciates the commenters concerns. The Agency did not receive additional 

information on the effects of air toxics and CO exposure associated with the use of small SI 

engines, and accordingly retains the position taken in the proposed rule; 

10.6 Modeling 

10.6.1 Summary ofthe Proposal 

EPA presented calculations of emission benefits from the Phase I regulation based on 

nationwide sales. 

10.6.2 Summary of the Comments 

NAEDA suggested subtracting the benefits from the CARB rule making along with the cost 

of the CARB rulemaking. If however, the costs of CARB studies are to be removed to satisfy ·the 

estimation of Phase 1 costs, then too, the benefits derived from CARB rules should be removed 

from the measurement of Phase 1 benefits. 

10.6.3 EPA's Response to the Comments 

EPA had subtracted costs in the NPRM costfbenefit analysis due to the work that engine 

manufacturers will have done before this rule is finalized. The emission benefits from CARB's 

rule had not been subtracted in the NPRM costfbenefit analysis. For the Final Rule, EPA has 

subtracted emission benefits for CARB's small engine rulemaking based on documented California 

sales estimates (as published in CARB's Technical support document) applied to the EPA 

inventory model. 

10.7 Estimate of Use of Fixed Jet Carburetors for Class V 

10.7.1 Summary ofthe Proposal 

The Phase I RIAlRSD for Small SI engines assumes that 50 percent of Class V engines 

will use fixed jet carburetors as engines use the technology of enleanment to meet emission 

standards. 

10.7.2 Summary ofthe Comments 

PPEMA stated that 7.5 percent, not 50 perce~t, of Class V engines will use fixed jet 

carburetors. EPA's assumption that 50 percent of Class V engines will use fixed jet carburetors to 

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avoid the need to use limiter caps is unrealistic because perfonnance and emissions requirements of 

professional handheld equipment requires some flexibility in the air/fuel mixture, thus eliminating 

widespread use of fixed jet carburetion. 

,. 10.7.3 EPA'S Response to the Comments 

Based on this comment EPA agrees to change the estimate of Class V engines which will 

use fixed jet carburetors to 7.5 percent from 50 percent. 

SECTION 11: ADDITIONAL ISSUES 

11.1 Absence of Averaging, Banking and Trading Programs 

11.1.1 Summary ofthe Proposal 

•

The Agency did not propose an averaging. banking. and trading program (ABT) for new 

small SI engines. Such market-based incentive programs can reduce the cost of controlling 

emissions, and have been utilized increasingly by EPA in recent rulemakings. For example, EPA 

does allow ABT in its on-highway heavy-duty engine program and in the new nonroad large CI 

engine program, because it believes that ABT programs provide manufacturers necessary flexibility 

in meeting the emission standards. 

However, EPA did not propose an ABT program for new small SI engines due to the 

uncertainties surrounding projected in-use emission levels. The Agency explained that, unless all 

engine families deteriorate at the same rate, EPA must have data on the in-use emission 

characteristics of specific small SI engine families in order to determine how ABT credits and 

standards should be set. The lifetime emissions of engine families must be averaged together in 

order to compute the average emission level of a manufacturer's product line. Knowledge of 

lifetime emissions is necessary because it may be the case that the emissions of one type of engine 

deteriorate at a higher rate than another type, or a smaller engine may deteriorate at a higher rate 

than a larger engine of the same type, with the result that lifetime emissions may vary in ways not 

predictable from data on new engines alone. 

The Agency stated in the proposal that it is not in a position to determine what in-use 

emission levels presently are, let alone what they would be under this Phase I regulation. The 

Agency's initial assessment was· that the emissions of these engines deteriorate somewhat over time 

and likely deteriorate at different rates between engine families, but that more research is necessary. 

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The limited information available to EPA at this time is primarily derived from engines currently on 

the market that may not adequately predict deterioration of the emissions of engines modified to 

meet Phase I standards. 

11.1.2 Summary of the Comments 

The Agency received four comments in support pfEPA's proposal to not include ABT and 

three in favor of implementing ABT for small SI engines. Comments jointly submitted by EMA 

and OPEl maintained that the advantages of an ART program recognized by EPA in the preamble 

outweigh concerns about uncertainties regarding in-use emission characteristics. l98 They pointed 

out that an ABT program is a means to preserve availability of certain engines that would have 

difficulty meeting the standards and which are not easily replaceable in some specialty applications . 

. Their comments described an outline for a small SI engine ABT program, consisting of (1) family 

emission limits for each exhaust constituent, (2) no averaging, banking. or trading across classes, 

(3) credit based on certification data only, with the assumption that all small SI engines deteriorate 

at the same rate within each class, (4) early banking, (5) trading between manufacturers, and (6) 

Phase I credits transferable to Phase 2, or if Phase 2 did not employ ABT~ credit expiration after 

Phase 1. 

Like EMA and OPEl, PPEMA supported an ABT program as being advantageous, even in 

the light of EPA's concerns over the uncertainties regarding in-use emissions~ however it proposed 

a different program than that outlined by EMA and OPEI.l99 PPEMA characterized its proposal as 

being similar to the one adopted in EPA's rulemaking on nonroad CI engines over 39 kW (50 

hp).200 The PPEMA proposal for an optional ABT program would include: (1) corporate-wide 

averaging, (2) family emission limits, with caps for the highest permissible family emission limits, 

(3) limited credit life, and (4) an option to establish a phased decrease in corporate-wide emissions, 

requiring that a manufacturer reduce its total calculated emissions by specified percentages over a 

set timetable. 

Briggs & Stratton submitted a report by National Economic Research Associates, Inc. 

(NERA) it had commissioned in conjunction with its request that EPA add an ABT program to the 

small SI engine rulemaking.201 The NERA report illustrates the potential gains of averaging, and 

how they can be extended-through banking and trading. This illustration showed how a 

manufacturer seeking to reduce its product lines' aggregate emissions by a given target percentage 

would be able to do so either with or without averaging, but that the target percentage could be 

achieved at a lower cost under an averaging regime. For example, a manufacturer could choose to 

attain a given percentage reduction in its aggregate fleet emissions by accounting for all the 

reductions among those engine families least costly to control, and not having to control the rest of 

its engine families. Briggs & Stratton argued that this would allow the same percentage of 

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aggregate fleet emissions reduction to be attained as could be achieved if each engine family had to 

individually accomplish that percentage reduction, but at a lower cost. Briggs and Stratton also 

cited the success of other ABT programs. It stated that, without ABT, the company might not be 

able to continue production of its full product line, and as a consequence, may have to reduce its 

workforce. Finally, it maintained that it had no reason to believe that emission factors would be 

biased one way or the other, and absent any bias to overstate emissions, an ABT program should 

be workable. 

One industry association, MECA, commented in support of EPA's position on ABT.202 It 

agreed with EPA's view that an effective ABT program cannot be developed given the uncertainty 

about in-use emissions, especially in the absence of any in-use provisions. While MECA 

expressed concerns about the general effectiveness of ABT programs, it indicated it would be 

appropriate for EPA to consider ABT in the context of Phase 2. 

In its comments, CARB supported EPA's contention that an ABT program is not necessary 

for Phase 1, because the relative stringency of Phase 1 standards is such that use of significantly 

advanced or costly technologies will not be required for manufacturers to achieve compliance.203 

Despite having beel! petitioned to include averaging in its small nonroad engines program, CARB 

has declined include it. Because EPA seeks consistency with CARB's regulations whenever it 

seems appropriate and practicable, CARB's reluctance to employ ABT at this time reinforces 

EPA's decision not to incorporate ABT in Phase 1. 

A very strong argument against incorporating ABT from STAPPAIALAPCO made five 

points: (1) questions concerning the certification test's ability to differentiate between various 

technologies without bias, (2) the variability of small engine emissions, even when new, (3) 

uncertainties regarding the rate, shape and level of deterioration of current engines, (4) 

uncertainties regarding the rate, shape and level of deterioration of Phase 1 engines, and (5) the 

absence of in-use enforcement. 204 

Moreover, NRDC pointed out that incorporating an ABT program would necessitate 

adjustment of the standards to more stringent levels if the projected emissions decreases were to be 

realized.205 It argued that adding ABT without revising the standards would allow the aggregate 

emissions to increase over levels projected for small SI engines in the absence of ABT. 

11.1.3 EPA's Response to the Comments 

It is EPA's experience that some proportion of engine families will exhibit emission levels 

lower than what is necessary to establish a "safety margin" that allows for test-to-test and engineto-engine variability. Therefore, when all engine families must individually meet the standard, the 

averaged emissions will lie at some point below the level corresponding to the averaged safety 

margin. However, when engine families need only meet the standard in the aggregate, fleetwide 

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average emissions may lie at levels as close to the standards as possible (even taking into account 

that there is still a safety margin below each family emissions limit that prudent manufacturers will 

maintain). This consideration is not problematic in and of itself; the problem arises when ABT is 

incorporated only after settling upon appropriate standards. Because adding ABT without revising 

the standards effectively weakens the standards, EPA decided against including such a program in 

this rulemaking. If EPA were to opt to include ABT as a feature of the Phase 2 rule, the Phase 2 

emission standards would be determined taking this factor into account. 

While it is possible that an ABT program would encourage manufacturers to bring forward 

technological advancements in emission control for the purpose of garnering credits, NRDC has 

argued that no one has produced analytical support for this position.206 No manufacturer has 

given any fIrm indication that it would implement specifIc technological advancements sooner if 

EPA adopts ABT in this rulemaking than it would otherwise. 

Even if it had no concerns regarding the potential for increased emissions, EPA would not 

consider it appropriate to approve an ABT program for new small SI engines at this time, because 

EPA has not encountered evidence that would convince it that approximately equal rates of 

deterioration occur !n use across engine families. The argument advanced by PPEMA that 

uncertainties concerning in-use emissions "did not prevent EPA from adopting an AB&T program 

for new nonroad diesel engines over 50 hp"207 is not convincing, because much more is known 

about in-use emissions of the large CI (diesel cycle) engines covered by that rulemaking than is 

known about the in-use emissions of small Sf engines. Many of the engines covered by the 

nonroad large CI engine rule are the same or very similar to those currently regulated under the 

ongoing certifIcation program for heavy-duty engines and vehicles; therefore, PPEMA's 

comparison between EPA's approach to nonroad large CI engines and its approach to nonroad 

small SI engines is not an apt one. 

These uncertainties will be resolved as part of the Phase 2 regulatory negotiations. Phase 2 

will directly assess in-use emission characteristics of engine families and incorporate enforcement 

of in-use emission levels. Once in-use emission levels are known with more confIdence, EPA 

expects that market-based programs such as ABT will be viewed more favorably by the regulatory 

negotiation committee during policy development. 

Finally, in response to Briggs & Stratton's contention that ABT could produce the same 

aggregate emissions reductions achievable without the program, EPA points out that its program 

was not set up the same way as Briggs & Stratton's example, and is not easily adaptable to it. The 

Agency's standards are defIned in terms of discrete emission limits, rather than percentage 

reductions in emissions. To allow averaging within a scenario involving emissions standards, 

family emission limits could be designated such that the fleets would have to meet the standard 

only in the aggregate. As described in the preceding paragraphs, the nature of an averaging 

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scheme is such that aggregate emissions are expected to be higher in such a scenario than when 

each engine family must individually meet the standard. If EPA were to adopt more stringent 

standards to compensate for this. or change to percent emissions reductions on the aggregate 

scheme like that proposed by Briggs & Stratton. it would have to generate a supplemental proposal 

and allow comment on this fundamentally different approach to regulating nonroad small SI 

engines. Again. EPA does not wish to delay promulgation of the Phase 1 standards unnecessarily, 

but will consider these arguments if raised during deliberations for the Phase 2 regulations. IfEPA 

were to opt to include ABT as a feature of the Phase 2 rule. the Phase 2 emission standards would 

be determined taking this factor into account. 

11 .2 Administrative Procedure Act 

11.2.1 Summary ofthe Proposal 

EPA stated in the proposal that the proposed regulatory language was not included as part 

of the Federal Register notice. but was available for free on computer diskette. via an electronic 

bulletin board. or at 'the EPA Air Docket. The NPRM provided explicit directions to aid the public 

in obtaining the regulatory language from anyone of these sources. 

11.2.2 Summary of the Comments 

Holliday Environmental Services submitted comment that EPA's failure to publish the 

regulatory text for the NPRM contravenes the Administrative Procedures Act. 208 

11.2.3 EPA IS Response to the Comments 

EPA has determined that regulatory text for an NPRM does not have to be published in the 

Federal Register in order to meet the requirements of the Administrative Procedures Act or the 

Clean Air Act. 5. U.S.c. § 553(b) requires that general notice of proposed rulemaking be 

published in the Federal Register. which shall include either the terms or substance of the proposed 

rule or a description of the subjects and issues involved. Where EPA publishes a notice of 

proposed rulemaking that describes the subjects and issues involved it is not required to publish the 

proposed rule text. Moreover, today's rule is subject to the procedural requirements of Clean Air 

Act section 307(d), not the Administrative Procedures Act. 42 U.S.C. § 7607(d)(1)(R). That 

provision requires EPA to publish notice of proposed rulemaking, accompanied by a statement of 

its basis and purpose. but does not require EPA to publish proposed regulatory text. Id .• 

7607(d)(3). 

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11.3 SIP Credits 

11.3.1 Summary ofthe Proposal 

The proposal did not discuss this issue, but in the California Federal Implementation Plan 

(FIP) the Agency allows States to include credits in their attainment State Implementation Plans 

(SIPs) from yet to be promulgated regulations establishing national nonroad engine emission 

standards. 

11.3.2 Summary ofthe Comments 

The Natural Resources Defense Council (NRDC) commented that" ...Supplying 

hypothetical II credits" to States can not ensure that areal reductions (sic) will occur. Instead, such 

policies impede attainment by allowing States to include unquantifiable and unenforceable 

measures in their implementation plans, instead of actual regulations that can deliver quantifiable 

pollution reductions ... "209 

11.3.3 EPA's Response to the Comments 

The Agency. acknowledges that for the national nonroad regulatory program and the small 

engine and marine pleasure craft programs in particular, the projected benefits are not exact since in 

both cases they depend on public comment to proposed rules and in the case of the small engine 

standards, they will also depend in part on the outcome of the regulatory negotiation process (for 

Phase II). However, the promulgation of most of these rules is imminent and all are legally 

compelled by specific dates. The range of uncertainty with regard to the benefits of the fmal rules 

is small, especially in comparison to the total emissions inventory. Consequently, the potential 

error in inventory estimates and therefore, the potential error in the required stringency for all other 

control measures in the non attainment areas, is smalL 

It is EPA's position, with respect to national programs and given certain conditions are 

met, that states may take an approach in their SIPs that is similar to that allowed in the California 

FIP. The fact that these nonroad rules are required Federal rules, and indeed with court-ordered 

deadlines, creates special circumstances that allow EPA to consider them enforceable SIP elements, 

provided states also commit to adopt gap-filling measures to account for any shortfalls, identified 

later, between currently anticipated and actual final rule benefits. These gap-filling measures do 

not necessarily have to be in the same inventory category as the rule for which they are meant to 

account. States must also be aware that implementation of additional programs within the nonroad 

category to compensate for any shortfalls in fmal federal nonroad engine rules may be very 

difficult. States may, therefore, wish to discount credits for these programs in their SIPs as a 

safety margin against potential shortfalls when these rules are finalized. 

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The Agency has concluded that this policy of authorizing SIPs to take credit for reductions 

from Federal measures is consistent with the overall scheme of the Clean Air Act ozone 

nonattainment provisions, as well as the relevant provisions by their terms. Congress anticipated 

that attainment of the ozone primary national ambient air quality standard would result from a 

combination of State and Federal actions. As a result, the reductions from Federal measures are an 

integral part of Congress's blueprint for attainment. Therefore, SIPs should be allowed to account 

for those reductions. In particular, the attainment demonstration provisions of sections 

183(b)(1)(A)(i) (Moderate areas) and 182(c)(2)(A) (Serious and higher classified areas); as well as 

the rate-of-Progress (RaP) provisions of sections 182(b)(1)(C) (initial 15 percent required 

reductions) and 182(c)(2)(B) (subsequent 3 percent per year required reductions) may be read to 

assume the creditability of reductions from Federal measures (other than those specifically 

identified in the Rap provisions as noncreditable). Further, denying SIP credit for reductions 

from Federal measures would unduly burden the States because States would be obliged to 

develop and begin to implement SIP measures to assure the full amount of reductions needed for 

Rap and attainment, but they could subsequently retract those SIP provisions when the Federal 

measures are promulgated and begin yielding reductions. Further information and guidance on this 

issue may be found 'in the Air Docket; specifically, refer to documents numbered A-93-25, IV-J-Ol 

and IV-J-02. 

11.4 Metric 

11.4.1 Summary ofthe Proposal 

Metric units are used throughout the proposed rule without English equivalents. This was 

done in compliance with the Metric Conversion Act of 1975, as amended, and Executive Order 

12770, July 25, 1981, which directs all federal agencies to use metric as the primary unit in 

regulations by September 30, 1992 and to only provide English equivalents when the affected 

party(s) uses English as the primary unit. 

In the NPRM, EPA solicited comments on the impact of using only metric units or the need 

for including the English equivalent. 

11.4.2 Summary ofthe Comments 

In its comments, NAEDA expressed concern that although manufacturers may use metric 

without English equivalents, equipment dealers and users usually use English as the primary 

unit21O• NAEDA requested that equipment specifications be stated in English for the United States 

marketplace. 

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11.4.3 EPA's Response to the Comments 

EPA has decided to retain metric measurements for the final rule. This does not preclude 

the additional use of English equivalents by manufacturers to provide darity for equipment dealers 

and users. 

11 .5 Service Information 

11.5.1 	 Summary ofthe Proposal 


There was no mention of service information in the NPRM. 


11.5.2 Summary ofthe Comments 

A comment was received from NAEDA expressing concern over the availability of 

necessary service information and suggesting that EPA address this topic in the forthcoming 

regulations.211 

11.5.3 EPA"s Response to the Comments 

Service information requirements were not proposed in this NPRM. They are outside the 

scope of this action and cannot be included in the FRM. 

11.6 Consumer/Commercial Terminology 

11.6.1 Summary ofthe Proposal 

EPA proposed to adopt a "class" structure for the Phase 1 regulation. In the NPRM, EPA 

explained that this rule proposed two broad use categories--nonhandheld and handheld. 

Nonhandheld engines would be required to meet either Class I or Class II standards while 

handheld engines would have to meet either Class III, IV, or V emission standards. Once the 

applicable use category is determined, the engine class would be selected on the basis of engine 

displacement as measured in cubic centimeters (cc). 

As stated in the NPRM, Class I engines are overwhelmingly found in lawnmowers. Class 

II engines primarily include engines used in generator sets, garden tractors, and commercial lawn 

and garden equipment. Only engines used in equipment defined as handheld would be allowed to 

meet Class ill, IV, or V emission standards. Class ill includes engines used in consumer 

handheld products, such as small string trimmers, edgers, and brush cutters. Class IV 

encompasses engines used in both residential and commercial settings and includes large trimmers, 

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edgers, blowers, and chain saws. Class V includes a majority of engines utilized in commercial 

chain saws. 

This proposed engine classification approach for Phase I harmonized federal small engine 

regulations with California's lawn and garden regulations. 

11.6.2 Summary of the Comments 

NAEDA objected to the equipment classifications EPA used throughout the preamble, RIA 

and RSD.212 NAEDA's concern is that use of the terms "residential," "consumer," or 

"professional" could cause dealers to be liable in court if, for example, they sold a "professional" 

piece of equipment to a residential consumer who subsequently was injured. As an alternative, 

NAEDA suggested that all equipment be classified using terms such as "Light Duty" or "Heavy 

Duty" that do not require the dealer to determine the fitness of the buyer to use the equipment. 

11.6.3 EPA's Response to the Comments 

The Agency appreciates NAEDA's comments on equipment terminology, and recognizes 

the dealers' concerns about potential liability. However, it is EPA's understanding that the terms 

"residential," "consumer," and "professional" are the terms that have traditionally been used in the 

field, and therefore EPA will not change the terminology for the purposes of the Phase 1 rule. 

1 U.S. Environmental Protection Agency. "Nonroad Engine and Vehicle Emission Study." EPA 

Air Docket #A-91-24, item ll-A-lO, November 1991. EPA publication number 21A-2001. 

Available from the National Technical Information Service, referenced as document PB 92­

126960. 

2 Portable Power Equipment Manufacturers Association. ""Comments of the Portable Power 

Equipment Manufacturers Association." EPA Air Docket #A-93-25, item IV -D-22A, August 5, 

1994, pp. 3-5. 

3 Natural Resources Defense Council. "Comments of the Natural Resources Defense Council." 

EPA Air Docket #A-93-25, item IV-D-27, August 5, 1994, p. 5. 

New York State Department of Environmental Conservation. "Comments on Proposed 

Emission Standards for New Nonroad Spark-ignition Engines At or Below 19 Kilowatts." EPA 

Air Docket #A-93-25, item IV-D-31, August 4, 1994, p. 1. 

Northeast States for Coordinated Air Use Management. "Comments on Emission 

Standards." EPA Air Docket #A-93-25, item IV-D-23, August 5, 1994, p. 1. 

State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officers. "Comments on the U.S. Environmental Protection Agency's Proposed 

Rulemaking on Emission Standards for New Nonroad Spark-ignition Engines At or Below 19 

Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4, 1994, pp. 5-7. 

State of Wisconsin Department of Natural Resources. "Notice of Proposed Ru1emaking: 

40 CFR Part 90, Control of Air Pollution; Emission Standards for New Nonroad Spark-Ignited 

Engines At or Below 19 Kilowatts." EPA Air Docket#A-93-25, item IV-D-18, August 3,1994, 

p. 1. 

4 Ibid. 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
-111­

5 Natural Resources Defense Council. "Comments," EPA Air Docket #A-93-25, item IV-D-27, 

August 5, 1994, p. 5. 

State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officers. "Comments," EPA Air Docket #A-93-25, item IV-D-08, August 4, 

1994, pp. 5-7. 

State of Wisconsin Department of Natural Resources. "Notice," EPA Air Docket #A-93­

25, item IV-D-18, August 3, 1994, p. 1. 

6 Black & Decker Corporation. "Comments of the Black & Decker Corporation Concerning 

EPA's Proposed Rulemaking on the Control of Air Pollution; Emission Standards for New 

Nonroad Spark-ignition Engines At or Below 19 Kilowatts." EPA Air Docket #A-93-25, item IVD-05, July II, 1994, pp. 2-3. 

State of California Air Resources Board. "Reference no. Z-94-15." EPA Air Docket #A93-25, item IV-D-30, August 5, 1994, p. 4. 

State of Louisiana Department of Environmental Quality. "Comments." EPA Air Docket 

#A-93-25, item IV-D-lO, August 2, 1994, p. 1. 

State of Tennessee Department of Environment and Conservation. "Proposed 40 CFR Part 

90." EPA Air Docket #A-93-25, item IV-D-04, June 29, 1994, pp. 2-3. 


7 State of California Air Resources Board. "Reference," EPA Air Docket #A-93-25, item IV-D30, August 5, 1994, p. 4. 


8 State of Louisiana Department of Environmental Quality. "Comments," EPA Air Docket #A-93­

25, item IV-D-lO, August 2, 1994, pp. 2-3. 


9 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 


Engine Manufacturers Association and the Outdoor Power Equipment Institute. It EPA Air Docket 


#A-93-25, item IV-D-07, August 5, 1994, pp. 13-16. 


Kohler Company. "Re: EPA Docket No. A-93-25." EPA Air Docket #A-93-25, item IVD-21, August 3, 1994, p. 2. 

Machinery and Electrical Products, Inc. "Proposed Phase I Emissions Regulations. " EPA 

Air Docket #A-93-25, item IV -D-12, August 2; 1994, p. 2. 

Tecumseh Products Company. "EPA Phase I NPRM Comments." EPA Air Docket #A93-25, item IV-D-28, August 5, 1994, p. 1. 


10 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," EPA 


Air Docket #A-93-25, item IV-D-07, August 5, 1994, pp. 13-14. 


11 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," EPA 


Air Docket #A-93-25, item IV-D-07, August 5, 1994, pp. 14-16. 


12 ECHO. "Attn: Docket A-93-25." EPA Air Docket #A-93-25, item IV-D-32, July 6, 1994, p. 


2. 

Portable Power Equipment Manufacturers Association. "Comments of the Portable Power 

Equipment Manufacturers Association." EPA Air Docket #A-93-25, item IV-D-22A, August 5, 

1994, p. 8. 

13 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22A, August 5, 1994, pp. 9-10. 

14 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22A, August 5, 1994, pp. 7-9. 

15 STIHL. ,. Additional Comments on the legislation for Non-Road Engines up to 19 kW (Par. 

90.103) - Effective Date." EPA Air Docket #A-93-25, item IV-D-_, September 23, 1994, pp. 1­

3. 

16 Auger and Power Equipment Manufacturers Association. "Comments on NPRM 40 CFR Part 


90." EPA Air Docket #A-93-25, item IV-D-13, August 4, 1994. p. 5. 


17 Ib.id. 


18 ECHO. "Attn," EPA Air Docket #A-93-25, item' IV-D-32, July 6, 1994, p. 2. 


Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5127/95 
-112­

19 ECHO. "Attn," EPA Air Docket #A-93-25, item IV-D-32, July 6, 1994, p. 5. 

Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 

EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, pp. 34-35. 

Natural Resources Defense Council. "Comments," EPA Air Docket #A-93-25, item IV-D27, August 5, 1994, p. II. 

Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A93-25, item IV -D-22A, August 5, 1994, p. 24. 

State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officers. "Comments," EPA Air Docket #A-93-25, item IV-D-08, August 4, 

1994, p. 12. 

20 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV -D-22A, August 5, 1994, p.24. 

21 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," EPA 


Air Docket #A-93-25, item IV -D-07, August 5, 1994, pp. 34-35. 


22 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22A, August 5, 1994, pp. 7-9. 


23 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 


Engine Manufacturers Association and the Outdoor Power Equipment Institute." EPA Air Docket 


#A-93-25, item IV-D-07, August 5, 1994, pp. 12-13. 


24 Portable Power Equipment Manufacturers Association. "Comments of the Portable Power 


Equipment Manufacturers Association." EPA Air Docket #A-93-25, item IV-D-22A, August 5, 


1994, p. 10. 


25 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22A, August 5, 1994, pp. 10-12. 


26 Portable Power Equipment Manufacturers Association. "Comments, " EPA Air Docket #A-93­

25, item IV -D-22A, August 5, 1994, p. 12. 


27 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22A, August 5, 1994, pp. 12-13. 


28 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22A, August 5, 1994, p. 13. 


29 State and Territorial Air Pollution Program Administrators and Association of Local Air 


Pollution Control Officers. "Comments on the U.S. Environmental Protection Agency's Proposed 


Rulemaking on Emission Standards for New Nonroad Spark-ignition Engines At or Below 19 


Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4, 1994, p. 3. 


30 State of California Air Resources Board. "Reference no. Z-94-15." EPA Air Docket #A93-25, item IV-D-30, August 5, 1994, p. 3. 


3 1 Natural Resources Defense Council. "Comments of the Natural Resources Defense 


Council." EPA Air Docket #A-93-25, item IV-D-27, August 5, 1994, p. 8. 


32 State and Territorial Air Pollution Program Administrators and Association of Local Air 


Pollution Control Officials. "Comments on the U.S. Environmental Protection Agency's 


Proposed Rulemaking on Emission Standards for New Nonroad Spark-Ignition Engines At or 


Below 19 Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4, 1994, p. 3. 


33 State and Territorial Air Pollution Program Administrators and Association of Local Air 


Pollution Control Officials. "Comments on the U.S. Environmental Protection Agency's 


Proposed Rulemaking on Emission Standards for New Nonroad Spark-Ignition Engines At or 


Below 19 Kilowatts." EPA Air Docket #A-93-25, item IV -D-08, August 4, 1994, p. 3. 


34 Natural Resources Defense Council. "Comments of the Natural Resources Defense 


Council." EPA Air Docket #A-93-25, item IV-D-27, August 5, 1994, p. 9. 


35 State and Territorial Air Pollution Program Administrators and Association of Local Air 


Pollution Control Officials. "Comments on the U.S. Environmental Protection Agency's 


Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
-113­

Proposed Rulemaking on Emission Standards for New Nonroad Spark-Ignition Engines At or 

Below 19 Kilowatts." EPA Air Docket #A-93-25, item IV-D-OS, August 4,1994, p. 3. 

36 State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officials. "Comments on the U.S. Environmental Protection Agency's 

Proposed Rulemaking on Emission Standards for New Nonroad Spark-Ignition Engines At or 

Below 19 Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4,1994, p. 3. 

37 Natural Resources Defense Council. "Comments of the Natural Resources Defense 

Council." EPA Air Docket #A-93-25, item IV-D-27, August 5, 1994, p. 9. 

38 Machinery and Electrical Products, Inc. "Attn: Docket Number A-93-25." EPA Air Docket 

#A-93-25, item IV -D-12, August 2, 1994, p. 3. 

39 Natural Resources Defense Council. "Comments of the Natural Resources Defense 

Council." EPA Air Docket #A-93-25, item IV-D-27, August 5, 1994, p. 9. 

40 State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officials. "Comments on the U.S. Environmental Protection Agency's 

. Proposed Rulemaking on Emission Standards for New Nonroad Spark-Ignition Engines At or 

Below 19 Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4, 1994, p. 4. 

41 State of California Air Resources Board. "Reference no. Z-94-15." EPA Air Docket #A93-25, item IV-D-30, August 5, 1994, p. 3. 

42 Natural Resources Defense Council. "Comments of the Natural Resources Defense 

Council." EPA Air Docket #A-93-25, item IV-D-27, August 5,1994, p. 9. 

43 State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officials. "Comments on the U.S. Environmental Protection Agency's 

Proposed Rulemaking on Emission Standards for New Nonroad Spark-Ignition Engines At or 

Below 19 Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4, 1994, p. 4. 

44 Kubota Corporation. "Attention: Docket Number A-93-25." EPA Air Docket #A-93-25, 

item IV-D-16, August 4, 1994, p. 1. 

45 General Equipment Company, "Attention: Docket Number A-93-25." EPA Air Docket #A93-25, item IV-D-15, August 1, 1995, p. 1. . 

46 Machinery and Electrical Products, Inc. "Attn: Docket Number A-93-25." EPA Air Docket 

#A-93-25, item IV-D-12, August 2, 1994, p. 2. 

47 Auger and Power Equipment Manufacturers Association. "Comments on NPRM 40 CFR 

Part 90." EPA Air Docket #A-93-25, item IV-D-13, August 4, 1994, p. 4. 

48 Ibid. 

49 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, pp. 19-21. 

50 Outdoor Power Equipment Institute. "Supplemental Comments." EPA Air Docket #A-93­

25, item IV-D-20, August 5, 1994, pp. 6-7. 

51 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, pp. 23-27. 

52 Tecumseh Products Company. "Attention: Docket Number A-93-25, EPA Phase NPRM 

Comments." EPA Air Docket #A-93-25, item IV-D-28, August 5, 1994, p. 2. 

53 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of 

the Engine Manufacturers Association and the Outdoor Power Equipment Institute." EPA Air 

Docket #A-93-25, item IV-D-07, August 5, 1994, pp.27-30. 

54 Portable Power Equipment Manufacturers Association. "Comments of the Portable Power 

Equipment Manufacturers Association." EPA Air Docket #A-93-25, item IV-D-22A, August 5, 

1994, pp. xx 

55 Snapp, Lisa, U.S. Environmental Protection Agency Office of Mobile Sources, 

Memorandum: "Meeting with Tecumseh re; Hover Mowers and CO Standards," EPA Air Docket 

#A-93-25, item D-IV -X, December 19, 1994. 

Emission Standards for New-Nonroad Spark.Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5127/95 
-1l4­

56 Portable Power Equipment Manufacturers Association. "Comments of the Portable Power 


Equipment Manufacturers Association." EPA Air Docket #A-93-25, item IV-D-22A, August 5, 


1994, pp. 15-16. . 


57 California is preempted by section 209 of the Clean Air Act from imposing standards on 


earth augers because they are included as farm and construction equipment. See the following 


paragraph. 


58 This is only a partial list of the equipment preempted from separate regulation in California. 


See California Code of Regulations, Title 13, Appendix to Section 2450 for a complete list, which 


is subject to revision. 


59 The Agency is aware that concrete/cutoff saws are sometimes attached to carts for extended 


or heavy-duty cuts. This occasional use does not negate their overall status as handheld 


equipment. The Agency agrees with the comment that cutoff saws are often used 


multipositionally, and thus fall into the general handheld category. Thus, the 14 kg weight limit 


does not apply. 


60 For augers, this break point is 20 kg. 


61 Lisa M. Snapp, U. S. Environmental Protection Agency Office of Mobile Sources, 


Memorandum: "Small Nonroad Spark-Ignition Engines -- Determination of Handheld Definition 


Weight Limit," EPA Air Docket #A-93-25, item IV-D-X, February 17, 1995. 


62 Additionally, the use of lawnmowers and, similarly, three- and four-wheeled edgers on 


hillsides is not considered to be muitipositional use and, hence, they do not qualify as handheld 


equipment. 


63 Kubota Corporation. "Attention: Docket Number A-93-25." EPA Air Docket #A-93-25, 


item IV-D-16, August 4, 1994, p. 1. . 


64 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 


Engine Manufacturers Association and the Outdoor Power Equipment Institute." EPA Air Docket 


#A-93-25, item IV-D-07, August 5, 1994, p. 32. 


Toro Company. "Comments of the Toro Company." EPA Air Docket #A-93-25, item IVD-22, received August 5, 1994, pp. 1, 18-23. 


65 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," EPA 


Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 31. 


Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, p. 1. 


66 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, p. 3, fn. 5. 


67 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, pp. 4-6. 


68 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, pp. 4, 7-9. 


69 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, p. 4. 


70 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, pp. 4-5, 10-15. 


71 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, pp. 16-18. 


Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5127/95 
-115­

72 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, p. 16. 


73 Ibid. 


74 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, p. 17. 


75 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, pp. 18-23. 


76 Dunaway & Cross. "Re: The Toro Company." EPA Air Docket #A-93-25, item IV-D-_, 


November 21, 1994, p. 1. 


77 North American Equipment Dealers Association. "EP A - 40 CFR Part 90 Emission Standards, 


New Nonroad SI Engines At or Below 19 KW." EPA Air Docket #A-93-25, item IV-D-02, June 


15, 1994, p. 2. 


78 Ibid. 


79 State of California Air Resources Board. "Reference nO.a Z-94-15." EPA Air Docket #A-93­

25, item IV -D-30, August 5, 1994, p. 3. 


80 Ibid. 


81 Id. 

82 Natural Resources Defense Council. "Comments of the Natural Resources Defense Council." 

EPA Air Docket #A-93-25, item IV-D-27, August 5, 1994, pp. 9-10. 

State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officers. "Comments on the U.S. Environmental Protection Agency's Proposed 

Rulemaking on EmIssion Standards for New Nonroad Spark-ignition Engines At or Below 19 


Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4, 1994, p.4. 


83 State and Territorial Air Pollution Program Administrators and Association of Local Air 


Pollution Control Officers. "Comments," EPA Air Docket #A-93-25, item IV -D-08, August 4, 


1994, p. 4. 


84 Ibid. 


85 Id. 

86 Natural Resources Defense Council. "Comments," EPA Air Docket #A-93-25, item IV-D-27, 

August 5, 1994, p. 10. 

State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officers. "Comments," EPA Air Docket #A-93-25, item IV-D-08, August 4, 

1994, pp. 4-5. 


87 Ibid. 


88 State and Territorial Air Pollution Program Administrators and Association of Local Air 


Pollution Control Officers. "Comments," EPA Air Docket #A-93-25, item IV-D-08, August 4, 


1994, p. 5. 


89 Ibid. 


90 Dunaway & Cross. "Re: The Toro Company," EPA Air Docket #A-93-25, item IV-D-_, 

November 21, 1994. 

Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994. 


91 Dunaway & Cross. liRe: The Toro Company," EPA Air Docket #A-93-25, item IV-D-_, 


November 21, 1994, p. 2. 


Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, p. 4. 


92 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, pp. 2-3. 


Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
-1l6­

93 Dunaway & Cross. "Re: The Toro Company," EPA Air Docket #A-93-25, item IV-D-_, 


November 21, 1994, p. 4. 


94 Dunaway & Cross. "Re: The Toro Company," EPA Air Docket #A-93-25, item IV-D-_, 


November 21, 1994, p. 10. 


95 Ibid. 


96 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, pp. 9-10. 


97 Ibid. 


98 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, pp. 10, 18, 20. 


99 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, p. 10. 


100 Dunaway & Cross. "Re: The Toro Company," EPA Air Docket #A-93-25, item IV-D-_, 


November 21, 1994, p. 12, fn. 6. 


101 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 


5, 1994, p. 27. 


102 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 


Engine Manufacturers Association and the Outdoor Power Equipment Institute." EPA Air Docket 


#A-93-25, item IV-D-07, August 5, 1994, p. 27. 


Outdoor Power Equipment Institute. "Supplemental Comments." EPA Air Docket #A-93­

25, item IV -D-20, August 5, 1994, p. 6. 

Tecumseh Products Company. "EPA Phase I NPRM Comments." EPA Air Docket #A93-25, item IV-D-28, August 5, 1994, p. 2. 

Toro Company. "Comments of the Toro Company." EPA Air Docket #A-93-25, item IVD-22, received August 5, 1994, p. 23. 

103 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 


EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 27. 


104 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, p. 23. 


105 Tecumseh Products Company. "EPA Phase I," EPA Air Docket #A-93-25, item IV-D-28, 


August 5, 1994, p. 2. 


106 U.S. Environmental Protection Agency. "Nonroad Engine and Vehicle Emission Study." 


EPA Air Docket #A-91-24, item II-A-lO, November 1991. EPA publication number 21A-2001. 


Available from the National Technical Information Service, referenced as document PB 92­

126960. 


107 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 

EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 27. 

Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93­

25, item IV-D-20, August 5, 1994, p. 6. 

Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, p. 25. 


108 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 


EPA Air Docket #A-93-25, item IV -D-07, August 5, 1994, pp. 28-29. 


Outdoor Power Equipment Institute. "Supplemental Comments'" EPA Air Docket #A-93­

25, item IV-D-20, August 5, 1994, pp. 6-7. 

Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, pp. 25-27. 

109 Il:!iQ. 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
-117­

110 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 

EPA Air Docket #A-93-25, item IV-D-07, August 5,1994, pp. 29-30. 

Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93­

25, item IV -D-20, August 5, 1994, p. 6. 

Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, pp. 28-29. 

III Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 

EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 29. 

Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93­

25, item IV-D-20, August 5, 1994, p. 6. 

Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, p. 28. 


112 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 


EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, pp. 30-31. 


Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93­

25, item IV-D-25, August 5, 1994, p. 7. 

Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, p. 29. 

113 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 

EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 29. 

Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 

5, 1994, p. 28. 

114 Ibid. 

115 Toro Company. "Comments," EPA Air Docket #A-93-25, item IV-D-22, received August 5, 


1994, p. 29. 


116 Ibid. 


117 Natural Resources Defense Council. "Comments of the Natural Resources Defense Council. II 


EPA Air Docket #A-93-25, item IV-D-27, August 5, 1994, p. 9. 


State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officers. "Comments on the V.S. Environmental Protection Agency's Proposed 

Rulemaking on Emission Standards for New Nonroad Spark-ignition Engines At or Below 19 

Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4, 1994, p. 4. 

118 Ibid. 

119 Id. 


120 Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93-25, 


item IV-D-20, August 5, 1994, attachment entitled Single-stage Snowthrowers. 


121 Power Systems Research,.Engindata North America and Parts Link Aftermarket, 1992, St. 


Paul-Minneapolis, Minnesota, EPA Air Docket #A-93-25, item #II-K-15. 


122 Drachand, Don, California Air Resources Board. Letter to Richard Wilson, V.S. 


Environmental Protection Agency, EPA Air Docket #A-93-25, item #IV-D-30, August 5, 1994, p. 


1. 

123 59 FR 55930. 

124 Portable Power Equipment Manufacturers Association. "Comments of the Portable Power 

Equipment Manufacturers Association." EPA Air Docket #A-93-25, item IV -D-22A, August 5, 

1994, pp. 16-17. 

125 Portable Power Equipment Manufacturers Association. "CommentS, " EPA Air Docket #A-93­

25, item IV -D-22A, August 5, 1994, pp. 10-13. 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
ll8­

Toro Company. "Comments ofthe Toro Company." EPA Air Docket #A-93-25, item IVD-22, received August 5, 1994, pp. 5-6. 

126 Natural Resources Defense CounciL "Comments of the Natural Resources Defense Council." 

EPA Air Docket #A-93-25, item IV-D-27, August 5, 1994, p. 10. 

State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officers. "Comments on the U.S. Environmental Protection Agency's Proposed 

Rulemaking on Emission Standards for New Nonroad Spark-ignition Engines At or Below 19 . 

Kilowatts." EPA Air Docket #A-93-25, item IV-D-08, August 4, 1994, p. 5. 

State of California Air Resources Board. "Reference no. Z-94-15." EPA Air Docket #A93-25, item IV-D-30, August 5, 1994, p.5. 


127 Engine Manufacturers Association and Outdoor Power Equipment Manufacturers Institute. 


"Statement of the Engine Manufacturers Association and the Outdoor Power Equipment Institute." 


EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, pp. 16. 


Outdoor Power Equipment Institute. "Supplemental Comments." EPA Air Docket #A-93­

25, item IV -D-20, August 5, 1994, pp. 1-4. . 

128 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 

EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 17. 

Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93­

25, item IV-D-20, August 5, 1994, pp. 4-5. 


129 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 


EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 16. 


130 General Equipment Company. "Comments to the Docket Proposal." EPA Air Docket #A-93­

25, item IV-D-15, August 1, 1994,p. 1. 


131 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 


EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 37. 


Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93­

25, item IV-D-20, August 5, 1994, pp. 7-8. 


132 Tecumseh Products Company. "EPA Phase I NPRM Comments." EPA Air Docket #A-93­

25, item IV-D-28, August 5, 1994, p. 3. 


133 ECHO. "Attn: Docket A-93-25." EPA Air Docket #A-93-25, item IV-D-32, July 6, 1994, 


p.2. 

Engine Manufacturers Association and Outdoor Power Equipment Institute, "Statement," 

EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 17. 

Onan Corporation. "Attention: Docket A-93-25." EPA Air Docket #A-93-25, item IV-D34, August 4, 1994, pp. 4-5. 

Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93­

25, item IV-D-20, August 5, 1994, pp. 1-6. 

Tecumseh Products Company. "EPA Phase I," EPA Air Docket #A-93-25, item IV-D-28, 

August 5, 1994, p. 2. . 


134 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement," 


EPA Air Docket #A-93-25, item IV-D-07, August 5, 1994, p. 17. 


135 State of Tennessee Department of Environment and Conservation. "Proposed 40 CPR Part 


90." EPA Air Docket #A-93-25, item IV-D-04, June 29, 1994, p. 1. 


136 Auger and Power Equipment Manufacturers Association. "Comments on NPRM 40 CPR Part 


90." EPA Air Docket #A-93-25, item IV-D-13, August 4, 1994, p. 5. 


137 Machinery and Electrical Products, Inc. "Proposed Phasea I Emissions Regulations." EPA 


Air Docket #A-93-25, item IV-D-12, August 2, 1994, p. 2. 


138 Natural Resources Defense Council. "Comments," EPA Air Docket #A-93-25, item IV-D27, August 5, 1994, p. 10. 


Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
119­

State and Territorial Air Pollution Program Administrators and Association of Local Air 

Pollution Control Officers. "Comments," EPA Air Docket #A-93-25, item IV-D-08, August 4, 

1994, p. 5. 

139 Tecumseh Products Company. "EPA Phase I," EPA Air Docket #A-93-25. item IV-D-28, 

August 5. 1994, p. 3. 

140 North American Equipment Dealers Association. "EPA - 40 CFR Part 90 Emission 

Standards, New Nonroad SI Engines At or Below 19 KW. EPA Air Docket #A-93-25, item IVD-02, June 15, 1994, p. 2. 

141 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of 

the Engine Manufacturers Association and the Outdoor Power Equipment Institute." EPA Air 

Docket #A-93-25, item IV-D-07, August 5, 1994. pp.32-33. 

142 Kohler Co. "Re: EPA Docket No. A-93-25," EPA Air Docket #A-93-25, item IV-D-21, 

August 3, 1994, pp. 3-4. 

143 Tecumseh Products Company. "EPA Phase I," EPA Air Docket#A-93-25. item IV-D-28, 

August 5, 1994,p. 3 

144 Onan Corporation. "Comments." EPA Air Docket #A-93-25. item IV-D-34, pp. 3-4. 

145 Onan, Kohler, EMA and OPEl. 

146 Kohler, OPEl 

147 EMA and OPEl, Tecumseh 

148 Letter to Debbie Wood, U.S.Environmental Protection Agency, from Engine 

Manufacturers Association, 11129194. 

149 Thrift, Michael, U.S. Environmental Protection Agency Office of General Counsel, 

Memorandum of telephone conversation with Ralph Hovnanian, EPA Air Docket #A-93-25, item 

IV-D-19, November 5, 1994. . 

150 Public Law 95-574, October 27, 1992, as amended by Public law 95-609, November 8 

1978. 

151 ECHO. "Attn: Docket A-93-25." EPA Air Docket #A-93-25, item IV-D-32, July 6, 1994, 

~5i' Some of the most common-used standards include ANSI B71.5 (a voluntary US standard, 

with a measurement and rating procedure, adhered to by OPEl members), EEC Council Directive 

841538IEEC (an EEC regulation dealing with permissible sound power levels of lawnmowers), 

ISO 11094 (an international standard relating to mowing equipment). 

153 ECHO. "Attn: Docket A-93-25." EPA Air Docket #A-93-25, item IV-D-32, July 6, 1994, p. 

xx. 

154 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket 

#A-93-25, item IV-D-22A, August 5, 1994, pp. 35-36. 

155 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket 

#A-93-25, item #IV -D-22A, August 5, 1994, pp. xx. 

156Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22 (part 2 of2), August 5, 1994, p.26. 

157Kohler Co. "Re: EPA Docket No. A-93-25," EPA Air Docket #A-93-25, item IV-D-21, 

August 3, 1994, p.4. 

1580nan Corporation. "Comments," EPA Air Docket #A-93-25, item IV-D-34, August 4, 1994, 

p.26; Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of 

Emission Standards for New-Nonroad Spark·lgnition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
-120­

the Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air 


Docket #A-93-25, item IV-D-07, August 5, 1994, p.50. 


1590nan Corporation. "Comments," EPA Air Docket #A-93-25; item IV-D-34. August 4, 1994, 


p.5. 


16DNatural Resources Defense Council. "Comments," EPA Air Docket #A-93-25, item IV-D-27. 


August 5, 1994, p.1l. 


161Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 


Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket 


#A-93-25, item IV-D-07, August 5, 1994, p.43. 


1620nan Corporation. "Comments," EPA Air Docket #A-93-25, item IV-D-34, August 4, 1994, 


p.28 


163Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement ofthe 


Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket 


#A-93-25, item IV-D-07, August 5, 1994, p.45 

164Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 

Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket 

#A-93-25, item IV-D-07, August 5, 1994, p.46 

165Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 

Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket 

#A-93-25, item IV-D-07, August 5, 1994, p.46?; Onan Corporation. "Comments," EPA Air 

Docket #A-93-25, item IV-D-34, August 4, 1994, p.26 

166Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 

Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket 

#A-93-25, item IV-D-07, August 5, 1994, p.46?; Onan Corporation. "Comments," EPA Air 

Docket #A-93-25, item IV-D-34, August 4, 1994, p.26 

167Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22 (part 2 of 2), August 5, 1994, p.26 

168Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 

Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket 

#A-93-25, item IV-D-07, August 5,1994, p.4S. 

169Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 

Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket 

#A-93-25, item IV-D-07, August 5, 1994, pp.?? 

1700nan Corporation. "Comments," EPA Air Docket #A-93-25, item IV -D-34, August 4, 1994, 

p.26 

171Honda Motor Co., Ltd. "Comments," EPA Air Docket #A-93-25, item IV-D-25, August 5, 


1994, p.l. 


172Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 


Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket. 


#A-93-25, item IV-D-07, August 5, 1994, p.49 


173Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of the 


Engine Manufacturers Association and The Outdoor Power Equipment Institute," EPA Air Docket 


#A-93-25, item IV-D-07, August 5,1994, p.?? 


1740nan Corporation. "Comments," EPA Air Docket #A-93-25, item IV-D-34, August 4, 1994, 


p.25. 


1750nan Corporation. "Comments," EPA Air Docket #A-93-25, item IV-D-34, August 4, 1994, 


p.27. 


1760nan Corporation. "Comments," EPA Air Docket #A-93-25, item IV-D-34, August 4,1994, 


p.27. 


Emission Standards for New-Nonroad Spark.-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5127/95 
-121­

177Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket #A-93­

25, item IV-D-22 (part 2 of 2), August 5, 1994, p.xx 


178North American Equipment Dealers Association. "Comments," EPA Air Docket#A-93-25, 


item IV-D-02, June 15, 1994, p.5. 


179 Natural Resources Defense Council, "Comments of the Natural Resource Defense Council 


Regarding Proposed Emission Standards for New Nonroad Spark Ignition Engines at or below 19 


Kilowatts." EPA Air Docket A-93-25, item IV-D-27, August 5, 1994, p. 8. 


180 Id. at p. 8. 


181 NRDC, item IV -D-27, STAPPN ALAPCO, "Comments of the ... on the U.S. Environmental 


Protection Agency's Proposed Rulemaking on Emission Standards for New Nonroad Spark­


Ignition Engines At or Below 19 Kilowatts." EPA Air Docket A-93-25, item IV-D-08, August 4, 


1994, p. 9-10. 


182 Tecumseh Products Company, "EPA Phase 1 NPRM Comments." EPA Air Docket A-93-25, 


item IV -D-28, August 5, 1994, p. 2-3. 


183 Portable Power Equipment Manufacturers Association, "Comments of the Portable Power 


Equipment Manufacturers Association." EPA Air Docket A-93-25, item IV-D-22, August 5, 


1994,p.30 


184 STAPPA?ALAPCO at p. 10. 


185 Kohler, Letter to Docket Clerk. EPA Air Docket A-93-25, item IV-D-21, August 3, 1995, p. 


3. Engine Manufacturers Association, "Statement of the Engine Manufacturers Association and the 

Outdoor Power Equipment Institute." EPA Air Docket A-93-25, item xxx, August 5, 1994, p. 51. 

186Id. . 

187 EMA at p. 52 


188 PPEMA, andEMA. 


189 City of Chicago. "RE: Proposed Rules for Emission Standards for New Nonroad Spark-


Ignition Engines at or Below 19 Kilowatts - 59 Fed. Reg. 25399." EPA Air Docket #A-93-25, 


item IV-D-26, July 19, 1994, pp. 1-2. 


190 Portable Power Equipment Manufacturers Association. "Comments of the Portable Power 


Equipment Manufacturers Association." EPA Air Docket #A-93-25, item IV-D-22A, August 5, 


1994, pp. 48-51. 


191 Outdoor Power Equipment Institute. "Supplemental Comments," EPA Air Docket #A-93­

25, item IV-D-20, August 5, 1994, pp. 5-8. 


192 Onan Corporation. "Comments," EPA Air Docket #A-93-25, item IV -D-34, p. 6. 


193 Engine Manufacturers Association and Outdoor Power Equipment Institute. "Statement of 


the Engine Manufacturers Association and the Outdoor Power Equipment Institute." EPA Air 


Docket #A-93-25, item IV -D-07, August 5, 1994, pp.63-64. 


194 North American Equipment Dealers Association. "EPA -- 40 CFR Part 90 Emission 


Standards, New Nonroad SI Engines At or Below 19 KW." EPA Air Docket #A-93-25, item IV­


D-02, June 15, 1994, p. 3. 


195 Tecumseh Products Company. "EPA Phase I," EPA Air Docket#A-93-25, item IV-D-28, 


August 5, 1994, p. 3. 


196 ECHO. "Attn: Docket A-93-25." EPA Air Docket #A-93-25, item IV-D-32, July 6,1994, 


p~. 5-6. 


1 7 For more discussion on the impact on small entities, see section VII. C. of the preamble, 


"Impact on Small Entities;" see also the corresponding section in the preamble to the NPRM at 59 


FR 25399, 25430 (May 16, 1994). 


198 Engine Manufacturers Association/Outdoor Power Equipment Institute. "Statement of the 

Engine Manufacturers Association and the Outdoor Power Equipment Institute," EPA Air Docket 

#A-93-25, item #IV-D-07, August 4, 1994, pp. 61-63. 

Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95 
-122­

199 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket 

#A-93-25, item #IV -D-22A, August 5, 1994, pp. 22-24. 

200 59 FR 31306 (June 17, 1994). 

201 Briggs & Stratton Corporation. liRe: Docket No. A-93-25," letter and attachment. EPA 

Air Docket #A-93-25, item # IV-D-33, August 18, 1994. 

202 Manufacturers of Emission Controls Association. liRe: Emission Standards for New 

Nonroad Spark-Ignition Engines at or below 19 Kilowatts, Docket No. A-93-25," letter and 

attachment. EPA Air Docket #A-93-25, item # IV-D-29, June 21, 1994, pp. 3-4. 

203 Drachand, Don, California Air Resources Board. Letter to Richard Wilson, U.S. 

Environmental Protection Agency, EPA Air Docket #A-93-25, item #IV -D-30, August 5, 1994, p. 

5. 

204 ST APPAl ALAPCO. "Comments of the State and Territorial Air Pollution Program 


Administrators and the Association of Local Air Pollution Control Officers on the U.S. 


Environmental Protection Agency's Proposed Rulemaking on Emission Standards for New 


Nonroad Spark-Ignition Engines at or below 19 Kilowatts," EPA Air Docket #A-93-25, item #IV­


D-08, August 4, 1994, pp. 10-11. 


205 Natural Resources Defense Council. "Comments of the Natural Resources Defense 


Council," EPA Air Docket #A-93-25, item #IV-D-27, August 5, 1994, pp. 6-8. 


206 Natural Resources Defense CounciL "Comments of the Natural Resources Defense 


Council," EPA Air Docket #A-93-25. item #IV-D-27, August 5, 1994, p. 7. 


207 Portable Power Equipment Manufacturers Association. "Comments," EPA Air Docket 


#A-93-25, item #IV-D-22A, August 5, 1994, p. xx. 


208Holliday Environmental Services. Written submission to EPA Air Docket #A-93-25, item IV­


D-Ol 


209NRDC, 8/25/94, Docket No. A-93-25, IV-D-27, p.xx. 


21ONorth American Equipment Dealers Association. Written submission to EPA Air Docket A-91­

21, item II-D-02, December 10, 1991, p.2. 


2l I North American Equipment De~ers Association. Written submission to EPA Air Docket A-91­

21, item II-D-02, December 10, 1991, p. 


2l2North American Equipment Dealers Association. Written submission to EPA Air Docket A-91­

21, item II-D-02, December 10, 1991, pp.l. 10. 


Emission Standards for New-Nonroad Spark-Ignition Engines at or Below 19 Kilowatts: 

Response to Comments on the NPRM 5/27/95