The Air Resources Board (the "Board" or "ARB") willconduct a public hearing at the time and place noted below to consideramendments to the small off-road engine regulations.

March 26, 1998
9:30 a.m.
Board Hearing Room, Lower Level
2020 L Street
Sacramento, California 95814

This item will be considered at a two-day meeting of the Board, whichwill commence at 9:30 a.m., March 26, 1998, and will continue at 8:30a.m., March 27, 1998. This item may not be considered until March 27, 1998.Please consult the agenda for the meeting, which will be available at least10 days before March 26, 1998, to determine the day on which this itemwill be considered.


Sections Affected: Amendment of the following chapter and sectionsof Title 13, California Code of Regulations, and the documents incorporatedby reference therein: Chapter 9, Off-road Vehicles and Engines PollutionControl Devices; Article 1, Utility and Lawn and Garden Engines; Sections2400, et seq., and the incorporated "California Exhaust Emission Standardsand Test Procedures for 1995 and Later Utility and Lawn and Garden EquipmentEngines;" and Article 3, Off-Highway Recreational Vehicles and Engines;Sections 2410 - 2414.

The California Clean Air Act as codified in the Health and Safety CodeSections 43013 and 43018 grants the ARB authority to regulate off-roadmobile source categories. Included are marine vessels, locomotives, utilityengines, off-road motorcycles, and off-highway vehicles.

In December, 1990, the Board approved emission control regulations forsmall off-road (utility) engines. (See Title 13, California Code of Regulations,sections 2400-2407 and the documents incorporated therein). The small off-roadengine category was the first off-road category subject to emission controlregulations because its emissions impact was significant and because acourt order required Board action on the category by January 1991. As initiallyadopted, the small off-road engine regulations applied to engines producedon or after January 1, 1994. On July 5, 1995, the United States EnvironmentalProtection Agency (U.S. EPA) approved California's authorization request;approval allows the state to enforce the regulations.

The small off-road engine regulations include exhaust emission standards,test procedures, and provisions for warranty and production engine complianceprograms. The adopted regulations consist of two tiers of emission standards.The Tier 1 took effect in 1995, while Tier 2 becomes effective in 1999.Exhaust emission standards were established for hydrocarbon (HC), oxidesof nitrogen (NOx), carbon monoxide, and particulate (PM) (for diesel-poweredand two-stroke engines only). Additionally, the regulations are dividedinto two major categories--handheld and nonhandheld. Engines used in handheldapplications, such as chainsaws and trimmers, may comply with the lessstringent set of emission standards.

The Board directed the ARB staff to present progress reports before implementingthe Tier 2 small off-road engine standards in 1999. The reports are intendedto inform the Board of industry's progress in developing the technologyrequired to comply with the standards, and of any issues that must be addressed.The staff made its initial report to the Board on January 25, 1996.The Board's directives at that time were for staff to investigate how theregulations could be improved, and to consider issues raised by industryin this process.

The proposal described below is the staff's response to the Board's directives.In general, the staff recommends that the regulations be modified to reflectthe realities of the small engine market and the technological capabilitiesof the industry. Specific major modifications are described below.

The staff proposes to revise the regulations to include all engines lessthan 25 horsepower that are used in off-road mobile applications. Thiswould also include specialty vehicles and golf cart engines below 25 horsepower.New golf carts for use in areas that do not meet the federal ozone standardswill continue to have a zero-emission requirement.

The staff proposes to replace the current standards categories of handheldand nonhandheld engines with standards categories based on engine displacement.Engines less than or equal to 60 cubic centimeters displacement would besubject to emissions standards formerly associated with handheld equipmentengines, while engines greater than 60 cubic centimeters displacement wouldbe subject to emissions standards formerly associated with nonhandheldequipment engines. The staff believes that the revised distinction willsimplify matters for most engine manufacturers and their customers.

The staff recommends that the implementation of the 1999 emissions standardsbe delayed one year. Thus, the current Tier 1 new engine standards wouldbe retained through 1999. The staff also proposes to add an emissions deteriorationrequirement for model year 2000 and subsequent engines. For engines lessthan or equal to 60 cubic centimeters (<=60cc) displacement, the proposed2000 and subsequent emission standards for HC and NOx remain essentiallyunchanged from the 1999 Tier 2 levels for "handheld" engines.The proposal would combine the HC and NOx standards for <=60cc enginesto enhance compliance flexibility while maintaining the same overall levelof ozone precursor emissions. For engines greater than 60 cubic centimetersdisplacement, the proposed emission standards for HC and NOx are a relaxationof the 1999 Tier 2 "nonhandheld" levels. Furthermore, the staffproposes to align with the U.S. EPA/ARB/industry Statement of Principles(1)regarding the regulation of compression-ignition engines.

Staff's data confirm the need to consider an additional level of reductionthat could apply to non-handheld engines. The Board will review all relevantevidence regarding the proposed Tier 2 standards and evidence supportingor opposing a standard more stringent than Tier 2 for non-handheld engines.Specific details on the proposed emission standards and implementationschedule are contained in the initial statement of reasons (staff report).

As noted above, the staff proposes to revise the regulations to ensurethat engines are "emissions durable," i.e., controlled throughouttheir useful life. The staff proposes to differentiate engines based onemissions durability periods:

Emissions Durability Periods


Emissions DurabilityPeriods (hours)

0-60 cubic centimeters



> 60 cubic centimeters




Staff proposes that manufacturers be required to note the durability periodon the engine label, on the equipment label, on the equipment packaging,and in the owner's manual.

Because the sampling equipment required for PM is extremely expensive,the staff proposes that compliance with the proposed PM standard be determinedthrough an engineering evaluation process, rather than through direct measurement.Specifically, the staff proposes that compliance with the 2-stroke particulatestandard be determined from dividing the HC emissions by the fuel/oil ratioused in the engine.

The staff recommends that emissions averaging and credits programs be addedto the certification and production line testing regulations, and thatportions of the existing program be revised to increase industry flexibilitywith regards to compliance with the regulations. In particular, the staffrecommends the addition of an option to the current quality-audit programthat requires testing of one percent of production engines. The optionwould reduce the testing burden on manufacturers through the use of a statisticalprocedure that would more closely align the California program with theproposed federal program. The staff also proposes to institute specialreduced testing considerations for small volume manufacturers that produceless than 500 engines annually for California.

Finally, the staff proposes to make other miscellaneous changes to theregulations and test procedures to conform with federal practices and toclarify existing regulatory language.

The U.S. EPA also has regulations for small off-road engines (Title 40,Code of Federal Regulations, Part 90). Those regulations are similar tothe California Tier 1 regulations that predated them. The U.S. EPA regulationsdiffer from the ARB staff's proposal in a number of ways, including lessstringent emissions standards, no control of engine deterioration, andno measures to increase industry flexibility such as averaging. The U.S.EPA is proposing a phase 2 regulation that will control engine deteriorationand introduce flexibility measures such as averaging, but the emissionsstandards remain less stringent than the staff proposal. The staff hasmade every effort to minimize conflicts with the proposed U.S. EPA rule,while retaining specific features needed by California. Those efforts includealigning the structure of the production-line testing programs and theaveraging programs. However, the proposal includes several differencesfrom the U.S. EPA proposal, including year-round production-line testing,and more stringent emissions standards.

The staff analysis of the proposal indicates that the proposal will reduceemissions from ozone precursors in a cost-effective manner, beyond whatwould be accomplished either by the existing federal rule or by the federalproposal. Thus, the cost of the separate California program is justifiedby the benefit to human health, public welfare, and the environment. Inaddition, the differences from the federal program are authorized by Healthand Safety Code sections 43013 and 43018.


The Board staff has prepared the staff report for the proposed action thatincludes a summary of the environmental impacts of the proposal. The staffreport and the full text of the proposed regulatory language may be obtainedfrom the Board's Public Information Office, 2020 L Street, Sacramento,California 95814, (916) 322-2990 at least 45 days prior to the scheduledhearing. The ARB has determined that it is not feasible to draft the regulationin plain English due to the technical nature of the regulation; however,a plain English summary of the regulation is available from the agencycontact person named in this notice, and/or is also contained in the staffreport for this regulatory action. Further inquiries regarding this mattershould be directed to Ms. Jackie Lourenco, Manager, Off-Road Controls Sectionat (626) 575-6676 or Air Resources Board, Mobile Source Control Division,9528 Telstar Avenue, El Monte, California 91731.


The determination of the Board's Executive Officer concerning the costsor savings necessarily incurred in reasonable compliance with the proposedregulations are presented below.

The Executive Officer has determined that the proposed regulatory actionwill not create costs or savings, as defined in Government Code section11346.5(a)(6), to any state agency or in federal funding to the state,costs or mandate to any local agency or school district whether or notreimbursable by the state pursuant to Part 7 (commencing with section 17500),Division 4, Title 2 of the Government Code, or other nondiscretionary savingsto local agencies.

In developing this regulatory proposal, the ARB staff evaluated the potentialeconomic impacts on private persons and businesses. The Executive Officerhas determined, pursuant to Government Code section 11346.5(a)(3)(B), thatthe regulation will affect small business. The proposed amendment is intendedto facilitate compliance with the small off-road engine regulations andto assure the continued availability of a full range of products to Californiabusinesses and individuals. Thus, the Executive Officer has also determinedthat adoption of the proposed regulatory action will not have a significantadverse economic impact on businesses, including the ability of Californiabusinesses to compete with businesses in other states.

The Executive Officer has determined that there will be no, or an insignificant,potential cost impact, as defined in Government Code section 11346.5(a)(9),on private persons or businesses directly affected resulting form the proposedaction.

Finally, the Executive Officer has determined that the proposed regulatoryaction will not affect the creation or elimination of jobs within the Stateof California, the creation of new businesses or elimination of existingbusinesses within California, or the expansion of businesses currentlydoing business within California. Assessment of the economic impacts ofthe proposed regulatory action can be found in the staff report.

Before taking final action on the proposed regulatory action, the Boardmust determine that no alternative considered by the agency would be moreeffective in carrying out the purpose for which the action is proposedor would be as effective and less burdensome of affected private personsthan the proposed action.


A written report and oral statements will be presented by staff at themeeting. Interested members of the public may also present comments orallyor in writing. To be considered by the Board, written comments must befiled with the Clerk of the Board, Air Resources Board, P.O. Box 2815,Sacramento, California 95812, no later than 12:00 noon March 25, 1998,or received by the Clerk of the Board at the meeting. It is requested butnot required that twenty copies of any written statement be submitted.


This regulatory action is proposed under that authority granted in Healthand Safety Code Sections 39600 and 39601. This action is proposed to implement,interpret, and make specific Health and Safety Code Sections 43013 and43018.

The public hearing will be conducted in accordance with the CaliforniaAdministrative Procedure Act, Title 2, Division 3, Part 1, Chapter 3.5(commencing with section 11340) of the Government Code.

Following the public hearing, the Board may adopt the regulatory languageas originally proposed, or with nonsubstantial or grammatical modifications.The Board may also adopt the proposed regulatory language with other modificationsif the text as modified is sufficiently related to the originally proposedtext that the public was adequately placed on notice that the regulatorylanguage as modified could result from the proposed regulatory action;in such event the full regulatory text, with the modifications clearlyindicated, will be made available to the public, for written comment, atleast 15 days before it is adopted. The public may request a copy of themodified regulatory text from the Board's Public Information office, 2020L Street, Sacramento, CA 95814, (916) 322-2990.


Michael P. Kenny
Executive Officer


1. The U.S. EPA, ARB, and members of industry negotiatedan agreement regarding compression-ignition engines that achieves the emissionsreductions called for by SIP measures M9 and M10, but through a combinationof different standards and timetables than those measures contain. Theagreement included compression-ignition engines below 25 horsepower.