List to Determine Preempt Off-Road Applications

This page last reviewed April 4, 2014

The 1990 amendments to the federal Clean Air Act preempt California control of emissions from new farm and construction equipment under 175 horsepower. Emissions from these new engines are beyond ARB's authority to regulate. The U.S. EPA has sole authority to establish emission standards for these preempt engines used in new farm and construction equipment under 175 horsepower.  However, these equipment types may become subject to ARB's In-Use Off-Road Vehicle Regulations which target diesel particulate matter (PM) and oxides of nitrogen (NOx) emissions from in-use (existing) off-road heavy-duty diesel vehicles, and hydrocarbons (HC) and NOx emissions from in-use large spark-ignition (LSI) engine forklifts and other industrial equipment. For more information, please refer to ARB's In-Use Off-Road Vehicle Regulations web pages for in-use off-road diesel vehicles and in-use LSI fleet requirements.  

Below is a description of applications for determining preempted equipment. Please also see information regarding the federal non-road engine emissions control program

The following preemption list has been modified. At the request of industry, staff has removed the term "Cleaners: high pressure" from the preemption list to avoid confusion with pressure washers. This modification is intended to clarify the ARB's interpretation that pressure washers have never been considered preempt equipment.

Equipment types with engines less than 25 horsepower are presumed not to be construction or farm equipment, with the exception of the following equipment types, which have been determined to be construction or farm equipment:

Aerial devices: vehicle mounted
Asphalt recycler/reclaimer, sealer
Augers: earth
Backpack Compressors
Boring machines: portable line
Breakers: pavement and/or rock
Brush cutters/Clearing saws 40 cc and above (blade capable only)
Burners: bituminous equipment
Cable layers
Chainsaws 45 cc and above
Cleaners: steam, sewer, barn
Compactor: roller/plate
Concrete buggy, corer, screed, mixer, finishing equipment
Continuous Digger
Conveyors: portable
Crawler excavators
Crushers: stone
Cultivators: powered
Cutting machine
Dumper: small on-site
Elevating work platforms
Farm loaders: front end
Feed conveyors
Fertilizer spreader
Forage box/Haulage and loading machine
Forklifts: diesel and/or rough terrain
Harvesters, crop
Light towers
Mixers: mortar, plaster, grout
Mowing equipment: agricultural
Mud jack
Pavers: asphalt, curb and gutter
Pipe layer
Plows: vibratory
Post hole diggers
Power pack: hydraulic
Pruner: orchard
Pumps 40 cc and above
Rollers: trench
Sawmill: portable
Saws: concrete, masonry, cutoff
Signal boards: highway
Silo unloaders
Skid-steer loaders
Specialized fruit/nut harvester
Sprayers: bituminous, concrete curing, crop, field
Stump cutters, grinders
Surfacing equipment
Tampers and rammers
Tractor: compact utility
Troweling machines: concrete
Vibrators: concrete, finisher, roller
Well driller: portable
Wheel loaders

Equipment types with engines 25 horsepower or greater are presumed to be construction or farm equipment, with the exception of the equipment types listed below, which have been determined not to be construction or farm equipment.

Aircraft Ground Power
Baggage Handling
Forklifts that are neither rough terrain nor powered by diesel engines
Generator Sets
Mining Equipment not otherwise primarily used in the construction industry
Off-Highway Recreational Vehicles
Other Industrial Equipment
Refrigeration Units less than 50 horsepower
Turf Care Equipment

Where Can I Get More Information?

For more information, please call Muthukumar Chidambaram at (626) 575-7040 or via e-mail at

Off-Road Emission Reduction Program