Image source does not exist News Release: 2010-12-17 Changes to diesel rules protect public health, provide relief and flexibility to California businesses

Release #:10-64

ARB PIO: (916) 322-2990

Karen Caesar

Stanley Young

Changes to diesel rules protect public health, provide relief and flexibility to California businesses

Public health still protected as economy recovers

SACRAMENTO - The California Air Resources Board today took further steps to fight air pollution and protect public health by offering businesses a variety of options to comply with regulations to reduce soot from diesel engines.

“No other state, and no other nation has such an extensive set of rules to slash pollution from diesel engines.  The diesel rules for vehicles cover almost everything that moves on or off the road, from trucks and buses to off-road construction equipment, and over the next 12 years they will prevent 3,900 premature deaths by removing thousands of tons of diesel soot from the air we breathe,” said ARB Chairman Mary D. Nichols.  “The changes we set in place today will continue those public health benefits while reducing the cost of compliance by more than 60 percent.”

The amendments complement earlier emission control measures that aggressively target diesel pollution, which is associated with a host of health ailments including cancer.  With the amended regulations in place, diesel particulate matter emissions will be reduced from today’s levels by 50 percent by 2014 and 70 percent by 2020.

Over the past year, ARB staff held 20 public workshops throughout the state to solicit stakeholder input and discuss options for revising diesel control measures affecting commercially owned trucks, buses, port trucks, tractor trailers and off-road vehicles, including construction and large-spark ignition equipment (e.g, forklifts). 

Statewide On-Road Truck and Bus Regulation:

Approved in December 2008, this regulation will clean up emissions from the nearly one million heavy duty diesel trucks that operate in California.  The approved amendments ensure that the regulation will continue to do its job, helping the state meet its federal obligations under the Clean Air Act while also allowing businesses more flexible compliance options.  Key amendments will:

In addition, the Board voted to require all school buses greater than 14,000 lbs. GVWR to be retrofit with diesel filters by 2014. If no retrofit is available, the buses have until 2018 to be replaced by vehicles with a 2010 model year engine or emissions equivalent.

For more details on the Statewide Truck and Bus Regulation, please see:

Off-Road (e.g., construction equipment) Regulation:

First approved in July 2007, this pioneering regulation – the first of its kind in the nation – is aimed at reducing diesel emissions from the state's estimated 150,000 "off-road" vehicles used in construction, mining, airport ground support and other industries.  The state’s economic downturn, which began after this regulation was adopted, heavily impacted this sector, causing emissions to decline primarily due to fewer pieces of equipment in use, along with reduced activity of the remaining equipment.  As amended, the regulation will:

For more details on the Off-Road Regulation, please see:

Port Truck Regulation:

Approved in December 2007, the port truck (or “drayage”) regulation was adopted to modernize and clean up some of the oldest, dirtiest trucks in the fleet – those that serve the state’s busiest ports and rail yards.  The regulation has already had an impact by banning pre-1994 trucks from these facilities and requiring diesel particulate filters on others earlier this year, enabling adjacent communities to breathe a little easier.  The new amendments will:

For more details on the Port Truck Regulation, please see:

Other amendments adopted today affect the Heavy Duty Diesel Greenhouse Gas Reduction Measure ( and the Large Spark Ignition Regulation (

California’s diesel emissions control measures were adopted under the ARB’s Diesel Risk Reduction Plan, which was approved by the Board in 2000, two years after diesel exhaust was declared a toxic air contaminant by the state’s Scientific Review Panel.  The ARB has already passed measures addressing urban buses, garbage trucks, school bus and truck idling, stationary engines, transport refrigeration units, cargo handling equipment at ports and rail yards, ship engines, harbor craft and fuel.  

ARB's mission is to promote and protect public health, welfare, and ecological resources through effective reduction of air pollutants while recognizing and considering effects on the economy. The ARB oversees all air pollution control efforts in California to attain and maintain health based air quality standards.