California Air Resources Board

SACRAMENTO – The Air Resources Board (ARB) commends the U.S. Environmental Protection Agency's (USEPA) decision today to minimize the emissions of particulate matter (PM) and oxides of nitrogen (NOx) from off-road diesel powered engines.

"We are very happy with EPA's decision to adopt stringent emissions standards for off road farming and construction equipment," said ARB Chairman Alan Lloyd. "This is an important step in California's journey to clean air. The inclusion of marine and locomotive engines under the low sulfur fuel requirement is also tremendously important."

The USEPA decision cuts by 90 percent the PM and NOx emissions from diesel engines used for construction, agriculture, and other nonroad equipment. In California that translates to a 20 percent reduction of NOx and PM from the all sources controlled by US EPA but contribute to the state's inventory. Other sources controlled by USEPA but not part of this regulation are locomotives, airplanes and marine engines. All federally controlled sources in California account for 20 percent of nitrogen oxides and particulate matter in the our State Implementation Plan.

Nitrogen oxides are major contributors to smog formation and acid deposition. PM10 (PM 10 microns in diameter and smaller) is among the most harmful of all air pollutants. When inhaled these particles evade the respiratory system's natural defenses and lodge deep in the lungs. Health problems begin as the body reacts to these foreign particles. PM10 can increase the number and severity of asthma attacks, cause or aggravate bronchitis and other lung diseases, and reduce the body's ability to fight infections.

"To reach the standards for clean air and to protect public health, emission sources under the federal government's jurisdiction require continued attention and more stringent standards," Chairman Lloyd added. "We particularly need USEPA to make national fuels as clean as California's, and to help us accelerate the retirement of older high emitting vehicles."

The Air Resources Board is a department of the California Environmental Protection Agency. 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.