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EPA redesignates Phoenix area as attaining 1-hour ozone standard; Area reports eight years of clean data

Release Date: 5/23/2005
Contact Information: Wendy Chavez, (415) 947-4248

SAN FRANCISCO – The U.S. Environmental Protection Agency Friday redesignated the Phoenix metropolitan area as having met the federal health standard for 1-hour ozone and approved the state’s plan to maintain clean air.

The Phoenix area has not violated the federal 1-hour ozone standard in the last eight years. However, the area is in violation of the newer 8-hour ozone standard, and will be submitting an air quality plan in 2007 showing how the area will attain that standard. The recent “ozone alerts” are related to the 8-hour ozone standard.

“State and local agencies implement a number of innovative programs that have reduced volatile organic compounds (VOCs), one of the precursors to ozone -- and we commend those efforts,” said Wayne Nastri, the EPA’s regional administrator for the Pacific Southwest region. “This translates into cleaner air for the more than 3 million residents of the Phoenix area. We will continue to work with the state and local agencies to address 8-hour ozone.”

Area sources and on-road and non-road mobile sources cause the majority of the Valley’s VOCs. The state’s clean air plan includes many programs that have reduced VOCs, including a nationally recognized vehicle emissions inspection program, a cleaner burning gasoline program, pollution reduction measures for commercial and industrial sources, and woodburning restrictions.

Ozone is a gas that occurs naturally in the upper atmosphere to protect the earth from the sun's harmful ultraviolet rays. At ground level, ozone is created by a chemical reaction involving sunlight, high temperatures and pollutants such as car exhaust, oil, solvent and gas vapors, and paint fumes. Power plants, gas stations, print shops, and lawn and garden equipment also contribute to smog formation.

Ground-level ozone irritates your nose, throat and lungs. It may also cause coughing, headaches, nausea, as well as premature aging of lung tissue. It can damage lung tissue and make it harder to breathe. Ozone pollution aggravates respiratory illnesses such as asthma, bronchitis and emphysema. Healthy people who are active outdoors on high ozone days may experience coughing, nasal congestion and itchy eyes.

After the 1990 Clean Air Act amendments, the Phoenix area did not meet the moderate 1-hour ozone standard by the Nov. 15, 1996 deadline. In 1997, the EPA reclassified the area to serious, with a new attainment date of November 15, 1999. The Phoenix metropolitan area has not exceeded the 1-hour ozone standard since 1996.

For more information, visit https://www.epa.gov/region09/air/phoenixoz/index.html#