But Environmental Protection Agency administrator Christie Todd Whitman claims this won't compromise air quality, CBS News Correspondent Bill Plante reports.
"This means we will be able to maintain clean air standards but allow for additional supply and this will help control cost impact," Whitman said in a brief interview following a speech at a National Governors Association meeting.
Whitman said the EPA's policy change "certainly should stabilize prices and keep them from having the kind of spike that you saw last summer."
She said would notify refiners on Monday that they can begin making cleaner-burning summer gasoline with the relaxed standards. "The letter we are sending gives them (refiners) the authority to go ahead."
Appearing with Whitman, House Speaker Dennis Hastert, R-Ill., said "Some people have predicted $3.00 for the cost per gallon this year and we hope this precautionary step will take care of that."
Gasoline prices in Milwaukee and Chicago soared as high as $2.75 a gallon last summer because of supply problems and the high costs of blending the fuel. The high prices sparked consumer outrage, congressional hearings and a federal antitrust investigation.
Environmentalists, still upset by the president's recent reversal of a campaign promise to reduce carbon dioxide emissions from electric power plants, aren't buying the assertion that the new gas formula won't pollute.
"This has a health impact, and I think the people who live in Wisconsin and Illinois who will be breathing this air that's less healthy now would think that this is a significant impact," said Deb Callahan of the League of Conservation Voters.
EPA's action means gasoline sold in Chicago and Milwaukee can temporarily contain larger amounts of pollutants known as volatile organic compounds (VOCs).
The VOC standard would be raised to 0.3 pounds per square inch Reid vapor pressure which measures the volatility of fuel from the current 0.2 pounds.
When added to gasoline, ethanol increases the evaporation rate of fuel, causing more VOC emissions, but ethanol reduces carbon monoxide emissions. Both pollutants play a role in ozone formation.
The EPA will not expand the relaxed standards to other areas because Chicago and Milwaukee are the only major cities that depend exclusively on ethanol-blended gasoline, Whitman said.
The EPA requires most major U.S. cities to use cleaner-burning gasoline during the hot summer months to reduce smog and air pollution. Illinois and Wisconsin refiners typically blend corn-based ethanol with a special kind of highly-refined gasoline to achieve the stricter standards.
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