[Editor's Note: Updated with comments from Dow, the Environmental Defense Fund and more.]

Bowing to pressure from business groups, President Barack Obama put the brakes on plans to toughen smog standards and ordered the Environmental Protection Agency this morning to withdraw its draft of updated rules.

The Washington Post's early report on Obama's about-face spread the news as the world inside the Beltway began slipping away for the long Labor Day weekend. Nevertheless, the response from environmental groups and other advocates of the stricter regulations was swift and sharp.

"The Obama administration is caving to big polluters at the expense of protecting the air we breathe," said Gene Karpinski, president of the League of Conservation Voters, in a statement issued in Washington, D.C. "This is a huge win for corporate polluters and huge loss for public health."

The Natural Resources Defense Council also weighed in.

"The White House is siding with corporate polluters over the American people," said NRDC President Frances Beinecke. "The Clean Air Act clearly requires the Environmental Protection Agency to set protective standards against smog-based on science and the law. The White House now has polluted that process with politics.

"Our public officials, including in the White House, serve to protect us from harm. They need to get on with doing their jobs. Inaction cannot be an option when it comes to ensuring a healthy and prosperous America."

Business groups had called for the delay of new regulations, saying that new pollution controls would be too expensive to put in place in an economic climate that remains poor.

"The signal today was that message is being heard," said Jack Gerard, president of the American Petroleum Institute, according to a report from Bloomberg.

The proposed EPA regulations would have tightened rules for ground-level ozone set by the Bush administration in 2008. Ground-level ozone, the main component in smog, is formed by emissions from factories, power plants, cars and other sources, like landfills, when they react with sunlight.

The standards for ground-level ozone are due for an update in 2013. But in January 2010 EPA Administrator Lisa Jackson said the rules on the books were not strict enough, given that the emission levels permitted by the 2008 regulations were significantly higher than those recommended by the agency's scientific advisory committee.

Here's how Obama explained his decision in a statement this morning:

"After careful consideration, I have requested that Administrator Jackson withdraw the draft Ozone National Ambient Air Quality Standards at this time. Work is already underway to update a 2006 review of the science that will result in the reconsideration of the ozone standard in 2013. Ultimately, I did not support asking state and local governments to begin implementing a new standard that will soon be reconsidered."

The American Lung Association threatened to go to court.

"For two years the administration dragged its feet by delaying its decision, unnecessarily putting lives at risk," said a statement from American Lung Association President and CEO Charles D. Connor. "Its final decision not to enact a more protective ozone health standard is jeopardizing the health of millions of Americans, which is inexcusable.

"The American Lung Association now intends to revive its participation in litigation with the administration, which was suspended following numerous assurances that the administration was going to complete this reconsideration and obey the law."

Reactions from both sides of the issue poured in throughout the day.

Leaders of the Business Roundtable, which held a media briefing earlier this week to push for the postponement, hailed Obama's decision.

"We applaud the president's decision to withdraw the ozone rule," said Dow Chemical Chairman and CEO Andrew Liveris, who chairs the Business Roundtable's Regulatory Reform Working Group.

"This was the right decision, and consistent with policy established in his executive order," Liveris said. "It will have a direct and positive impact on the business community providing more certainty and will contribute to economic growth and job creation."

Environmental Defense Fund President Fred Krupp said, "This unfortunate decision puts millions of Americans, particularly children, at risk from industrial pollution. We're deeply disappointed that the administration has chosen to leave in place outdated standards that lag far behind what scientists have unanimously recommended."

The American Center for Progress also decried Obama's turnabout.

"Today's announcement from the White House that they will retreat from implementing the much needed -- and long-overdue -- ozone pollution standard is deeply disappointing and grants an item on Big Oil's wish list at the expense of the health of children, seniors and the infirm," the center's statement said. "A new standard for smog would save 4,300 lives and prevent 7,000 hospital visits and tens of thousands of cases of asthma and other serious respiratory illnesses each year."

The Heartland Institute offered a different take.

"This move is a fake to the right by the Obama administration and a superficial and deceptive one at that," said Maureen Martin, the Heartland Institute's senior fellow for legal affairs, in one of a series of statements from the organization. "EPA has unleashed a wrecking ball of new regulations that will jeopardize our supply of electricity by putting many coal-fired electrical power plants out of business. The set of ozone regulations withdrawn today is only one part of them."

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