The EPA is required by the Clean Air Act to review and, if necessary, update its standards every five years to keep up with the latest science and research. The agency was required to finish its current review in March, five years after the previous analysis, but has not yet finalized its evaluation.
Current standards are based on data from 2006.
"So we're now looking at science that is seven years old," Nolen said. "Most of us would not be happy if our doctors stopped looking at the science seven years ago and said, 'This is how you're going to be treated.' So this is the reason for the same requirement that they keep up and take a look at the current research."
Health and environmental groups want the EPA to impose stricter standards for ozone, a greenhouse gas.
Tougher standards could prevent up to 12,000 premature deaths per year, according to an analysis by the EPA, but industry groups warn they could cost businesses up to $1 trillion.
Protecting lives and health should come first, the organizations argue. They cite a 2001 Supreme Court decision that ruled the EPA should set air quality standards based on health, not costs, though economic impacts should be considered in the standards' implementation.
"EPA is continuing to work with its independent scientific advisors on the ongoing review of the ozone standard to determine whether a revision is appropriate based on the extensive body of research that will inform EPA's decision," the agency said in a statement. "The agency is following its normal open and transparent review process that allows for extensive public comment."
The agency plans to release documents on its review in December and a group of independent science advisors are scheduled to meet to discuss the standards in March.
The four groups filing the lawsuit are the American Lung Association, the Environmental Defense Fund, the Natural Resources Defense Council and the Sierra Club. The law firm Earthjustice is handling the case.
The EPA tried to update ozone standards during President Obama's first term, but in a blow to environmentalists, the White House shelved that regulation in 2011 to perform a full review this year.