The skyline of downtown Los Angeles through a layer of smog in 2006. (Fred Prouser/Reuters)

The U.S. Court of Appeals for the District of Columbia Circuit granted the Environmental Protection Agency’s request Tuesday to delay oral argument in a case over its 2015 smog standard, allowing the agency time to reconsider the Obama-era rule.

EPA asked on Friday for the postponement, saying President Trump’s appointees “are closely reviewing the 2015 Rule to determine whether the Agency should reconsider the rule or some part of it.” The new standard, which imposes tighter restrictions on ground-level ozone, was challenged both by several industry groups and Republican-controlled states as too tough and by a coalition of environmental and public health organizations as not stringent enough.

The three-judge panel ordered EPA “to file status reports on the agency’s review of the 2015 Rule at 90-day intervals beginning 90 days from the date of this order,” adding that within “30 days of the agency notifying the court and the parties what action it has or will be taking with respect to the 2015 Rule, the parties are directed to file motions to govern future proceedings in these consolidated cases.”

How Trump is rolling back Obama’s legacy

EPA has not yet said exactly what it plans to do about the ozone National Ambient Air Quality Standards (NAAQS), which the agency lowered from 75 parts per billion to 70 parts per billion. Ozone, generated by the burning of fossil fuels by cars, trucks and factories, produces hazy skies and is linked to lung and heart disease.

Scott Pruitt joined attorneys general from nine other states in challenging the rule before he took the helm of EPA.

“We are thankful to the court for granting our motion to postpone oral argument,” EPA spokeswoman Liz Bowman said in an email. “In light of President Trump’s pro-growth agenda, EPA continues to carefully review the broad implications of the 2015 ozone standard and ensure that we are supporting American jobs and protecting human health and the environment.”

But Earthjustice attorney Seth Johnson, who is suing the agency over the standard, said in an email that any delay in implementing the tighter standards “will likely result in unnecessary asthma attacks and deaths.”

“We will continue to fight to protect public health under the Clean Air Act and for the continued implementation of the more protective 2015 smog standards,” Johnson added. “The EPA has no justification to weaken anything about these key pollution reduction measures, and we’ll fight against that. We look forward to having our day in court in the future to fight for stronger protections.”