A federal court late Tuesday afternoon granted a request from the U.S. Environmental Protection Agency to delay court proceedings over the more protective 2015 smog standards. The agency had requested the delay to give it additional time to review those standards.

The U.S. Court of Appeals for the District of Columbia Circuit granted the EPA’s request in a summary order.

Attorneys for public health and environmental organizations think the delay is likely an indication that the federal government will seek to stop defending or weaken implementation of the smog standards.

"Any delay in implementing the 2015 smog 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," Earthjustice attorney Seth Johnson said. "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."

NRDC Clean Air Director John Walke said: "Because the court order leaves safer health standards for smog pollution in effect, EPA must continue to enforce those protections. Any honest review by EPA will make clear that there is no legal or scientific basis to worsen clean air safeguards for Americans. NRDC will vigorously oppose in court any attempt by the Trump administration to sabotage Americans’ right to safe air quality."

Health and environmental groups had argued that reasons for the delay were baseless and that any delay in moving forward with implementation of the more protective smog standard set in 2015 would imperil lives.

The groups filed their opposition to the EPA’s request for a delay Monday morning in response to the EPA’s request, filed late Friday, in which the agency asked to put off a scheduled April 19 court date for oral arguments over the smog standard.

The 2015 smog standard led to multiple lawsuits over smog protections. Polluters and allied states, including Oklahoma, under the direction of Scott Pruitt who was then the state’s attorney general, sued the EPA for setting a standard they claimed was too strong. Several leading public health and environmental organizations, represented by Earthjustice, and some states including California and New York, joined the litigation to oppose the arguments the polluters and their allies were making. The groups represented by Earthjustice in opposing the polluter and allied challenges are the American Lung Association, Sierra Club, Physicians for Social Responsibility, and the Natural Resources Defense Council.

In October 2015, following litigation by health and environmental groups for missing its legally required deadline to review the ozone standard, the EPA established a more protective standard further limiting the amount of smog allowed in the air people breathe. The standard was strengthened from 75 parts per billion to 70 ppb.

The EPA estimates that, by 2025, the 2015 standard will save hundreds of lives, prevent 230,000 asthma attacks in children, and prevent 160,000 missed school days for kids each year. Although stronger than the prior 2008 standard, leading medical societies have found that an even more protective standard is needed to safeguard children, asthmatics, seniors and others.

Under the Clean Air Act, the standard must be based solely on scientific evidence about the impact ozone has on people’s health.

Ozone is a corrosive greenhouse gas, formed by emissions from cars, trucks and factories, which is linked to asthma attacks and can cause death in people. It also harms plants, stunting their growth and discoloring and killing their leaves.

In addition to defending the current standard, public health and environmental organizations sued EPA to further strengthen the standard, arguing that a 70 ppb standard still allowed smog levels that the EPA’s own scientific research showed harmed people and plants. Earthjustice is representing the Sierra Club, Physicians for Social Responsibility, West Harlem Environmental Action, Appalachian Mountain Club, and the National Parks Conservation Association in that challenge.

Read the legal document.