The Court of Appeals for the District of Columbia Circuit will hear oral arguments on February 16, 2017 in a challenge to the  Environmental Protection Agency’s (“EPA”) rule regarding ground-level ozone limits.

Under the authority of the Clean Air Act (42 U.S.C. §7401 et seq.) (“CAA”), the EPA is authorized to establish National Ambient Air Quality Standards (“NAAQS”) to regulate emissions of hazardous air pollutants. In October 2015, the EPA announced a rule reducing the NAAQS for ground-level ozone limits from 75 parts per billion (“ppb”) down to 70 ppb. Ground-level ozone is created by emissions released into the air by manufacturing plants, utilities and vehicles

Initially businesses were relieved the EPA did not lower the limit to the originally proposed limit of 65 ppb, a standard businesses claimed would have been unattainable for anyone in the manufacturing industry. Subsequently, however, an industry coalition, including the U.S. Chamber of Commerce and the National Association of Manufacturers, challenged the rule, claiming the regulation goes too far and violates the Clean Air Act. The coalition states the rule did not properly account for background ozone that cannot be controlled or for various economic, social and other impacts from lowering the ozone limit.

The EPA claims that the regulation is in line with the CAA – which requires that ozone levels are calculated based only on public health and environmental standards, not the costs of compliance.

Further, a coalition of environmental and health groups, including the Sierra Club and Physicians for Social Responsibility, sued the EPA claiming that the regulation is not strict enough. The group will argue at the hearing that while the new limit offers greater protection than the previous standard, it does not reflect what is necessary to protect public health.