EPA revises smog standard

In October 2015, the U.S. Environmental Protection Agency (EPA) improved America's national air quality standard for ground-level ozone—more commonly known as smog.

Smog is a dangerous air pollutant that is linked to premature deaths, asthma attacks and other serious heart and lung diseases.

EPA improved our national smog standard from 75 parts per billion to 70 parts per billion. That was the least protective end of the range recommended by the EPA's independent scientific advisors and the nation's leading health and medical societies. They had recommended a standard of 60 to 70 parts per billion. In spite of that, former EPA Administrator Scott Pruitt delayed implementing the standards.

The first step in implementing the 2015 smog standard is to identify the areas that have unhealthy pollution levels – formally known as finalizing the initial area designations. EPA faced a legal deadline of October 1, 2017 to take that step – but it missed the deadline. EPA finalized a portion of designations, for areas meeting the standard in November 2017. In December, 2017, a coalition of public health, environmental, and community groups – including EDF – filed a lawsuit to compel EPA to carry out his duties under the law and fully implement the smog standard.

In March, 2018, a U.S. District Court ordered the agency to move forward with implementation of these life-saving protections to reduce smog. By July, EPA had designated areas across the country that were meeting or exceeding our health-based smog standards. EDF will keep working to make sure EPA takes the next steps necessary to protect all Americans from smog.

Smog press releases and resources