Under the Clean Air Act, the EPA is charged with reviewing and setting standards for pollutants considered harmful to public health and the environment every five years. These pollutants include ozone, particulate matter, carbon monoxide, nitrogen, sulfur dioxide, and lead.

Ozone is the main ingredient in smog, which is created when vehicle and industrial emissions mix in sunlight and heat.

Regulations Could Cost $1 Trillion and Millions of Jobs

In 2011 (two years ahead of schedule), the EPA proposed lowering the ozone standard from 75 parts per billion to 60-70 parts per billion (ppb). The economic implications of such a low standard are astounding—complying with the law is projected to cost businesses $20 billion to $90 billion annually, making it the most expensive-ever U.S. regulation. Other estimates of the economic implications put the total cost to the economy as high as $1 trillion.

The proposed ozone standards could also threaten millions of U.S. jobs. A 2010 study by the Manufacturing Alliance projected that approval of such a low ozone standard could result in the loss of as many as 7.3 million jobs by 2020. And the U.S. Senate Committee on Environment and Public Works estimated that a 60 ppb standard would create a $14.8 billion decline in production and the loss of 91,700 jobs by 2030 in the Cincinnati-Dayton, Ohio region alone.

Not only would the new standards hinder the economy, but according to a 2010 analysis by the Congressional Research Service, a 60 ppb ozone standard would also render up to 96 percent of U.S. counties noncompliant. This presents a particular challenge for the economy—counties in non-compliance risk a loss of federal highway funding and are subject to additional EPA regulation and oversight. Business expansion in those counties would also be more difficult due to additional regulatory burdens.

The EPA went beyond even the Obama Administration’s environmental agenda. Because of the huge impact such a low standard would have on the economy, the White House blocked the EPA’s proposed standard from taking effect. Instead, the administration encouraged further study before promulgating a lower ozone standard.

Environmental Impact Questionable

The EPA’s new proposal for lowering the ozone standard to 60-70 ppb is particularly questionable given that just a few years ago, in 2008, the EPA reviewed 2006 data and studies on the effects of ozone on humans and set the national standard for ambient ozone at 75 ppb.

The research supporting a low 60 ppb ozone standard is severely lacking. In 2013, after an extensive review of studies of ozone exposure below 80 ppb, the Applied Journal of Toxicology found the evidence does not demonstrate a causal association between the current 75 ppb ozone standard and adverse effects on lung function. The only new study to provide new clinical data on the effects of ozone on humans since the EPA last updated ozone standards in 2008 did not find that statistically significant pulmonary function effects occur at 60 ppb.

In other words, there is insufficient evidence to support reducing ozone levels to 60 ppb, yet the EPA continues to charge ahead in the face of enormous risks to the economy.

The EPA has been accused of cherry-picking studies that show negative effects of ozone exposure at lower levels and neglecting to consider the flaws in many of the studies relied upon. For instance, two of the main panel studies that purport to prove low levels of ozone exposure are hazardous rely on self-reported data, which can be unreliable. Though the EPA acknowledges the flaws in those studies, the agency still uses them as part of the basis for pushing a lower ozone threshold.