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  • Allison Stalker

EPA Proposes Updates to Ozone Standards

Updated: Aug 28, 2023

The Environmental Protection Agency (EPA) is proposing to strengthen ground-level ozone, or smog, standards. The EPA proposed a range of 65 to 70 parts per billion (ppb) while also taking comments on a level as low as 60 ppb. The last update to these standards was completed in 2008, setting the current standard to 75 ppb.

In order to set the new proposed standard, the EPA examined more than 1,000 new studies that have been completed since the current standard was set in 2008. The consensus of the studies indicated that exposure to levels of ozone below 75 ppb can pose serious threats to public health, harm the respiratory system, cause or aggravate asthma and other lung diseases, and is link to premature death from respiratory and cardiovascular causes. Ozone is formed when nitrogen oxides and volatile organic compounds “bake” in the sun from sources like vehicles, industries, power plants, and various solvents and paints.

“Bringing ozone pollution standards in line with the latest science will clean up our air, improve access to crucial air quality information, and protect those most at-risk. It empowers the American people with updated air quality information to protect our loved ones – because whether we work or play outdoors – we deserve to know the air we breathe is safe,” said EPA Administrator Gina McCarthy. “Fulfilling the promise of the Clean Air Act has always been EPA’s responsibility. Our health protections have endured because they’re engineered to evolve, so that’s why we’re using the latest science to update air quality standards – to fulfill the law’s promise, and defend each and every person’s right to clean air.”

Some other standards that have recently been finalized and proposed will help meet these standards, including the Tier 3 clean vehicle and fuels standards. The EPA estimates that the majority of U.S. counties will be able to meet the new standards with the rules and programs currently in place or underway. The proposal would allow for counties to have between 2020 and 2037 to meet the standards. The EPA is also proposing to extend the ozone monitoring season for 33 states.

The EPA plans to issue final ozone standards by October 1, 2015.



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