(Adds more detail about ruling)
By Jan Wolfe and Valerie Volcovici
Aug 23 (Reuters) - A U.S. appeals court on Friday mostly upheld Obama-era Environmental Protection Agency regulations from 2015 that set a more stringent standard for ozone, a pollutant linked to several serious health conditions, rejecting claims from industry groups that the limits were too hard to attain.
The U.S. Court of Appeals for the D.C. Circuit largely rejected claims from energy companies, including coal company Murray Energy, the Chamber of Commerce and the American Petroleum Institute that the Obama administration's decision to tighten the National Ambient Air Quality Standard from 75 parts per billion of ozone to 70 parts per billion was too difficult for companies to achieve.
Though the three-judge panel was unanimous in upholding the Obama-era standard, it directed the EPA to revisit secondary public welfare standards which are meant to protect animals and vegetation, and vacated a provision which held certain energy and industrial facilities in the middle of their permitting processes to a less stringent ozone standard.
The Trump administration EPA last year decided not to scrap the Obama-era ozone standard and continued to defend the measure through the ongoing legal challenges. (Reporting by Jan Wolfe Editing by Chizu Nomiyama and Chris Reese)
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