WASHINGTON (CN) — The D.C. Circuit blocked the government Tuesday from stripping limits on a class of chemicals known as hydrofluorocarbons, or HFCs, that spew harmful greenhouse gases.
HFCs tend to appear in aerosol sprays, air conditioning units, insulation and refrigerators. Though industries initially embraced them as a replacement for substances found to deplete the ozone layer, HFCs fell out of favor amid research about their contribution to climate change with harmful greenhouse gas emissions.

The Environmental Protection Agency tried to ban HFCs all together in 2015 but had to retool the rule following a court challenge. Under then-Administrator Scott Pruitt, the agency instead removed the designation of HFCs as unsafe for use, prompting a new challenge by the National Resource Defense Council.
The D.C. Circuit vacated this rule in a split decision Tuesday, saying the agency failed to follow necessary notice-and-comment procedures.
NRDC attorney Peter DeMarco lauded the court for restoring what he called “common-sense” restrictions.
“EPA must ensure that as companies complete their transition away from ozone-depleting substances, they switch to alternatives safer than climate-polluting HFCs,” DeMarco said in a statement.
Writing for the majority, Chief U.S. Circuit Judge Srikanth Srinivasan emphasized that a number of options were available to the EPA when the court concluded in 2017 that the ban put in place a year earlier had been too ambitious.
“The one option EPA could not permissibly pursue was the one it chose: promulgating a legislative rule without abiding by notice-and-comment requirements and without invoking any exception to those obligations,” wrote Srinivasan, who was appointed to the bench by President Obama.
U.S. Circuit Judges David Tatel and Neomi Rao rounded out the panel when the court heard arguments in March. The Clinton-appointed Tatel concurred Tuesday, while the Trump-appointed Rao dissented.
Rao said lifting the rule was the only practical solution available to the EPA administrator and that Tuesday’s holding would force future interpreters of the Clean Air Act to read it with a “judicial asterisk” in mind.
While true that agencies are dutybound to follow procedure in establishing new obligations, Rao said the 2018 guidance from the EPA was a different animal.
“Because the 2018 guidance advised the public of the EPA’s interpretation of legal obligations created by this court, it was an interpretive rule properly issued without notice and comment procedures,”
The EPA did not immediately return request for comment.
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