The Supreme Court on Tuesday let stand a lower court ruling that allows the continued use of hydrofluorocarbons (HFCs), a powerful class of climate-damaging chemicals, in millions of consumer products ranging from air conditioners to aerosol sprays.

An Obama-era rule limiting the use of HFCs was struck down by the U.S. Court of Appeals for the District of Columbia Circuit — in an opinion authored by then-D.C. Circuit Judge Brett Kavanaugh — in August 2017. Kavanaugh, who was sworn in as a Supreme Court justice on Saturday despite facing numerous allegations of sexual misconduct, did not participate in the Supreme Court deliberations in the HFC case, Honeywell v. Mexichem Fluor.

The Supreme Court’s decision not to hear the appeal of the D.C. Circuit decision came one day after the Intergovernmental Panel on Climate Change (IPCC) released a major report detailing the devastating effect climate change will have on the world if widespread action isn’t immediately taken.

“Coming only a day after the world’s leading climate scientists called for urgent action to curb dangerous carbon pollution, the court’s decision lets irresponsible companies to continue harming our planet — even though safer alternatives exist,” David Doniger, an attorney and senior strategic director of the Climate and Clean Energy Program at the Natural Resources Defense Council (NRDC), said Tuesday in a statement.

Despite the Supreme Court’s decision not to hear the case, Doniger expressed hope in response to action taken at the state level to limit the use of HFCs. Four states — California, New York, Maryland, and Connecticut — have already committed to curb HFCs, with more states expected to follow, he said.


The Environmental Protection Agency (EPA) rule, issued during the Obama administration, required companies to phase out HFCs used in refrigerators and air conditioning in favor of new chemicals that do not harm the ozone layer and contribute little or nothing to climate change.

In 2015, the EPA determined there were safer alternatives for many HFC uses. The agency put those HFC uses on the prohibited list. The EPA was sued by two chemical companies — Mexichem Fluor and Arkema — which had failed to invest in safe alternatives. They argued the EPA lacked authority to order the replacement of HFCs because — no matter how dangerous HFCs are to the climate — they do not deplete the ozone layer.

In the August 2017 opinion authored by Kavanaugh, though, the D.C Circuit decided the EPA lacked authority to regulate the companies already using HFCs.

“EPA’s well-intentioned policy objectives with respect to climate change do not on their own authorize the agency to regulate,” Kavanaugh wrote. “Under the Constitution, congressional inaction does not license an agency to take matters into its own hands, even to solve a pressing policy issue such as climate change.”

In June, NRDC petitioned the Supreme Court to reverse the D.C. Circuit Court’s ruling.

If allowed to remain in place, the HFC rules would have ensured the safety of the chemicals used to replace ozone-depleting substances in millions of air conditioners, refrigerators, aerosol cans, insulating foams, and other products Americans used nearly every day, NRDC said.


The Supreme Court’s decision not to hear the appeal will allow all of the current users of HFCs to keep using them in perpetuity, even though companies have developed much safer substitutes, some with far less the heat-trapping power of HFCs.

The EPA, under Trump’s leadership, has sought to remove any mention of climate change on its website and its documents, including the role of HFCs in exacerbating climate change.

Last week, E&E News reported that the Trump administration removed language about how climate change affects children’s health from a draft EPA proposal on HFCs. An earlier draft of an EPA proposal on HFCs contained language about how children are more vulnerable to the impacts of climate change. That language was removed during a review by the White House Office of Information and Regulatory Affairs.