R-22 was mostly phased out in new equipment in the United States by regulatory action by the EPA under the Significant New Alternatives Program (SNAP) by rules 20 and 21 of the program, due to its high global warming potential. The EPA program was consistent with the Montreal Accords, but international agreements must be ratified by the US Senate to have legal effect. A 2017 decision of the US Court of Appeals for the District of Columbia Circuit held that the US EPA lacked authority to regulate the use of R-22 under SNAP. In essence the court ruled the EPA's statutory authority was for ozone reduction, not global warming. The EPA subsequently issued guidance to the effect that the EPA would no longer regulate R-22. A 2018 ruling by the same court held that the EPA failed to conform with required procedure when it issued its guidance pursuant to the 2017 ruling, voiding the guidance, but not the prior ruling that required it. The refrigeration and air conditioning industry had already discontinued production of new R-22 equipment. The practical effect of these rulings is to reduce the cost of imported R-22 to maintain aging equipment, extending its service life, while preventing the use of R-22 in new equipment.