When was the production of CFCs phased out in the United States?

The concept behind this question

The Montreal Protocol is the international treaty that set the phase-out schedule for ozone-depleting substances; Section 608 of the U.S. Clean Air Act is the domestic regulation that implements it for refrigerants. Section 608 is why technician certification exists at all: it makes it unlawful to knowingly vent regulated refrigerants during the maintenance, service, repair or disposal of appliances, and it requires that anyone doing that work be certified.