The answer is "clean air act".
Production of R12 or CFC 12 was ended by the Clean Air act on 1 January 1996. Today the rest of the provisions are items which has been recouped and recovered back to an artificially unadulterated state as per ARI-700 gauges. The ARI standard is fundamentally a virgin detail. The supply of virgin item is restricted as the greater part of the virgin was drained in the principal year after creation stopped. Creation stopped in 1995.
Dichlorodifluoromethane (R-12), generally sold under the name Freon-12, is a chlorofluorocarbon (CFC) halomethane utilized as a refrigerant and airborne shower force until the point when its produce was stopped in 1995, because of worries about harm to the ozone layer.