What year did they stop using r12?

The use of R-12 refrigerant, also known as dichlorodifluoromethane, was largely phased out in the United States starting in 1996 due to its ozone-depleting properties. The Montreal Protocol, an international treaty aimed at protecting the ozone layer, led to the gradual reduction of R-12 production and consumption. By 2010, the production and import of R-12 were banned in many countries, solidifying its discontinuation.