The official reason that R-12 was phased out starting in 1991, is that it is a gas that when released into the atmosphere, destroys o-zone leading to GLOBAL WARMING. Now in 2015, R-22 in most Household and Commercial A/C systems and quite a few Commercial Refrigeration systems, is being phased out. The EPA has put in place regulations forcing everyone to recover the refrigerant instead of just dumping the gas into the air as was done pre 1991, back in the day if we had to repair a line on a system we dumped the gas to the atmosphere if it was 1 lb. or 500lbs, no recovery machines existed. Now even before we recovered the gas it is stated that we contributed 8% to the whole global warming deal...it would have made more sense to put the recovery regs in place and keep the three common refrigerants in the game (R-12, R-22, R-502), which by the way all were cheap and worked very well. Now there is well over 20 refrigerants in the game and none of them are as cheap as R-12 used to be...pre Govenment 1.00 tax increase per pound per six months. R-12 used to cost .50 cents per pound back in the 80's now it is $500.00 to $700.00 per 30 lb. drum, all Tax. But then again i'm just a stupid A/C and Refrigeration Contractor so what do I know about saving the planet and besides saving the environmant has become a HUGE bussiness... BIG money.