That has been coming for a long time.They are afraid of the enviro. hazards and want to cut out the DIY'ers.As was mentioned,the refrigerant R-12 was phased out,almost completely,but there is still some around.Everyone in the HVAC field complained about the certification requirement so the industry made it dum-as-mud simple to pass it. The automotive paint industry is already finding alternative products to sell to the public, they couldn't survive if the only people they could sell to had to be liscensed and certified to use their products. And there would be a new market/industry created by someone to meet the demand if the Fed's. come down to hard on current products.As you already know the issocyanates and other products will become hard to buy and/or eliminated. Just a guess here,but I would suspect that eventially the industry will react to the demand ( $$$ talks ) but the best products on the market will require liscense and certification AND,,,,LOTS MORE MONEY TO BUY. But that will hurt the low cost production shops. So I wonder what the PPG's and other bigboys are planning to put out .