A service ban is now in place on the use of virgin refrigerants with a GWP over 2,500 . R404A and R507A along with R434A and R422D are affected. It is important to recognise that the ban is on the use of these refrigerants, not the purchase. This means that even if you are stocking virgin R404A for example, you cannot use it after 31st of December 2019.
There are exemptions for those people using these gasses on systems operating below -50 0C. All other users will be required to use either a drop in replacement or reclaimed refrigerant should the systems require recharging. There are 3 options for dealing with this, they are as follows
Retrofit your system with a drop in replacement with a lower GWP. This may require modifications to your system but it usually results in improved energy efficiency. Your refrigeration contractor will be able to advise you on the options available.
Service your plant using reclaimed refrigerant if available.
Fit new plant using a low GWP refrigerant. This may be a good option particularly if your plant is old. Efficiencies have improved immensely over the years and you may find that the improved equipment and reliability more than pays back the cost of the new plant.