How do I learn of what refrigerant will be allowed in new systems in Canada?
To use a refrigerant in Canada there are many things an installation needs to comply with such as but not limited to the NBC, the equipment design standards such as UL/CSA 60335 2-89, and be allowed to be imported or manufactured in accordance with The ODSHAR GWP limits. Canada does not have a mechanism like the USA SNAP that allows or disallows certain refrigerants in certain applications, so ECCC implemented the GWP limits within the ODSHAR regulations for imported or manufactured equipment.
There is also the DSL or Domestic Substances list which essentially controls import or manufacture of all chemicals not just refrigerants, and it applies to the components in the blends.
Here is a link to the DSL search tool (the easiest way to search is to use the CAS Number)