I asked the Ontario government if the ODP card was required to purchase 410a refrigerant, as it's not listed as a Class 1 ozone depleting substance.
This is their reply,
QuoteR410A is a combination of R32 and R125 which are halocarbons regulated by O. Reg. 463/10. Under the definition of "halocarbon" in O. Reg. 463/10 clause (w) states:
(w) any mixture that contains any of the substances listed in the preceding clauses.
This means that you must have an ODP card to purchase R410A.
If you have any further questions, please do not hesitate to contact me.