No. You cannot purchase R-22 refrigerant if you are only certified under 609. You will need to have a valid 608 certification as well in order to legally purchase or handle R-22 refrigerant. 609 certification only covers automotive air conditioning units. If the vehicle you are working on either has a secondary cooling unit or the vehicle takes a different type of refrigerant such as R-22 or R-404A you will need to be 608 certified.
You can read more on this subject by reviewing the excerpt from the EPA’s site below or by clicking this link to the EPA’s site.
“Effective, September 22, 2003, EPA has limited the sale of ozone-depleting refrigerants intended for use with stationary refrigeration and air-conditioning equipment to section 608 technicians. Therefore, section 609 technicians cannot purchase R-22, regardless of container size.
Note, that for purposes of maintenance, repair, service, or disposal, that buses using R-22 are not defined as MVACs; therefore, Section 608 certification (Type II or Universal) is required to service buses using R-22.”