What type of refrigerant is used in the PURY-HP72 and can I substitute another refrigerant?

The CITY MULTI H2i R2 series uses R410A refrigerant exclusively. You must not use any other refrigerant, as doing so may cause the unit or pipes to burst, result in explosion or fire, or cause the refrigerant oil to deteriorate and damage the compressor. Mitsubishi Electric cannot be held responsible for malfunctions or accidents resulting from the use of the wrong refrigerant. (Page 2)