"High pressure gas" is defined by the High Pressure Gas Safety Act as follows.
1.
A compressed gas whose pressure is 1 MPa or more at normal working temperature and whose pressure is actually 1 MPa or more, or a compressed gas whose pressure is 1 MPa or more at 35 ° C.
2.
Compressed acetylene gas whose pressure is 0.2 MPa or more at normal working temperature and whose pressure is actually 0.2 MPa or more, or compressed acetylene gas whose pressure is 0.2 MPa or more at 15 ° C.
3.
Liquefied gas with a pressure of 0.2 MPa or more at normal working temperature and actually with a pressure of 0.2 MPa or more, or a liquefied gas with a temperature of 35 ° C or less when the pressure is 0.2 MPa or more.
4.
In addition to the gas listed in the previous item, liquefied gas exceeding 0 MPa at 35 ° C specified by Cabinet Order.
Specific examples of the refrigerant include ammonia, R12, R22, and R134a.