What refrigerant is considered high or high pressure refrigerant?

High-pressure refrigerants typically include substances such as R-410A and R-134A. These refrigerants operate at higher pressures compared to low-pressure refrigerants like R-22. The designation of "high pressure" can vary depending on the specific application and system design, but generally, refrigerants that function above 50 psi at standard operating conditions are classified as high-pressure refrigerants.