A blend of R125, R143a, and R134a intended for low and medium temperature refrigeration applications where R502 was previously used. Most new supermarket and refrigeration equipment has been built for an HFC such as R404A, R507, or R407A. It is also possible to retrofit charge R507 systems with R404A. R404A has slightly lower pressures than R507 (from the small amount of R134a added), and generally both blends have slightly higher pressures than R502. R404A requires Poly Olester Oil (POE) lubricant, which is usually charged into new equipment. If retrofitting existing equipment, the original oil must be replaced with POE.