Axial face seals are well suited for dynamic shaft sealing in CO2 (R744) refrigerant compressors for air-conditioning units in regard to design. An axial face seal by Kaco Dichtungstechnik GmbH has been released for series production and is currently being run in at nearly all producers of compressors worldwide. In multiple fleet tests the seal has been proven beyond doubt and fulfils all required criteria within its specification. With the presented test results it is proven that shaft sealing for CO2 refrigerant compressors can be mastered.