A RABS device is a self-standing device with a vertical laminar air flow. It provides protection of pharmaceutical process carried out within the protected area of the device. The critical part of the line where the substance and the packaging are exposed to contamination from the surroundings is washed with a HEPA filtered laminar air flow, generated by the RABS device over the line. The protection offered by the device belongs to class 5 of ISO 14644 classification or in class A according to GMP guidelines.