This standard specifies the basic principles for the design of process cells for the handling of radioactive materials for planners, manufacturers, subsequent users and competent authorities and experts. This standard applies to the design, construction, installation and operation of process cells. The process cells described are not accessible. Due to the work and processes taking place in the cells, the cells are generally smaller than 6 m3 and usually have less than 0,5 m of concrete as shielding (see also 1999/188/Euratom Additional Protocol). This standard for process cells is distinct from hot cells of the DIN 25420 and 25407-3 series of standards and from hot cells as described in the 1999/188/Euratom Additional Protocol. This standard does not apply to enclosed work areas in which the operation is mainly carried out by means of glove ports. Here DIN 25412-1 applies. As soon as open radioactive materials are handled in these process cells, the installation site is always a room which shall meet the requirements of the DIN 25425 series of standards; in particular the requirements for fire protection shall be implemented through the room. If radioactive materials are to be kept or stored in the process cell, then DIN 25422 applies. The ventilation of both the room and the process cell shall be coordinated with each other in such a way that the requirements with regard to air exchange, air filtration and air conduction are fulfilled for both the room and the process cell. This document has been prepared by Working Committee NA 062-07-62 AA "Strahlenschutzeinrichtungen" ("Radiation protection") at DIN Standards Committee Materials Testing (NMP).