A room in which the air is highly filtered in order to keep out impurities. Chip fabrication plants use clean rooms where the air is completely exchanged as much as seven times per minute. Workers go through an elaborate procedure to gown themselves in the "bunny suits" which are required to keep them from contaminating the atmosphere. Clean rooms are also used in the manufacture of hard disks. In the biotech industry, clean rooms keep the environment free of infectious bacteria and viruses. See also clean room technique.