[Reference] Since the Standard emphasizes the special protection of the critical parts of the operating room (the operating table and its surroundings), it is necessary to define the operating zone. The operating zone of a Class Ⅰ operating room refers to the area including the operating table after extending 0.9m outward on each of the two sides and 0.4m outward at each of the two ends; the operating zone of a Class Ⅱ operating room refers to the area including the operating table after extending 0.6m outward on each of the two sides and 0.4m outward at each of the two ends; and the operating zone of a Class Ⅲ operating room refers to the area extending 0.4m outward on all four sides of the operating table.

The other areas within the clean operating room apart from the operating zone are defined as the surrounding zone.