Legal basis: Article 3 of the Technical Specification for Hospital Isolation: Clean area: the area where patients are not easily polluted by blood, body fluids, pathogenic microorganisms and other substances, and the area where patients with infectious diseases are not allowed to enter. Including duty room, bathroom, men's and women's locker room, bathroom, storage room, dining room, etc. Medical personnel; Potential contaminated area: the area between clean area and contaminated area in the ward for diagnosis and treatment of respiratory infectious diseases may be contaminated by patients' blood, body fluids and pathogenic microorganisms. Including medical staff office, treatment room, nurse station, patient supplies and medical equipment treatment room, inner corridor, etc. Contaminated area: the area where patients with infectious diseases and suspected infectious diseases are treated in the ward for diagnosis and treatment of respiratory infectious diseases, including places where articles contaminated by their blood, body fluids, secretions and excreta are temporarily stored and disposed of. Including ward, disposal room, dirt room and patient admission and discharge treatment room.