1, chemical plants, clean rooms, food factories, electronics, optics, precision instrument workshops, biopharmaceutical laboratories, laboratories and other places with high cleanliness requirements and strong chemical odor.

2. Banks, computer instrument rooms, meeting rooms and other places.

3, hospitals, isolation wards, infectious disease areas, operating rooms, clinics, rehabilitation centers, blood stations, sterile rooms, etc.

4. Houses, hotels, bathing places, libraries, science and technology museums, waiting rooms (buses), gyms, fitness places, shopping malls, conference rooms, business centers, computer rooms and other places.

5, garbage transfer stations, landfills, sewage treatment plants, pumping stations, sewage pools and other malodorous places.