Table 1.

Control level (zone) and disinfection policies

Control level (zone)	Disinfection and sterilization	Machine, surface, and floor disinfection
Level 1: “contaminated” zone	Air sterilizer continuous operation/UV irradiation (1 hour each time, at least 2 times per day with 2 hours terminal disinfection)	2000 mg/L chlorine disinfectant (with an action time of at least 30 minutes followed by cleaning with water after using disinfectant on metal instruments), 75% ethanol (use as directed in manufacturer instructions)
Level 2: “semicontaminated” zone	Disinfection according to the regulation of disinfection techniques in the health care setting as issued by the country before COVID-19	Disinfection as according to the regulation of disinfection techniques in health care settings as issued by the country before COVID-19
Level 3: “clean” zone

Abbreviations: COVID-19 = coronavirus disease 2019; UV = ultraviolet.