Tan Zhi, deputy head of the Disinfection and Vector Control Institute at the Jiangsu Center for Disease Control and Prevention, outlined scientific methods of disinfection amid efforts to resume work in an orderly manner while continuing to curb the spread of the novel coronavirus (COVID-19).
Q: How are public places kept clean and disinfected?
A: In public places without confirmed COVID-19 cases or asymptomatic patients, the main efforts are through preventive disinfection such as good ventilation and wet cleaning every day.
Objects or surfaces touched frequently by people such as door handles, doorbells, elevator buttons, handrails, public electronic equipment and keyboards, seats and handrails need to be disinfected after cleaning. How many different times is based on the flow of people.
During the cleaning process, rags need to be kept separately, washed and changed frequently, and placed under the sun to dry or air-dried in a cool and ventilated place. It’s recommended to use 500mg/L chlorine solution to regularly disinfect rags and then clean them with fresh water after 30 minutes.
Q: How to disinfect public toilets?
A: Keep good ventilation in public toilets through the use of a mechanical ventilation system. Other equipment needs to be operating normally to ensure people can use hand cleaner and wash their hands. If possible, the toilet can also be equipped with fast-drying hand sanitizer or an induction-type hand sanitizer dispenser.
Taps, toilets, toilet buttons, seats, lids and dustbins are easily contaminated and must be carefully disinfected, by using a 500mg/L~1000mg/L chlorine solution and then cleaned with water after 30 minutes.
The toilet floor can be disinfected by using 500mg/L~1000mg/L chlorine solution and then cleaned with water after 30 minutes.
Q: How to ensure hygiene in cafeterias?
A: Cooking utensils need to be kept clean, with knives and cutting boards for raw and cooked food separated. It’s also necessary to separate raw and cooked food when storing.
After use, the cutting boards and knives need to be cleaned, dried in a timely manner and placed in a cool and ventilated place. If needed, they can be sterilized by boiling water or hot steam for 15-30 minutes.
After use, tableware should be cleaned in time, sterilized by boiling water, hot steam or in a disinfection cabinet that meets national standards. It can also be soaked in 500mg/L~1000mg/L chlorine solution and after 30 minutes then rinsed with water and air dried.
Tables, chairs and the floor need to be kept clean and through the wet cleaning, assisted by the regular use of a 500mg/L chlorine solution to sterilize and then cleaned with water after 30 minutes. Cleaned rags and mops need to be put under the sun or air-dried in a ventilated place.
Q: How to keep shopping malls and supermarkets clean and disinfected?
A: Disinfection priority needs to be given to counters, trolleys and elevator handrails. Increased ventilation is recommended to reduce the bacterial load of indoor air through use of a mechanical ventilation system if possible. It’s also necessary to keep public toilets in such places well-ventilated, clean and disinfected.
Q: How to keep parks clean and disinfected?
A: Exercise equipment, large toys, public seats, gates, fences and handrails as well as public toilets in such places need to be kept disinfected. It’s also necessary to disinfect counters and dustbins in kiosks. The outdoor ground needs to be kept clean and cleared of contaminants followed by disinfection of any place found to have contaminants. Objects or surfaces that few people have touched such as plants only need to be kept clean if they are not contaminated by vomit or fecal matter.
Q: How to clean up and disinfect trash in public places?
A: The trash needs to be sorted and collected separately every day. It is recommended to use a dustbin with a plastic bag inside and a lid. The dustbin needs to be regularly cleaned and disinfected, such as by spraying a 500mg/L-1000mg/L chlorine solution on the surfaces until wet and soaking for 30 minutes.
Q: Does it mean the more disinfection the better?
A: No. There’s no need to disinfect many times every day. The purpose of disinfection is for the inactivation or destruction of micro-organisms that cause disease. There’s no need to disinfect at home numerous times because the environment is relatively stable and not affected by external contamination, so it’s enough to it keep clean.
Some of the chemical disinfectants are irritating to respiratory system and skin. Excessive use of disinfectants is harmful to the human body and can cause damage to items as well as environmental pollution. The concentration of disinfection solution should not be too high. For preventive purposes, the concentration of chlorine in disinfection solution should not exceed 1000mg/L. People also need to protect themselves while performing disinfection.
