This section draws information from the US Centers for Disease Control and Prevention (CDC) guidance on household cleaning and disinfection and detailed disinfection guidance, the World Health Organization’s Interim guidance on Cleaning and disinfection of environmental surfaces in the context of COVID-19, Water, Sanitation and Hygiene Technical Brief and Interim guidance for home care of COVID-19 patients, as well as the European Centre for Disease Prevention and Control (ECDC) Interim guidance for environmental cleaning in non-healthcare facilities exposed to SARS-CoV-2.
Infected individuals may shed SARS-CoV-2 even if they develop no or mild symptoms, and we know that the viral load of patients is highest when symptoms first appear. Therefore it is important to clean surfaces and objects in your home even if nobody appears sick in your household. Additional recommendations are provided below if a COVID-19 case occurs in your household.
What is the difference between cleaning and disinfection?
Cleaning typically refers to the physical removal of dirt and germs from surfaces, normally with soap or detergent and water, before disinfection. Disinfection is the process of inactivating (killing) germs like SARS-CoV-2 on surfaces, often by using chemicals such as chlorine (bleach) after cleaning.
Daily cleaning and disinfection of frequently touched household surfaces such as doorknobs, light switches, toilets, and faucets is recommended.
If surfaces are visibly dirty, they should be cleaned with water and regular soap/detergent prior to disinfection. Cleaning should be done systematically, from clean to soiled areas, and from high to low areas. Cleaning materials (cloth, gloves) can become contaminated and should be laundered (as described below) or disposed of safely.
What are the types of surfaces found in homes?
Household surfaces and objects can be porous or non-porous. A few examples are provided in the following table. Porous surfaces and objects have lots of very small holes that let liquid pass through, whereas nonporous surfaces do not. Because of this difference, recommended cleaning and disinfection practices are different for porous and non-porous surfaces.
Adapted from: National Pesticide Information Center
The WHO recommends identifying ‘high-touch’ surfaces in the household for priority disinfection. High-touch surfaces may include door, window, cabinet, and appliance handles, kitchen and food preparation surfaces, countertops, bathroom surfaces, toilets and flush handles, water faucets, and electronic devices such as phones, tablets, keyboards, and computer mice.
Non-porous surfaces
Commonly available disinfectants like household bleach can be used to disinfect non-porous surfaces after they have been cleaned. Household bleach usually contains 5-6% sodium hypochlorite (chlorine) and should be diluted with clean water before use to a final concentration of at least 0.1% chlorine (see diagram below for instructions). Please note that concentration of chlorine in bleach may vary by context, if it is lower than 5-6%, dilutions should be adjusted accordingly. For more information on creating chlorine solutions try this calculator.
Chlorine solutions are corrosive; they should never be stored in metallic containers and, in case of application onto a metallic surface for disinfection, thorough rinsing with water after disinfection can prevent corrosion. Alcohol-based disinfectants with at least 70% alcohol can be used as an alternative to chlorine for disinfection of metallic items and surfaces.
Chlorine can cause irritation to skin and eyes. People should be instructed to prepare dilutions in well ventilated areas and to avoid contact between the bleach/dilution and skin or eyes. Additional safety recommendations related to the use of chemical disinfectants are summarized here.
Source: Karin Gallandat
For disinfection to be effective, sufficient contact between the disinfectant and the virus is needed. This means applying the disinfectant so that the surface is completely covered (visibly wet) and leaving the disinfectant - 0.1% chlorine or 70% ethanol - for at least 1 minute before wiping dry.
Diluted chlorine solutions become less effective over time and should be remade daily and stored in a cool, dry place away from direct sunlight.
Porous surfaces
Porous surfaces (such as rugs, curtains, or wood) should be cleaned as regularly as possible with soap and warm or hot water. If possible, this should be followed by generous application of a disinfectant (0.1% chlorine or 70% ethanol) for at least 1 minute. In any case, after cleaning and/or disinfection, items or surfaces should be allowed to dry thoroughly, ideally in sunlight.
The ECDC recommends that fabrics that are likely to be contaminated (e.g. clothes, towels, or bed linens used by a confirmed or suspected COVID-19 patient) should be stored in a dedicated laundry bag and washed separately. Heavy duty gloves should be used to handle these fabrics if possible and care should be taken not to carry soiled linen against the body. Any soil excrement should be scraped off first with a flat, firm object into the toilet used by the patient, or in a covered bucket which will later be disposed of in the toilet if it is not in the patient’s room. Fabrics should then be machine washed in hot water (60oC-90oC) using laundry detergent or soaked in hot water with soap in a large drum, using a stick to stir. If hot water is not available, fabrics should be soaked in 0.05% chlorine for 30 minutes and then rinsed in clean water. Please note that chlorine may permanently stain some fabrics.
A 0.05% chlorine solution can be prepared by mixing equal volumes of clean water and 0.1% chlorine solution prepared as described above. In any case, with or without disinfection, it is important to ensure thorough drying of laundered items in direct sunlight.
If no one in the household is a suspected or confirmed COVID-19 patient it is not necessary to use a washing machine or drier, or very hot water. Laundry can be carried out in the household’s usual way.
What if disinfection or laundry facilities are limited?
In contexts where limited disinfection and/or laundry options are available, drying objects including kitchen utensils and fabrics in the sun may help kill viruses on surfaces and objects. Most viruses are sensitive to sunlight and heat, including the influenza virus and coronaviruses.
What can we recommend for people living in improvised shelters or houses with dirt floors?
One billion people live in informal settlements. Additionally the UNHCR estimates that 70 million people are currently displaced and living in temporary, improvised or tented housing. Maintaining cleanliness in these settings is a daily challenge, as floors, walls and surfaces often consist of unfinished or natural materials such as wood, mud or plastic and availability of cleaning and disinfection supplies is likely to be limited.
In these settings, it may be impossible to entirely prevent hands getting contaminated by surfaces but handwashing with soap can still interrupt transmission and prevent people becoming infected. We suggest that you recommend the following:
Where possible, look at options for increasing the amount of water and soap available to households so that more regular wet cleaning is possible. Encourage handwashing with soap regularly and remind people to avoid touching their face. Encourage parents to wash the hands of young children frequently. This is important because young children are likely to come into contact with surfaces that are hard to clean (e.g. dirt floors) and then put their hands into their mouth.
Sweeping is a widespread cleaning practice, particularly in places where houses have dirt floors. Sweeping may lead to aerosolization of viruses from the floor: like dust, viruses can move from the floor surface into the air (Study 1, Study 2). The risk of SARS-CoV-2 transmission through aerosols generated by sweeping has not been directly evaluated. As a caution, however, wet cleaning practices should be encouraged whenever possible.
UNICEF recommends that Infection Prevention and Control (IPC) kits be distributed to vulnerable households, including the following key items - to be adapted to local contexts: soap or hand sanitizer, detergent and chlorine-based products, mop and bucket or basin, and, if relevant, a bucket with tap for handwashing. For further information read our resources on distributing hygiene kits for COVID-19 response.
What if someone in my home has been sick?
The cleaning and disinfection processes described above can be followed for all frequently touched surfaces in homes where a suspected or confirmed COVID-19 case occurs. If someone is sick in the household the following additional measures of cleaning and disinfection should be used:
Household items such as eating utensils, dishes, bed linens or towels used by the patient should be cleaned and disinfected separately from other household members’ items following the procedures described under “How should I clean surfaces in my home?”.
If possible, the use of a dedicated bedroom and bathroom by the ill person is recommended. In that case, the cleaning frequency in the spaces used by the ill person should be kept to a minimum (e.g., only clean soiled surfaces), to avoid unnecessary contact with the patient and contaminated surfaces. Alternatively, cleaning and disinfection supplies may be provided to the ill person for them to clean the spaces that they use.
If it is not possible to have dedicated spaces for the ill person, frequent cleaning and disinfection of household surfaces by the ill person (e.g., after each use of the bathroom) is recommended. If the ill person is unable to perform these tasks, the caregiver should use a face mask and gloves (see guidance on use here) to clean and disinfect high-touch and soiled surfaces.
For further guidance about how to shield vulnerable individuals see this article.
Summary of recommendations:
Non-porous surfaces should be regularly cleaned and disinfected where possible with diluted bleach (0.1% chlorine) or 70% ethanol
Porous surfaces should be regularly cleaned, laundered and aired in the sun.
Encourage hand washing with soap as an additional way of interrupting transmission.
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Editor's Note
Author: Karin Gallandat
Review: Karen Levy, Jacqueline Knee, Sian White, Robert Dreibelbis
Last Update: 09.06.2020