The use of masks to prevent transmission of COVID-19 raises many questions, and many countries recommend that their populations wearing them.
Wearing a mask may limit the spread of some viral respiratory diseases, including COVID-19.
However, masks alone do not provide an adequate level of protection. Other measures such as physical separation and hand hygiene must be adopted.
For countries considering the use of masks, WHO advises decision-makers to apply a risk-based approach and to consider the following :
Purpose of mask use:
If the intention is to prevent the carrier from transmitting the infection to others (i.e. source control) or to protect the carrier from infection (i.e. prevention).
Risk of exposure to COVID-19:
- Due to epidemiology/population level: if there is high community transmission and other measures such as contact tracing or testing are not possible.
- Depending on occupation: e.g. people working in close contact with the public (e.g. community health worker, cashier).
Vulnerability of the mask wearer / population:
If supplies are adequate, the masks can be used by people with cardiovascular disease or diabetes, the elderly and immunocompromised patients.
Environment in which the population lives:
Densely populated environments (e.g. refugee camps, cramped living conditions) and environments where individuals cannot maintain a safe distance (e.g. crowded buses or other means of transport).
Availability and cost of masks, access to clean water for washing cloth masks, and the ability of masks wearers to tolerate the side effects of wearing a mask.
Type of mask:
Medical versus non-medical masks (priority to medical masks for health care providers symptomatic individuals and their caregivers).
In addition to these factors, the potential benefits of mask use by healthy people in the community include the potential risk of exposure of an infected person during the "pre-symptomatic" period or if an infected person is asymptomatic. There are potential risks and disadvantages that need to be taken into account in any decision-making process on the use of masks:
Cloth masks may increase the risk of COVID-19 infection if the mask is contaminated by dirty hands and touched frequently, or if it is placed on other parts of the face or head and then repositioned over the mouth and nose.
Depending on the type of mask used, breathing difficulties may result as they can also lead to facial skin degradation. They can also make it more difficult in communicating clearly and they can be uncomfortable to wear.
It is possible that wearing a mask, may create a false sense of security for the wearer, leading to a decrease of using preventive measures such as social distancing and hand hygiene.
What type of masks are used to prevent COVID-19 from spreading?
These masks are made from a minimum of three layers of non-woven synthetic materials, and configured to have filtration layers sandwiched in the middle. They are available in different thicknesses, have different levels of fluid resistance and two levels of filtration. These masks reduce the transfer of saliva or respiratory droplets from the wearer to others and to the environment. They also reduce the probability of infectious droplets from other people to reach the mouth and the nose of the mask wearer.
Masks filtration efficiency and materials
FFP3 : 99,9%
FFP2 : 99%
N95 : 98%
Our masks (Masks For Belgium) : 95%
Cloth masks: 70%