What face mask to use to protect against SARS-CoV-2?

Many countries around the world have introduced an order to cover the lower parts of the face, nose, and mouth in public places to reduce the risk of SARS-CoV-2 infection. It is widely advised to cover mouth and nose at least until an effective coronavirus vaccine is developed and widely available. Many different types of protective face masks can be currently found in pharmacies and stores. They have different purposes and are made of different materials. However, the question is - does a face mask protect against the coronavirus? 

According to the recommendations of the WHO (World Health Organization), protective masks should be worn by those: 

sick, coughing, sneezing, with clear symptoms of the disease,

attending the sick.

The European Center for Disease Prevention and Control agrees with the position of the WHO but also points out that wearing masks in public places, shops or public transport can reduce the risk of spreading the virus by people who do not exhibit symptoms of the disease. 

Keep in mind that the coronavirus is airborne - it is spread through coughing, sneezing, or even a conversation with an infected person. The virus can enter the body through the nose, mouth, and eyes (directly or by touch). Wearing protective masks reduces the risk of this happening.  

What types of protective masks are there? 

The degree to which a mask can protect you depends on the type of mask you use. On the market, you can find surgical masks that protect the lower part of your face and protective masks, the so-called half masks that protect the respiratory tract against the ingress of microorganisms.  

A surgical mask is made of two or three layers of plastic - polypropylene. There are two types of surgical masks: 

type I – with the filtration efficiency of >95 (two-layer mask),

type II – with the filtration efficiency of >98; exhibits resistance to permeation (three-layer mask). 

Surgical masks are subject to European Standard EN 14683: 2019 + AC. This type of face mask is a barrier to body fluids (saliva, blood, lymph) that can transfer from a sick person to a healthy person. Surgical masks are a barrier to microorganisms with a diameter of up to 1 micrometer. It is therefore permeable to viruses whose size is measured in nanometers. A surgical mask protects very well against further transmitting the virus by spreading in the cloud of aerosol generated when sneezing or coughing. The bodily fluids carrying the virus are stopped on the inside of the mask, potentially containing a virus.  

Surgical masks can be tied in two ways: 

with straps - the user adjusts the mask to his face and ties the strings of the mask at the back of their head,

with elastic bands - comfortable bands that are pulled behind the user's ear. 

Every surgical mask has a sewn-in wire at the top that allows the mask to tightly fit over the nose. 

A surgical mask is a single-use medical mask. It should be disposed of after a single use or after contact with an infected person. A surgical mask provides short-term protection - up to several dozen minutes, depending on its saturation with bodily fluids and steam.   

The second type of protective masks are the half masks. They are made of 4 or 5 layers of polypropylene. They are stiffer than surgical masks and are also meant to adhere to the nose. They stop dust and aerosols. Half masks are divided into three types based on their filtration:

FFP1 - stops approximately 80% of particles smaller than 2 micrometers in diameter,

FFP2 - stops approximately 94% of particles smaller than 0.5 micrometers in diameter,

FFP3 - stops approximately 99.95% of particles smaller than 0.5 micrometers in diameter.

The European standard for half masks has the mark 149:2010+A1:2019. The half masks adhere well to the face. They are tied at the back of the head or have an elastic band. FFP2 and FFP3 masks are recommended for protection against viruses that may be airborne or in a cloud of aerosol emitted when coughing or sneezing. Disposable half masks can be used for up to 8 hours or until they are in contact with an infected patient. There are also reusable masks with replaceable filters. Such a filter should be replaced in accordance with the manufacturer's recommendations so that the mask retains its protective properties. Half masks are usually equipped with valves to facilitate breathing. The exhaled air inside the mask is discharged through these valves, which prevents the accumulation of moisture. The valve only works in one direction - it is not possible for air to enter the mask through the valve.  

Due to regulations being introduced, many people have begun sewing masks at home. Three-layer cotton is mainly used for this, usually lined with fleece. These masks can be used multiple times. Like surgical masks, they will not stop viruses from entering the respiratory system. They act as a barrier against airborne aerosols and against spreading the virus by people who may not show symptoms of the disease. Such protective masks should be disinfected after each use, washing them at 60 degrees Celsius or exposing them to hot steam, e.g. an iron (set at about 100 degrees Celsius). The mask should be changed when it gets wet from the water vapor released during breathing and after suspected contact with an infected person.

How to properly put on a face mask?

Face masks do not provide 100% effective protection against the virus and at the same time can be dangerous in case of improper use. So how do you use them properly? 

Before putting on the mask, wash your hands with soap and water or disinfect them with a special alcohol-based liquid.

Check that the mask is not damaged.

Make sure the outside of the mask is facing the correct way.

Adjust the mask to your face using strings or elastic bands. Adjust the mask to your nose and check that it covers the lower part of your face.

Do not touch the mask or face (eyes) with your hands during use. If you do, wash your hands immediately with soap and water or disinfect them using a sanitizer.

Change the mask for a new one if it gets wet. Do not re-use disposable masks.

After use, remove the mask touching only its elastics or strings. Be careful that the mask does not touch the skin of your face or clothes. Do not touch the outside of the mask.

Throw the used mask into a closed garbage can.

After removing the mask, wash your hands with soap and water or a disinfectant.