COVID is a disease spread through tiny droplets and particles that are released into the air when talking, singing, coughing, or sneezing. This has led to preventive measures such as the physical distancing, regular hand washing, and use of a mask, which have become the three most effective ways to fight the spread of COVID. Since the obligation to wear a mask was implemented and the proliferation of different types and models, doubts and questions have not stopped circulating about which ones to use and what function each one of them performs.
The different types of masks
Not all masks are the same or protect in the same way. Broadly speaking, and as indicated by the Ministry of Health, the masks can be divided into hygienic, surgical, Personal Protective Equipment (PPE) and other commercial masks.
The hygienic masks they cover the mouth, nose and chin and have a harness that goes around the head or behind the ears. They are made up of one or more layers of textile material and can be reusable (in this case the manufacturer must indicate the maximum number of washes) or for a single use (it is recommended not to use it for more than four hours). They are not considered a PPE or a medical device. They are indicated above all for healthy people.
The surgical called masks they are what we are used to seeing in clinical settings because healthcare workers are more likely to be exposed to COVID. They are also those that are indicated for sick people, whether symptomatic or asymptomatic. The goal in all cases is to prevent people who use them from transmitting infectious agents. To achieve this, its design allows exhaled air to be filtered. In this way, people who are around are protected by preventing the spread of the virus when sneezing, coughing or talking. Most of them have a mechanism that allows it to be fitted over the nose, mouth and chin. They have a maximum usage time of between four and eight hours.
The World Health Organization (WHO) issued in January 2020 a guide on how medical personnel have to use masks, as well as other PPE equipment such as a surgical gown, gloves or eye protector.
They are also the EPI masks, Basically recommended for professionals who need to create a barrier between a potential risk and the user or in vulnerable groups due to medical indications. This type of mask filters the inhaled air and prevents the entry of polluting particles into the body. They can be of three types, depending on the filtration efficiency: FFP1, FFP2 and FFP3.
Finally, the use of cloth face masks it has become widespread in Spain in recent months. But to be effective, the WHO states that they must include several layers, they must be washable and reusable. Thus, they must be composed of an inner layer of absorbent fabric, such as cotton; another intermediate layer of non-absorbent nonwoven material, such as polypropylene and, finally, an outer layer of non-absorbent material such as polyester.
Masks described as surgical, one of the most effective
According to a study published in Science Advances, in which the effectiveness of the different types of masks has been analyzed, the FFP2 are the most effective because they manage to reduce the transmission of droplets by more than 99,9%. The second most effective are surgical since they manage to reduce the transmission of droplets by more than 90% (they prevent the virus from leaving an infected person and infecting others).
In Spain, Masks BéjarIn recent months, a company located in Salamanca has been manufacturing high-filtration surgical masks, such as the NAN300, made up of four layers: a first 100% polyester offers impermeability; the second is made up of a nanofilament membrane that prevents the entry and exit of viruses and bacteria and has a bacterial filtration efficiency of 99,7%; the third is made up of 80% polyamide and 20% ethanol, which offer great breathability; the fourth layer is made of 100% polypropylene, an additional protective barrier. The great advantage of this type of mask is that they prevent the entry and exit of particles, trapping them in a sterile area.
According to the Ministry of Health, cloth fabrics are less protective than surgical ones and, if they are not used properly, they can even increase the risk of infection due to humidity, the diffusion of liquids and the retention of the virus. Therefore, they are not considered appropriate for use in hospital settings. This has led some hospitals in the Basque Country and Galicia, which are being joined by other autonomous communities, to prohibit the entry of people with cloth masks and replace them with a surgical one. And they have done it to prevent the virus from entering health centers without control. Opting for this type of mask in a health center is logical considering that the risk of transmission of the virus is greater. This does not mean that the use of fabric for other circumstances is not effective, provided that the established conditions are met.