Homemade masks as an alternative to lack of supplies: what you need to know about their effectiveness, manufacture and use
After days ruling out the widespread use, today the Ministry of Health has opened the door to a 180º change in the recommendations for the use of masks. Fernando Simón, director of the Center for Coordination of Health Alerts and Emergencies, has stated unequivocally that Spanish society should "learn from how other societies (such as the Japanese, for example) normally work with influenza" and that "we have to learn to use personal protective equipment as it becomes available in large quantities. "
While this change in criteria is officially consumed, the lack of 'personal protective equipment' in Spain can lead many citizens to consider the possibility of developing their own cloth masks. The good news is that it makes sense to consider doing this type of protection. The bad news is that it is not worth making them in any way. This is what we know about the effectiveness, manufacture and use of homemade face masks.
Are the masks useful for something?
As we have explained on other occasions, surgical masks are very useful to prevent the spread of the virus, but "do not provide complete protection" against it. Essentially, a surgical mask is a piece (smooth or pleated) of tissue that is placed in front of the nose and mouth.
The name "surgical" (which sometimes gives them a certain aura of sophistication) simply comes from the fact that they are often used in all kinds of operations to protect patients from possible flows by the professional team. As they are not hermetic nor do they require elaborate mechanisms, at theoretical level there is no reason to rule out that these types of barriers can be elaborated at home.
Of course, the fact that they can be done at home does not mean that they can be done in any way. It is important to note that although the evidence in favor of masks has been accumulating in recent years, it is still not as solid as it should be. And if this is true for masks made with sanitary guarantees, it is much more so for homemade ones.
In summary, the available scientific evidence tells us that, well made, homemade masks give worse results than approved ones, yes; but they can be an acceptable alternative if we do not have another type of mask.
Things to keep in mind to make a mask wellUPDATE After the publication of this article, the Ministry has published a guide to manufacture them.
The material: As the European Directive and the technical standard do not establish specific obligations on the type of tissues to be used, surgical masks of different materials can be found on the market. However, the one that currently gives the best results is manufactured using a molten polymer extrusion process that creates a very dense mesh of micro and nanofibers that acts as a filter. What is known as a conventional non-woven fabric (TNT) of 50-60 g / m2 or thickness of 0.3-0.5 mm. The problem is that this type of material is usually not available at home.
For this reason, some Spanish institutions, such as the Generalitat of Catalonia, have already given some basic advice on the material recommended for the elaboration of this type of mask: “water-repellent fabrics that expel moisture, such as dry baby wipes, handkerchiefs or cloths from wash glasses and cushion covers ”can be interesting materials; however, "the material that has the best filtering efficiency and is best suited to the face is 100% cotton T-shirt fabric."
If we want more precise analysis, we have some studies that, in the context of disaster medicine, offer us several references. Although the best material appears to be that of homologated "surgical masks" (85% effective against 0.02 micron particles), vacuum cleaner bags (86%) closely follow. kitchen (73%), cotton blend fabrics (70%) and antimicrobial pillowcases (68%). Much further away are linen, silk or scarves.
Ergonomics A quick search for mask patterns on the internet yields a great deal. Our colleagues from Jared have a fantastic article that includes several alternatives. This element is very important.
Although it may seem trivial, as we will see later, the shape and comfort of the mask are essential to ensure its usefulness. As the authorities point out, discomfort in using this type of prophylactic measures can increase the number of times we touch our faces (increasing the risk of "contact contagion"). The chosen model must therefore combine a good fit and insulation with comfort of use.
How to use the homemade mask?
Another crucial element is learning to use them. As we have explained on other occasions, personal protective equipment can generate a "feeling of security" that can lead us to commit more "risky behaviors" than we would without them. Hence the insistence that "masks are only effective if combined with frequent hand washing with a hydroalcoholic solution or with soap or water."
And, of course, if "we learn to use and eliminate them correctly". It is surprisingly common to see how many people make mistakes when putting on and taking off masks. In the case of placement, it is important that the mask covers the nose and mouth correctly (and that it does not leave gaps or openings through which unfiltered air can sneak in or out).
When removing them, we must remember that we must touch the surface of the mask as little as possible to avoid contaminating our hands without realizing it. Examples can be seen in the video above, and certainly many of the steps may seem like common sense. However, the important thing in this case is to take extreme precautions (because it is precisely when we let our guard down when we make mistakes that expose us to the virus).
Image | Pixabay