Does your homemade mask work? Researcher shares a simple way to test it

If a surgeon came to the operating room wearing a mask they had made that morning with a dish cloth, they would probably be fired. This is because equipment used for important tasks, such as surgery, must be tested and certified to ensure compliance with specific standards.

But anyone can design and cover their faces to meet new public health requirements for using public transportation or going to stores.

In fact, arguments about the quality and standard of facial coatings underlie recent controversies and explain why many people think they are not effective in protecting themselves against COVID-19.

Even the language distinguishes between face masks (which are normally considered to be built to a certain standard) and face covers that can be just about anything else.

Perhaps the main problem is that while we know that well-designed face masks have been used effectively for many years as personal protective equipment (PPE), during the COVID-19 outbreak the shortage of PPE has made it little. Practical for the entire population to use Regulated and trained masks to use them effectively.

As a result, the argument has moved away from the use of face masks for personal protection and towards the use of “face covers” for public protection.

The idea is that, despite the fact that unregulated facial covers are highly variable, on average they reduce the spread of the virus, perhaps in a similar way to that which covers the mouth when coughing.

But given the wide variety of unregulated face covers that people now wear, how do we know which is the most effective?

The first thing is to understand what we mean by cash. Since the coronavirus particles are approximately 0.08 microns and the tissues within a typical cloth covering have spaces approximately 1,000 times larger (between 1 and 0.1 millimeters), “effectiveness” does not mean reliably trapping the virus.

Instead, just like covering our mouths when we cough, the goal of using cloth covers is to reduce the distance your breath separates from your body.

The idea is that if you have COVID-19, depositing any virus that you can breathe out on yourself or nearby (within a meter) is much better than blowing it on other people or surfaces.

Therefore, effective coverage of the face is not intended to prevent the user from contracting the virus. Although from a personal perspective we may want to protect ourselves, to do so we must use specially designed EPP, such as FFP2 masks (also known as N95). But, as mentioned, doing so runs the risk of creating mask shortages and potentially putting health workers at risk.

Instead, if you want to avoid contracting the virus yourself, it is most effective to avoid crowded places by staying ideally at home, not touching your face, and frequently washing your hands.

If the effectiveness of facial covers means preventing our breathing from traveling too far from our bodies, how would we compare different designs or materials?

Perhaps the easiest way, as evidenced by several increasingly shared images or videos on social media, is to find someone to “vape” and film your breath while wearing a mask to cover your face. A glance at that image dispels any suggestion that these facial covers prevent your breath from escaping.

Instead, these images show that your breathing is directed over the top of your head, toward your chest, and behind you. Breathing is also turbulent, which means that although it stretches, it does not go far.

In comparison, if you look at an image of someone who is not wearing a face cover, you will see that exhalation is mostly done forward and down, but at a significantly greater distance than with the face cover.

Such a test is probably ideal for examining different designs and settings. Do liners that wrap around the ears work better than scarves? How far should a cover go under the chin? What is the best nose fit? How do face shields compare to face masks? These are all the questions that could be answered using this method.

But, in performing this experiment, we should appreciate that the “vaping” particles are approximately 0.1 to 3 microns, significantly larger than the virus.

A simple test

While it is probably fair to assume that the smaller virus particles will travel in roughly the same directions as the vaping particles, there is also a chance that they may still be able to advance directly through the face covering.

To get an idea of ​​how much this could happen, a simple test could be tried that involves trying to put out a candle directly in front of the user.

Initially, distance could be investigated along with the strength of exhalation, but then facial coatings made of different materials and critically with different numbers of layers could be tested.

The design of the face covering that made it more difficult to deflect the candle flame will probably provide the best barrier to project the virus forward and through the face cover.

Without more sophisticated equipment, it would be difficult to conduct more simple experiments at home.

However, the combination of the previous two tests would give users a good idea of ​​which of their facial covers would work best if the goal was to avoid breathing potential infection on other people.The conversation

Simon Kolstoe, Senior Lecturer in Evidence-Based Healthcare and College Ethics Advisor, University of Portsmouth.

This article is republished from The Conversation under a Creative Commons license. Read the original article.