Masks in epidemics: towards a paradigm shift?

Abstract

Let us take advantage of the lessons learned during this unprecedented pandemic, which could be long-lasting, to change our convictions, to question our truths in terms of protecting men and women in general and people who, because of their job, their function or their responsibilities are, on a daily basis, exposed to the risks of transmission of contamination by others and by the sick, whether declared or not.

What’s this about?

Le Sars-CoV-2 responsible for Covid-19 caused a serious crisis in the management of the epidemic: to control an epidemic with a respiratory virus requires both material and strategic means.

Material resources:

• Masks capable of both preventing the virus from being thrown into the atmosphere when sneezing, coughing or simply speaking (sputtering) is protection in the exhalation direction and also preventing the virus in the atmosphere from reaching a healthy person is protection in the inhalation direction;
• Virological tests to identify positive subjects with the dual purpose of administering treatment and identifying contact subjects;
• Serological tests to identify subjects who have had the disease (especially in the case of Covid-19 for which there are a very large number of asymptomatic patients) to best manage the release from confinement, positive subjects being immunized;
• A treatment against the virus, which is not yet the case for the moment;
• A vaccine, which, as in the previous case, does not yet exist, but which will allow better control of the disease should it return.

Strategic resources: barrier measures

– Hand washing to remove viruses caught by contact with a contaminated surface;
– Coughing and sneezing into the crease of the elbow or into a disposable tissue;
– Do not put your hands in contact with your face;
– Stand more than three feet away from each other;
– Do not shake hands or hug;
– Lockdown of at-risk populations or the entire population.

And the masks!

Since the beginning of the Covid-19 epidemic, the word “mask” is surely the most pronounced word in the media!

In the medical field, the use of masks responds to a real “dogma” formulated by medical and then political authorities. There are only 2 types of masks:

– the surgical mask originally used by the surgeons in order not to contaminate the surgical field. It works in the exhalation direction;
– the respiratory protection mask type FFP, whose filtration and inward leakage characteristics make it possible to distinguish 3 categories: FFP1, FFP2 and FFP3 (FFPx).

We have already detailed all features in this article.

As the SARS-CoV-2 virus is transmitted in respiratory droplets (larger than 5 µm in size) and not by aerosols with particles smaller than 5 µm), the wearing of a simple surgical mask by all the individuals in a population, each protecting his neighbor, would probably have made it possible to slow down the spread of the germ, provided of course that the barrier measures described above were respected. These measures have been taken in other countries, such as South Korea, which have thus been able to avoid confinement thanks also to a large number of screening tests and strict monitoring of positive patients.

In the hospital environment, caregivers are in the presence of a very high concentration of viruses, especially during medical procedures that cause the patient to cough (intubation for example). For them, the indication of an FFP2 mask is completely justified.

The critical lack of masks at the beginning of the epidemic made the dogma waver. Due to the lack of FFP2 masks, caregivers were equipped with surgical masks when their inward leakage rate was too high for this type of use but “it was better than no mask at all”. The symptom-free population was then advised not to wear masks (even though it was known that a very large number of sick people were asymptomatic). Everything possible was done to protect caregivers as a priority, which is entirely justified.

The dogma was further challenged when certifying organizations such as AFNOR certified “alternative masks” or “masks for the general public” made of fabric, home-made and meeting criteria of filtration and breathability. Two types of classes were introduced: class 1 (filtering 90% of particles) and class 2 (filtering 70% of particles). Those in class 1 are used by professionals in the presence of other non-masked persons (a policeman for example) and those in class 2, which are less demanding, are used within a group of people who are all protected (it is then recognized that the wearing of masks by the whole population is an important element of non-dissemination!)

The sacrosanct paper mask is shaken to the point where it can no longer be used according to the usual prescriptions. More than anything else, we realize that, under special conditions, it can be officially replaced by paper towels or vulgar pieces of “normalized fabrics”.

Paradigm shift! Replacing the FFPx by the FMPx

We have already seen in this blog that the wearing of masks by the population was born during the 3rd plague pandemic and in particular during the Manchurian plague 1910-1911 and that it allowed not only to stop the plague epidemic but also to make the Chinese people responsible for hygiene measures. The masks used at the time to protect against the plague were thicker versions of the surgical mask used as early as 1897.

Currently, a “mask” is a more or less elaborate piece of paper, fixed with 2 elastics behind the ears and protecting the nose and mouth. The product is not very elaborate and its effectiveness in protecting an individual is measured by the rate of filtration and backward leakage, the proportion of particles entering directly behind the mask without being filtered. For the most protective mask FFP2 (Filtering Facepiece Particles), it is a filtration rate of 94% and an internal leak rate of 8% that characterizes it (the more difficult FFP3 are less used in the case of viral epidemics).

Why not replace FFPx (Filtering Facepiece Particles) with FMPx (Face Mask Particles)?

In other words, why not replace paper filters with real reusable half-masks? Let’s ask ourselves the question.

FMP masks are certified according to EN 1827/A1.

Unlike paper filters, FMPs are real breathing apparatus with a skirt that fits perfectly to the shape of the face. The filters are interchangeable depending on the protection required.

These masks have several advantages:

– reusable they can be cleaned with a disinfectant and their destruction has a much lower ecological impact than paper filters;
– light and physiologically adapted they can be worn for several hours;
– polyvalent by the choice of the filter according to the desired protection;
– cost much less by recovering the filter and washing;
– guaranteed efficiency even when wet, unlike FFP.

Let’s compare the FFPx and FMPx masks.

The standards for FFPx (NF EN 149 + A1) and FMPx (EN 1827+ A1) categorize performance according to filtration capacities and inward leakage rates. The characteristics are identical for both categories.

FFP1 and FMP1 >= 80% filtration for an inward leakage rate of <=22% for FFP1 and <= 2 % for FMP1.

FFP2 and FMP2 > = 94% filtration for an inward leakage rate <= 8% for FFP2 and <= 2 % for FMP2.

For FMP1,2, which are true half-masks, other characteristics such as cleanability, disinfection, durability, etc. are taken into account.

The Ouvry® FMP1,2 OCOV® mask includes a soft facepiece covering the nose, mouth, and chin. It can be fitted with different filters depending on the desired performance. The filters are replaceable and disinfectable 100 times. Its weight is 60 g.

The adaptation of the hood to the face allows for extremely low leakage rates (2%), so that virtually all the incoming air passes through the filter. This results in maximum efficiency.

It is, therefore, necessary to collectively question the current situation so that a protective equipment policy can emerge and be developed that recommends, for professionals who work in contact with the public in periods of risk of contamination and containment, the wearing of FMPx type masks, which are recognized as being much more effective than the FFPx “paper filter”. These include, for example, police and gendarmerie personnel, postal workers, store clerks, industrial workers, garbage collectors, in short, all those who are exposed to the risk of contamination as part of a public service or a service vital to the citizen’s daily life.

Indeed, the FMpx type mask, which has equivalent efficiency but is less expensive, is more practical and has a very small ecological footprint. It is also much more reassuring for the wearer, who maintains it himself and keeps it at his disposal in case of a bio-alert. It is possible, and even likely, that ordinary citizens, working alongside professionals who are equipped with them, will also become accustomed to the use of these masks.

Conclusion

In any case, and without waiting for this epidemic to be stopped, it must be questioned. The FMP, which has the advantage of being reusable and providing the wearer with a higher level of protection than the corresponding FFP type mask, has its rightful place in the range of protective equipment against the risks of infection after the mask against the “general public” Covid-19 that Ouvry manufactures on the basis of one of the technical fabrics of the Polycombi® CBRN suit, intended for the emergency world.

A few years ago, when Ouvry replaced the waterproof, plastic, uncomfortable and disposable protective suits with the more comfortable, more efficient (without pumping effects) and washable Polycombi®, he had already shaken up the paradigm of protective suits.

With OCOV today, he has opted for “innovation that is attentive to the needs of the end-user”.