A booster shot on the masks can not hurt, in this period when the questioning of the type of protection to be favored against a very contagious Omicron variant resurfaces, but it seems less dangerous.
For more than two years, over the recommendations of the authorities, whether outdoors, in closed places, with the family, in transport, in companies, at school ... surgical masks have supplanted the others, in France at least, as part of the panoply of barrier gestures.
Without doubt, because they are the simplest and the cheapest.
Most often in paper, they are worth a few cents.
They are very useful for sick people.
By wearing them, they avoid contaminating their loved ones, because they prevent the projection of infected droplets, during coughing or sneezing for example.
Remember that there are several types, depending on the efficiency of the filtering material in the direction of expiration: type I has a bacterial filtration efficiency greater than 95%.
The efficiency is over 98% for type II.
The R types are also resistant to projections.
They are to be thrown away as soon as they are soiled and must be changed every four hours.
Most of the time we used type IIR.
Respiratory protection masks: two-way protection
FFP (Filtering Facepiece Particle) masks, known as respiratory protection masks, are much more elaborate.
They are also more expensive.
They are the ones that Philippe Juvin recommends today to favor against Omicron.
On Twitter, the trained anesthesiologist asked: "
Faced with Omicron, why (the FFP2 mask) is not recommended, at least indoors?"
".
"
Could it be that there aren't enough of them?"
", Questioned the mayor of La Garenne-Colombes, affirming that this type of mask"
filters and protects much better than the surgical mask
".
Thanks to their filtration device, they protect those around them, but above all the wearer of the mask against projections of droplets and particles suspended in the air. They can have several forms, including the famous duckbill. At the start of the pandemic, they were primarily reserved for doctors, nurses, dentists or other health specialists, providing care in an area of active circulation of the virus. These masks need to be particularly well adjusted. Their duration of protection is longer, it is estimated at 8 hours.
The mask consists of several layers of materials whose very fine mesh prevents the passage of particles. It is mechanical filtration. In addition, it is electrostatically charged. In the same way that after being rubbed, a balloon attracts hair or dust, electrostatic charges will retain the particles which adhere to the material and are thus trapped. It is electrostatic filtration.
FFP masks are classified according to their effectiveness according to European standard EN 149. This typology is based on the percentage of aerosol filtration and leakage to the outside (see graph above). Thus, three performance classes are distinguished: the FFP1 mask, with a filtration percentage of 80% and an outward leakage percentage of 22%, is mainly used as an anti-dust mask. The best performing types are FFP2 and FFP3, having the following characteristics, respectively: a filtration percentage of 94% and 99% and an outward leakage percentage of 8% and 2%.
Being thicker than surgical masks, they are also more uncomfortable.
The FFP2 and FFP3 can be fitted with a valve, to reduce resistance to expiration (the valve allows air to pass through on expiration and closes on inspiration) while avoiding condensation of the humidity which can settle on the filter.
Even if it has a foam seal, the mask must be adapted to the morphology of the face.
Some models are also available in different sizes.
Wearing a beard can lead to loss of waterproofness.
An ill-fitting mask will be a real strainer.
Once in place, it should no longer be touched.
Finally, in its opinion of 14 December 2021, the National Agency for Food, Environmental and Occupational Health Safety, Anses, due to the lack of data on the toxicity of graphene, recommended to prioritize on the market of FFP2 masks without graphene.
What about fabric masks?
Fabric masks are not getting too much of a talk anymore.
In the first months of 2020, they made up for the shortage of other surgical masks and FFP2.
They remain nevertheless economical and ecological, because washable, but they are no longer accepted everywhere, health establishments and airlines refuse them.
Already faced with the Delta variant, the High Council of Public Health (HCSP) recommended turning to other more secure and controlled protections.
He recommended the use of barrier masks that comply with the UNS1 standard (masks for Non-Sanitary Use 1).
That is to say having a filtration capacity of more than 90% of the droplets of a size less than or equal to 3 microns (0.003 millimeters).
USN2 category masks, on the other hand, are no longer recommended, they were only for occasional contact.
Their filtration efficiency is only 70% for these same particles.
The French Standardization Agency (Afnor) is posting on its website a reference document, validated by the Directorate General of Armament, allowing the manufacture of a UNS1 mask (according to the S76-001 standard) intended for individuals and professionals.
If the masks are directly purchased in stores, it must be checked that the inscription UNS1 or category 1 appears next to the abbreviation Afnor.
