Although the health authorities ’recommendations are very clear regarding the inability to reuse medical masks, with the accumulation of waste and the cost borne by the citizens, there are voices calling for reuse according to certain conditions, while a researcher said that it is better to change the masks every 4 hours. , And to wash like underwear.
The World Health Organization stresses that “medical masks are used only once,” and it calls for “the immediate disposal of used masks.”
However, in the event of a severe shortage of stock, similar to what happened during the early stages of the pandemic, the organization approves exceptional procedures based on disinfecting used masks in order to reuse them.
And the US Agency for Emergency Medicines has previously allowed the disinfection of the “N95” masks for medical personnel, and the parallel masks of the type “FFP2” (FFP2), by spraying them with hydrogen peroxide.
There are other methods of disinfection by exposing masks to high temperatures, or by using ultraviolet rays.
But Dr. Donnie Courbet, a specialist in microbiology, a hygiene expert and a member of the “Adios Corona” association, which includes French scientists from various specialties, stresses that “this matter (disinfection) is not practical for individuals.”
To reduce the plastic pollutants resulting from the polypropylene masks and the cost that families bear, Adios Corona calls for the use of “envelope technology” to disinfect the masks used in the family setting, as the risks of exposure to viruses are much lower compared to medical personnel.
The technique is based on placing the used muzzle – provided that it is not damaged – in a paper envelope, writing the date on it, and leaving it for a period of 7 days.
Courbet says that “several practical studies show that corona viruses – whose scientific name is SARS-Cove 2 – found on the muzzle, almost all of them die within 7 days.”
And a study prepared by the University of Hong Kong and published in the “The Lancet” magazine, showed that after a week, the percentage of viruses that can be detected on the outside of the muzzle is limited to only 0.1%.
Peter Tsai, the inventor of the electrostatic charge technology (static electricity) used in “N95” masks, which is based on attracting particles to prevent their entry, confirms the effectiveness of the “envelope technology”.
“In order to reduce consumption and protect the environment, I recommend to the general population to re-use the mask after 7 days, between 5 and 10 times, as I do,” Tsai said.
The retired expert, who returned to his work at the University of Tennessee after the Covid-19 crisis, indicates that the muzzle can be placed in the oven and exposed to sufficient heat to kill the virus without burning plastic materials, explaining, “The temperature must range between 70 and 75 degrees Celsius.”
Tsai recommends not washing masks, and says that “washing without washing powder may not remove the virus, and washing with washing powder will damage the static electricity charge.”
But he considers that in the latter case, despite the decline in the purification capacity, a washed muzzle may still be more effective than a cloth muzzle.
This is the conclusion of tests conducted by the French consumer protection group UFC-Que Choisir, whose results were published this week.
The results of the tests showed that the repeated washing process of 3 masks with 95% purification capacities of 3 micron particles in the washing machine at a temperature of 60 ° C, and placing them in the washing drying machine and then under the iron, 10 times, in the most cases losing it only 5% of its purification capacity .
This week, the French group confirmed that “despite the slight flocculation, laundered medical masks are equivalent in terms of protection capacity to the best masks made of fabrics, and may exceed them.”
More like underwear
Tests conducted by Philippe Froman, a researcher at the French College of Textile Engineering in Roubaix, on 3 types of masks, concluded similar results.
His study showed that after washing them at least 5 times, “there is practically no difference in the purification of 3-micron particles. The difference appears in the purification of smaller particles,” according to preliminary results that have not yet been published, according to the researcher.
He considers that these masks “remain in an ideal position to perform their role in protecting the general public,” referring to the standards applied in France for masks made of fabric, whose ability to purify does not exceed 90% of particles with a size of 3 microns.
The researcher says, “I prefer changing the muzzle every 4 hours and washing it, rather than wearing it for consecutive days as some do. It is somewhat like underwear.”
But until the results of the tests are published in scientific references, the health recommendations will remain the same.
This week, the French Public Health Directorate stressed the need to “throw medical masks after their use in the trash,” noting that the issue of reuse is currently “under consideration” in France.
But director of the Department of Biomedical Engineering at Binghamton University, Cheming Yee, says, “I do not think that medical masks are washable.”
Yi, who is working on setting standards for ultraviolet disinfection to protect the ozone layer, added to the French Press Agency that it might be possible to “reuse” medical masks, but it requires “in-depth studies.”