Recently, the US Centers for Disease Control and Prevention (CDC) changed its view on the use of masks during the COVID-19 pandemic.
The recommendation given by the CDC is that masks made of ordinary household items should be used instead of hoarding medical surgical masks and N95 masks.
The CDC pointed out that these should be given priority to those who fight the new coronavirus on the front line, including doctors, nurses, emergency personnel and other people who often deal with patients.
Although the CDC recommends that the American people wear cloth masks that can be made with ordinary household materials to slow down the spread of the new coronavirus, this does not mean that they can relax their vigilance.
First of all, that physical barrier cannot guarantee 100% that it will not be infected with viruses.
Secondly, the public should not stop maintaining the design distance and proper hygiene habits because of wearing a mask.
To further strengthen this view, two recent studies have analyzed the survival ability of the SARS-CoV-2 virus. And one of the studies found that the microbial traces on the mask lasted up to 7 days.
A study in mid-March pointed out that the new coronavirus can survive up to 3 hours in the air and up to 3 days on plastic and stainless steel.
Then, CDC found traces of the virus on one of the cruise ships used to contain and isolate COVID-19 patients. CDC found traces of the virus on one of the cruise ships 17 days after they left.
This does not mean that the virus will be transmitted after so long, but this discovery further explains why SARS-CoV-2 is so dangerous.
In early April, a new study published in The Lancet by the University of Hong Kong stated that researchers analyzed the stability of the virus in different environments.
The study stated, "On day 7, the outer layer of the surgical mask may still contain detectable infectious viruses."
After each use, be sure to discard disposable masks frequently and wash your home-made reusable masks.
In addition, it is important to avoid touching the mask when using the mask and avoid touching your face during the use of the mask.
The following are other findings from the study.
The virus is very stable at 4 ° C/39.2 ° F, but it is sensitive to high temperatures.
The virus is inactivated in only 5 minutes at 70 ° C/158 ° F.
Printing and paper: The virus died after 3 hours (22 ° C/71.6 ° F and 65% humidity).
Wood and cloth: The virus died after 2 days (22 ° C/71.6 ° F and 65% humidity).
Glass and banknotes: The virus died 4 days later (22 ° C/71.6 ° F and 65% humidity).
Stainless steel and plastic: The virus died after 7 days (22 ° C/71.6 ° F and 65% humidity).
The study found that the virus is very stable in a large pH range (3-10), but will die after disinfection.
In other words, it is necessary to keep common surfaces clean and wash clothes worn out, and maintain proper hygiene. In addition, after handling items brought in from the outside, keep hands washed with soap for at least 20 seconds.
Conversely, exposure to high temperatures will kill viruses, which is a critical detail for food. There will be no signs of viruses after heating.
A similar study conducted by the Chinese Center for Disease Control and Prevention focused on the sensitivity of viruses to heating and ultraviolet radiation:
The results showed that the SARS coronavirus under test conditions can survive for at least 96 hours in serum, 1:20 diluted sputum and feces, and at least 72 hours in urine, with low infectivity.
The ability to survive on the surface of 8 different materials and water is comparable, showing a decrease in infectivity after 72 to 96 hours of exposure.
The virus remains stable for at least 2 hours at [4 ° C/39.2 ° F], room temperature [20 ° C/68 ° F] and [37 ° C/98.6 ° F], while there is no significant change in infectivity, but in [ After irradiation at 56 ° C/132.8 ° F], [67 ° C/152.6 ° F], and [75 ° C/167 ° F] for 90, 60, and 30 minutes, the virus was transformed into non-infectious, respectively.
After 60 minutes of UV irradiation, under [75 ° C/167 ° F] and [67 ° C/152.6 ° F] conditions, irradiate 90-60-60 and [75 ° C/132.8 ° F] and [75 °, respectively C/167 ° F] after the conversion to non-infectious.