At a time when N95 and surgical masks are short in supply, the Centre has issued an advisory to use homemade masks as a preventive measure against the novel Coronavirus.
Coronavirus preventive measures: Using homemade masks? Use two fabrics! At a time when N95 and surgical masks are short in supply, the Centre has issued an advisory to use homemade masks as a preventive measure against the novel Coronavirus. While the Indian advisory is to use cotton to make masks, the US Centre for Disease Control and Prevention has not recommended any specific fabric that should be used for making a mask. However, a study has noted that various materials have different abilities to keep the respiratory particles (can be applied for Coronavirus as well) and therefore, two fabrics should be mixed and used, the IE reported.
The report citing the study in the American Chemical Society’s journal ACS Nano mentioned that best possible combinations for masks can be made from either silk and cotton, or cotton and chiffon. The idea is, depending on the fit, masks can be made which can effectively help to keep the aerosol particles out. It is to note that an aerosol can be defined as suspension of particles or droplets in the air. The novel Coronavirus, on the other hand, is transmitted mainly through droplets in the air which are suspended if a COVID-19 infected person sneezes or coughs.
How does using two materials help prevent entry of droplets? The report stated that when a mask is tightly woven from fabrics like cotton, it can act as a mechanical barrier to particles. Fabrics like chiffon or silk help to hold a static charge and therefore they act as an electrostatic barrier. These kinds of mixed fabrics are able to prevent the smallest droplets from entering the human body. To be sure, the World Health Organization (WHO) has defined the droplets into two sizes that can transmit the novel Coronavirus. One size is of 5-10 microns in diameter for respiratory droplets while the others are known as droplet nuclei and are less than 5 microns in diameter. Having said this, respiratory droplets are mainly responsible for COVID-19 transmission, however, the possibility of transmission from droplet nuclei has not been ruled out, the report said.
Therefore, it becomes crucial that the mask worn should be able to prevent the entry of droplets. The report further said that wearing a fitted mask also becomes crucial as even a 1 percent gap between the mask and face reduces the efficiency of the mask to filter the droplets.