While the hunt for a vaccine against the novel coronavirus continues, researchers across the world have been evaluating the best materials for filtering Covid-19, especially protective gears like face masks. As face masks become the new fashion accessory and the most effective tool in the battle against coronavirus, it is important that you opt for a covering which offers sufficient protection.
A face mask comes handy not only because it blocks the large respiratory droplets from coughs or sneezes and prevents passing of the virus to others but also because it blocks the smaller airborne particles or aerosols, which are produced when people talk or exhale. The proper way to wear a mask is to make sure that it seals the entire area around the nose and mouth since any small opening, holes, vents or gaps can allow droplets to leak out and potentially infect another person.
Public mask-wearing has resulted in notable drops in Covid-19 cases but not all masks are created equal as they vary in efficacy and comfort. Here are some of the best and worst face coverings as per latest data and research:
Masks with built-in valves or vents
Never opt for masks with exhalation valves or vents. Though their efficiency at filtering large droplets is 90% and efficiency at filtering aerosols is also 90%, they do not protect others as they are designed only to benefit the wearer. The wearer exhales through the valve and the one-way vents can expel viral droplets that can promote coronavirus transmission to others.
Scarf or bandana
Suggested to be worn as the last resort, a scarf or a bandana has been found to be the worst face covering as its efficiency at filtering large droplets is only 44% and efficiency at filtering aerosols is merely 49%. They can be used as a substitute for masks as a scarf or a bandana is better than no face covering at all.
Natural silk mask
While a mask made of natural silk can be worn in outdoor areas, its efficiency at filtering large droplets is 56% and efficiency at filtering aerosols is 54%, which is slightly better than a scarf or bandana.
The scarcity of masks in the market as Covid-19 peaked at the onset of the year, saw the entry of homemade cloth face masks which have become the defining image of the coronavirus pandemic. Though comfortable, they offer moderate efficacy in preventing dissemination of virus particles. They can be worn in outdoor areas as their efficiency at filtering large droplets is 97-98% and efficiency at filtering aerosols ranges between 51% to 72.5%. Standard disinfection methods should be used to clean them as the SARS-CoV-2 is thought to live on cloth for up to 2 days.
Recommended to be worn in healthcare settings, their efficiency at filtering large droplets is 98.5% and efficiency at filtering aerosols is 89.5%. They are three times more effective than homemade masksat blocking virus droplets transmission. They should be disposed with care as detectable levels of infectious virus have been found to remain on the outside of surgical masks for up to 7 days.
These are the most effective masks as their efficiency at filtering large droplets is 99.9% and efficiency at filtering aerosols is 95%. Recommended to be worn in healthcare settings, the filtering facepiece respirator or N95, N97, N99, N100 as they are commonly termed, filter even smaller 0.075 um solid particles.
While their efficiency in reducing viral spread is unclear, they do provide superior protection against splash and spray of respiratory secretions. This prevents spread of Covid-19 through the mucous membranes of the eye as face shields are hooded and extend from forehead to the chin while wrapping the sides of the wearer’s face. Since they are reusable, they should be cleaned and disinfected after every use.
More layers of fabric increase mask efficiency. While one layer may reduce droplets emitted during speaking, two layers block the droplets produced by coughing and sneezing. Cloth masks with three layers have also been recommended by World Health Organisation (WHO).