Those face masks you see with coin-sized valves on the front may look appealing yet they are not as acceptable at forestalling the spread of the novel coronavirus as the non-valved veils.
A few masks are intended for hot, dusty development work — where the goal is to sift through residue before it causes infection to lungs. They have “exhaust” valves that permit the breathed out air to stream out more effectively, to have cooler air.
The 3M organization, which makes valve masks, outlines on its site how they function: breathed in air is separated through the texture part of the cover, and hot, muggy breathed out air releases out via the valve.
Medical health experts have strongly recommended wearing mask to inhibit spreading respiratory droplets into the air when you exhale, speak, cough or sneeze.
What many people claim about N-95?
Needless to say there are numerous whatsappp forwards and social media shares that valued N-95 can filter 95 % of virus droplets. It suggests that N-95, which is a type of respirator facilitates more protection than a surgical mask does because it can expel out both large and small particles in case the wearer inhales. Some N95 masks have valves that are designed to make breathing easier.
What’s the actual truth?
A study published by Annals of internal medicine find that a cloth mask gives more protection than a surgical mask for people who are in close proximity with others. Although the respirator filters 95% of airborne particles and small jet of aerosol particles, it’s effectiveness depends on how tightly it fits the wearer’s face. In the recent guidelines set for mask-wearing, any mask that has one way valve (approximately about the size of a quarter on the front or side of the mask) that is developed to allow easy exhaling allows droplets to be released from the mask too, putting others lives at peril.
The San Francisco department of Public Health stated recently that these filtered valve masks may actually propel the germs even further. It prohibited its usage in the public health order during the pandemic. Both CDC and World health organization recommend individuals to wear a cloth mask in public when 6 ft rule of social distancing is not possible.
Researchers took the swabs from each mask’s outer surface and inner surface. Interestingly, most swabs residing in the inner mask were negative while those from exterior were found positive. This is the actual reason why experts recommend not to partly open the masks and put it below the chins. They advice to either fully wear the mask or completely remove it.
In India, the Director General of Health Services (DGHS) in the ministry of health recently notified the state authorities that public has been using N-95 masks inappropriately, which has been designed specifically for front line health workers.
DGHS Rajiv Garg intimated in the letter that “It is to bring to your knowledge that the use of valved respirator N-95 masks are found to be detrimental in preventing covid-19”.
The Ministry of health suggested to avoid wearing a mask that has prominent valves or openings on the front. They act as one way valve to filter the air via inhalation. Although it protects the wearer, the unfiltered air exhaled can be harmful to others surroundings the wearer. The advisory states that any cotton cloth can be prepared at home and used instead.
It further shared that colour of the fabric doesn’t matter and had put forth certain guidelines to prepare a mask without any gaps in the sides and said the masks have to be reused only after boiling them in salt water.