The latest update released by the World Health Organisation says that the use of masks is a vital part of a comprehensive set of measures to prevent and limit the spread of COVID-19.
The report further states that you can use the masks either to protect yourself when in contact with an infected individual or for source control (worn by an infected individual to prevent onward transmission).
One of the masks we see being used by people outside is one with a valved respirator.
According to the latest circular released by the Ministry of Health, India, the use of N-95 masks with the valved respirators can be “detrimental” to the measures adopted for the containment of COVID-19
An N-95 respirator mask is a respiratory protective device with high filtration efficiency for airborne particles. To provide the requisite air seal to the wearer, such masks are designed to achieve a very close facial fit.
Dr Jawahar Singh, of AIIMS, tells The Better India (TBI), “The valve masks work in such a way that the air you inhale is filtered but the air that you exhale if you are symptomatic or even asymptomatic, will result in you exhaling the virus particle. This could potentially result in you infecting many more people unknowingly.”
“Now that the Ministry of Health has also come out with an advisory, the hope is that more people are made aware of the consequences of using a valved N95 mask,” he adds.
Is wearing a cotton mask better?
“I cannot vouch for the cotton masks preventing the spread of COVID-19. It prevents the droplets from escaping from the one who is wearing it,” informs Dr Jawahar.
However, Dr Giridhara R Babu, Professor and Head, Lifecourse Epidemiology, Indian Institute of Public Health, PHFI, Bengaluru, tells TBI, “My only message to everyone is to use masks. It doesn’t matter what material it is made of.”
What do the manufacturers of N-95 masks have to say?
Ashwar of SAV International, a PPE kit and N-95 mask manufacturer based in Delhi says, “Wearing an N-95 mask with a valve leads to the virus being exhaled out, and that is detrimental. However, there are N-95 masks that we manufacture without the valve as well and those can safely be used.”
These are masks available for two purposes – bacteria filter efficiency and particle filter efficiency. “It is essential for both these to be above 95 per cent efficiency marking. The valved ones are to be used only by health professionals and we have been supplying it to hospitals,” he says.
What is an N-95 mask?
These are masks with a 95 per cent efficiency value. These masks filter out contaminants like dust and fumes. According to the Center for Disease Control (CDC), the minimum size of .3 microns of particulates and large droplets will not be able to pass through this barrier.
According to the Department of Health and Welfare, Government of Punjab, if the medical staff is involved in any aerosol-generating procedures like suction, intubation, nebulisation, etc. they must use N95 Respirator. If the medical personnel need to collect clinical samples from patients then also they should use N95 Respirators.
Why are we using masks?
The primary purpose of the mask is to protect others from you, in case you are a symptomatic or asymptomatic carrier. According to Trisha Greenhalgh, Medical Professor, Oxford University, “Wearing masks with valves is worse than wearing no masks at all.”
The Center for Disease Control and Prevention (CDC) does not recommend that the general public wear N-95 masks with respirators to protect themselves from respiratory diseases, including coronavirus (COVID-19). Those are critical supplies that must continue to be reserved for health care workers and other medical first responders.
(Edited by Saiqua Sultan)