The use of N-95 masks with valve respirators as a COVID-19 protective gear does more harm than good, the Centre has written to state and union territories.
The Director General of Health Services (DGHS) in the Ministry of Health, in a letter to the Principal Secretaries of health and medical education of states, said that they have been observing "inappropriate use" of N-95 masks, particularly those with valved respirators, by the public other than designated health workers.
DGHS Rajiv Garg said in the letter, "It is to bring to your knowledge that the use of valved respirator N-95 masks is detrimental to the measures adopted for preventing the spread of coronavirus as it does not prevent the virus from escaping out of the mask. In view of the above, I request you to instruct all concerned to follow the use of face/mouth cover and prevent inappropriate use of N-95 masks."
To understand why using masks with valves is counterproductive, it is important to understand how a mask works in preventing the spread of COVID-19.
Earlier in the pandemic, it was advised that only people who are symptomatic or sick wear the mask so as to prevent the virus from escaping from their nose or mouth when they breathe or speak. However, later on, it was advised that everyone wear a mask as the number of coronavirus patients rose, as a precaution, seeing everyone as potential carriers of the virus.
However, the primary purpose of the mask is to prevent a carrier of the virus from spreading the virus when they exhale or talk. A valve prevents this.
Some masks, such as N-95 respirators used by healthcare workers, can make it hard to breathe over a period of time. While a respiratory valve makes it easier to breathe, it allows unfiltered air when the wearer exhales to escape through the valve. This is dangerous if the wearer is affected by SARS-CoV-2.
The Centre’s advisory against masks with valves comes quite late into the pandemic, whereas experts have been advising against these masks’ usage for a while now, especially for frontline and healthcare workers who are in proximity with COVID-19 patients.
The DGHS referred to the advisory on the use of homemade protective cover for face and mouth available on the website of the Ministry of Health.
The government had in April issued an advisory on the use of homemade protective cover for face and mouth, asking people to wear it, particularly when they step out of their residences.
The advisory stressed such face covers must be washed and cleaned each day, as instructed, and stated that any used cotton cloth can be used to make this face cover.
The colour of the fabric does not matter but one must ensure that the fabric is washed well in boiling water for five minutes and dried well before making the face cover. Adding salt to this water is recommended, it said.
It also listed the procedures of making such homemade masks, asking to ensure it fits the face well and there are no gaps on the sides.
It urges people to wash hands thoroughly before wearing the face cover, switching to another fresh one as the face cover becomes damp or humid, and never reusing it after single use without cleaning it.
"Never share the face cover with anyone. Every member in a family should have separate face cover," the advisory stated.
India's COVID-19 case tally crossed the 11-lakh mark on Monday, while the total number of recovered patients increased to over seven lakh, according to Union health ministry data.
(With PTI inputs)