Health ministry warns against use of N95 masks with valves

The Director General of Health Services, Ministry of Health, has warned against the "inappropriate use of N95 masks, especially those that contain respiratory valves" to help users breathe.

"The use of valved respirator N95 masks is detrimental to the measures adopted for preventing spread of coronavirus as it doesn't prevent the virus from escaping out of the mask," the Director-General, Dr Rajiv Garg, wrote in a letter to states and union territories.

He further said that states and union territories should encourage the use of homemade cloth masks, which can be made by following guidelines issued by the Health Ministry.

The advisory comes amid rising concerns over the ineffectiveness of the valved masks to prevent the spread of the coronavirus.

Valved masks are typically used in industrial settings, where a user needs protection from the environment. While the masks filter in air that the user inhales, the valves help release exhaled air back into the environment.

When used to prevent the spread of COVID-19, valved masks would protect the user but could potentially end up harming others near them.

“Respirators with exhalation valves should not be used in situations where a sterile field must be maintained because the exhalation valve allows unfiltered exhaled air to escape into the sterile field,” says the US CDC.

In fact, several governments around the world, such as in California's Bay Area, have banned the usage of masks with valves.Separately, in India, the government has also urged the general public to use homemade masks instead of N95 masks (without valves) to allow the latter to be used to healthcare workers who are at greater risk.