Government, health experts warn against using N95 masks with valves

The government of India, as well as various health experts have warned states in the country against the use of N95 respirators, which are available with a valve.

The central government told the states via official communication that the N95 masks containing valves do not stop the new coronavirus called SARS-CoV-2 from spreading, and instead can cause more harm in the effort to stop the COVID-19 infection from spreading further.

The Directorate General of Health Services (DGHS) under the Ministry of Health said in a letter to the chief secretaries of health and medical education of the states, "It has come to be known that it is inappropriate for common people and health workers to use the N95 mask, especially the N95 masks with valves." With this warning, DGHS in its advisory has advised the use of homemade masks or protective face covers available on the Ministry of Health and Family Welfare's website to avoid contracting the coronavirus infection.

The DGHS advisory states, "You are informed that N95 masks with valves are detrimental to the steps taken to prevent the coronavirus from spreading, as it does not prevent the virus. Keeping this in mind, I pray that they (health officers) instruct all concerned to use face masks or mouth covers and stop the inappropriate use of N95 (masks)."

According to the Centers for Disease Control and Prevention of the United States, an N95 respirator with an exhalation valve does not provide the same level of protection to the wearer as one without it, as the valve helps in easing exhalation. It says that "respirators with exhalation valves should not be used in situations where a sterile field must be maintained, because the valve allows unfiltered air to escape into the sterile field".

Significantly, the government had issued an advisory last April instructing people to use protective face covers made at home, especially while stepping outside. The advisory further advised that these masks or face covers be washed daily after wearing them.

According to the government, any cotton cloth used at home can be used to make such masks or face covers. However, the fabric does not matter much. The advisory stated that the more important thing is that the clothes must be thoroughly washed with lukewarm water for five minutes after use. While doing this, washing of clothes can be done well by adding salt to water.

The government's directive to discontinue the use of N95 masks may surprise the common people, but for experts in the health sector, the decision is not surprising at all.

Indeed, based on several recent studies, medical experts have stated that certain types of N95 masks are not capable of preventing the coronavirus from spreading. The valved N95 masks do not prevent virus droplets from going out of the mask, even though the masks may filter the air that is being breathed in. This is even more worrying for health workers, as many countries of the world - including India - had previously been instructed to save the N95 masks for them.

In an earlier report, Dr. Ali Raza, a professor at Harvard Medical School and executive vice-president of the Department of Emergency Medicine at Massachusetts General Hospital had said, "The virus can transmit through valves, which does not work at all." According to Dr. Ali, masks with a side valve only protect the person wearing the mask, but the people around do not get any protection from it.