GoI: “N95 masks with respiratory valves does not prevent COVID-19”

The Minister of Health and Family Welfare Dr Harsh Vardhan recently announced that the N95 masks with valved respirators do not prevent COVID-19 from spreading out.

What are N95 masks?

The N95 masks are protective equipment that protects the wearers from airborne particles contaminating the face. The N95 masks filter particles that are less than 300 nano metres. The size of COVID-19 virus is between 65-125 nano metres.

Function of valve in N95 masks

The valve in N95 masks is a plastic gasket that filters air inhaled by the person and blocks entry of pathogens. The valve helps to prevent humidity, reduce heat and carbon-dioxide build up in the mask.


The Health Ministry states that N95 masks with valved respirators do not prevent virus from escaping out of the mask. It is a one-way mask. It only protects the person wearing the mask and does not filter aerosols coming out. Therefore, when an asymptomatic patient of COVID-19 wears the mask, he can easily spread the infection to others when the valve releases unfiltered air.

Asymptomatic patient is a person who shows no COVID-19 symptoms but is still infected by the virus. He is in his early stages.


The Health Ministry advises to use masks made of cloth, preferably cotton as an alternate to N95 masks.