'COVID-19 and public health' Why N95 face masks should be avoided

In India, the Director General of Health Services (DGHS), in the ministry of health, wrote a letter to state authorities on Monday observing that the public has been using the N95 masks inappropriately, particularly those with a ‘valved respirator’ which are essentially meant to be used by designated health workers.

“It is to bring to your knowledge that the use of valved respirator N95 masks is detrimental to the measures adopted for preventing the spread of coronavirus,” said DGHS Rajiv Garg in the letter. Here is all you need to know:

What are N95 respirators

N95 respirator is personal protective equipment (PPE) used to protect the wearer from airborne particles and from liquid contaminating the face. It reduces wearer’s exposure to particles including small particle aerosols and large droplets (only non-oil aerosols). N-95 respirators filter out at least 95% of airborne particles and the edges of the respirator are designed to form a seal around the nose and mouth. These respirators are primarily designed for health care workers and are also used at construction sites to protect the wearer from dust particles.

Type of N95 respirator that you need to avoid

However, a certain type of N95 respirators—the ones with a valve—are not as beneficial as you might have been told.

Avoid wearing a mask which has valves or openings on the front as it might be a ‘one-way valve’ which is only going to protect the person wearing it. Maks with a one-way valve does not filter aerosols coming out of your mouth, hence, immediately putting those around you at risk.

The idea of an effective face mask to prevent you from catching a respiratory illness is that it protects others too. A mask which will protect you but put those around you at risk cannot help in containing Covid-19.

An N95 respirator that has a two-way valve is capable of filtering out particles during both inhaling and exhaling, however, these are mostly used by health professionals given the extent of their exposure to virus droplets.

What is the best type of mask for general public

Garg in his letter to state authorities notes that a valved N95 respirator “does not prevent the virus from escaping out of the mask….” and refers to government’s advisory issued in April on the use of ‘homemade protective cover for face and mouth’, particularly when they step out of their residences.

The advisory says that any used cotton cloth can be cut out into a face cover, stressing that such cloth-based homemade masks must be washed and cleaned each day.

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, as per the government advisory.

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 their hands thoroughly before wearing the face cover. When the face cover gets damp or humid, it should be changed and a fresh mask should be used. Never reuse a cloth mask without cleaning it.

“Never share the face cover with anyone. Every member in a family should have separate face cover,” the advisory stated.