As Omicron — the fastest-spreading variant of SARs-CoV-2 — continues to affect people across the globe, the importance of wearing masks and maintaining social distancing becomes even more important. But there is still confusion regarding the most effective masks against the virus and its many variants. While some people still wear cloth masks, experts say that they may prove ineffective against filtering particles.
So, which mask is the best? Here’s what you need to know.
Why are cloth masks not effective?
A research paper published in PeerJ, which analysed 20 different types of cloth masks, found that their pore sizes ranged from 80-500 micrometers as against the novel coronavirus which is about 0.12 micrometers. This meant that tiny droplets can be inhaled through the voids or gaps near the nose and cheeks.
Agreed Dr Pritam Moon, consultant physician, Wockhardt Hospital Mira Road, and said that cloth masks are effective only for larger particles. “High-filtration masks, on the other hand, can help keep Omircron at bay when compared to cloth and surgical masks,” he said.
While surgical masks are better than cloth masks, they still lack protection against the Omicron variant. Dr Shubhang Aggarwal, Director, NHS Hospital, Jalandhar said, “Cloth masks are generally not that effective in blocking aerosols. Their effectiveness lies somewhere around 50 to 60 per cent range. Putting a surgical mask under a cloth mask can get you over 91 per cent removal efficiency for air and dust particles. That’s also the reason why we are seeing people either double masking or doing a version of an N95.”
As per Dr Niranjan Patil, microbiology and molecular biology – head and biosafety officer, Metropolis Healthcare Ltd, “A cloth mask alone may not be useful. It was being prescribed in the first wave for general public because there was a shortage of N95 masks for healthcare workers and lab professionals. A three-layer surgical mask and cloth mask, when used together, are effective instead of using them alone. As Omicron is highly transmissible, protection by cloth mask is non-existent and in fact, may contribute to its spread as it may give a false sense of security with reference to transmission and protection.”
The Ministry of Health and Family Welfare has said that N-95 mask/respirator have filter efficiency of 95 per cent or more against particulate aerosols. The mask should be provided with expiration valve, should be disposable and fit for wide range of face sizes. It should accompany certification from NIOSH or equivalent certification.
According to United States’ FDA (Food and Drug Administration), an N95 mask “is a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles”. Similarly, Centers for Disease Control and Prevention (CDC) said that KN95 masks are a cheaper alternative to N95 masks, as long as they “meet requirements similar to those set by CDC’s National Institute for Occupational Safety and Health (NIOSH) for respirators”.
The Ministry’s revised guidelines for home isolation said a Covid-19 patient should, at all times, use triple layer medical mask. “They should discard mask after eight hours of use or earlier if the mask becomes wet or visibly soiled. In the event of caregiver entering the room, both caregiver and patient may preferably consider using N-95 mask.
“N95 masks will help to filter even minute particles. Do not go for a mask that has a valve as it will not help in filtering the exhaled air if one is infected and not aware of the same. If you are using a surgical mask then double masking is essential. Make sure that the mask fits the face properly,” Dr Moon said.
According to American Conference of Governmental Industrial Hygienists, N95 masks are the best when it comes to offering maximum protection against the transmission of the virus. If the infected person is not wearing a mask, it takes at least 2.5 hours to transmit the infection from one person to another person. If both are wearing N95 masks, then the virus takes 25 hours to transmit.
Dr Patil advised against using masks with vents or exhalation valves as they allow the unfiltered breath to escape. “Besides, people who have a condition or are taking medications that weaken their immune system may not be fully protected even if they are fully vaccinated. They should continue to take all precautions recommended for unvaccinated people, including wearing a well-fitted mask, until advised otherwise by their healthcare provider. If you are fully vaccinated, to maximise protection and prevent possible spreading of Covid-19 to others, wear a mask indoors and outdoors in public if you are in an area of substantial or high transmission,” said Dr Patil.
Wearing two masks together, N95 and a surgical mask under it, is the best way to protect yourself from the variant, said Dr Sanket Jain, pulmonologist consultant, Masina Hospital, Mumbai. “N95 mask, in particular, can be reused, as they are rated for their ability to filter a lot of dust. The mask will not get saturated even after few days of normal use, so it can be reused. After the use of N95 mask for a routine day, it is to be kept aside in a dust-free environment for two-three days and then used again. Generally, there are many washable and reusable N95 masks available in the market, which can be washed with detergent powder and properly air dried for reuse,” said Dr Jain.
What about people who can’t wear N95 due to breathing issues?
“A combination of three-layer surgical and a cloth mask is for someone with COPD, asthma or any other breathing difficulty issues who cannot wear an N95 mask,” said Dr Patil.
According to Dr Rakesh Rajpurohit, MD, consultant pulmonologist and critical care medicine at Jain Multi Specialty Hospital, Mira Road, while cloth mask won’t give complete protection, but if chosen properly and used correctly can offer some form of protection. “It should be properly washed using disinfectants. It should cover the nose and mouth completely. It should be with a nose wire, to prevent any air leaks. It should be of multiple layer, tightly woven, and of breathable fabric. One can check the fabric by holding against a source of light, if it completely blocks the light, it is suitable,” said Dr Rajpurohit.
According to WHO, here’s how you should use a mask
*Before putting on a mask, clean hands with alcohol-based hand rub or soap and water.
*Cover mouth and nose with mask and make sure there are no gaps between your face and the mask.
*Avoid touching the mask while using it; if you do, clean your hands with alcohol-based hand rub or soap and water.
*Replace the mask with a new one as soon as it is damp, and do not re-use single-use masks.
“Wearing your mask correctly is just as important, even while double masking. Your nose needs to be covered, both masks should go over the bridge of your nose and under your chin. Masks should be cleaned and disposed of properly. Surgical masks are only good for one-time use,” stated Dr Aggarwal.
*To remove the mask: Remove it from behind (do not touch the front of the mask); discard immediately in a closed bin; clean hands with alcohol-based hand rub or soap and water.”
How to discard mask?
According to MoHFW, mask should be discarded after cutting them to pieces and putting in a paper bag for a minimum of 72 hours.
*Perform hand hygiene after disposal of the mask.
*Avoid touching own face, nose or mouth.