BENGALURU : Face masks safeguards people against COVID infection, but many tend to reuse masks which reduce their efficacy, warn experts. Many people use triple-layer surgical masks as they are easily available at pharmacies and are affordable. But these masks are worn over many days and experts have warned against this.
Dr C Nagraj, Director, Rajiv Gandhi Institute Of Chest Diseases, said, "The triple-layer mask is effective only for 4-5 hours and one has to dispose it of after that. If people continue to wear it, they have a higher chance of catching the infection if they come in contact with a COVID-positive patient. This mask tends to become loose and it does not block small particles in air that can be transmitted through sneezing or coughing."
A study published by researchers of the University of Massachusetts Lowell and California Baptist University found that re-wearing of a three-layer surgical mask is as good as not wearing one. While pleated three-layer surgical masks are 65 per cent effective in filtering air particles, their efficacy drops to 25 per cent when they are used more than once.
Experts said that even the use of cloth masks is not advisable. “The cloth mask is not ideal for prevention. As the virus is very small, it can pass through small pores in the mask. A lot of people wash their mask and reuse them which is not recommended as it contaminates the mask,” said Dr Sunil Kumar K, Consultant, Interventional Pulmonology, Aster CMI Hospital.
Dr Nagaraj advised that like the surgical triple-layer mask, the cloth mask too should be used only for four to five hours a day. Dr Hirenappa Udnur, Consultant - Pulmonologist, Columbia Asia Hospital Hebbal, said, “Triple-layer masks and cotton masks are are less effective if you are close to a Covid positive person or you have symptoms of Covid.”
Experts suggested that people can opt for N95 mask and it can also be reused. "It can be reused with proper sterilisation. Though these masks are not meant for reuse, with other protection like PPE and face shield, one can reuse a N95 mask," said Dr Udnur. One can wear a reused N95 mask up to seven days. Only of people wearing masks maintain a 6 ft distance, will the risk of infection fall to zero per cent, said Dr Nagaraju
Triple or double layer surgical masks: These surgical masks are loosely fitted and can protect one from large particle droplets. they can also filter out smaller aerosol particles. Experts state is it better to dispose of the surgical masks after every use.
Cloth masks: Homemade face masks only offer a small degree of protection, but they may help prevent the transmission of SARS-CoV-2 from asymptomatic people. The CDC recommends using them in public settings, as well as practising physical distancing and proper hygiene. It can be disinfected and reused.
N95 mask: An N95 respirator is a more tight-fitted mask. In addition to splashes, sprays, and large droplets, this respirator can also filter out 95 per cent trusted source of very small particles. These masks can be reused for up to five-seven days.