N-95 masks protect users, not those around: Experts

CAUTION Valves could act as easy passage for germs and endanger those in proximity

NEW DELHI: People using N-95 masks with respiratory valves may be protecting themselves, but those around them could be at high risk of contracting an infection, according to experts who recommend the use of face covers without valves in a viral outbreak such as the coronavirus disease (Covid-19) pandemic.

Using N-95 masks with valves is recommended when pollution levels are high as they do not allow carbon dioxide to accumulate inside, experts said. But the same valve — used for exhalation — could act as an easy passage for germs and endanger those in close proximity if user has an infection. “If you’re using N-95 masks, use those without a valve,” said GC Khilnani, a member of Delhi CM’s advisory committee on Covid-19 preparedness and chairman, PSRI Hospital New Delhi.

While all masks filter air users are inhaling, ones without valves also trap most germs coming out with exhalation, protecting people around those wearing them.

The Union health ministry has been issuing regular advisories, asking people to avoid wearing N-95 masks, which are used as part of PPE kit for frontline workers dealing with Covid-19 cases.

Harsh Mahajan, owner of Mahajan Imaging, a diagnostic centre, said N-95 masks should be prohibited even for health care workers. “In fact, in Covid times, N-95 masks with valve should be banned as these are meant to be used during high pollution levels...valve meant to breathe out air will also let germs (viruses and bacteria) pass, making it

unsafe for others in close proximity. Purpose of wearing a mask to protect others will get defeated in the time of Covid-19,” he said.

Khilnani said it is important to wear a mask in way it covers the face snugly from upper part of nose to chin. “If you use washable masks, wash, dry and reuse after five days...Surgical masks should be disposed of after every use.”

Surgical masks are recommended by World Health Organization for health care and sanitation workers not directly involved in dealing with Covid patients. These masks create a barrier around nose and mouth, but such face covers should be discarded after each use. Another option is a homemade face cover (preferably made of cotton fabric)

that can be reused after washing.

SK Chhabra, a senior pulmonologist at Primus Hospital in New Delhi, said: “For healthy persons stepping out, face covers should provide some protection as these will stop exposure to bigger droplets. However, use of handkerchiefs or stoles should be avoided as there will be too many leak points.”