Amid the COVID-19 pandemic, if you step out wearing a valve mask you bought to tackle pollution, you should consider changing it. Health experts have advocated for face masks to prevent COVID-19 spread, but masks with valves only filter inhaled air. So, if you’re a COVID carrier, you will infect others if your mask has a valve.
‘Valve masks work for pollution, not COVID-19’
Arvind Kumar, Chairman, Centre for Chest Surgery and Director in Institute of Robotic Surgery at Sir Ganga Ram Hospital, explains, “In COVID-19, the primary purpose of the mask is to protect others from you. The secondary purpose is to protect yourself. In air pollution, the only purpose is to protect yourself. That is the fundamental difference. In pollution, you need to clean 100% of the air you are breathing in and what you are breathing out can be allowed to go out back into the environment without resistance so that you don’t rebreathe your own air. But for COVID-19, you need 100% filtration during exhalation and effective filtration during inhalation.With a valve mask, everything that you breathe through the mask is filtered, but when you breathe out, the valve opens and allows unfiltered air to come out. So, if one is infected with COVID-19 and is wearing a valve mask, they are infecting others.”
The three important features in a mask
Jai Dhar Gupta, founder, Nirvana Being, and founder of the citizen movement My Right To Breathe, says, “Many hospitals, offices, and supermarkets don’t allow access if you wear a mask with a valve, because they expose those around you to the virus, adding, “If we think of the mask as a barrier against COVID, three features are important – 1) certified viral filtration efficiency (VFE) – should be 95%,2) breathability of the material used – this is important for comfort, and 3) the mask’s fit – if it doesn’t seal your face, it’s useless. All features are irreplaceable. The new direction for masks with efficacy against COVID are ones utilising nanotechnology – this elevates filtration capacity and lowers breathing resistance.”
In India, hospitals have been putting up notices, prohibiting masks that have valves
Global experts warn against valve masks
The Centre for Disease Control (CDC) recommends cloth masks, as layers of cotton can prevent the potentially infectious respiratory droplets from entering or escaping. San Francisco government’s website states that masks with a one-way valve are designed for easier breathing, but allow droplets to go out of the mask, putting those around at risk. William Schaffner, MD, Professor of preventive medicine & infectious disease, Vanderbilt University Medical Center, US says, “We want to protect you from me. And so, the valved N95 (mask) doesn’t function in this COVID environment – either in the health care setting, or in the community.”
‘Valves don’t filter exhaled air’
Vivek Nangia, Principal Director & HOD, Institute of Respiratory Pulmonary Intensive Care (Saket Complex) from Max Super Speciality Hospital, says, “Masks with a one-way valve don’t filter exhaled air, so if an asymptomatic COVID carrier wears a valve mask, the air they breathe out will carry viruses. So, a valve mask will prevent the individual from catching the infection but will be harmful to those around, so it’s better to opt for masks without valves.”
Anupam Sibal, Group Medical Director and Senior Pediatrician, Apollo Hospitals Group, emphasizes, “If one has COVID-19, theSARS-CoV-2 virus can escape with the unfiltered exhaled air and spread. In many places, such masks have been banned.”
Arvind Kumar, Chairman, Centre for Chest Surgery and Director in Institute of Robotic Surgery at Sir Ganga Ram Hospital, says, “Since the exhaled air comes out of a small hole, the speed is faster, and chances of infection increase.” Jai Dhar Gupta says, “The demand for N95 with valves hasn’t stopped. Valve masks are designed for people working in industrial settings where protection is needed against dust or asbestos, not viruses.”
Atul Gawande, a surgeon, public health researcher, and staff writer at The New Yorker tweeted such masks should be banned in the current scenario.
By – Niharika Lal and Riya Sharma