N95 Masks with Front Valve are not Effective Against SARS-CoV-2 Virus

Subhra Adhikari, MSc, Neucrad Health Desk , July 21, 2020

Since the government of many countries are now easing out restrictions of the COVID-19 lockdown, we need to follow appropriate measures to prevent the spread of the infection. Among them, wearing face covers and maintaining touchless screening at railway stations and airports are crucial. However, recent studies have revealed that a specific variety of N95 masks with a front valve cannot prevent the spread of the virus. These valves act as a one-way outlet for air and microbes so that the person wearing it does not feel suffocated. In this way, it let out the viral particles to escape from the wearer’s nose and infect others in the process. Let us know more about the N95 mask with ventilators.

What is the function of ventilators in N95 masks?

People often feel suffocated and extremely hot after wearing a mask. It is especially true for workers functioning in hot and humid conditions, like construction sites, mines, and roads. To make them feel comfortable, after wearing a mask, manufacturers have included a ventilator cum valve in the personal protective kit. These valves do not allow viral particles to enter the nose. However, they can let out pathogens to flow out through the valve and infect others if the wearer is suffering from a viral infection. Even the San Francisco Department of Public Health issued a warning against the wearing of masks with ventilators. Though they are successful in safeguarding the health of the wearer, the masks can put others life at risk. So, this mask is not effective in preventing the spread of SARS-CoV2 virus.

What are the different types of face masks available in the market?

Governments of most countries have made it mandatory for people to cover their face whenever they venture out of the house. You can use various types of face covers to protect yourselves as well as others from the novel coronavirus. Here is a list of different kinds of face-covers available in the market.

Cloth Mask

Cloth masks are one of the most widely available face covers in the current condition. It comes at an economical price range, and you can even prepare it in your house. All you require is a two-ply cotton cloth (thick cotton cloth), elastic lace, thread and needle to make the mask. Though it is not as effective as the N95 mask in protecting against the COVID-19 infection, in low-risk areas, it is far better than roaming without any face covers. These masks are also reusable. Once you return home after wearing the mask, you can wash it in a disinfectant solution and dry it under the sun for reusing it.

Surgical Mask

Surgical masks are single-use face cover made with a nonwoven fabric through the melt blowing process. Medical professionals like doctors and nurses use these masks while attending to patients in the health care facilities. Manufacturers design it in such a fashion that liquid droplets and aerosols from the wears’ mouth do not come in contact with the patient. However, they are effective in preventing the spread of SARS-CoV-2 virus. But, in the unavailability of N95 masks, people of many countries use it as a protective gear during the ongoing COVID-19 pandemic.

N95 Mask

N95 masks without valves are an effective face cover for protection against the COVID-19 pandemic. Studies reveal that SARS-CoV-2 virus has a diameter of 125 nanometres (nm). According to the National Institute for Occupational Safety and Health (NIOSH), the N95 masks can filter 95 per cent of microbes in the 100 to 300 nm size range. Similarly, N99 respirators can filter 99 per cent of pathogens and N100 masks filter 99.7 per cent of viral particles. Ideally, uses can wear these protective kits for a maximum of five times. However, due to the extreme crisis of these face covers during the COVID-19 pandemic, you can use it beyond the shelf life provided the straps, nose bridge, and mask is of good quality.

Always remember to cover your face with mask and practise physical distancing to prevent SARS-CoV-2 infection.