Study: Face shield and mask with valve ineffective against coronovirus

According to the Centers for Disease Control and Prevention, face coverings are effective ways to prevent the spread of coronaviruses. But a new study found that two popular options, the face shield and the N95 respirator mask that have one or two exhale ports or valves, still release infectious droplets into the air.

According to the study final, researchers at Florida Atlantic University used laser light to illuminate the flow of aerosols left when people cough or sneeze. In a university news release, FAU’s College of Engineering and computer science scientists said they used mannequins to prevent coughing and sneezing while doing both types of face covering.

Their visualization showed that a large number of potentially infectious droplets were able to escape from the exhale valve on the N95s and around the edges or edges of the face.

The lead author of the study, Sid Verma, Ph.D. “A driving force to adopt this enhancement is better comfort than regular masks. However, the face shields have noticeable gaps at the bottom and sides, and masks with exhalation ports include a one-way valve, which restricts airflow when inhaling, but allows free outflow of air. . The inhaled air is filtered through the mask material, but the exhalation valve passes through the valve. ”

According to Fox News, the San Francisco Department of Public Health has already warned residents that N95 masks are not safe with a valve or front. In the Bay Area of ​​California, there is a stipulation that you can wear any style mask you want, as long as it does not have a valve.

San Francisco city officials followed up with advice on how to make these masks safe. He suggested covering them with surgical masks or other cloths or covering the valves with tape.

According to Fast Company, even the CDC does not recommend that hospitals use the N95 with valves because “the exhalation valve allows unfiltered air to escape within a sterile area.”