Plastic Shields Don’t Stop Aerosol Transmission of Coronavirus

• New research finds that while wearing a surgical face mask can provide protection against airborne infection, face shields offer little or no protection.
• Evidence suggests that SARS CoV-2, the virus that causes COVID-19, is transmitted when people expel virus-containing droplets when they sneeze or cough.
• Studies have found that breathing and talking can expel droplets containing the virus. These particles remain airborne and may spread widely through a room.

Throughout the COVID-19 pandemic, people have used plastic visors and face shields for protection against potential infection in shops and other places where crowds gather.

However, new research presented at this year’s European Congress of Clinical Microbiology & Infectious Diseases finds that while wearing a surgical face mask can provide similar protection against airborne infection as wearing a respirator, face shields offer little or no protection.

The study, conducted by researchers at Philipps University Marburg in Marburg, Germany, compared 32 types of masks intended for use in hospitals, including cloth and surgical masks, respirators, and face shields.

The surgical masks included some with EN 14683 certification (EU quality standard) and others that were noncertified. Both FFP2 and KN95 respirators were tested.

“To protect against airborne pathogens, a mask that [needs to] fit well around the nose and mouth and also have the ability to filter or prevent pathogens from crossing the material,” Dr. David Hirschwerk, an attending physician in infectious diseases at Northwell Health in New York, told Healthline.