Do Plexiglass Dividers Really Protect Against COVID-19?

We encounter plexiglass dividers everywhere both in indoor and outdoor settings to protect us against COVID-19. But the big question is: Do they really work? Princeton University researchers designed an experiment using a fog machine to find out if the plexiglass panels truly block airborne transmission.

Professor Howard Stone, who specializes in the mechanics of fluid transmission at the university, told Good Morning America that ”plexiglass dividers do compartmentalize air, and reduce the risk to some degree.”

During the experiment, green fog was propelled toward a plexiglass barrier mimicking how particles travel when a person speaks continuously. Since the fog can’t move through the barrier, it travels around it, says Stone, mixing with other air and becomes diluted, reducing the viral load and lowering the risk of infection.

According to WebMD, both the Centers for Disease Control and Prevention and the Occupational Safety and Health Administration recommend plexiglass barriers to protect against COVID-19, and sales of the plastic product have tripled since the pandemic.

However, Dr. William Ristenpart, associate professor of chemical engineering at the University of California, Davis, says the dividers work like face shields, blocking large droplets of virus and are less effective in impeding aerosols that hang in the air.

An engineering team from the University of Central Florida calculated the effectiveness of plexiglass barriers in indoor restaurants with standard ventilation systems. They found that the breath from an infected person dining in an area flanked by the barriers rose and interacted with the ventilation system. Our breath is generally hotter than indoor air, so as the warm air rises, it can spread over and around the barrier and infect others.

While plexiglass dividers have their benefits, they are not zero risk, said experts, according to GMA, and are not a substitute for masks and social distancing.