From hairdressers to waiters, many professionals have taken to wear face shields amid the coronavirus pandemic.
But a new study has warned that these plastic shields don’t work, and can actually allow airborne coronavirus droplets to escape.
Researchers from the Riken Centre in Japan, have performed a simulation using Fugaku – the world’s fastest supercomputer.
The simulation found that almost 100% of airborne droplets of less than 5 micrometers in size escaped through plastic visor, while 50% of larger droplets found their way into the air.
Speaking to The Guardian, Makoto Tsubokura, team leader, said: “Judging from the results of the simulation, unfortunately the effectiveness of face guards in preventing droplets from spreading from an infected person’s mouth is limited compared with masks.
“This is especially true for small droplets of less than 20 micrometres. At the same time, it somehow works for the droplets larger than 50 micrometres.”
The researchers suggest that people who are advised not to wear face masks could wear face shields instead, but only outdoors, or in well-ventilated indoor areas.
In England, there is currently no specific guidance about whether you can wear a plastic face shield instead of a mask.
However, in Scotland, the use of face shields instead of face masks is permitted.
The Scottish government website explains: “You may also use, if you prefer, a face visor but it must cover your nose and mouth completely.”
Meanwhile, the Centres for Disease Control and Prevention in the US states that it is currently unknown whether or not face shields can protect you from coronavirus.
It states: “The CDC does not recommend the use of face shields for normal everyday activities or as a substitute for cloth face coverings.”