Negative Pressure Escape Masks are specialized respiratory devices designed to protect users from hazardous atmospheres. These masks create a negative pressure environment, enabling the wearer to ...

As such, they are more likely to escape a face shield or a poorly-fitted mask. "They're very light, so they're able to flow around the sides of the visor and the bottom very, very easily," Verma said.

Wearing two face masks is only slightly better at stopping droplets from a cough from escaping than properly wearing one mask, a simulation by the world’s fastest supercomputer showed.