Wearing facial masks is a commonly recommended prophylactic measure against the spread of airborne pathogens [138,139] such as the influenza A virus [140]. It is even recommended that patients suspected of being infected with SARS-CoV-2 should be fitted with masks during surgery or procedure requiring anesthesia [141] and also during transport to the hospital [142]. FFP2 and FFP3/N95 masks offer significant protection against airborne particles and even then the FFP3 masks filter at least 99% of airborne particles, leaving a gap for some particle penetration. These masks also still pose the risk of improper sealing [143].