1.1 Surgical Masks
Surgical masks are fluid resistant. They filter particulate, droplets
and bacteria. They are not designed for a tight seal, thus will allow
unfiltered air to flow around the sides. The materials are not regulated
for their ability to filter small particles and vary between models.
They are not considered respiratory protection. They are worn to protect
HCWs from large droplets or sprays of infectious body fluids from
patients that may be directly transmitted to the mucus membrane in the
wearer’s nose or mouth. When worn by patients, they reduce the
concentration and amount of large infectious particles released when
coughing, talking or sneezing, and thus infection risk to others.(67)
They have a reported failure rate of 10-90%, which is inadequate for
droplet nuclei protection.(68) Birschoff et al conducted a pilot study
testing surgical masks against N95 respirators using a human exposure
model, and they only protected 1 in 4 participants with influenza.(66)