One of the most important tools in the prevention and spread of an influenza pandemic is the use of protective masks. The Centers for Disease Control and Prevention (CDC) and the Occupational Safety and Health Administration (OSHA) has guidelines for the different types of masks.
Facemasks are loose fitting disposable masks that cover the nose and mouth and are commonly used to prevent the spread of infection during surgical, dental and medical procedures. These masks are also used in isolation. These Facemasks help to prevent spread to and by the person wearing thee mask by stopping droplets from being spread by the person wearing them. They also keep splashes or sprays from reaching the mouth and nose of the person wearing the protective Masks. They are not designed to protect you against breathing in very small particles. Facemasks should be used once and then they should be discarded.
The US department of Labor recommends air-purifying respirators as a program for workers involved directly with influenza infected patients or birds. This is part of a comprehensive respiratory protection program. As part of the recommendation is air-purifying respirators such as N95, N99 or N100 masks.
These masks have advantages of typical cloth or surgical masks. They are greater than 95% effective at filtering .3 -µm particles. A typical droplet generated during coughing, sneezing and talking is 5 -um, which is significantly larger thus preventing it from passing through the filter. Another advantage is that these masks are fit tested to eliminate the possibility that droplets or particles do not leak around the mask.