Why should a surgical mask not be used to protect against inhalation of biohazards or bioaerosols?

A surgical mask is not suitable for protection against inhalation of biohazards or bioaerosols primarily because it may not be impervious to liquids. In settings where biohazards or bioaerosols are present, it is crucial for personal protective equipment to effectively prevent the passage of liquids and small particles, including pathogens that may be suspended in aerosol form. Surgical masks can allow droplets and aerosols to pass through due to their construction and filtration capabilities, which do not offer the level of protection required against fine particles or infectious agents.

The effectiveness of a mask in a biohazard situation is heavily dependent on its ability to act as a barrier against smaller sizes and not just larger droplets. Therefore, relying on a surgical mask could lead to inadequate protection for individuals working in environments where they are exposed to potentially infectious aerosols. Proper respiratory protection, such as N95 respirators or other specific filtration devices designed for airborne contaminants, is essential in these circumstances.