Surgical/medical masks: These masks come in a variety of ‘grades’ or ‘levels’.
Level 1: Usually white in colour. These are used when there is no concern of serious infection and the risk of airborne virus transmission is very low (e.g. NOT during a global pandemic).
Level 2: Usually blue in colour. These are used when there is no current outbreak of an airborne virus (not sufficient for highly contagious airborne viruses such as the Omicron variant).
Level 3: Usually purple in colour. These 4-ply masks are considered maximum barrier protection masks and can provide protection from airborne viruses if properly fitted.
KN95/N95: These masks fit more closely to the face than regular surgical masks and are rounded or ‘duck-billed’ in shape. If the mask is a legitimate KN95 or N95 mask that fits properly (no gaps around sides), it can filter 95% of “particulate matter”. Most harmful airborne particles will be stopped by this filter.