Microbicidal air filter (10) for use with an air passageway, which comprises an immobilization network (12) having substantially impregnated therein an amount of at least one antimicrobial substance sufficient to substantially immobilize, retain and kill microbes suspended in a volume of air moving through the air passageway. The immobilization network (12) is substantially permeable to air. A microbicidal facemask (24) and a microbicidal air filter (10) used in an air circulation system (40) using the immobilization network (12) are disclosed.
