Abstract: Provided herein is a positive air pressure facemask, a multi-staged filter system for a positive air pressure facemask, and exemplary methods for replacing the filter system of a positive air pressure facemask while the mask is in continuous use and actively worn by a user. The multi-staged filter system includes a front filter assembly having a plurality of removable filter layers for collecting debris and particulate matter on the exterior of the filter system, a blower assembly, and at least two staged filter inserts contained in the housing of the filter system. The staged filter inserts are easily replaceable and can be changed without requiring the user to remove the facemask or to be exposed to the ambient air.