Abstract: A filter system particularly adapted to remove particulate aerosol and vapor contamination from air comprising, an outer shell having a contaminated air inlet cap connected to one end and a clean air outlet cap connected to the other end, and a plurality of filter units mounted axially in the shell, each of said units comprising two containers, one of the containers having a particle/aerosol filter element therein such as paper, and the other of the containers having a vapor filter element therein, such as charcoal, the two containers of each filter unit being positioned in contiguous relation. A vapor passage is provided from one container to the other container of each unit and an annulus is provided between the outer periphery of the containers and the inner surface of the shell.