Abstract: An air filtration system for use in filtering a pressurized air flow, the system comprising a primary particulate filter for removal of at least a portion of particulate matter entrained in the air flow, at least one ultraviolet lamp, and a permeable reaction filter. The ultraviolet lamp is positioned downstream of the primary particulate filter and the permeable reaction filter is positioned downstream of the ultraviolet light. The permeable reaction filter has a substrate member and a plurality of titanium dioxide particles bonded to portions of the substrate member to form a photo-catalytic oxidizer layer disposed thereon a portion of the substrate member. The ultraviolet lamp irradiates at least a portion of the permeable reaction layer so that at least a portion of contaminants entrained in the air flow. The system may also include an adsorption filter positioned downstream of the permeable reaction filter.