An exhaust apparatus for connection to a personal protection respiratory device that defines a filtered air volume adjacent to the face of a wearer and comprises at least one exhalation, the apparatus comprising a blower in fluid connection with the at least one exhalation valve, the blower being responsive to the wearer's respiratory cycle to draw a substantial portion of the wearer's exhaled breath through the at least one exhalation valve wherein, in response to the wearer's respiratory cycle, the blower operates throughout the wearer's exhale breath, or a substantial period thereof, and does not operate throughout the wearer's inhale breath, or a substantial period thereof