Abstract: A filtering apparatus (50) for removing noxious gases from an environment including: a source of compressed gas (60) connected to a regulating valve (62) to regulate a supply of compressed gas; at least one airflow device (5) including a compressed gas inlet (10) for receiving gas from the supply of compressed gas at greater than ambient atmospheric pressure, the gas inlet (10) being operably connected to the regulating valve (62); and a permeable noxious gas filter (55) arranged in gaseous communication with the airflow device (5); wherein the supply of compressed gas to the airflow device (5) causes the airflow device (5) to draw ambient air (64) from the environment through a primary intake (42), thereby generating a flow of air through the noxious gas filter (55) and causing the substantial removal of noxious gases from the flow of air.