Abstract: The present invention relates to a device for specific inhalation challenges, especially bronchical provocation tests, including a compressed air supply, a particle generator an exposure room, an orofacial mask, a gas-aerosol photometer, a manometer, a valve and a suction pump. The invention also relates to a method of using the device and to an improved particle generator.

Abstract: Closed circuit emergency breathing apparatus is disclosed which is comprised of concentrically associated oxygen container and scrubber components, and a flow control valve assembly mounted on the open end of the compressed oxygen container and against the corresponding end of the scrubber. Unique valve structures enable the provision of all valve functions by valve components provided in a common support arrangement by which the valve assembly is mounted on the compressed oxygen container and structurally interrelated with the corresponding end of the scrubber. Breathing hose, pressure gauge and burst valve components are also mounted on the common support, and a breathing bag is mounted on the scrubber between the opposite ends thereof.