A breathing assistance apparatus adapted to deliver humidified gases to a patient comprising: an integrated gases supply and humidifying device comprising gases supply means or a blower combined in one housing with humidification means, and an inlet, a manifold on or about said inlet on the inlet side of the gases supply means or blower, wherein said manifold includes at least one aperture (16, 17) to allow drawing, by the gases supply means or blower, of ambient gases into said manifold and into the gases supply and humidification device via the inlet, and an oxygen inlet port capable of being connected to an oxygen supply, the manifold configured to enable oxygen to be added to said ambient gases, and wherein the humidification means includes a humidification chamber having an outlet, the breathing assistance apparatus configured such that, in use, said ambient and oxygen gases flow in sequence from said inlet through said gases supply means or blower, said humidification chamber and out said outlet, and wherein said at least one aperture (16, 17) is an air intake when said gases supply means or blower is supplying gases and a gases outlet to allow auxiliary gases to spill to ambient when said gases supply means or blower is not supplying gases, thereby enabling safe addition of oxygen to the input air stream of the gases supply and humidifying device and reducing the amount of accumulation of oxygen within the gases supply and humidifying device, reducing fire risk should sparking occur within the gases supply and humidifying device. an integrated gases supply and humidifying device comprising gases supply means or a blower combined in one housing with humidification means, and an inlet, a manifold on or about said inlet on the inlet side of the gases supply means or blower, wherein said manifold includes at least one aperture (16, 17) to allow drawing, by the gases supply means or blower, of ambient gases into said manifold and into the gases supply and humidification device via the inlet, and an oxygen inlet port capable of being connected to an oxygen supply, the manifold configured to enable oxygen to be added to said ambient gases, and at least one aperture (16, 17) to allow drawing, by the gases supply means or blower, of ambient gases into said manifold and into the gases supply and humidification device via the inlet, and an oxygen inlet port capable of being connected to an oxygen supply, the manifold configured to enable oxygen to be added to said ambient gases, and wherein the humidification means includes a humidification chamber having an outlet, the breathing assistance apparatus configured such that, in use, said ambient and oxygen gases flow in sequence from said inlet through said gases supply means or blower, said humidification chamber and out said outlet, and wherein said at least one aperture (16, 17) is an air intake when said gases supply means or blower is supplying gases and a gases outlet to allow auxiliary gases to spill to ambient when said gases supply means or blower is not supplying gases, thereby enabling safe addition of oxygen to the input air stream of the gases supply and humidifying device and reducing the amount of accumulation of oxygen within the gases supply and humidifying device, reducing fire risk should sparking occur within the gases supply and humidifying device.