A negative pressure respirator assembly may have an exchangeable filter elements, at least one intake valve, a facepiece body comprising a headband and a face shield, an outflow valve, an outflow tube coupled to the outflow valve, the outflow tube directing exhaust in at least one direction selected from the group consisting of parallel to the user's torso and down the user's shirt, into the user's personal protective equipment, and over the user's shoulder.

A face mask with purified air inside has a mask element formed so as to cover at least a part of a user's face including at least a user's nose and a user's mouth, and components for supplying into a space between the mask element and the user's nose and the user's mouth a purified air from a source outside the mask element.

A face mask with purified air inside has a mask element formed so as to cover at least a part of a user's face including at least a user's nose and a user's mouth, and components for supplying into a space between the mask element and the user's nose and the user's mouth a purified air from a source outside the mask element.

A face mask includes a space formed therein by a peripheral wall extending from the periphery of the space. At least one first path and at least one second path are respectively formed in the space so that outside air enters into the space via the at least one first pat, and air in the space is released from the space via the at least one second path. The face mask covers a large area of the wearer's face to reduce foreign objects from entering into the wear's body so as to reduce the chance of being infected.

A face mask includes a space formed therein by a peripheral wall extending from the periphery of the space. At least one first path and at least one second path are respectively formed in the space so that outside air enters into the space via the at least one first pat, and air in the space is released from the space via the at least one second path. The face mask covers a large area of the wearer's face to reduce foreign objects from entering into the wear's body so as to reduce the chance of being infected.

A bayonet connector (112, 128) suitable for connecting a filter cartridge (72) or an air supply tube to a respirator (10, 14). The bayonet connector (112) has a tubular male part (112) and a female part. The male part has a tube (114) with two or more lugs (130, 132) formed on it, which engage with engaging ribs (136, 138) located on an interior sidewall of the female part (128), or vice versa. The lugs (130, 132) and their corresponding engaging ribs (136, 138) are located at different axial positions.

A bayonet connector (112, 128) suitable for connecting a filter cartridge (72) or an air supply tube to a respirator (10, 14). The bayonet connector (112) has a tubular male part (112) and a female part. The male part has a tube (114) with two or more lugs (130, 132) formed on it, which engage with engaging ribs (136, 138) located on an interior sidewall of the female part (128), or vice versa. The lugs (130, 132) and their corresponding engaging ribs (136, 138) are located at different axial positions.

Described are oxygen control systems that utilize compressed air or oxygen. The oxygen control systems may include a control device having a first inlet that enables the flow of a supply gas from a high pressure gas source at an input pressure into the control device. The control device also includes a second inlet that enables a flow of atmospheric air into the control device and an outlet in fluid communication with the first inlet and the second inlet. The control device also includes a pressure regulator that is operable in a first mode and a second mode. In the first mode, the pressure regulator reduces input pressure of the gas to a first outlet pressure at the outlet, and, in the second mode, the pressure regulator reduces the input pressure of the gas to a second outlet pressure at the outlet that is greater than the first outlet pressure.

Described are oxygen control systems that utilize compressed air or oxygen. The oxygen control systems may include a control device having a first inlet that enables the flow of a supply gas from a high pressure gas source at an input pressure into the control device. The control device also includes a second inlet that enables a flow of atmospheric air into the control device and an outlet in fluid communication with the first inlet and the second inlet. The control device also includes a pressure regulator that is operable in a first mode and a second mode. In the first mode, the pressure regulator reduces input pressure of the gas to a first outlet pressure at the outlet, and, in the second mode, the pressure regulator reduces the input pressure of the gas to a second outlet pressure at the outlet that is greater than the first outlet pressure.

Disclosed is a headgear-type device for hazardous air quality warning and air quality improvement, wherein the device can collect biometric information of a worker, wired and wireless communications, and information about the quality of outside air around the worker so as to warn the worker of a hazard or improve air quality at the site. The headgear-type device for hazardous air quality warning and air quality improvement according to the present invention may comprise: a headgear-type biometric sensor which comes into close contact with the head of the worker so as to sense biometric information of the worker and thus allow measurements of the worker's physical conditions; a terminal which is wiredly or wirelessly connected to the headgear-type biometric sensor so as to transmit and receive the biometric information; and a server which receives the biometric information from the terminal, calculates, on the basis thereof, whether the biometric information is in a normal condition range, according to a program, and when the biometric information is not in the normal condition range, issues a warning to the worker by transmitting a warning state to the terminal.