A handheld device for treating air to a user includes an airflow path having an illumination chamber with a reflective surface, wherein the reflective surface is sufficiently reflective and configured to impart multiple reflections of at least a portion of the light introduced into the illumination chamber. The introduced light is produced by an onboard UV light generator, wherein the UV light generator can be cycled corresponding to at least one of a pressure and an airflow in the airflow path.

A handheld device for treating air to a user includes an airflow path having an illumination chamber with a reflective surface, wherein the reflective surface is sufficiently reflective and configured to impart multiple reflections of at least a portion of the light introduced into the illumination chamber. The introduced light is produced by an onboard UV light generator, wherein the UV light generator can be cycled corresponding to at least one of a pressure and an airflow in the airflow path.

A particle retainer having a support frame including at least one air flow port configured to permit contaminated ambient air to reach the filtration element of the particulate matter filtration mask. The particle retainer also has a mask mount fixed to the support frame configured to removably attach the particle retainer to the mask. The particle retainer further includes an air flow port cover affixed to the support frame, in which the air flow port cover features manually operable open state and closed state configurations for permitting and restricting air flow and particulate matter transfer.

An air flow system for reducing pathogens in a breathable airstream in an environment has a device having an airstream intake for receiving a volume of untreated air located in a first position, an airstream outlet for expelling a volume of treated air, the airstream outlet located in a second position extending above the first position, a flow path extending between the airstream intake and the airstream outlet, at least one of a UV generator and a UV-C emitter optically coupled to the flow path, a power source operably connected to the one of the at least one of the UV generator and the UV emitter, and a pressure generator fluidly connected to the airstream intake, the pressure generator configured to impart a flow from the airstream intake to the airstream outlet, wherein the pressure generator can be at least one of a force of flow from in line pressurized source or provided by a fan within the housing, and wherein a portion of the flow path includes a UV-C highly reflective surface.

A personal respiratory protection device comprising an upper panel, a central panel, and a lower panel, the central panel being separated from the upper and lower panels by a first and second fold, seam, weld or bond, respectively, such that device is capable of being folded flat for storage along first and second fold, seam, weld or bond and opened to form a cup-shaped air chamber over the nose and mouth of the wearer when in use, wherein the upper panel has a nose conforming element for conforming at least part of the upper panel to the nose of a wearer when in use, the nose conforming element having a resiliently flexible central portion and first and second rigid outer portions extending outwardly from the central portion, the central portion deforming upon donning of the respirator so that the central and outer portions conform to the profile of the nose.

A personal respiratory protection device comprising an upper panel, a central panel, and a lower panel, the central panel being separated from the upper and lower panels by a first and second fold, seam, weld or bond, respectively, such that device is capable of being folded flat for storage along first and second fold, seam, weld or bond and opened to form a cup-shaped air chamber over the nose and mouth of the wearer when in use, wherein the upper panel has a nose conforming element for conforming at least part of the upper panel to the nose of a wearer when in use, the nose conforming element having a resiliently flexible central portion and first and second rigid outer portions extending outwardly from the central portion, the central portion deforming upon donning of the respirator so that the central and outer portions conform to the profile of the nose.

A directional valve includes a fixing lug (13), which is arranged eccentrically to a valve membrane (16) and is arranged at a valve housing (15). The dimensions of the fixing lug (13) are selected for fixing the valve membrane (16) relative to the sealing surface (2) of valve seat (1). The size of the eccentric offset (x) is in a range between 8% and 15% of the axis length (D) of the greatest longitudinal extension of valve membrane (16).

A directional valve includes a fixing lug (13), which is arranged eccentrically to a valve membrane (16) and is arranged at a valve housing (15). The dimensions of the fixing lug (13) are selected for fixing the valve membrane (16) relative to the sealing surface (2) of valve seat (1). The size of the eccentric offset (x) is in a range between 8% and 15% of the axis length (D) of the greatest longitudinal extension of valve membrane (16).

A personal respiratory protection device (10) comprising an upper panel (18), a central panel (16), and a lower panel (20), the central panel (16) being separated from each of the upper and lower panels (18) by a first and second fold (36), seam, weld (76) or bond, respectively, such that device is capable of being folded flat for storage along the first and second fold (36), seam, weld (76) or bond and opened to form a cup-shaped air chamber over the nose and mouth of the wearer when in use, wherein the lower panel (20) includes a stiffening sheet (40) which has a longitudinal crease line, wherein the stiffening sheet (40) is folded about the longitudinal crease line when the device is in use.

A personal respiratory protection device (10) comprising an upper panel (18), a central panel (16), and a lower panel (20), the central panel (16) being separated from each of the upper and lower panels (18) by a first and second fold (36), seam, weld (76) or bond, respectively, such that device is capable of being folded flat for storage along the first and second fold (36), seam, weld (76) or bond and opened to form a cup-shaped air chamber over the nose and mouth of the wearer when in use, wherein the lower panel (20) includes a stiffening sheet (40) which has a longitudinal crease line, wherein the stiffening sheet (40) is folded about the longitudinal crease line when the device is in use.