"Approval of Respiratory Protective Devices: Subpart H: Half-mask facepieces, full facepieces, mouth pieces, fit; minimum requirements"

(a) Half-mask facepieces and full facepieces shall be designed and constructed to fit persons with various facial shapes and sizes, either: (1) By providing more than one facepiece size; or (2) By providing one facepiece size which will fit varying facial shapes and sizes. (b) Full facepieces shall provide for the optional use of corrective spectacles or lenses which shall not reduce the respiratory protective qualities of the apparatus. (c) Apparatus with mouthpieces shall be equipped with noseclips which are securely attached to the mouthpiece or apparatus and provide an airtight seal. (d) Facepieces shall be designed to prevent eyepiece, spectacle, and lens fogging.

"Approval of Respiratory Protective Devices: Subpart H: Inhalation and exhalation valves; minimum requirements"

(a) Inhalation and exhalation valves shall be provided where necessary and protected against damage and distortion. (b) Exhalation valves shall be— (1) Protected against external influence; and (2) Designed and constructed to prevent inward leakage of contaminated air.

"Approval of Respiratory Protective Devices: Subpart H: Breathing gas; minimum requirements"

(a) Breathing gas used to supply apparatus shall be respirable and contain no less than 19.5 (dry atmosphere) volume percent of oxygen. (b) Oxygen, including liquid oxygen, shall contain not less than 99.0 percent, by volume, of pure O2, not more than 0.03%, by volume, carbon dioxide, and not more than 0.001%, by volume, carbon monoxide. Methods for making these determinations can be found in the U.S. Pharmacopeia National Formulary. Containers used for oxygen must not be treated with any toxic, sleep-inducing, narcosis-producing, or respiratory tract irritating compounds. (c) Compressed, gaseous breathing air shall meet the applicable minimum grade requirements for Type I gaseous air set forth in the Compressed Gas Association Commodity Specification for Air, G-7.1, 1966 (Grade D or higher quality). G-7.1 is incorporated by reference and has been approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards Institute, Inc (d) Compressed, liquefied breathing air shall meet the applicable minimum grade requirements for Type II liquid air set forth in the Compressed Gas Association Commodity Specification for Air, G-7.1, 1966 (Grade B or higher quality). G-7.1 is incorporated by reference and has been approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards Institute, Inc.,

"Approval of Respiratory Protective Devices: Subpart H: Compressed breathing gas and liquefied breathing gas containers; minimum requirements"

(a) Compressed breathing gas and liquefied breathing gas containers shall meet the minimum requirements of the Department of Transportation for interstate shipment of such containers when fully charged. (b) Such containers shall be permanently and legibly marked to identify their contents, e.g., compressed breathing air, compressed breathing oxygen, liquefied breathing air, or liquefied breathing oxygen. (c) Containers normally removed from apparatus for refilling shall be equipped with a dial indicating gage which shows the pressure in the container. (d) Compressed breathing gas contained valves or a separate charging system or adapter provided with each apparatus shall be equipped with outlet threads specified for the service by the American Standards Association, Compressed Gas Cylinder Valve Outlet and Inlet Connections, B57.1-1965. B57.1-1965 is incorporated by reference and has been approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

"Approval of Respiratory Protective Devices: Subpart H: Timers; elapsed time indicators; remaining service life indicators; minimum requirements"

This standard specifies the minimum requirements for timers, elapsed time indicators; remaining service life indicators on self-contained breathing apparatus. See detailed view for additional notes.