R 325.2442c Respiratory protective equipment; supplies and components.

Rule 42c. (1) Compressed or liquid oxygen used with respiratory protective equipment shall be of high purity. Compressed oxygen shall not be used in supplied-air respirators or in open-circuit self-contained breathing apparatus that have previously used compressed air. (2) Air may be supplied to equipment from cylinders or air compressors with proper pressure regulation and control. Air shall contain 19-23% oxygen and not more than 20 ppm carbon monoxide and 5 mg/m3 oil mist. (3) A compressor or compressor air intake shall be situated so as to prevent entry of contaminants into the system in amounts which may be injurious to the health of an exposed person. (4) An oil lubricated compressor shall incorporate suitable inline air purifying sorbents and filters, temperature regulators, and high-temperature cut-off to assure breathing air quality. An oil lubricated compressor shall not use vegetable oil lubricants. (5) An air-line coupling or connector shall be incompatible with outlets for other gas systems to prevent connection with nonrespirable gases or oxygen. (6) A self-contained breathing apparatus and universal type gas mask shall incorporate an audible or visible alarm or window to indicate impending failure of the device to provide respirable air. It is recommended that warning be given when 20- 25% of rated service time remains.