(1) Ventilation. An automatic air quality monitoring system acceptable to the director, department of labor and industries, shall be installed in the pressurized working chamber and shall at all times be maintained in proper working condition. The system shall provide continuous sampling and monitoring of the air and shall indicate by visual and audible alarm the presence of dangerous air contaminants in excess of the following:
Carbon monoxide | 0.01% | 100 ppm |
Carbon dioxide | 0.50% | 5000 ppm |
Oxides of nitrogen | 0.0005% | 5 ppm |
Methane | 0.25% | 2500 ppm |
Hydrogen sulphide | 0.002% | 20 ppm |
The director in his discretion may change these concentrations to conform with good practices as recommended by the American Conference of Governmental Industrial Hygienists.
The system shall also indicate and give alarm at any time the oxygen content is less than 19.5 percent.
The system shall be so arranged that the visual and audible alarm will give warning in the working chamber and at the lock tender's station at the low pressure side of the locks.
In addition to the specific requirements contained in these standards of safety chapter
296-62 WAC shall apply for rock dust and ventilation.
(2)
Protection against atmospheric containments: The requirements of chapters
296-62 and
296-155 WAC, Part Q shall apply.
[Statutory Authority: Chapter
49.17 RCW. WSR 90-17-051 (Order 90-10), § 296-36-145, filed 8/13/90, effective 9/24/90; Rules (Part VII C), filed 12/28/62; § 25, filed 3/23/60.]