California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 7 - General Industry Safety Orders › Group 26 - Driving and Pressurized Worksite Operations › Article 154 - Pressurized Worksite Operations › Section 6090 - Air Locks

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a)
						Except in emergency, no employees employed in compressed air shall be permitted
						to pass from the working chamber to atmospheric pressure until after
						decompression, in accordance with Section
						6085.
(b) The time of decompression shall be posted
						in each air lock.
(c) The lock
						attendant shall be under the direct supervision of the physician required by
						Section 6120 and stationed at the lock
						controls on the free air side during the period of compression and
						decompression. The lock attendant shall remain at the lock control station
						whenever there are employees in the working chamber or in the air
						lock.
(d) Except where air pressure
						in the working chamber is below 12 psig, each air lock shall be equipped with
						suitable automatic controls which automatically regulate decompressions. It
						shall also be equipped with manual controls to permit the lock attendant to
						override the automatic system in the event of an emergency.
(e) A manual control, which can be used in
						the event of an emergency, shall be placed inside the air lock.
(f) For each 8-hour shift, a record of
						employees employed under compressed air shall be kept by the lock attendant.
						This record shall show period of stay in the working chamber of each employee
						and the time taken for decompression.
(g) A clock, thermometer, and continuous
						recording pressure gauge with a 4-hour graph shall be installed outside of each
						air lock and shall be changed prior to each shift's decompression. The chart
						shall be of sufficient size to register a legible record of variations in
						pressure within the air lock and shall be visible to the lock attendant. A copy
						of each graph shall be submitted to the physician after each shift. In
						addition, a pressure gauge, clock, and thermometer shall also be installed in
						each air lock. Additional fittings shall be provided so that test gauges may be
						attached whenever necessary.
(h)
						Except where air pressure is below 12 psig and there is no danger of rapid
						flooding, all caissons having a working greater than 150 square feet and each
						bulkhead in tunnels of 14 feet or more in diameter, or equivalent area, shall
						have at least 2 locks in perfect working condition, 1 of which shall be used
						exclusively as an air lock. Where only a combination air and materials lock is
						required, this single lock shall be of sufficient capacity to hold the
						employees constituting two successive shifts. If emergency locks are provided,
						they shall be large enough to hold an entire heading shift and a limit
						maintained of 12 psig. There shall be a chamber available for oxygen
						decompression therapy to 28 psig.
(i) The air lock shall be large enough so
						that those using it are not compelled to be in a cramped position, and shall
						not have less than 5 feet clear head room at the center and a minimum of 30
						cubic feet of air space per occupant.
(j) Locks on caissons shall be so located
						that the bottom door shall be not less than 3 feet above the water level
						surrounding the caisson on the outside. (Note: The water level, where it is
						affected by tides, is construed to mean high tide.)
(k) In addition to the pressure gauge in the
						locks, an accurate pressure gauge shall be maintained on the outer and inner
						side of each bulkhead. These gauges shall be accessible at all times and shall
						be kept in accurate working order.
(l) Air locks shall be illuminated and shall
						have an observation port at least 4 inches in diameter located in such a
						position that all occupants of the air lock may be observed from the working
						chamber and from the free air side of the lock.
(m) Air locks shall be maintained at a
						minimum temperature of 70 degrees Fahrenheit, dry bulb.
(n) When locks are not in use and employees
						are in the working chamber, lock doors shall be kept open to the working
						chamber, where practicable.
(o) All
						locks shall be constructed in accordance with the Unfired Pressure Vessel
						Safety Orders of the Division.
(p)
						Adequate ventilation shall be provided in accordance with Section
						5143.
1. New
						  section filed 4-4-2006; operative 5-4-2006 (Register 2006, No.
						  14).
2. Amendment of subsection (a) filed 3-10-2010; operative
						  4-9-2010 (Register 2010, No. 11).
Note: Authority cited: Section
							 142.3, Labor
							 Code. Reference: Section
							 142.3, Labor
							 Code.