This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at

Subchapter 7. General Industry Safety Orders



Return to index
New query

§6095. Special Decompression Chamber.

(a) General. A special decompression chamber of sufficient size to accommodate the entire force of employees being decompressed at the end of a shift shall be provided whenever the regularly established working period requires a total time of decompression exceeding 75 minutes.

(b) Size, Capacity, and Construction. The headroom in the special decompression chamber shall be not less than 7 feet and the cubical content shall provide at least 50 cubic feet of air space for each person. For each occupant there shall be provided 4 square feet of free walking area and 3 square feet of seating space exclusive of area required for lavatory and toilet facilities. The rated capacity shall be based on the stated minimum space per person and shall be posted at the chamber entrance. The posted capacity shall not be exceeded, except in case of emergency. The chamber shall be constructed in accordance with the Unfired Pressure Vessel Safety Orders.

(c) Equipment. Each special decompression chamber shall be equipped with the following:

(1) A clock or clocks suitably placed so that the attendant and the chamber occupants can readily ascertain the time;

(2) Pressure gauges which will indicate to the attendants and to the chamber occupants the pressure in the chamber;

(3) Valves to enable the attendant to control the supply and discharge of compressed air into and from the chamber;

(4) Valves and pipes in connection with the air supply and exhaust arranged so that the chamber pressure can be controlled from within and without;

(5) Effective means of oral communication between the attendant, occupants of the chamber, and the air compressor plant;

(6) An observation port at the entrance to permit observation of the chamber occupants

(7) Suitable mufflers at large air pressure drops.

(d) Seating Facilities. Seating facilities in special decompression chambers shall so arranged as to permit a normal sitting posture. Seating space not less than 18 inches by 24 inches wide shall be provided per occupant.

(e) Automatic Controls. Special decompression chambers shall be equipped with automatic controls complying with Section 6090(d) and (e).

(f) Sanitation. Adequate toilet and washing facilities in a screened or enclosed recess shall be provided. Toilet bowls shall have a built-in protector on the rim so that an air space is created when the seat lid is closed. Potable drinking water shall be provided. This may be accomplished by either piping water into the special decompression chamber and providing drinking fountains, or by providing individual canteens or by some other sanitary means. Common drinking vessels shall be prohibited. The chamber shall be kept clean.

(g) Location. Unless the special decompression chamber is serving as the air lock to atmospheric pressure, the special decompression chamber shall be situated where practicable, adjacent to the air lock on the atmospheric pressure side of the bulkhead. A passageway shall be provided connecting the special chamber with the air lock to permit employees in the process of decompression to move from the air lock to the special chamber without a reduction in the ambient pressure from that designated for the next stage of decompression. The passageway shall be so arranged as to not interfere with the normal operation of the air lock nor with the release of the occupants of the special chamber to atmospheric pressure upon the completion of the decompression procedure.

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. New section filed 4-4-2006; operative 5-4-2006 (Register 2006, No. 14).

Go BackGo Back to Article 154 Table of Contents