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 6100 - Temperature, Illumination, Sanitation and Ventilation

(a) Temperature of all working chambers which are subjected to compressed air shall, by means of after-coolers or other suitable devices, be maintained at a temperature not to exceed 85 degrees Fahrenheit.

(b) Illumination in compressed air chambers shall be by electricity exclusively and two independent electric-lighting systems with independent sources of supply shall be used. The emergency source shall be arranged to become automatically operative in the event of failure of the regularly used source. Electrical installations and equipment shall comply with applicable portions of the Electrical Safety Orders in Title 8 of the CCR.

(c) The minimum intensity of illumination on any walkway, ladder, stairway, or working level shall not be less than 10-foot candles, and in all work places the illumination shall at all times be such as to enable employees to see clearly.

(d) Sanitary, heated, illuminated, and ventilated dressing rooms and drying rooms shall be provided for all employees engaged in compressed air work. Such rooms shall contain suitable benches and lockers. Bathing accommodations (showers at the ratio of 1 to 10 employees per shift) equipped with running hot and cold water along with suitable and adequate toilet accommodations shall be provided. One toilet for each 15 employees, or fractional part thereof, shall be provided. While in a compressed air environment and the toilet bowl is shut by a cover, there shall be an air space so that the bowl or bucket does not implode when the pressure is increased. All parts of caissons and other working compartments shall be kept in a sanitary condition.

(e) Ventilation in the locks and chambers, with the exception of the medical chamber, shall be such that the air quality meets the requirement of Section 5144(i).

(f) Exhaust valves and exhaust pipes shall be provided and operated so that the working chamber shall be well ventilated, and there shall be no pockets of dead air. Outlets may be required at intermediate points along the main low pressure air supply line to the heading to eliminate such pockets of dead air. Ventilating air shall be not less than 30 cubic feet per minute per person.

(g) The air in the workplace shall be analyzed by the employer not less than once each shift, and records of such tests shall be kept on file at the place where the work is in progress. The test results shall be within the permissible exposure limits (PEL's) specified in the Section 5155, for hazardous gases and within 10 percent of the lower explosive limit of flammable gases.

(h) Forced ventilation shall be provided during decompression. During the entire decompression period, forced ventilation through chemical or mechanical air purifying devices that will ensure a source of fresh air shall be provided.

(i) When an oxygen breathing gas system is used during decompression, the employer shall take one, or both, of the following steps to ensure that the concentration of oxygen inside the chamber or lock does not exceed twenty five percent (25%) by volume: