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 6115 - Fire Prevention

(a) Tunnels shall be provided with a 2-inch minimum diameter water line extending into the working chamber and to within 100 feet of the working face. Such line shall have hose outlets with 100 feet of fire hose properly attached and maintained as follows: one at the working face; one immediately inside the bulkhead of the working chamber; and one immediately outside such bulkhead. In addition, hose outlets shall be provided at 200-foot intervals throughout the length of the tunnel and 100 feet of fire hose shall be attached to the outlet nearest to any location where flammable material is being kept or stored or where any flame is being used.

(b) Fire hose shall be at least 1 1/2 inches in nominal diameter. Water pressure shall at all times be adequate for efficient operation of the type of nozzle used and the water supply shall be such as to ensure an uninterrupted flow. Fire hose, when not in use, shall be located or guarded to prevent injury thereto.

(c) In addition to fire hose protection required by this section, on every floor of every building not under compressed air, but used in connection with the compressed air work, there shall be provided at least one approved extinguisher of the proper type for the hazard involved. At least two approved fire extinguishers shall be provided in the working chamber as follows: one at the working face and one immediately inside the bulkhead (pressure side). Extinguishers in the working chamber shall use water as the primary extinguishing agent and shall not use any extinguishing agent which could be harmful to the employees in the working chamber. The fire extinguisher shall be protected from damage.

(d) No persons shall be permitted to smoke or carry smoking materials in compressed air.

(e) While welding or flame cutting is being done in compressed air, a watch person with a fire hose or approved extinguisher shall stand by until such operation is completed.

(f) Highly combustible materials shall not be used or stored in the working chamber. Wood, paper, and similar combustible material shall not be used in the working chamber in quantities which could cause a fire hazard. The compressor building shall be constructed of noncombustible materials.

(g) Air locks shall be equipped with a manual-type fire extinguisher system that can be activated inside the air lock and also by the outside lock attendant. In addition, a fire hose and portable fire extinguisher shall be provided inside and outside the air lock. The portable fire extinguisher shall be the dry chemical type.

(h) Equipment, fixtures, and furniture in air locks and special decompression chambers shall be constructed of noncombustible materials. Bedding and other furnishings shall be chemically treated so as to be fire-resistant.

(i) Oxygen Safety.