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 18 - Explosive Materials
Article 116 - Handling and Use of Explosive Materials in Blasting Operations
Section 5307 - Blasting in Excavation Work Under Compressed Air

(a) Detonators and explosives shall not be stored or kept in caissons. Detonators and explosives for each round shall be taken directly from the magazines to the blasting zone and immediately loaded. Detonators and explosives left over after loading a round shall be removed from the working chamber before the connecting wires are connected up.

(b) When detonators or explosives are brought into an air lock, no employee except the licensed blaster, lock tender and the employees necessary for carrying, shall be permitted to enter the air lock. No other material, supplies, or equipment shall be locked through with the explosives.

(c) Detonators and explosives shall be taken separately into pressure working chambers.

(d) The licensed blaster shall be responsible for the receipt, unloading, storage, and on-site transportation of explosives and detonators.

(e) The explosives suitable for use in wet holes shall be water-resistant and shall be Fume Class I.

(f) All metal pipes, rails, air locks and steel tunnel lining shall be electrically bonded together and grounded at or near the portal or shaft, and such pipes and rails shall be cross-bonded together at not less than 1,000-foot intervals throughout the length of the tunnel. In addition, each low-air supply pipe shall be grounded at its delivery end.