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Subchapter 20. Tunnel Safety Orders
Article 1. Introduction
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§8403. Scope and Application.

(a) In accordance with the provisions of Labor Code, Division 5, Part 9 et al., these orders establish minimum safety standards in places of employment at tunnels, shafts, raises, inclines, underground chambers, and premises appurtenant thereto during excavation, construction, alteration, repairing, renovating or demolishing and the following:

(1) Cut-and-cover operations such as subway stations which are both physically connected to ongoing underground construction operations and are covered in such a manner as to create conditions characteristic of underground construction.

(2) Boring and pipejacking operations 30 inches in diameter or greater in size.

Exceptions: These safety orders do not apply to utility natural gas pipelines subject to the jurisdiction of the California Public Utilities Commission or the U.S. Department of Transportation, Office of Pipeline Safety, where a person does not bodily enter the bore during boring or pipejacking operations.

(3) Pipelines which are connected to and/or are an integral part of a tunnel where persons are working inside and the conditions are similar to a lined tunnel construction or repair project.

(4) All shaft excavations intended to exceed 20 feet in depth where employees may enter the shaft and/or approach the shaft area. A shaft will be considered a shaft from its inception. For shafts 20 feet or less in depth and excavations unrelated to the Tunnel Safety Orders, refer to, CCR, Title 8, Section 1533 and Article 6, commencing with Section 1539 of the Construction Safety Orders.

(b) With the following exception these orders take precedence at tunnels over any other safety orders of the Division that are inconsistent with them. Where employees work under the pressure of air in excess of atmospheric pressure, in connection with tunnel work, the Compressed Air Safety Orders also apply and take precedence over any Tunnel Safety Orders that are in conflict.

(c) Machines, equipment, processes and operations not specifically covered by these orders shall be governed by all other applicable general safety orders contained in Title 8, California Code of Regulations.

Note: Authority cited: Sections 142.3 and 7997, Labor Code. Reference: Sections 142.3 and 7997, Labor Code.


1. Amendment of subsection (a) filed 7-6-79 as procedural and organizational; effective upon filing (Register 79, No. 27).

2. Amendment of section and new Note filed 3-5-96; operative 4-4-96 (Register 96, No. 10).

3. Change without regulatory effect amending subsection (a)(3) filed 4-20-2004 pursuant to section 100, title 1, California Code of Regulations (Register 2004, No. 17).

4. Amendment of subsection (a)(4) filed 5-1-2012; operative 5-31-2012 (Register 2012, No. 18).

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