Excavation is any man-made cut, cavity, trench, or depression in an earth surface, formed by earth removal.
A trench is a narrow excavation (in relation to its length) made below the surface of the ground. In general, the depth is greater than the width, but the width of a trench (measured at the bottom) is no greater than 15 feet (4.6 m).
What are the hazards associated with excavations?
Excavation work presents serious hazards to all workers involved. Cave-ins pose the greatest risk and are much more likely than other excavation-related accidents to result in worker fatalities. Other potential hazards include falls, falling loads, hazardous atmospheres and incidents involving mobile equipment adjacent to excavations.
What can I do to protect myself?
Employers are required to designate a competent person who has the knowledge and training to properly classify soil types, including how to determine if soil has been previously disturbed, and to specify the appropriate type of sloping or reinforcement necessary to prevent a cave-in while workers are working within an excavation, especially a trench. Identify the nearest means of egress from a trench. The employer must ensure that means of egress are available within 25 feet for workers in a trench.
What resources are available to assist employers?
Training and Outreach Services
The trenching and excavation presentation can be downloaded and modified to address site-specific conditions and hazards. In addition, the education, training and technical assistance bureau provides free online safety and health training and outreach services (i.e., speaker's bureau requests, safety booths) upon request. This pre-recorded webinar on excavations and trenching can also be accessed at any time.
Lastly, the NCDOL Library offers free safety and health videos (including streaming video services) and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC).
A-Z Safety and Health Topics
In addition, the A-Z topics page on confined spaces can provide additional resource information.
The consultative services bureau provides free and confidential onsite consultation regarding worksite safety and health hazards.
Which standards apply?
OSH has adopted the following standards which are applicable to excavation and trenching in North Carolina. Note: Please also check the standards information and activity webpage to see if there has been any recent or upcoming regulatory activity on this topic.
29 CFR 1926 Subpart P - excavations
29 CFR 1926.650 - scope, application, and definitions applicable to this subpart
29 CFR 1926.651 - specific excavation requirements
29 CFR 1926.652 - requirements for protective systems
Appendix A to 29 CFR 1926 Subpart P - soil classification
Appendix B to 29 CFR 1926 Subpart P - sloping and benching
Appendix C to 29 CFR 1926 Subpart P - timber shoring for trenches
Appendix D to 29 CFR 1926 Subpart P - aluminum hydraulic shoring for trenches
Appendix E to 29 CFR 1926 Subpart P - alternatives to timber shoring
Appendix F to 29 CFR 1926 Subpart P - selection of protective systems
Other Applicable Standards
The Which OSHA Standards Apply webpage can help identify other standards that may be applicable to your worksite.
Where can I learn more?
- Industry Guide 48 - OSHA Construction Industry Standards Requiring Programs, Inspections, Procedures, Records and/or Training provides requirements for standards related to trenching and excavations in construction.
- NCDOL Investigates Trench Collapse, discusses the investigation process for a fatality involving a trench collapse.
- Compliance Directive: CPL 02-00-069, National Emphasis Program: Trenching and Excavations established a national emphasis program for the programmed inspections of trenching and excavation operations.
- Compliance Directive: CPL 02-00-087, Inspection Procedures for Enforcing the Excavation Standards - 29 CFR 1926 Subpart P, establishes the enforcement policy and provides an explanation of the standard to ensure uniform enforcement.
- Standards Notice: SN 61 - Residential Construction - Foundation or Basement Excavations addresses the conditions in which 29 CFR 1926.652 (requirement for protective systems) will not be applied to house foundation and basement excavations in residential construction.
If you would like to receive interpretive guidance on this or any other OSH standard or topic, you can submit your questions using the Ask OSH web form, by e-mail to email@example.com or by calling 919-707-7876.