Excavations requirements overview

The excavation standard covers construction work involving excavations and trenches on construction sites, including digging, trenching, and related activities. See the general 1926 Subpart P Excavations standard for the full scope and requirements.

• This includes operations where soil is removed to form a cavity, trench, or hole (commonly called excavations and trenches).
• It does not automatically cover underground tunnel construction that falls under Subpart S when that work is physically connected and creates underground conditions; see the Subpart S interpretation about when underground rules apply.

Subpart S applies when the work is construction of underground tunnels, shafts, chambers, or passageways, or when a cut-and-cover excavation is physically connected to ongoing underground construction and covered so it creates conditions characteristic of underground construction. See the Subpart S scope and application discussion in OSHA's interpretation and the general 1926 construction standards.

• If an excavation is not physically connected to underground construction operations, Subpart P (Excavations) generally applies.
• If the excavation is connected and creates underground conditions (for example covered cut-and-cover that behaves like a tunnel), Subpart S covers the work instead of Subpart P.

Yes — the check-in/check-out procedure applies even when a single employee is working underground; the requirement is intended to let aboveground personnel know the exact count of persons underground at any time. This is explained in OSHA's interpretation of 1926.800(c) and related provisions, and the broader construction requirements are in the 1926 standards.

• The rule is designed to ensure the employer can determine if anyone is still underground during an emergency, regardless of whether that is one person or many.
• The check-in/check-out exception only applies when permanent environmental controls are effective and remaining activities do not create hazards.

An employer must use a protective system for excavations or trenches that are 5 feet (1.52 m) deep or greater unless the excavation is made entirely in stable rock or a competent person determines there is no potential for cave-in hazards. See the 1926 construction excavation requirements for details.

• Protective systems include sloping, benching, shoring, and shielding (trench boxes).
• For trenches less than 5 feet, a protective system is still required if a competent person identifies a potential cave-in hazard.

Acceptable protective systems include sloping, benching, shoring, and shielding (such as trench boxes); the employer must select a system that protects workers from cave-ins and related hazards. This guidance is provided in the 1926 excavation and trenching standards.

• Sloping or benching changes the angle of the excavation face to reduce collapse risk.
• Shoring supports the sides of the excavation with hardware or hydraulic systems.
• Shielding (trench boxes) protects workers inside the excavation from cave-ins while leaving the excavation walls unsupported behind the shield.
• Selection should be based on soil classification, depth, water content, and site-specific conditions, and must be done or approved by a competent person.

Excavated material, spoil piles, and equipment must be kept at least 2 feet (0.6 m) away from the edge of an excavation to avoid overloading the edge and increasing cave-in risk. See the general 1926 excavation requirements for this provision.

• Keep spoils, tools, and heavy equipment well back from the edge to prevent falls or collapse.
• Provide barricades or berms when necessary to keep materials and personnel away from the excavation edge.

A safe means of egress (like a ladder) must be provided for employees in trenches 4 feet (1.22 m) or deeper, and egress must be located so an employee does not have to travel more than 25 feet (7.62 m) laterally to reach it. See the 1926 excavation and trenching standards for the exact requirements.

• Ladders, steps, ramps, or other safe access must be provided and maintained.
• Employers should position egress points so workers can escape quickly in an emergency.

A competent person is someone capable of identifying hazards related to excavations and authorized to take corrective action; they must inspect excavations, adjacent areas, and protective systems before work starts, daily, and after any event that could increase hazards (e.g., rain, vibrations). See the 1926 excavation provisions and competent person requirements.

• The competent person must evaluate soil, water, and other site conditions and decide on protective systems.
• They must stop work when hazardous conditions are found and ensure corrective actions are taken before work resumes.

Yes — portable trench boxes (shielding) are an accepted protective system when properly designed, installed, and used to protect employees from cave-ins while working inside an excavation. This is covered by the 1926 excavation standards.

• Shields protect workers by withstanding the forces of a cave-in and preserving a safe work space inside the shield.
• Use of shields does not remove the need for a competent person to evaluate site conditions and supervise installation.

Atmospheric testing must be performed where there is a reasonable possibility of a hazardous atmosphere (such as low oxygen, toxic gases, or flammable vapors) in the excavation; employers must test and provide appropriate respiratory protection or ventilation when hazards are present. See the 1926 excavation standards for atmospheric hazard guidance.

• Testing is commonly required in deeper excavations, excavations where hazardous substances are present, or when soils or nearby operations may release gases.
• If hazardous atmospheres are found, control measures (ventilation, respiratory protection, or removal of the hazard) must be implemented before workers enter.

Yes — employers must train workers and supervisors about excavation hazards, safe work practices, and the use of protective systems so employees can work safely around excavations. This requirement is part of the broader 1926 construction standards.

• Training should cover hazard recognition, emergency procedures, proper use of shields/shoring/sloping, and the meaning of warning signs or signals.
• Supervisors and competent persons must be able to recognize hazards and enforce safe practices.

Yes — an excavation made entirely in stable rock is exempt from the mandatory protective system requirement that applies at 5 feet and deeper, because stable rock is not likely to cave in; this exception is described in the 1926 excavation provisions.

• The determination that rock is 'stable' must be made by a competent person.
• If the rock shows signs of fracturing, weathering, or other instability, protection must be provided despite the rock classification.

Yes — surface encumbrances such as sidewalks, pavements, adjacent structures, and underground utilities must be evaluated and controlled because they can add loads to excavation edges or create other hazards; this is part of hazard evaluation under the 1926 standards.

• Competent persons must assess nearby structures and encumbrances and take steps (like placing spoils further back or using shoring) to prevent collapse or damage.
• Utilities require specific locating and control measures before excavation work begins.

Yes — OSHA requires self-rescuers or other approved respirators to be immediately available at work stations in underground areas where employees might be trapped by smoke or gas, and this requirement applies even if only one worker is present, as explained in the OSHA interpretation of 1926.800 and the general 1926 standards.

• Respirator selection, issuance, use, and care must also follow 29 CFR 1926.103 (respiratory protection requirements).
• Employers must ensure the equipment is readily accessible and that employees are trained in its use.

Employers can consult the appendices to the excavation standards for diagrams and guidance on sloping, benching, and protective systems; the 1926 construction standards page lists the Subpart P appendices and related guidance.

• The appendices include visual aids and practical examples to help select and implement protective systems.
• Although appendices provide helpful guidance, employers must follow the regulatory text and competent person determinations for site-specific conditions.