Does "Subpart P - Excavations" Apply to You?

Subpart P applies to all open excavations made in the earth's surface. Note: Excavations are defined to include trenches. Are your employees engaged in excavations or trenching work? If yes, then you need to comply with subpart P. Scope, application, and definitions applicable to this subpart provides key definitions including:

Excavation means any man-made cut, cavity, trench, or depression in an earth surface, formed by earth removal.

Shield (Shield system) means a structure that is able to withstand the forces imposed on it by a cave-in and thereby protect employees within the structure. Shields can be permanent structures or can be designed to be portable and moved along as work progresses. Additionally, shields can be either premanufactured or job-built in accordance with the standards. Shields used in trenches are usually referred to as "trench boxes" or "trench shields."

Sloping (Sloping system) means a method of protecting employees from cave-ins by excavating to form sides of an excavation that are inclined away from the excavation so as to prevent cave-ins. The angle of incline required to prevent a cave-in varies with differences in such factors as the soil type, environmental conditions of exposure, and application of surcharge loads. Reference appendix B - sloping and benching for more guidance.

Trench (Trench excavation) means 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 not greater than 15 feet. If forms or other structures are installed or constructed in an excavation so as to reduce the dimension measured from the forms or structure to the side of the excavation to 15 feet or less (measured at the bottom of the excavation), the excavation is also considered to be a trench.

The standard on specific excavation requirements covers surface encumbrance, underground installations, access and egress, exposure to vehicular traffic, exposure to falling loads, warning system for mobile equipment, hazardous atmospheres (reference subparts D - occupational health and environmental controls and E -  personal protective and life saving equipment), emergency rescue equipment, protection from hazards associated with water accumulation, stability of adjacent structures, protection of employees from loose rock or soil, and daily inspections. Reference appendix A - soil classification for information on classifying soil.

The subpart also provides requirements for protective systems such as design of support systems, shield systems, other protective systems, materials and equipment, installation and removal of support, shield systems, and design of sloping and benching systems. Reference appendix F - selection of protective systems for additional non-mandatory information regarding protective systems. 

Other appendices for this subpart include: appendix C pertains to timber shoring for trenches; appendix D pertains to aluminum hydraulic shoring for trenches; and appendix E pertains to alternatives to timber shoring.

Additional related information can be found on the A-Z safety and health topics pages for excavation and trenchingelectrical safetypersonal protective equipment, and hazard communication