Subpart P
Under 1926 Subpart P App F, any protective system for an excavation more than 20 feet in depth must be designed by a registered professional engineer. Employers may use Appendix F’s graphic guidance only for excavations 20 feet or less; deeper excavations require an engineered design in accordance with 1926.652(b) and 1926.652(c).
Yes. Under 1926 Subpart P App F, the Appendix F figures are intended as a graphic summary for selecting protective systems for excavations 20 feet or less in depth, so you may use them to help choose a protective system for a 12-foot trench. Always ensure the selected system matches site conditions, soil classification, and the competent person’s determination consistent with 1926.652 and the guidance in 1926 Subpart P App F.
Under 1926 Subpart P App F, choose sloping/benching, shoring, or shielding based on the excavation depth (≤20 ft), the soil type and stability, the presence of water or adjacent loads, and access/work requirements; Appendix F provides the common options and when each is typically used. The final choice must be validated by the competent person and comply with 1926.652 and the Appendix F guidance in 1926 Subpart P App F.
Under 1926 Subpart P App F, the competent person must evaluate site-specific conditions (soil classification, water, equipment loads, and changes) and determine whether an Appendix F option is appropriate; the figures do not remove the need for a competent person’s on-site judgment. This responsibility is part of the excavation requirements in 1926.652.
Under 1926 Subpart P App F, you must base protective system selection on the actual soil conditions present in the excavation; if multiple soil types occur, the competent person must evaluate the worst-case conditions and select a protective system that protects workers for those conditions in accordance with 1926.652 and the guidance in 1926 Subpart P App F.
Under 1926 Subpart P App F, the presence of water or seepage makes soils less stable and may require more conservative protective systems (for example, steeper slopes, dewatering, or engineered shoring/shields); you must account for water when the competent person selects or approves the system consistent with 1926.652.
Under 1926 Subpart P App F, a trench box (shield) can be an appropriate protective system for excavations 20 feet or less when the box is sized and installed so it protects workers from cave-ins given the site conditions; Appendix F lists shielding as one of the acceptable options for such depths. The competent person must confirm the shield’s suitability and its installation must comply with 1926.652 and the Appendix F guidance in 1926 Subpart P App F.
No. Under 1926 Subpart P App F, Appendix F does not remove the employer’s obligation to consider adjacent loads; the competent person must evaluate nearby vehicles, spoil piles, and structures and adjust protective systems accordingly to prevent cave-ins, per 1926.652.
Yes. Under 1926 Subpart P App F, the figures are intended for excavations 20 feet or less in depth, so they apply to an excavation that is exactly 20 feet deep; for any excavation deeper than 20 feet, a registered professional engineer must design the protective system in accordance with 1926.652(b) and 1926.652(c).
Under 1926 Subpart P App F, protective systems and excavations must be inspected by the competent person daily and as conditions change (for example, after a rain, vibration, or nearby work that could affect stability); those inspections confirm the chosen system from Appendix F remains protective and compliant with 1926.652.
Under 1926 Subpart P App F, you must locate and identify underground utilities and account for them when selecting a protective system, because utilities can affect soil stability and create additional hazards; the competent person must consider these conditions when applying Appendix F guidance and ensure compliance with 1926.652.
Under 1926 Subpart P App F, while the excavation standard governs protective systems, employers must also assess hazards and provide appropriate PPE; when PPE is required, OSHA’s PPE standard requires an assessment and a written certification that PPE was evaluated, as explained in OSHA’s PPE hazard assessment letter of interpretation (March 28, 2024) at https://www.osha.gov/laws-regs/standardinterpretations/2024-03-28. Employers should coordinate this PPE assessment with excavation decisions under 1926.652.
Under 1926 Subpart P App F, if site conditions change after you select a sloped system (for example, water, nearby loads, or changed soil), the competent person must re-evaluate and modify or replace the protective system as needed to keep workers safe, consistent with 1926.652 and the Appendix F guidance in 1926 Subpart P App F.
Under 1926 Subpart P App F, Appendix F provides general protective system options for excavations 20 feet or less in depth and can be used for many excavation types (utility trenches, basements, pits) provided the competent person confirms the chosen system fits the specific site conditions; employers must still comply with 1926.652.
Under 1926 Subpart P App F, the official graphic guidance for selecting protective systems for excavations 20 feet or less is in 1926 Subpart P App F, and the regulatory requirements for excavation protective systems and required engineering design for deeper excavations are in 1926.652 (see also 1926.652(b) and 1926.652(c)).