Standard Interpretations

OSHA requirements are set by statute, standards, and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. Each letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information.

1926.651 - Clarification of Standards - 01/09/1991
1926.651 - Clarification of utility "owner" as used in the Safety and Health Standards for Excavations, Underground Installations. - 09/21/2001
1926.651 - Evaluation of the use of aluminum forms as an exit route from trench excavations - 05/11/2004
1926.651 - Fall protection requirements where employees are required or permitted to cross over excavations. - 08/10/1995
1926.651 - Requirement for Air Sampling in trenches. - 11/19/1991
1926.651 - Use of explosion proof certified equipment inside of pipes and manholes. - 09/21/1995
1926.651 - Use of hydro-vacuum excavation equipment and other acceptable means to locate underground utility installions. - 10/23/2003
1926.651(b) - Clarification of utility "owner" as used in the Safety and Health Standards for Excavations, Underground Installations. - 09/21/2001
1926.651(b)(2) - Clarification of utility "owner" as used in the Safety and Health Standards for Excavations, Underground Installations. - 09/21/2001
1926.651(b)(2) - OSHA jurisdiction over oil and gas pipelines may be preempted by DOT standards. - 05/28/2004
1926.651(b)(2) - Use of hydro-vacuum excavation equipment and other acceptable means to locate underground utility installions. - 10/23/2003
1926.651(b)(3) - Use of hydro-vacuum excavation equipment and other acceptable means to locate underground utility installions. - 10/23/2003
1926.651(c)(1)(i) - Can a person who qualifies as a "competent" person under one section of support P also qualify as a competent designer of structural ramps under 1926.651(c)(1)(i)?. - 07/01/2010
1926.651(c)(2) - Evaluation of the use of aluminum forms as an exit route from trench excavations - 05/11/2004
1926.651(c)(2) - Removing ladders during trenching activities; compliance with 29 CFR 1926.651(c)(2). - 03/17/2009
1926.651(d) - Requirements for use of high-visibility warning garments by construction workers in highway work zones. - 05/11/2004
1926.651(e) - Whether it is permissible for an employee to remain in a trench box when materials are being lowered into it by a backhoe. - 12/19/2007
1926.651(f) - Clarification concerning fall protection and vertical walled trenches with depth of 6 feet or greater and use of controlled access zones. - 06/24/2002
1926.651(g) - Application of the Confined Spaces Advisor to construction; personal fall arrest system requirements. - 11/03/2000
1926.651(g) - Soil testing for excavations and confined spaces. - 06/15/1992
1926.651(g)(1)(iii) - Limitation on Enforcement of Certain Subsections of the Excavation Standard. - 08/01/1990
1926.651(g)(2)(i) - Limitation on Enforcement of Certain Subsections of the Excavation Standard. - 08/01/1990
1926.651(h) - Construction standards addressing excavations. - 03/23/1992
1926.651(i)(1) - 29 CFR 1926.651(i)(1); excavation operations. - 01/10/2006
1926.651(j) - Requirements to prevent trench collapse during sheet-pile operations. - 10/17/2000
1926.651(j)(2) - Trench shield must extend 18" above excavation walls when below grade. - 08/10/2000
1926.651(l) - Fall protection requirements where employees are required or permitted to cross over excavations. - 08/10/1995

OSH Act - Section 5(a)(1)