Safety and Health Standards

OREGON OCCUPATIONAL

SAFETY AND HEALTH STANDARDS

Oregon Administrative Rules, Chapter 437

DIVISION 3 (29 CFR 1926)

CONSTRUCTION

Subdivision P

Excavations

Oregon Occupational Safety and Health Division (Oregon OSHA)

Department of Consumer and Business Services

Salem, Oregon 97301-3882

AO 4-2011

The Oregon Department of Consumer and Business Services adopted these rules pursuant to ORS

654.025(2).

The Secretary of State Designated OAR Chapter 437 as the “Oregon Occupational Safety and Health Code.”

Six general subject areas within this code are designated as “Divisions.”

Division 1 General Administrative Rules
Division 2 General Occupational Safety and Health Rules
Division 3 Construction
Division 4 Agriculture
Division 5 Maritime Activities
Division 7 Forest Activities
Oregon Revised Statutes (ORS) 654 The Oregon Safe Employment Act (OSEAct)

Oregon-initiated rules in this division of the Oregon Occupational Safety and Health Code are numbered in a uniform system developed by the Secretary of State. This system does not number the rules in sequence (001, 002, 003, etc.). Omitted numbers may be assigned to new rules at the time of their adoption.

Oregon-initiated rules are arranged in the following Basic Codification Structure adopted by the Secretary of

State for Oregon Administrative Rules (OAR):

ChapterDivisionRuleSectionSubsection Paragraphs

4370031760(1)(a)(A)(i)(I)

The majority of Oregon OSHA codes are adopted by reference from the Code of Federal Regulations (CFR),

and are arranged in the following basic federal numbering system:

ChapterDivisionPartSubpartSection Paragraphs

(Subdivision)

4370031926M.502(a)

The terms “subdivision” and “subpart” are synonymous within OAR 437, Oregon Occupational Safety and

Health Code.

To obtain an order form or copies of these codes, address:

Department of Consumer & Business Services

Oregon Occupational Safety & Health Division (Oregon OSHA)

350 Winter St. NE, Room 430

Salem, OR 97301-3882

Or call the Oregon OSHA Resource Library at 503-378-3272

The rules referenced in this division are available for viewing in the Office of the Secretary of State, Administrative Rules and Office Document Section, Oregon State Archives Building, Salem, Oregon 97310,

or the Central Office, Oregon Occupational Safety and Health Division of the Department of Consumer and Business Services, Room 430, 350 Winter St. NE Salem, OR 97301-3882. Please visit our web site at:

Oregon Administrative Rules
Oregon Occupational Safety
and Health Division /

EXCAVATIONS

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TABLE OF CONTENTS

1926.650Scope, application, and definitions applicable to this subdivision.....P-1

1926.651Specific excavation requirements...... P-5

437-003-0096Underground installations...... P-5

1926.652Requirements for protective systems...... P-11

Appendix A – Soil classification...... P-17

Appendix B – Sloping and benching...... P-23

Appendix C – Timber shoring for trenches...... P-33

Appendix D – Aluminum hydraulic shoring for trenches...... P-45

Appendix E – Alternatives to timber shoring...... P-55

Appendix F – Selection of protective systems...... P-57

Subdivision PP-1Table of Contents

Oregon Administrative Rules
Oregon Occupational Safety
and Health Division /

EXCAVATIONS

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OAR 437, DIVISION 3

CONSTRUCTION

SUBDIVISION P – EXCAVATIONS

437-003-0001 Adoption by Reference. In addition to, and not in lieu of, any other safety and health codes contained in OAR Chapter 437, the Department adopts by reference the following federal regulations printed as part of the Code of Federal Regulations, in the Federal Register:

(16) Subdivision P – Excavations.

(a)29 CFR 1926.650 Scope, application, and definitions applicable to this subdivision, published 10/31/89, FR vol. 54, no. 209, pp. 45959-45961.

(b)29 CFR 1926.651 General requirements, published 8/9/94, FR vol. 59, no. 152, p. 40730.

(d)Appendices A-F to Subdivision P, Excavations, published 10/31/89, FR vol. 54, no. 209, pp. 45962-45991.

These standards are available at the Oregon Occupational Safety and Health Division, Oregon Department of Consumer and Business Services, and the United States Government Printing Office.

Stat. Auth.: ORS 654.025(2) and 656.726(4).

Stats. Implemented: ORS 654.001 through 654.295.

Hist:APD Admin. Order 5-1989, f. 3/31/89, ef. 5/1/89 (temp).

APD Admin. Order 8-1989, f. 7/7/89, ef. 7/7/89 (perm).

APD Admin. Order 14-1989, f. 7/20/89, ef. 8/1/89 (temp).

APD Admin. Order 15-1989, f. 9/13/89, ef. 9/13/89 (perm).

APD Admin. Order 16-1989 (temp), f. 9/13/89, ef. 9/13/89.

OR-OSHA Admin. Order 2-1989, f. 10/17/89, ef. 10/17/89.

OR-OSHA Admin. Order 3-1990, f. 1/19/90, ef. 1/19/90 (temp).

OR-OSHA Admin. Order 7-1990, f. 3/2/90, ef. 3/2/90 (perm).

OR-OSHA Admin. Order 8-1990, f. 3/30/90, ef. 3/30/90.

OR-OSHA Admin. Order 13-1990, f. 6/28/90, ef. 8/1/90 (temp).

OR-OSHA Admin. Order 19-1990, f. 8/31/90, ef. 8/31/90 (perm).

OR-OSHA Admin. Order 27-1990, f. 12/12/90, ef. 2/1/91.

OR-OSHA Admin. Order 6-1991, f. 3/18/91, ef. 4/15/91.

OR-OSHA Admin. Order 7-1991, f. 4/25/91, ef. 4/25/91.

OR-OSHA Admin. Order 15-1991, f. 12/13/91, ef. 12/13/91.

OR-OSHA Admin. Order 16-1991, f. 12/16/91, ef. 1/1/92.

OR-OSHA Admin. Order 6-1992, f. 5/18/92, ef. 5/18/92.

OR-OSHA Admin. Order 11-1992, f. 10/9/92, ef. 10/9/92.

OR-OSHA Admin. Order 1-1993, f. 1/22/93, ef. 1/22/93.

OR-OSHA Admin. Order 16-1993, f. 11/1/93, ef. 11/1/93 (Lead).

OR-OSHA Admin. Order 1-1994, f. 4/27/94, ef. 4/27/94.

OR-OSHA Admin. Order 4-1994, f. 8/4/94, ef. 8/4/94 (HazCom).

OR-OSHA Admin. Order 6-1994, f. 9/30/94, ef. 9/30/94.

OR-OSHA Admin. Order 1-1995, f. 1/19/95, ef. 1/19/95 (DOT markings, placards & labels).

OR-OSHA Admin. Order 3-1995, f. 2/22/95, ef. 2/22/95 (Haz Waste).

OR-OSHA Admin. Order 4-1995, f. 3/29/95, ef. 3/29/95 (Asbestos).

OR-OSHA Admin. Order 5-1995, f. 4/6/95, ef. 4/6/95 (HazCom).

OR-OSHA Admin. Order 6-1995, f. 4/18/95, ef. 6/1/95 (Fall Protection).

OR-OSHA Admin. Order 8-1995, f. 8/25/95, ef. 8/25/95 (Asbestos).

OR-OSHA Admin. Order 5-1996, f. 11/29/96, ef. 11/29/96.

OR-OSHA Admin. Order 6-1996, f. 11/29/96, ef. 11/29/96.

OR-OSHA Admin. Order 2-1997, f. 3/12/97, ef. 3/12/97.

OR-OSHA Admin. Order 4-1997, f. 4/2/97, ef. 4/2/97.

OR-OSHA Admin. Order 6-1997, f. 5/2/97, ef. 5/2/97.

OR-OSHA Admin. Order 7-1997, f. 9/15/97, ef. 9/15/97 (Fall Protection).

OR-OSHA Admin. Order 8-1997, f. 11/14/97, e. 11/14/97 (Methylene Chloride).

OR-OSHA Admin. Order 1-1998, f. 2/13/98, e. 2/13/98 (Methylene Chloride).

OR-OSHA Admin. Order 3-1998, f. 7/7/98, ef. 7/7/98 (Respiratory Protection).

OR-OSHA Admin. Order 6-1998, f. 10/15/98, ef. 10/15/98 (Slings 3/H).

OR-OSHA Admin. Order 7-1998, f. 12/28/98, ef. 12/28/98 (Asbestos).

OR-OSHA Admin. Order 1-1999, f. 3/22/99, e. 3/22/99 (Methylene Chloride).

OR-OSHA Admin. Order 4-1999, f. 4/30/99, ef. 4/30/99.

OR-OSHA Admin. Order 6-1999, f. 5/26/99, ef. 5/26/99.

OR-OSHA Admin. Order 3-2000, f. 2/8/00, ef. 2/8/00.

OR-OSHA Admin. Order 3-2001, f. 2/5/01, ef. 2/5/01 (Fall Protection/Oregon Exceptions).

OR-OSHA Admin. Order 3-2002, f. 4/15/02, ef. 4/18/02 (Steel Erection).

OR-OSHA Admin. Order 5-2002, f. 6/28/02, ef. 10/1/03 (GFCI 3/K).

OR-OSHA Admin. Order 6-2002, f. 7/19/02, ef. 7/19/02 (Fall Protection/Steel Erection).

OR-OSHA Admin. Order 1-2003, f. 1/30/03, ef. 4/30/03 (3/Q Masonry Wall Bracing).

OR-OSHA Admin. Order 2-2003, f. 1/30/03, ef. 1/30/03 (3/G).

OR-OSHA Admin. Order 7-2003, f. 12/5/03, ef. 12/5/03 (3/O).

OR-OSHA Admin. Order 8-2003, f. 12/30/03, ef. 1/1/04 (3/R).

OR-OSHA Admin. Order 1-2005, f. 4/12/05, ef. 4/12/05 (3/D and 3/Z).

OR-OSHA Admin. Order 2-2006, f. 4/28/06, ef. 4/28/06 (3/R).

OR-OSHA Admin. Order 4-2006, f. 7/24/06, ef. 7/24/06.

OR-OSHA Admin. Order 5-2006, f. 8/7/06, ef. 1/1/07.

OR-OSHA Admin. Order 6-2006, f. 8/30/06, ef. 8/30/06.

OR-OSHA Admin. Order 10-2006, f. 11/30/06, ef. 11/30/06.

OR-OSHA Admin. Order 6-2007, f. 9/26/07, ef. 9/26/07 (3/O).

OR-OSHA Admin. Order 5-2008, f. 5/1/08, ef. 5/15/08 (PPE).

OR-OSHA Admin. Order 5-2009, f. 5/29/09, ef. 5/29/09.

OR-OSHA Admin. Order 3-2010, f. 6/10/10, ef. 6/15/10.

OR-OSHA Admin. Order 1-2011, f. 2/9/11, ef. 2/9/11.

OR-OSHA Admin. Order 4-2011, f. 12/8/11, ef. 12/8/11.

OR-OSHA Admin. Order 5-2011, f. 12/8/11, ef. 7/1/12.

OR-OSHA Admin. Order 1-2012, f. 4/10/12, ef. 4/10/12.

OR-OSHA Admin. Order 5-2012, f. 9/25/12, ef. 9/25/12.

OR-OSHA Admin. Order 1-2013, f. 2/14/13, ef. 2/14/13.

OR-OSHA Admin. Order 2-2013, f. 2/15/13, ef. 4/1/13.

OR-OSHA Admin. Order 4-2013, f. 7/19/13, ef. 7/19/13.

OR-OSHA Admin. Order 5-2013, f. 9/13/13, ef. 9/13/13.

OR-OSHA Admin. Order 6-2013, f. 10/9/13, ef. 10/9/13.

OR-OSHA Admin. Order 7-2013, f. 12/12/13, ef. 12/12/13.

OR-OSHA Admin. Order 6-2014, f. 10/28/14, ef. 5/1/15.

OR-OSHA Admin. Order 7-2014, f. 11/7/14, ef. 11/9/14.

437-003-0001P-1(16)(a) – (16)(d)

Oregon Administrative Rules
Oregon Occupational Safety
and Health Division /

SCOPE, APPLICATION, &

DEFINITIONS APPLICABLE

TO THIS SUBDIVISION

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SUBDIVISION P

EXCAVATIONS

Authority: Sec. 107, Contract Work Hours and Safety Standards Act (Construction Safety Act) (40 U.S.C. 333); Sections 4, 6, 8, Occupational Safety and Health Act of 1970 (29 U.S.C. 653, 655, 657); Secretary of Labor’s Order No. 12-71 (36 FR 8754), 8-76 (41 FR 25059), or 9-83 (48 FR 35736), as applicable; and 29 CFR part 1911.

§1926.650 Scope, Application, and Definitions Applicable to this Subdivision.

(a)Scope and application. This subpart applies to all open excavations made in the earth’s surface. Excavations are defined to include trenches.

(b)Definitions applicable to this subdivision.

Accepted engineering practices means those requirements which are compatible with standards of practice required by a registered professional engineer.

Aluminum Hydraulic Shoring means a pre-engineered shoring system comprised of aluminum hydraulic cylinders (crossbraces) used in conjunction with vertical rails (uprights) or horizontal rails (walers). Such system is designed, specifically to support the sidewalls of an excavation and prevent cave-ins.

Bell-bottom pier hole means a type of shaft or footing excavation, the bottom of which is made larger than the cross section above to form a belled shape.

Benching (Benching system) means a method of protecting employees from cave-ins by excavating the sides of an excavation to form one or a series of horizontal levels or steps, usually with vertical or near-vertical surfaces between levels.

Cave-in means the separation of a mass of soil or rock material from the side of an excavation, or the loss of soil from under a trench shield or support system, and its sudden movement into the excavation, either by falling or sliding, in sufficient quantity so that it could entrap, bury, or otherwise injure and immobilize a person.

Competent person means one who is capable of identifying existing and predictable hazards in the surroundings, or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them.

Cross braces mean the horizontal members of a shoring system installed perpendicular to the sides of the excavation, the ends of which bear against either uprights or wales.

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

Faces or sides means the vertical or inclined earth surfaces formed as a result of excavation work.

Failure means the breakage, displacement, or permanent deformation of a structural member or connection so as to reduce its structural integrity and its supportive capabilities.

Hazardous atmosphere means an atmosphere which by reason of being explosive, flammable, poisonous, corrosive, oxidizing, irritating, oxygen deficient, toxic, or otherwise harmful, may cause death, illness, or injury.

Kickout means the accidental release or failure of a cross brace.

Protective system means a method of protecting employees from cave-ins, from material that could fall or roll from an excavation face or into an excavation, or from the collapse of adjacent structures. Protective systems include support systems, sloping and benching systems, shield systems, and other systems that provide the necessary protection.

Ramp means an inclined walking or working surface that is used to gain access to one point from another, and is constructed from earth or from structural materials such as steel or wood.

Registered Professional Engineer means a person who is registered as a professional engineer in the state where the work is to be performed. However, a professional engineer, registered in any state is deemed to be a “registered professional engineer” within the meaning of this standard when approving designs for “manufactured protective systems” or “tabulated data” to be used in interstate commerce.

Sheeting means the members of a shoring system that retain the earth in position and in turn are supported by other members of the shoring system.

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 pre-manufactured or job-built in accordance with §1926.652(c)(3) or (c)(4). Shields used in trenches are usually referred to as “trench boxes” or “trench shields.”

Shoring (Shoring system) means a structure such as a metal hydraulic, mechanical or timber shoring system that supports the sides of an excavation and which is designed to prevent cave-ins.

Sides. See “Faces.”

1926.650P-1(a) – (b)

Oregon Administrative Rules
Oregon Occupational Safety
and Health Division /

SCOPE, APPLICATION, &

DEFINITIONS APPLICABLE

TO THIS SUBDIVISION

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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.

Stable rock means natural solid mineral material that can be excavated with vertical sides and will remain intact while exposed. Unstable rock is considered to be stable when the rock material on the side or sides of the excavation is secured against caving-in or movement by rock bolts or by another protective system that has been designed by a registered professional engineer.

Structural ramp means a ramp built of steel or wood, usually used for vehicle access. Ramps made of soil or rock are not considered structural ramps.

Support system means a structure such as underpinning, bracing, or shoring, which provides support to an adjacent structure, underground installation, or the sides of an excavation.

Tabulated data means tables and charts approved by a registered professional engineer and used to design and construct a protective system.

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 (4.6 m). 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 (4.6 m) or less (measured at the bottom of the excavation), the excavation is also considered to be a trench.

Trench box. See “Shield.”

Trench shield. See “Shield.”

Uprights means the vertical members of a trench shoring system placed in contact with the earth and usually positioned so that individual members do not contact each other. Uprights placed so that individual members are closely spaced, in contact with or interconnected to each other, are often called “sheeting.”

Wales means horizontal members of a shoring system placed parallel to the excavation face whose sides bear against the vertical members of the shoring system or earth.

Stat. Auth.: ORS 654.025(2) and 656.726(4).

Stats. Implemented: ORS 654.001 through 654.295.

Hist:APD Admin. Order 4-1989, f. 3/31/89, ef. 5/1/89 (temp).

APD Admin. Order 8-1989, f. 7/7/89, ef. 7/7/89 (perm).

1926.650P-1(b)

Oregon Administrative Rules
Oregon Occupational Safety
and Health Division /

SPECIFIC EXCAVATION REQUIREMENTS /

UNDERGROUND INSTALLATIONS / P

§1926.651 Specific Excavation Requirements.

437-003-0096 Underground Installations. In addition to and not in lieu of any rules relating to “underground installations” adopted in Oregon Administrative Rules, Chapter 437, the following Oregon Revised Statutes and Oregon Administrative Rules administered by the Oregon Public Utility Commission (PUC) shall apply:

1. ORS 757.541 through 757.571; and

2. OAR 952-001-0050 and OAR 860-024-0007.

Stat. Auth.: ORS 654.025(2) and 656.726(4).

Stats.Implemented: ORS 654.001 through 654.295.

Hist:OR-OSHA Admin. Order 8-1990, f. 3/30/90, ef. 9/1/90.

OR-OSHA Admin. Order 4-2011, f. 12/8/11, ef. 12/8/11.

(a)Surface encumbrances. All surface encumbrances that are located so as to create a hazard to employees shall be removed or supported, as necessary, to safeguard employees.

(b)Underground installations.

(1)The estimated location of utility installations, such as sewer, telephone, fuel, electric, water lines, or any other underground installations that reasonably may be expected to be encountered during excavation work, shall be determined prior to opening an excavation.

Note: 1910.651(b)(2) was NOT adopted by OR-OSHA. In Oregon OAR 437-003-0096 (printed in italics above) applies.

(3)When excavation operations approach the estimated location of underground installations, the exact location of the installations shall be determined by safe and acceptable means.

(4)While the excavation is open, underground installations shall be protected, supported or removed as necessary to safeguard employees.

(c)Access and egress.

(1)Structural ramps.

(i)Structural ramps that are used solely by employees as a means of access or egress from excavations shall be designed by a competent person. Structural ramps used for access or egress of equipment shall be designed by a competent person qualified in structural design, and shall be constructed in accordance with the design.

(ii)Ramps and runways constructed of two or more structural members shall have the structural members connected together to prevent displacement.

(iii)Structural members used for ramps and runways shall be of uniform thickness.

(iv)Cleats or other appropriate means used to connect runway structural members shall be attached to the bottom of the runway or shall be attached in a manner to prevent tripping.

(v)Structural ramps used in lieu of steps shall be provided with cleats or other surface treatments on the top surface to prevent slipping.

(2)Means of egress from trench excavations. A stairway, ladder, ramp or other safe means of egress shall be located in trench excavations that are 4 feet (1.22 m) or more in depth so as to require no more than 25 feet (7.62 m) of lateral travel for employees.

(d)Exposure to vehicular traffic. Employees exposed to public vehicular traffic shall be provided with, and shall wear, warning vests or other suitable garments marked with or made of reflectorized or high-visibility material.

(e)Exposure to falling loads. No employee shall be permitted underneath loads handled by lifting or digging equipment. Employees shall be required to stand away from any vehicle being loaded or unloaded to avoid being struck by any spillage or falling materials. Operators may remain in the cabs of vehicles being loaded or unloaded when the vehicles are equipped, in accordance with §1926.601(b)(6), to provide adequate protection for the operator during loading and unloading operations.

(f)Warning system for mobile equipment. When mobile equipment is operated adjacent to an excavation, or when such equipment is required to approach the edge of an excavation, and the operator does not have a clear and direct view of the edge of the excavation, a warning system shall be utilized such as barricades, hand or mechanical signals, or stop logs. If possible, the grade should be away from the excavation.

(g)Hazardous atmospheres.

(1)Testing and controls. In addition to the requirements set forth in subparts D and E of this part (29 CFR 1926.50-1926.107) to prevent exposure to harmful levels of atmospheric contaminants and to assure acceptable atmospheric conditions, the following requirements shall apply:

(i)Where oxygen deficiency (atmospheres containing less than 19.5 percent oxygen) or a hazardous atmosphere exists or could reasonably be expected to exist, such as in excavations in landfill areas or excavations in areas where hazardous substances are stored nearby, the atmospheres in the excavation shall be tested before employees enter excavations greater than 4 feet (1.22 m) in depth.

437-003-0096P-11926.651(c)(1)(i)

Oregon Administrative Rules
Oregon Occupational Safety
and Health Division / SPECIFIC EXCAVATION
REQUIREMENTS / P

(ii)Adequate precautions shall be taken to prevent employee exposure to atmospheres containing less than 19.5 percent oxygen and other hazardous atmospheres. These precautions include providing proper respiratory protection or ventilation in accordance with subparts D and E of this part respectively.

(iii)Adequate precaution shall be taken such as providing ventilation, to prevent employee exposure to an atmosphere containing a concentration of a flammable gas in excess of 20 percent of the lower flammable limit of the gas.

(iv)When controls are used that are intended to reduce the level of atmospheric contaminants to acceptable levels, testing shall be conducted as often as necessary to ensure that the atmosphere remains safe.

(2)Emergency rescue equipment.

(i)Emergency rescue equipment, such as breathing apparatus, a safety harness andline, or a basket stretcher, shall be readily available where hazardous atmospheric conditions exist or may reasonably be expected to develop during work in an excavation. This equipment shall be attended when in use.

(ii)Employees entering bell-bottom pier holes, or other similar deep and confined footing excavations, shall wear a harness with a life-line securely attached to it. The lifeline shall be separate from any line used to handle materials, and shall be individually attended at all times while the employee wearing the lifeline is in the excavation.

(h)Protection from hazards associated with water accumulation.

(1)Employees shall not work in excavations in which there is accumulated water, or in excavations in which water is accumulating, unless adequate precautions have been taken to protect employees against the hazards posed by water accumulation. The precautions necessary to protect employees adequately vary with each situation, but could include special support or shield systems to protect from cave-ins, water removal to control the level of accumulating water, or use of a safety harness and lifeline.