U.S. Geological Survey Manual
SM 445-2-H CHAPTER 44
Fall Protection Program
Instruction: This chapter is being revised to include appendices and additional definitions.
1. Purpose. To specify the minimum requirements to reduce fall hazard risks for USGS employees.
A. 29 CFR 1910 Subpart D (1910.21 through 1910.30), Walking-Working Surfaces.
B. 29 CFR 1926 Subpart M (1926.500 through 1926.503), Fall Protection.
C. OSHA Instruction STD 1-1.10 June 30, 1981, Height of Guardrails in General Industry Applications.
D. USGS Occupational Safety and Health Program Requirements Handbook, Chapter 41, Cableway Safety.
A. The Fall Protection Program applies to USGS employees and others for whom the Government assumes workers’ compensation liability and whose duties may expose them to falls of 4 feet or more to a surface below or to dangerous machinery from any height. This includes volunteers covered by a properly executed USGS Form 9-2080, Individual Volunteer Services Agreement, and students acquired by purchase orders citing Public Law 106-113 as the authority for the award. Note: Supervisors are to keep visitors (or volunteers not covered by a Form 9-2080) away from such circumstances, as is customary at construction or other hazardous sites where notices are posted and visitors are not allowed to proceed at all or without proper protection.
In order to simplify the requirements, the program is more protective in some areas than is required by the Occupational Safety and Health Administration (OSHA).
B. Examples of USGS fall hazards include, but are not limited to, the following: stairs; ladders; floor and wall openings; roofs; balconies; ramps and walkways; telecommunication towers; drilling rigs; trees; bridges; dams; cliffs; excavations; roof skylights; overhead work areas; powered platforms; man lifts; vehicle-mounted work platforms; mobile ladder stands; scaffolds; pits and trapdoor floor openings; stilling wells; manholes; pools; and boats.
A. In general, authorized employees who are within 8 feet from being exposed to a fall hazard of 4 feet or more to a surface below or to dangerous machinery from any height will be provided with fall protection. The preferred fall protection method is an engineering control such as standard railings or elimination of the fall hazard from the workplace.
(1) Standard Railing. The first choice for fall protection is a standard railing. A standard railing consists of a top rail, intermediate rail, and posts. The height of the railing should be between 36 inches to 44 inches, 42 inches being preferred. The top rail should be smooth surfaced. The ends of the rails should not overhang the terminal posts except where the overhang does not make a projection hazard. The railing should be capable of withstanding a force of at least 200 pounds applied within 2 inches of the top edge, in any outward or downward direction, at any point along the top edge.
A cover or barricade may be used in place of a standard railing.
(2) Stair Railings and Handrails. Flights of stairs with four or more risers will have standard stair railings or standard handrails. Stair railings should be from 30 to 34 inches high from the upper surface of the top rail to the surface of tread in line with face of riser at forward edge of tread.
(3) Safety Nets. In general, safety nets will not be used.
(4) Personal Fall Arrest Systems. The second choice for fall protection is a personal fall arrest system. This consists of a full body harness, connectors, and an anchorage capable of supporting at least 5,000 pounds. Alternatively, it must be designed and installed as part of a complete personal fall arrest system, which maintains a safety factor of at least two (e.g., will support at least twice the maximum force in a fall), and under the supervision of a qualified person. All free falls must be limited to no more than 6 feet. USGS employees are prohibited from using body belts for fall arrest.
The kind of personal fall arrest system selected should match the particular work situation, and any possible free-fall distance should be kept to a minimum, not to exceed 6 feet. The presence of acids, dirt, moisture, oil, grease, etc., and their effect on the system should be evaluated. Hot or cold environments may also have an adverse effect on the system. Wire rope should not be used where an electrical hazard is anticipated.
(a) Anchor Point. One of the most important aspects of personal fall protection systems is fully planning the system before it is put to use. Probably the most overlooked component is planning for suitable anchor points. Ideally, planning should be done before the structure or building is constructed so that anchor points can be incorporated during construction for use later for window cleaning or other building maintenance. If properly planned, these anchor points may be used during and after construction.
Properly planned anchor points should be used if they are available. In some cases, anchorages must be installed immediately prior to use. In such cases, a registered professional engineer with experience in designing fall protection systems, or another qualified person with appropriate education and experience, should design an anchor point to be installed.
In other cases, there will be a need to devise an anchor point from existing structures. Examples of what might be appropriate anchor points are steel members or I-beams if an acceptable strap is available for the connection (do not use a lanyard with a snap hook clipped onto itself); large eyebolts made of an appropriate grade steel; guardrails or railings if they have been designed for use as an anchor point; or masonry or wood members only if the attachment point is substantial and precautions have been taken to assure that bolts or other connectors will not pull through. A qualified person should evaluate the suitability of these "makeshift" anchor points with a focus on proper strength.
(b) Tie-Offs. When a tie-off is made using a knot in a rope lanyard or lifeline (at any location), it can reduce the lifeline or lanyard strength by 50 percent or more. If a knot must be used, a stronger lanyard or lifeline should be used to compensate for the weakening effect of the knot. Alternatively, the lanyard length should be reduced or the tie-off location should be raised to minimize free-fall distance. When possible, the lanyard or lifeline should be replaced by one with a connector that eliminates the need for a knot.
Tie-off of a rope lanyard or lifeline around an "H" or "I" beam or similar support can reduce its strength as much as 70 percent due to the cutting action of the beam edges. Therefore, use a webbing lanyard or wire core lifeline around the beam; or protect the lanyard or lifeline from the edge; or minimize the free-fall distance.
Tie-off where the line passes over or around rough or sharp surfaces reduces strength drastically. Such a tie-off should be avoided or an alternative tie-off rigging should be used. Such alternatives may include use of a snap hook/d-ring connection, wire rope tie-off, an effective padding of the surfaces, or an abrasion-resistance strap around or over the problem surface.
(c) Horizontal Lifelines. Horizontal lifelines may, depending on their geometry and angle of sag, be subjected to greater loads than the impact load imposed by an attached component. When the angle of a horizontal lifeline sag is less than 30 degrees, the impact force imparted to the lifeline by an attached lanyard is greatly amplified. For example, with a sag angle of 15 degrees, the force amplification is about 2:1; with a sag angle of 5 degrees, it is about 6:1. Depending on the angle of sag and the line's elasticity, the strength of the horizontal lifeline and the anchor points to which it is attached should be increased a number of times over that of the lanyard. Extreme care should be taken in considering a horizontal lifeline for multiple tie-offs. In the case of multiple tie-offs to a horizontal lifeline, if one person falls, the movement of the falling person and the horizontal lifeline during arrest of the fall may also cause others to fall. Horizontal lifeline and anchor point strength should be increased for each additional person to be tied off. For these and other reasons, the design of systems using horizontal lifelines must only be done by qualified persons. Testing of installed lifelines and anchors prior to use is recommended.
(d) Eyebolts. The strength of an eyebolt is rated along the axis of the bolt, and its strength is greatly reduced if the force is applied at an angle to this axis (in the direction of shear). Care should be exercised in selecting the proper diameter of the eyebolt to avoid accidental disengagement of snap hooks not designed to be compatible for the connection. Vendors can provide expert advice in selecting equipment.
(e) Sliding Hitch Knot. Due to the significant reduction in the strength of the lifeline/lanyard (in some cases, as much as a 70 percent reduction), the sliding hitch knot (prusik) should not be used for lifeline/lanyard connections except in emergency situations where no other available system is practical. The "one-and-one" sliding hitch knot should never be used because it is unreliable in stopping a fall. The "two-and-two”, or the preferred "three-and-three," knot may be used in emergency situations; however, care should be taken to limit free-fall distance to a minimum, not to exceed 6 feet, because of reduced lifeline/lanyard strength.
(f) Vertical Lifelines. Each person should have a separate lifeline when the lifeline is vertical.
(g) Snap Hooks. Locking snap hooks designed for connection to suitable objects are required. Locking snap hooks incorporate a positive locking mechanism in addition to the spring loaded keeper, which will not allow the keeper to open under moderate pressure without someone first releasing the mechanism. Such a feature, properly designed, effectively prevents rollout from occurring.
B. Protection from Falling Objects. Where persons work under or pass under a work area, a method to prevent tools and materials from falling on these persons must be provided. This protection can be a solid canopy, a barricade for the area, or it can be toe boards, screens, or mesh from the top rail to the walking/working level and along the entire opening between top rail supports. Personnel who work under or pass under a work area that may have falling objects must wear hard hats.
(1) Ladders. Additional fall protection is not required for fixed ladders that are 20 feet long or less. Fixed ladders that are more than 20 feet long may have landing platforms, ladder safety devices, or cages. Portable ladders that are more than 20 feet long should be used with caution and always used with another person present to assist.
(2) Restraints. Whenever possible, personal fall protection systems should be designed to prevent a worker from reaching the fall hazard (e.g., edge of the roof). When the worker is restrained and cannot reach the fall hazard, the anchor point may be less than 5,000 pounds, but at least 200 pounds such as a standard railing.
(3) Working over Water. When working over water on bridges, dams, pools, and boats, the preferred fall protection is a standard railing. When a standard railing is not available, the second choice is a personal fall arrest system, followed by a personal flotation device (PFD). In some cases, a PFD is required. However, methods to prevent the fall should be implemented whenever possible.
(4) Fall Protection Plans. When standard railings and personal fall arrest systems are infeasible or create a greater hazard, a written fall protection plan must be prepared showing the method used to provide equivalent protection from falls. The fall protection plan should include the following:
(a) The reason why the use of a guardrail system or personal fall arrest system is infeasible, or why its use would create a greater hazard.
(b) Measures that will be taken to reduce or eliminate the fall hazard for workers who cannot be provided with protection from a guardrail system or personal fall arrest system. For example, explain how scaffolds, ladders, or vehicle-mounted work platforms can be used to provide a safer working surface and, thereby, reduce the hazard of falling.
(c) Identify the locations where guardrail systems or personal fall arrest systems cannot be used.
(d) Include a statement which provides the name or other method of identification of each employee who is designated to work in controlled access zones. No other employees may enter controlled access zones.
(e) In the event that a worker falls, or some other related, serious incident occurs (e.g., a near miss), the circumstances of the fall or other incident will be investigated to determine if the fall protection plan needs to be changed (e.g., new practices, procedures, or training). If necessary, changes will be made to the fall protection plan to prevent similar types of falls or incidents.
(f) Name, date, and signature of the qualified person who prepared the fall protection plan.
(1) Railings, Stairs, and Ladders. All personnel should be trained in the nature of fall hazards in the work area; the proper construction, use, placement, and care in handling of all stairways and ladders; the maximum intended load-carrying capacities of ladders; how to report fall hazards; and other pertinent requirements of the OSHA standards.
(2) Scaffolds. Workers who assemble or use scaffolds must have additional training by a competent person on the type of scaffolding used. They should also be trained in the nature of electrical hazards and the correct procedures for dealing with those hazards; fall hazards and falling object hazards in the work area; erecting, maintaining, and disassembling the fall protection systems; the falling object protection systems being used; the proper use of the scaffold; the proper handling of materials on the scaffold; design criteria; the maximum intended load and the load-carrying capacities of the scaffolds used; correct procedures for erecting, disassembling, moving, operating, repairing, inspecting, and maintaining the type of scaffold in question; and other pertinent requirements of the OSHA standards.
(3) Personal Fall Arrest Systems. Personnel who use personal fall arrest systems must have additional training by a competent person in the selection and use of the personal fall arrest systems being used. This training should include the following: application limits; proper anchoring and tie-off techniques; estimation of free-fall distance, including determination of deceleration distance, and total fall distance to prevent striking a lower level; methods of use; and inspection and storage of the system. Careless or improper use of the equipment can result in serious injury or death. Personnel should become familiar with the manufacturer's recommendations before a system is used. Particular attention should be paid to the reduction in strength caused by certain tie-offs (e.g., using knots, tying around sharp edges, etc.) and the maximum permitted free-fall distance of 6 feet. Inspections prior to use are critically important as well as limitations of the equipment and unique conditions at the worksite. All three of these factors may be important in determining the type of system to be used.
(4) Certified Written Record. A certified written record will be made of the training to include the name of the employee trained, the date of the training, and either the signature of the person conducting the training or the supervisor.
E. Rescue. When personal fall-arrest systems are used, there must be a plan to assure that anyone who falls can be promptly rescued or can rescue one’s self. The availability of rescue personnel, ladders, devices which have descent capability, or other rescue equipment should be evaluated. In some situations, equipment which allows someone to rescue one’s self after the fall has been arrested may be desirable.
F. Inspections. All fall protection equipment requires routine inspection. The frequency of inspections will depend on the use and the risk. Inspections once or twice a year may be appropriate for permanent railing while personal fall arrest systems should be inspected before each shift.
(1) Ladders. Ladders are to be inspected by a competent person for visible defects on a periodic basis and after any occurrence that could affect their safe use. Ladders with structural defects, such as broken or missing rungs, cleats, or steps; broken or split rails; corroded components; or other faulty or defective components, shall either be immediately marked in a manner that readily identifies them as defective, or be tagged with "Do Not Use" or similar language and withdrawn from service until repaired.
(2) Stairs. Stairs are to be inspected by a competent person for visible defects such as variations in riser height or tread depth; metal pan landings and metal pan treads not secured; hazardous projections; slippery conditions; and missing or damaged handrails.
(3) Personal Fall Arrest Systems. Components of personal fall arrest systems are to be inspected for visible defects such as cuts, tears, and abrasions; mold; undue stretching; alterations or additions which might affect its efficiency; damage due to deterioration; contact with fire, acids, or other corrosives; distorted hooks or faulty hook springs; tongues unfitted to the shoulder of buckles; loose or damaged mountings; or non-functioning parts. Worn or deteriorating ropes must be withdrawn from service immediately and either marked as unusable or destroyed.
(4) Scaffolds. Scaffolds and scaffold components are to be inspected by a competent person for visible defects before each work shift and after any incident that could affect the scaffold's structural integrity.
(5) Aerial Lifts. Aerial lift controls are to be tested daily before use. Prior to moving an aerial lift for travel, the boom is to be inspected to see that it is properly cradled and outriggers are in stowed position.
G. Reducing Risk. All risk cannot be eliminated from a job, but substitutions can be made to reduce the risk. Whenever it is reasonable, fall-hazard risks should be reduced. In general,
(1) Standard railings are better than personal fall arrest systems.
(2) Stairs are better than ladders.
(3) Fixed ladders are better than portable ladders.
A. Bureau Safety Manager.
(1) Provides Bureau-wide oversight and direction for the Fall Protection Program.
(2) Conducts reviews and evaluates the effectiveness of headquarters and regional Fall Protection Programs and modifies policy and procedures as applicable.
(3) Provides assistance, including training, to Regional Safety Managers in the development of Fall Protection Programs.
B. Regional Safety Managers.
(1) Provide region-wide direction and oversight for the administration of an appropriate Fall Protection Program, serving as the focal point for program development and implementation in the regions; provide technical advice to Regional Safety Officers and Collateral Duty Safety Program Coordinators (CDSPCs).
(2) Evaluate effectiveness of regional Fall Protection Programs and make recommendations for improvement.
C. Regional Safety Officers.
(1) Oversee the administration of Fall Protection Programs for regional science program field locations.
(2) Serve as the focal point for the implementation of the regional science Fall Protection Programs and provide technical advice to field level CDSPCs and regional management.
(3) Provide assistance to managers and CDSPCs in regional science program field locations in developing Fall Protection Programs.
(4) Evaluate effectiveness of regional science program field-level Fall Protection Programs and make recommendations for improvement.
D. Collateral Duty Safety Program Coordinators.
(1) Assist management and supervisors in the implementation of the Fall Protection Program, including training and education.
(2) Assist supervisors in identifying personnel with potential for occupational exposure to falls and help conduct or coordinate appropriate training programs.
(3) Assist in the development of a fall protection plan when standard railings and personal fall arrest systems are not feasible.
(4) Assist supervisors in reviewing and updating the program as needed.
E. Managers and Supervisors.
(1) Coordinate personnel training and education by qualified instructors on the Fall Protection Program.
(2) Determine the personnel who have possible occupational exposure to falls. Ensure that they receive required training and that training is properly documented.
(3) Establish and maintain an effective Fall Protection Program.
(4) Review and update the Fall Protection Program if someone falls; if some other related, serious incident occurs (e.g., a near miss); or if there are new or revised jobs with fall exposures.
(1) Participate in required training programs.
(2) Be familiar with the facility’s Fall Protection Program.
(3) Wear appropriate personal protective equipment and observe appropriate work practice controls.
(4) Report fall hazards (e.g., damaged or missing railings and holes in floors or walls) to the Supervisor or Manager.
6. Additional Resources.
A. OSHA Publication 3146, Fall Protection in Construction.
B. OSHA Safety and Health Topics, Fall Protection.
C. Appendix 44-1, Sample Fall Protection Program.
D. Appendix 44-2, Job Hazard Analysis.
E. Appendix 44-3, Hazard Control Options.
F. Appendix 44-4, Sample Fall Protection Plan.
A. Anchor Point. A secure point of attachment for lifelines, lanyards or deceleration devices. An anchor point must be capable of supporting at least 5,000 pounds (3,600 pounds if engineered/ certified by a qualified person) per person and must be independent of any anchorage being used to support or suspend platforms.
B. Authorized Person. A person approved or assigned by the USGS to perform a specific type of duty or duties or to be at a specific location or job site (e.g., building maintenance, roof repair, etc.).
C. Body Belt (safety belt). A strap that can be secured about the waist or attached to a lanyard, lifeline, or deceleration device. USGS employees are prohibited from using body belts for fall arrest.
D. Body Harness. Straps which may be secured about the employee in a manner that will distribute the fall arrest forces over at least the thighs, pelvis, waist, chest, and shoulders with means for attaching it to other components of a personal fall arrest system.
E. Buckle. Any device for holding the body belt or body harness closed around the employee's body.
F. Carabiner. A metal loop with a sprung or screwed gate. It can quickly and reversibly connect components in safety-critical systems.
G. Clearance. The distance required to prevent the worker from striking the next level or any other obstruction below.
H. Competent Person. 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 those conditions. The employer (manager) should decide if an employee has the knowledge, training, and authority to be a "competent person."
I. Connector. A device which is used to couple (connect) parts of the personal fall arrest system and positioning device systems together. It may be an independent component of the system, such as a carabiner, or it may be an integral component of part of the system (e.g., a buckle or D-ring sewn into a body harness, or a snap hook spliced or sewn to a lanyard or self-retracting lanyard).
J. Controlled Access Zone. An area in which certain work (e.g., overhand bricklaying) may take place without the use of guardrail systems, personal fall arrest systems, or safety net systems and access to the zone is controlled.
K. Dangerous Equipment. Equipment (e.g., pickling or galvanizing tanks, degreasing units, machinery, electrical equipment, and other units) which, as a result of form or function, may be hazardous to employees who fall onto or into such equipment.
L. Deceleration Device. Any mechanism (e.g., a rope grab, rip-stitch lanyard, specially woven lanyard, tearing or deforming lanyards, automatic self-retracting lifelines/lanyards, etc.) which serves to dissipate a substantial amount of energy during a fall arrest or, otherwise, limits the energy imposed on an employee during fall arrest.
M. Deceleration Distance. The additional vertical distance a falling employee travels, excluding lifeline elongation and free-fall distance, before stopping, from the point at which the deceleration device begins to operate. It is measured as the distance between the location of an employee's body belt or body harness attachment point at the moment of activation (at the onset of fall arrest forces) of the deceleration device during a fall and the location of that attachment point after the employee comes to a full stop.
N. Equivalent. Alternative designs, materials, or methods to protect against a hazard which the employer can demonstrate will provide an equal or greater degree of safety for employees than the methods, materials, or designs specified in the standard.
O. Failure. Load refusal, breakage, or separation of component parts. Load refusal is the point where the ultimate strength is exceeded.
P. Free Fall. The act of falling before a personal fall arrest system begins to apply force to arrest the fall.
Q. Free-Fall Distance. The vertical displacement of the fall arrest attachment point on the employee's body belt or body harness between onset of the fall and just before the system begins to apply force to arrest the fall. This distance excludes deceleration distance and lifeline/lanyard elongation, but includes any deceleration device slide distance or self-retracting lifeline/lanyard extension before they operate and fall arrest forces occur. Free-fall distance must not exceed 6 feet.
R. Full Body Harness: Webbing/straps which are secured about an employee's body in a manner that will distribute the fall arrest forces over the thighs, pelvis, waist, chest, and shoulders. Having means for attaching it to other components of a personal fall arrest system, preferably at the shoulders and/or middle of the back.
S. Guardrail System. A barrier erected to prevent employees from falling to lower levels. This system includes a toe board, midrail and toprail able to withstand 200 pounds of force applied in any direction.
T. Hole. A gap or void, 2 inches or more in its least dimension, in a floor, roof, or other walking/working surface.
U. Infeasible. It is impossible to perform the construction work using a conventional fall protection system (e.g., guardrail system, safety-net system, or personal fall arrest system) or that it is technologically impossible to use any one of these systems to provide fall protection.
V. Lanyard. A flexible line of rope, wire rope, or strap which generally has a connector at each end for connecting the body belt or body harness to a deceleration device, lifeline, or anchor point.
W. Leading Edge. The edge of a floor, roof, or formwork for a floor or other walking/working surface (e.g., deck) which changes location as additional floor, roof, decking, or formwork sections are placed, formed, or constructed. A leading edge is considered to be an "unprotected side and edge" during periods when it is not actively and continuously under construction.
X. Lifeline. A component consisting of a flexible line for connection to an anchor point at one end to hang vertically (vertical lifeline), or for connection to anchor points at both ends to stretch horizontally (horizontal lifeline), and which serves as a means for connecting other components of a personal fall arrest system to the anchor point.
Y. Lower Levels. Areas or surfaces to which an employee can fall. Such areas or surfaces include, but are not limited to, ground levels, floors, platforms, ramps, runways, excavations, pits, tanks, material, water, equipment, structures, or portions thereof.
Z. Low Slope Roof. A roof having a slope of less than or equal to 4 in 12 (vertical to horizontal). A roof with approximately a 19.5 degree slope or less.
AA. Mechanical Equipment. All motor- or human-propelled wheeled equipment used for roofing work, except wheelbarrows and mop carts.
BB. Opening. A gap or void, 30 inches or more high and 18 inches or more wide, in a wall or partition through which employees can fall to a lower level.
CC. OSHA. Occupational Safety and Health Administration.
DD. Personal Fall Arrest System. A system used to arrest an employee in a fall from a working level. It consists of an anchor point, connectors, a body belt, or body harness and may include a lanyard, deceleration device, lifeline, or suitable combinations of these. USGS employees are prohibited from using body belts for fall arrest.
EE. Qualified Person. An individual, who by possession of a recognized degree, certificate, or professional standing or who by extensive knowledge, training, and experience, has successfully demonstrated his or her ability to solve or resolve problems relating to the subject matter, work, or project.
FF. Roof. The exterior surface on top of a building. This does not include floors or formwork which, because a building has not been completed, temporarily become the top surface of a building.
GG. Roofing Work. The hoisting, storage, application, and removal of roofing materials and equipment, including related insulation, sheet metal, and vapor barrier work, but does not include the construction of the roof deck.
HH. Rope Grab. A deceleration device which travels on a lifeline and automatically, by friction, engages the lifeline and locks so as to arrest the fall of an employee. A rope grab usually employs the principle of inertial locking, cam/level locking, or both.
II. Safety-Monitoring System. A safety system in which a competent person is responsible for recognizing and warning employees of fall hazards.
JJ. Self-Retracting Lifeline/Lanyard. A deceleration device containing a drum-wound line which can be slowly extracted from or retracted onto the drum under slight tension during normal employee movement and which, after onset of a fall, automatically locks the drum and arrests the fall.
KK. Snap Hook. A connector comprised of a hook-shaped member with a normally closed keeper, or similar arrangement, which may be opened to permit the hook to receive an object and, when released, automatically closes to retain the object. The locking type has a self-closing, self-locking keeper which remains closed and locked until unlocked and pressed open for connection or disconnection.
LL. Steep Slope Roof. A roof having a slope greater than 4 in 12 (vertical to horizontal). A roof with a slope greater than 19.5 degrees.
MM. Toe Board. A low, protective barrier that will prevent the fall of materials and equipment to lower levels and provide protection from falls for personnel.
NN. Total Fall Distance. The maximum vertical change in distance from the bottom of an individual's feet at the onset of a fall, to the position of the feet after the fall is arrested. This includes the free-fall distance and the deceleration distance.
OO. Unprotected Sides and Edges. Any side or edge (except at entrances to points of access) of a walking/working surface (e.g., floor, roof, ramp, or runway) where there is no wall or guardrail system at least 39 inches high.
PP. Walking/Working Surface. Any surface, whether horizontal or vertical, on which an employee walks or works including, but not limited to, floors, roofs, ramps, bridges, runways, formwork, and concrete reinforcing steel but not including ladders, vehicles, or trailers, on which employees must be located in order to perform their job duties.
QQ. Warning Line System. A barrier erected on a roof to warn employees that they are approaching an unprotected roof side or edge, and which designates an area in which roofing work may take place without the use of guardrail, body belt, or safety net systems to protect employees in the area.
RR. Work Area. That portion of a walk/work surface where job duties are being performed.
/s/ Karen D. Baker
Karen D. Baker Date
Associate Director for Administrative Policy and Services
Designated Agency Safety and Health Official