This section does not apply to aerial lifts, the criteria for which are set out exclusively in 1926.453.
1926.451(a) "Capacity"
1926.451(a)(1) Except as provided in paragraphs (a)(2), (a)(3), (a)(4), (a)(5) and (g) of this section, each
scaffold and scaffold component shall be capable of supporting, without failure, its own weight and at least 4 times the maximum intended load applied
or transmitted to it.
1926.451(a)(2) Direct connections to roofs and floors, and counterweights used to balance adjustable suspension
scaffolds, shall be capable of resisting at least 4 times the tipping moment imposed by the scaffold operating at the rated load of the hoist, or 1.5
(minimum) times the tipping moment imposed by the scaffold operating at the stall load of the hoist, whichever is greater.
1926.451(a)(3) Each suspension rope, including connecting hardware, used on non-adjustable suspension scaffolds
shall be capable of supporting, without failure, at least 6 times the maximum intended load applied or transmitted to that rope.
..1926.451(a)(4)
1926.451(a)(4) Each suspension rope, including connecting hardware, used on adjustable suspension scaffolds shall
be capable of supporting, without failure, at least 6 times the maximum intended load applied or transmitted to that rope with the scaffold operating
at either the rated load of the hoist, or 2 (minimum) times the stall load of the hoist, whichever is greater.
1926.451(a)(5) The stall load of any scaffold hoist shall not exceed 3 times its rated load.
1926.451(a)(6) Scaffolds shall be designed by a qualified person and shall be constructed and loaded in accordance
with that design. Non-mandatory Appendix A to this subpart contains examples of criteria that will enable an employer to comply with paragraph (a) of
this section.
1926.451(b) "Scaffold platform construction."
1926.451(b)(1) Each platform on all working levels of scaffolds shall be fully planked or decked between the front
uprights and the guardrail supports as follows:
1926.451(b)(1)(i) Each platform unit (e.g., scaffold plank, fabricated plank, fabricated deck, or fabricated
platform) shall be installed so that the space between adjacent units and the space between the platform and the uprights is no more than 1 inch (2.5
cm) wide, except where the employer can demonstrate that a wider space is necessary (for example, to fit around uprights when side brackets are used
to extend the width of the platform).
..1926.451(b)(1)(ii)
1926.451(b)(1)(ii) Where the employer makes the demonstration provided for in paragraph (b)(1)(i) of this section,
the platform shall be planked or decked as fully as possible and the remaining open space between the platform and the uprights shall not exceed 9 1/2
inches (24.1 cm).
Exception to paragraph (b)(1): The requirement in paragraph (b)(1) to provide full planking or decking does not apply to platforms used
solely as walkways or solely by employees performing scaffold erection or dismantling. In these situations, only the planking that the employer
establishes is necessary to provide safe working conditions is required.
1926.451(b)(2) Except as provided in paragraphs (b)(2)(i) and (b)(2)(ii) of this section, each scaffold platform
and walkway shall be at least 18 inches (46 cm) wide.
1926.451(b)(2)(i) Each ladder jack scaffold, top plate bracket scaffold, roof bracket scaffold, and pump jack
scaffold shall be at least 12 inches (30 cm) wide. There is no minimum width requirement for boatswains' chairs.
Note to paragraph (b)(2)(i): Pursuant to an administrative stay effective November 29, 1996 and published in the Federal Register on
November 25, 1996, the requirement in paragraph (b)(2)(i) that roof bracket scaffolds be at least 12 inches wide is stayed until November 25, 1997 or
until rulemaking reguarding the minimum width of roof bracket scaffolds has been completed, whichever is later.
1926.451(b)(2)(ii) Where scaffolds must be used in areas that the employer can demonstrate are so narrow that
platforms and walkways cannot be at least 18 inches (46 cm) wide, such platforms and walkways shall be as wide as feasible, and employees on those
platforms and walkways shall be protected from fall hazards by the use of guardrails and/or personal fall arrest systems.
1926.451(b)(3) Except as provided in paragraphs (b)(3)(i) and (ii) of this section, the front edge of all platforms
shall not be more than 14 inches (36 cm) from the face of the work, unless guardrail systems are erected along the front edge and/or personal fall
arrest systems are used in accordance with paragraph (g) of this section to protect employees from falling.
..1926.451(b)(3)(i)
1926.451(b)(3)(i) The maximum distance from the face for outrigger scaffolds shall be 3 inches (8 cm);
1926.451(b)(3)(ii) The maximum distance from the face for plastering and lathing operations shall be 18 inches (46
cm).
1926.451(b)(4) Each end of a platform, unless cleated or otherwise restrained by hooks or equivalent means, shall
extend over the centerline of its support at least 6 inches (15 cm).
1926.451(b)(5)
1926.451(b)(5)(i) Each end of a platform 10 feet or less in length shall not extend over its support more than 12
inches (30 cm) unless the platform is designed and installed so that the cantilevered portion of the platform is able to support employees and/or
materials without tipping, or has guardrails which block employee access to the cantilevered end.
1926.451(b)(5)(ii) Each platform greater than 10 feet in length shall not extend over its support more than 18
inches (46 cm), unless it is designed and installed so that the cantilevered portion of the platform is able to support employees without tipping, or
has guardrails which block employee access to the cantilevered end.
..1926.451(b)(6)
1926.451(b)(6) On scaffolds where scaffold planks are abutted to create a long platform, each abutted end shall
rest on a separate support surface. This provision does not preclude the use of common support members, such as "T" sections, to support abutting
planks, or hook on platforms designed to rest on common supports.
1926.451(b)(7) On scaffolds where platforms are overlapped to create a long platform, the overlap shall occur only
over supports, and shall not be less than 12 inches (30 cm) unless the platforms are nailed together or otherwise restrained to prevent
movement.
1926.451(b)(8) At all points of a scaffold where the platform changes direction, such as turning a corner, any
platform that rests on a bearer at an angle other than a right angle shall be laid first, and platforms which rest at right angles over the same
bearer shall be laid second, on top of the first platform.
1926.451(b)(9) Wood platforms shall not be covered with opaque finishes, except that platform edges may be covered
or marked for identification. Platforms may be coated periodically with wood preservatives, fire-retardant finishes, and slip-resistant finishes;
however, the coating may not obscure the top or bottom wood surfaces.
1926.451(b)(10) Scaffold components manufactured by different manufacturers shall not be intermixed unless the
components fit together without force and the scaffold's structural integrity is maintained by the user. Scaffold components manufactured by different
manufacturers shall not be modified in order to intermix them unless a competent person determines the resulting scaffold is structurally
sound.
..1926.451(b)(11)
1926.451(b)(11) Scaffold components made of dissimilar metals shall not be used together unless a competent person
has determined that galvanic action will not reduce the strength of any component to a level below that required by paragraph (a)(1) of this
section.
1926.451(c) "Criteria for supported scaffolds."
1926.451(c)(1) Supported scaffolds with a height to base width (including outrigger supports, if used) ratio of
more than four to one (4:1) shall be restrained from tipping by guying, tying, bracing, or equivalent means, as follows:
1926.451(c)(1)(i) Guys, ties, and braces shall be installed at locations where horizontal members support both
inner and outer legs.
1926.451(c)(1)(ii) Guys, ties, and braces shall be installed according to the scaffold manufacturer's
recommendations or at the closest horizontal member to the 4:1 height and be repeated vertically at locations of horizontal members every 20 feet (6.1
m) or less thereafter for scaffolds 3 feet (0.91 m) wide or less, and every 26 feet (7.9 m) or less thereafter for scaffolds greater than 3 feet (0.91
m) wide. The top guy, tie or brace of completed scaffolds shall be placed no further than the 4:1 height from the top. Such guys, ties and braces
shall be installed at each end of the scaffold and at horizontal intervals not to exceed 30 feet (9.1 m) (measured from one end [not both] towards the
other).
1926.451(c)(1)(iii) Ties, guys, braces, or outriggers shall be used to prevent the tipping of supported scaffolds
in all circumstances where an eccentric load, such as a cantilevered work platform, is applied or is transmitted to the scaffold.
..1926.451(c)(2)
1926.451(c)(2) Supported scaffold poles, legs, posts, frames, and uprights shall bear on base plates and mud sills
or other adequate firm foundation.
1926.451(c)(2)(i) Footings shall be level, sound, rigid, and capable of supporting the loaded scaffold without
settling or displacement.
1926.451(c)(2)(ii) Unstable objects shall not be used to support scaffolds or platform units.
1926.451(c)(2)(iii) Unstable objects shall not be used as working platforms.
1926.451(c)(2)(iv) Front-end loaders and similar pieces of equipment shall not be used to support scaffold
platforms unless they have been specifically designed by the manufacturer for such use.
1926.451(c)(2)(v) Fork-lifts shall not be used to support scaffold platforms unless the entire platform is attached
to the fork and the fork-lift is not moved horizontally while the platform is occupied.
1926.451(c)(3) Supported scaffold poles, legs, posts, frames, and uprights shall be plumb and braced to prevent
swaying and displacement.
..1926.451(d)
1926.451(d) "Criteria for suspension scaffolds."
1926.451(d)(1) All suspension scaffold support devices, such as outrigger beams, cornice hooks, parapet clamps, and
similar devices, shall rest on surfaces capable of supporting at least 4 times the load imposed on them by the scaffold operating at the rated load of
the hoist (or at least 1.5 times the load imposed on them by the scaffold at the stall capacity of the hoist, whichever is greater).
1926.451(d)(2) Suspension scaffold outrigger beams, when used, shall be made of structural metal or equivalent
strength material, and shall be restrained to prevent movement.
1926.451(d)(3) The inboard ends of suspension scaffold outrigger beams shall be stabilized by bolts or other direct
connections to the floor or roof deck, or they shall have their inboard ends stabilized by counterweights, except masons' multi-point adjustable
suspension scaffold outrigger beams shall not be stabilized by counterweights.
1926.451(d)(3)(i) Before the scaffold is used, direct connections shall be evaluated by a competent person who
shall confirm, based on the evaluation, that the supporting surfaces are capable of supporting the loads to be imposed. In addition, masons'
multi-point adjustable suspension scaffold connections shall be designed by an engineer experienced in such scaffold design.
1926.451(d)(3)(ii) Counterweights shall be made of non-flowable material. Sand, gravel and similar materials that
can be easily dislocated shall not be used as counterweights.
..1926.451(d)(3)(iii)
1926.451(d)(3)(iii) Only those items specifically designed as counterweights shall be used to counterweight
scaffold systems. Construction materials such as, but not limited to, masonry units and rolls of roofing felt, shall not be used as
counterweights.
1926.451(d)(3)(iv) Counterweights shall be secured by mechanical means to the outrigger beams to prevent accidental
displacement.
1926.451(d)(3)(v) Counterweights shall not be removed from an outrigger beam until the scaffold is
disassembled.
1926.451(d)(3)(vi) Outrigger beams which are not stabilized by bolts or other direct connections to the floor or
roof deck shall be secured by tiebacks.
1926.451(d)(3)(vii) Tiebacks shall be equivalent in strength to the suspension ropes.
1926.451(d)(3)(viii) Outrigger beams shall be placed perpendicular to its bearing support (usually the face of the
building or structure). However, where the employer can demonstrate that it is not possible to place an outrigger beam perpendicular to the face of
the building or structure because of obstructions that cannot be moved, the outrigger beam may be placed at some other angle, provided opposing angle
tiebacks are used.
..1926.451(d)(3)(ix)
1926.451(d)(3)(ix) Tiebacks shall be secured to a structurally sound anchorage on the building or structure. Sound
anchorages include structural members, but do not include standpipes, vents, other piping systems, or electrical conduit.
1926.451(d)(3)(x) Tiebacks shall be installed perpendicular to the face of the building or structure, or opposing
angle tiebacks shall be installed. Single tiebacks installed at an angle are prohibited.
1926.451(d)(4) Suspension scaffold outrigger beams shall be:
1926.451(d)(4)(i) Provided with stop bolts or shackles at both ends;
1926.451(d)(4)(ii) Securely fastened together with the flanges turned out when channel iron beams are used in place
of I-beams;
1926.451(d)(4)(iii) Installed with all bearing supports perpendicular to the beam center line;
1926.451(d)(4)(iv) Set and maintained with the web in a vertical position; and
1926.451(d)(4)(v) When an outrigger beam is used, the shackle or clevis with which the rope is attached to the
outrigger beam shall be placed directly over the center line of the stirrup.
1926.451(d)(5) Suspension scaffold support devices such as cornice hooks, roof hooks, roof irons, parapet clamps,
or similar devices shall be:
..1926.451(d)(5)(i)
1926.451(d)(5)(i) Made of steel, wrought iron, or materials of equivalent strength;
1926.451(d)(5)(ii) Supported by bearing blocks; and
1926.451(d)(5)(iii) Secured against movement by tiebacks installed at right angles to the face of the building or
structure, or opposing angle tiebacks shall be installed and secured to a structurally sound point of anchorage on the building or structure. Sound
points of anchorage include structural members, but do not include standpipes, vents, other piping systems, or electrical conduit.
1926.451(d)(5)(iv) Tiebacks shall be equivalent in strength to the hoisting rope.
1926.451(d)(6) When winding drum hoists are used on a suspension scaffold, they shall contain not less than four
wraps of the suspension rope at the lowest point of scaffold travel. When other types of hoists are used, the suspension ropes shall be long enough to
allow the scaffold to be lowered to the level below without the rope end passing through the hoist, or the rope end shall be configured or provided
with means to prevent the end from passing through the hoist.
1926.451(d)(7) The use of repaired wire rope as suspension rope is prohibited.
..1926.451(d)(8)
1926.451(d)(8) Wire suspension ropes shall not be joined together except through the use of eye splice thimbles
connected with shackles or coverplates and bolts.
1926.451(d)(9) The load end of wire suspension ropes shall be equipped with proper size thimbles and secured by
eyesplicing or equivalent means.
1926.451(d)(10) Ropes shall be inspected for defects by a competent person prior to each workshift and after every
occurrence which could affect a rope's integrity. Ropes shall be replaced if any of the following conditions exist:
1926.451(d)(10)(i) Any physical damage which impairs the function and strength of the rope.
1926.451(d)(10)(ii) Kinks that might impair the tracking or wrapping of rope around the drum(s) or
sheave(s).
1926.451(d)(10)(iii) Six randomly distributed broken wires in one rope lay or three broken wires in one strand in
one rope lay.
1926.451(d)(10)(iv) Abrasion, corrosion, scrubbing, flattening or peening causing loss of more than one-third of
the original diameter of the outside wires.
1926.451(d)(10)(v) Heat damage caused by a torch or any damage caused by contact with electrical wires.
..1926.451(d)(10)(vi)
1926.451(d)(10)(vi) Evidence that the secondary brake has been activated during an overspeed condition and has
engaged the suspension rope.
1926.451(d)(11) Swaged attachments or spliced eyes on wire suspension ropes shall not be used unless they are made
by the wire rope manufacturer or a qualified person.
1926.451(d)(12) When wire rope clips are used on suspension scaffolds:
1926.451(d)(12)(i) There shall be a minimum of 3 wire rope clips installed, with the clips a minimum of 6 rope
diameters apart;
1926.451(d)(12)(ii) Clips shall be installed according to the manufacturer's recommendations;
1926.451(d)(12)(iii) Clips shall be retightened to the manufacturer's recommendations after the initial
loading;
1926.451(d)(12)(iv) Clips shall be inspected and retightened to the manufacturer's recommendations at the start of
each workshift thereafter;
1926.451(d)(12)(v) U-bolt clips shall not be used at the point of suspension for any scaffold hoist;
..1926.451(d)(12)(vi)
1926.451(d)(12)(vi) When U-bolt clips are used, the U-bolt shall be placed over the dead end of the rope, and the
saddle shall be placed over the live end of the rope.
1926.451(d)(13) Suspension scaffold power-operated hoists and manual hoists shall be tested by a qualified testing
laboratory.
1926.451(d)(14) Gasoline-powered equipment and hoists shall not be used on suspension scaffolds.
1926.451(d)(15) Gears and brakes of power-operated hoists used on suspension scaffolds shall be enclosed.
1926.451(d)(16) In addition to the normal operating brake, suspension scaffold power-operated hoists and manually
operated hoists shall have a braking device or locking pawl which engages automatically when a hoist makes either of the following uncontrolled
movements: an instantaneous change in momentum or an accelerated overspeed.
1926.451(d)(17) Manually operated hoists shall require a positive crank force to descend.
1926.451(d)(18) Two-point and multi-point suspension scaffolds shall be tied or otherwise secured to prevent them
from swaying, as determined to be necessary based on an evaluation by a competent person. Window cleaners' anchors shall not be used for this
purpose.
..1926.451(d)(19)
1926.451(d)(19) Devices whose sole function is to provide emergency escape and rescue shall not be used as working
platforms. This provision does not preclude the use of systems which are designed to function both as suspension scaffolds and emergency
systems.
1926.451(e) "Access." This paragraph applies to scaffold access for all employees. Access requirements for
employees erecting or dismantling supported scaffolds are specifically addressed in paragraph (e)(9) of this section.
1926.451(e)(1) When scaffold platforms are more than 2 feet (0.6 m) above or below a point of access, portable
ladders, hook-on ladders, attachable ladders, stair towers (scaffold stairways/towers), stairway-type ladders (such as ladder stands), ramps,
walkways, integral prefabricated scaffold access, or direct access from another scaffold, structure, personnel hoist, or similar surface shall be
used. Crossbraces shall not be used as a means of access.
1926.451(e)(2) Portable, hook-on, and attachable ladders (Additional requirements for the proper construction and
use of portable ladders are contained in subpart X of this part -- Stairways and Ladders):
1926.451(e)(2)(i) Portable, hook-on, and attachable ladders shall be positioned so as not to tip the
scaffold;
1926.451(e)(2)(ii) Hook-on and attachable ladders shall be positioned so that their bottom rung is not more than 24
inches (61 cm) above the scaffold supporting level;
..1926.451(e)(2)(iii)
1926.451(e)(2)(iii) When hook-on and attachable ladders are used on a supported scaffold more than 35 feet (10.7 m)
high, they shall have rest platforms at 35-foot (10.7 m) maximum vertical intervals.
1926.451(e)(2)(iv) Hook-on and attachable ladders shall be specifically designed for use with the type of scaffold
used;
1926.451(e)(2)(v) Hook-on and attachable ladders shall have a minimum rung length of 11 1/2 inches (29 cm);
and
1926.451(e)(2)(vi) Hook-on and attachable ladders shall have uniformly spaced rungs with a maximum spacing between
rungs of 16 3/4 inches.
1926.451(e)(3) Stairway-type ladders shall:
1926.451(e)(3)(i) Be positioned such that their bottom step is not more than 24 inches (61 cm) above the scaffold
supporting level;
1926.451(e)(3)(ii) Be provided with rest platforms at 12 foot (3.7 m) maximum vertical intervals;
1926.451(e)(3)(iii) Have a minimum step width of 16 inches (41 cm), except that mobile scaffold stairway-type
ladders shall have a minimum step width of 11 1/2 inches (30 cm); and
1926.451(e)(3)(iv) Have slip-resistant treads on all steps and landings.
..1926.451(e)(4)
1926.451(e)(4) Stairtowers (scaffold stairway/towers) shall be positioned such that their bottom step is not more
than 24 inches (61 cm.) above the scaffold supporting level.
1926.451(e)(4)(i) A stairrail consisting of a toprail and a midrail shall be provided on each side of each scaffold
stairway.
1926.451(e)(4)(ii) The toprail of each stairrail system shall also be capable of serving as a handrail, unless a
separate handrail is provided.
1926.451(e)(4)(iii) Handrails, and toprails that serve as handrails, shall provide an adequate handhold for
employees grasping them to avoid falling.
1926.451(e)(4)(iv) Stairrail systems and handrails shall be surfaced to prevent injury to employees from punctures
or lacerations, and to prevent snagging of clothing.
1926.451(e)(4)(v) The ends of stairrail systems and handrails shall be constructed so that they do not constitute a
projection hazard.
1926.451(e)(4)(vi) Handrails, and toprails that are used as handrails, shall be at least 3 inches (7.6 cm) from
other objects.
..1926.451(e)(4)(vii)
1926.451(e)(4)(vii) Stairrails shall be not less than 28 inches (71 cm) nor more than 37 inches (94 cm) from the
upper surface of the stairrail to the surface of the tread, in line with the face of the riser at the forward edge of the tread.
1926.451(e)(4)(viii) A landing platform at least 18 inches (45.7 cm) wide by at least 18 inches (45.7 cm) long
shall be provided at each level.
1926.451(e)(4)(ix) Each scaffold stairway shall be at least 18 inches (45.7 cm) wide between stairrails.
1926.451(e)(4)(x) Treads and landings shall have slip-resistant surfaces.
1926.451(e)(4)(xi) Stairways shall be installed between 40 degrees and 60 degrees from the horizontal.
1926.451(e)(4)(xii) Guardrails meeting the requirements of paragraph (g)(4) of this section shall be provided on
the open sides and ends of each landing.
1926.451(e)(4)(xiii) Riser height shall be uniform, within 1/4 inch, (0.6 cm) for each flight of stairs. Greater
variations in riser height are allowed for the top and bottom steps of the entire system, not for each flight of stairs.
1926.451(e)(4)(xiv) Tread depth shall be uniform, within 1/4 inch, for each flight of stairs.
..1926.451(e)(5)
1926.451(e)(5) Ramps and walkways.
1926.451(e)(5)(i) Ramps and walkways 6 feet (1.8 m) or more above lower levels shall have guardrail systems which
comply with subpart M of this part -- Fall Protection;
1926.451(e)(5)(ii) No ramp or walkway shall be inclined more than a slope of one (1) vertical to three (3)
horizontal (20 degrees above the horizontal).
1926.451(e)(5)(iii) If the slope of a ramp or a walkway is steeper than one (1) vertical in eight (8) horizontal,
the ramp or walkway shall have cleats not more than fourteen (14) inches (35 cm) apart which are securely fastened to the planks to provide
footing.
1926.451(e)(6) Integral prefabricated scaffold access frames shall:
1926.451(e)(6)(i) Be specifically designed and constructed for use as ladder rungs;
1926.451(e)(6)(ii) Have a rung length of at least 8 inches (20 cm);
1926.451(e)(6)(iii) Not be used as work platforms when rungs are less than 11 1/2 inches in length, unless each
affected employee uses fall protection, or a positioning device, which complies with 1926.502;
1926.451(e)(6)(iv) Be uniformly spaced within each frame section;
..1926.451(e)(6)(v)
1926.451(e)(6)(v) Be provided with rest platforms at 35-foot (10.7 m) maximum vertical intervals on all supported
scaffolds more than 35 feet (10.7 m) high; and
1926.451(e)(6)(vi) Have a maximum spacing between rungs of 16 3/4 inches (43 cm). Non-uniform rung spacing caused
by joining end frames together is allowed, provided the resulting spacing does not exceed 16 3/4 inches (43 cm).
1926.451(e)(7) Steps and rungs of ladder and stairway type access shall line up vertically with each other between
rest platforms.
1926.451(e)(8) Direct access to or from another surface shall be used only when the scaffold is not more than 14
inches (36 cm) horizontally and not more than 24 inches (61 cm) vertically from the other surface.
1926.451(e)(9) Effective September 2, 1997, access for employees erecting or dismantling supported scaffolds shall
be in accordance with the following:
..1926.451(e)(9)(i)
1926.451(e)(9)(i) The employer shall provide safe means of access for each employee erecting or dismantling a
scaffold where the provision of safe access is feasible and does not create a greater hazard. The employer shall have a competent person determine
whether it is feasible or would pose a greater hazard to provide, and have employees use a safe means of access. This determination shall be based on
site conditions and the type of scaffold being erected or dismantled.
1926.451(e)(9)(ii) Hook-on or attachable ladders shall be installed as soon as scaffold erection has progressed to
a point that permits safe installation and use.
1926.451(e)(9)(iii) When erecting or dismantling tubular welded frame scaffolds, (end) frames, with horizontal
members that are parallel, level and are not more than 22 inches apart vertically may be used as climbing devices for access, provided they are
erected in a manner that creates a usable ladder and provides good hand hold and foot space.
1926.451(e)(9)(iv) Cross braces on tubular welded frame scaffolds shall not be used as a means of access or
egress.
1926.451(f) "Use."
1926.451(f)(1) Scaffolds and scaffold components shall not be loaded in excess of their maximum intended loads or
rated capacities, whichever is less.
1926.451(f)(2) The use of shore or lean-to scaffolds is prohibited.
..1926.451(f)(3)
1926.451(f)(3) Scaffolds and scaffold components shall be inspected for visible defects by a competent person
before each work shift, and after any occurrence which could affect a scaffold's structural integrity.
1926.451(f)(4) Any part of a scaffold damaged or weakened such that its strength is less than that required by
paragraph (a) of this section shall be immediately repaired or replaced, braced to meet those provisions, or removed from service until
repaired.
1926.451(f)(5) Scaffolds shall not be moved horizontally while employees are on them, unless they have been
designed by a registered professional engineer specifically for such movement or, for mobile scaffolds, where the provisions of 1926.452(w) are
followed.
1926.451(f)(6) The clearance between scaffolds and power lines shall be as follows: Scaffolds shall not be erected,
used, dismantled, altered, or moved such that they or any conductive material handled on them might come closer to exposed and energized power lines
than as follows:
*Insulated Lines
_____________________________________________________________________
| |
Voltage | Minimum distance | Alternatives
____________________|________________________|_______________________
| |
Less than 300 volts.| 3 feet (0.9 m) |
300 volts to 50 kv.| 10 feet (3.1 m) |
More than 50 kv.....| 10 feet (3.1 m) plus | 2 times the length
| 0.4 inches (1.0 cm) | of the line
| for each 1 kv over | insulator, but never
| 50 kv. | less than 10
| | feet (3.1 m).
____________________|________________________|_______________________
*Uninsulated lines
_____________________________________________________________________
| |
Voltage | Minimum distance | Alternatives
____________________|________________________|_______________________
| |
Less than 50 kv.....| 10 feet (3.1 m). |
More than 50 kv.....| 10 feet (3.1 m) plus | 2 times the length of
| 0.4 inches (1.0 cm) | the line insulator,
| for each 1 kv over | but never less than
| 50 kv. | 10 feet (3.1 m).
____________________|________________________|_______________________
Exception to paragraph (f)(6): Scaffolds and materials may be closer to power lines than specified above where such clearance is necessary
for performance of work, and only after the utility company, or electrical system operator, has been notified of the need to work closer and the
utility company, or electrical system operator, has deenergized the lines, relocated the lines, or installed protective coverings to prevent
accidental contact with the lines.
1926.451(f)(7) Scaffolds shall be erected, moved, dismantled, or altered only under the supervision and direction
of a competent person qualified in scaffold erection, moving, dismantling or alteration. Such activities shall be performed only by experienced and
trained employees selected for such work by the competent person.
..1926.451(f)(8)
1926.451(f)(8) Employees shall be prohibited from working on scaffolds covered with snow, ice, or other slippery
material except as necessary for removal of such materials.
1926.451(f)(9) Where swinging loads are being hoisted onto or near scaffolds such that the loads might contact the
scaffold, tag lines or equivalent measures to control the loads shall be used.
1926.451(f)(10) Suspension ropes supporting adjustable suspension scaffolds shall be of a diameter large enough to
provide sufficient surface area for the functioning of brake and hoist mechanisms.
1926.451(f)(11) Suspension ropes shall be shielded from heat-producing processes. When acids or other corrosive
substances are used on a scaffold, the ropes shall be shielded, treated to protect against the corrosive substances, or shall be of a material that
will not be damaged by the substance being used.
1926.451(f)(12) Work on or from scaffolds is prohibited during storms or high winds unless a competent person has
determined that it is safe for employees to be on the scaffold and those employees are protected by a personal fall arrest system or wind screens.
Wind screens shall not be used unless the scaffold is secured against the anticipated wind forces imposed.
1926.451(f)(13) Debris shall not be allowed to accumulate on platforms.
..1926.451(f)(14)
1926.451(f)(14) Makeshift devices, such as but not limited to boxes and barrels, shall not be used on top of
scaffold platforms to increase the working level height of employees.
1926.451(f)(15) Ladders shall not be used on scaffolds to increase the working level height of employees, except on
large area scaffolds where employers have satisfied the following criteria:
1926.451(f)(15)(i) When the ladder is placed against a structure which is not a part of the scaffold, the scaffold
shall be secured against the sideways thrust exerted by the ladder;
1926.451(f)(15)(ii) The platform units shall be secured to the scaffold to prevent their movement;
1926.451(f)(15)(iii) The ladder legs shall be on the same platform or other means shall be provided to stabilize
the ladder against unequal platform deflection, and
1926.451(f)(15)(iv) The ladder legs shall be secured to prevent them from slipping or being pushed off the
platform.
1926.451(f)(16) Platforms shall not deflect more than 1/60 of the span when loaded.
1926.451(f)(17) To reduce the possibility of welding current arcing through the suspension wire rope when
performing welding from suspended scaffolds, the following precautions shall be taken, as applicable:
..1926.451(f)(17)(i)
1926.451(f)(17)(i) An insulated thimble shall be used to attach each suspension wire rope to its hanging support
(such as cornice hook or outrigger). Excess suspension wire rope and any additional independent lines from grounding shall be insulated;
1926.451(f)(17)(ii) The suspension wire rope shall be covered with insulating material extending at least 4 feet
(1.2 m) above the hoist. If there is a tail line below the hoist, it shall be insulated to prevent contact with the platform. The portion of the tail
line that hangs free below the scaffold shall be guided or retained, or both, so that it does not become grounded;
1926.451(f)(17)(iii) Each hoist shall be covered with insulated protective covers;
1926.451(f)(17)(iv) In addition to a work lead attachment required by the welding process, a grounding conductor
shall be connected from the scaffold to the structure. The size of this conductor shall be at least the size of the welding process work lead, and
this conductor shall not be in series with the welding process or the work piece;
1926.451(f)(17)(v) If the scaffold grounding lead is disconnected at any time, the welding machine shall be shut
off; and
1926.451(f)(17)(vi) An active welding rod or uninsulated welding lead shall not be allowed to contact the scaffold
or its suspension system.
..1926.451(g)
1926.451(g) "Fall protection."
1926.451(g)(1) Each employee on a scaffold more than 10 feet (3.1 m) above a lower level shall be protected from
falling to that lower level. Paragraphs (g)(1)(i) through (vii) of this section establish the types of fall protection to be provided to the employees
on each type of scaffold. Paragraph (g)(2) of this section addresses fall protection for scaffold erectors and dismantlers.
Note to paragraph (g)(1): The fall protection requirements for employees installing suspension scaffold support systems on floors, roofs,
and other elevated surfaces are set forth in subpart M of this part.
1926.451(g)(1)(i) Each employee on a boatswains' chair, catenary scaffold, float scaffold, needle beam scaffold, or
ladder jack scaffold shall be protected by a personal fall arrest system;
1926.451(g)(1)(ii) Each employee on a single-point or two-point adjustable suspension scaffold shall be protected
by both a personal fall arrest system and guardrail system;
1926.451(g)(1)(iii) Each employee on a crawling board (chicken ladder) shall be protected by a personal fall arrest
system, a guardrail system (with minimum 200 pound toprail capacity), or by a three-fourth inch (1.9 cm) diameter grabline or equivalent handhold
securely fastened beside each crawling board;
1926.451(g)(1)(iv) Each employee on a self-contained adjustable scaffold shall be protected by a guardrail system
(with minimum 200 pound toprail capacity) when the platform is supported by the frame structure, and by both a personal fall arrest system and a
guardrail system (with minimum 200 pound toprail capacity) when the platform is supported by ropes;
..1926.451(g)(1)(v)
1926.451(g)(1)(v) Each employee on a walkway located within a scaffold shall be protected by a guardrail system
(with minimum 200 pound toprail capacity) installed within 9 1/2 inches (24.1 cm) of and along at least one side of the walkway.
1926.451(g)(1)(vi) Each employee performing overhand bricklaying operations from a supported scaffold shall be
protected from falling from all open sides and ends of the scaffold (except at the side next to the wall being laid) by the use of a personal fall
arrest system or guardrail system (with minimum 200 pound toprail capacity).
1926.451(g)(1)(vii) For all scaffolds not otherwise specified in paragraphs (g)(1)(i) through (g)(1)(vi) of this
section, each employee shall be protected by the use of personal fall arrest systems or guardrail systems meeting the requirements of paragraph (g)(4)
of this section.
1926.451(g)(2) Effective September 2, 1997, the employer shall have a competent person determine the feasibility
and safety of providing fall protection for employees erecting or dismantling supported scaffolds. Employers are required to provide fall protection
for employees erecting or dismantling supported scaffolds where the installation and use of such protection is feasible and does not create a greater
hazard.
..1926.451(g)(3)
1926.451(g)(3) In addition to meeting the requirements of 1926.502(d), personal fall arrest systems used on
scaffolds shall be attached by lanyard to a vertical lifeline, horizontal lifeline, or scaffold structural member. Vertical lifelines shall not be
used when overhead components, such as overhead protection or additional platform levels, are part of a single-point or two-point adjustable
suspension scaffold.
1926.451(g)(3)(i) When vertical lifelines are used, they shall be fastened to a fixed safe point of anchorage,
shall be independent of the scaffold, and shall be protected from sharp edges and abrasion. Safe points of anchorage include structural members of
buildings, but do not include standpipes, vents, other piping systems, electrical conduit, outrigger beams, or counterweights.
1926.451(g)(3)(ii) When horizontal lifelines are used, they shall be secured to two or more structural members of
the scaffold, or they may be looped around both suspension and independent suspension lines (on scaffolds so equipped) above the hoist and brake
attached to the end of the scaffold. Horizontal lifelines shall not be attached only to the suspension ropes.
1926.451(g)(3)(iii) When lanyards are connected to horizontal lifelines or structural members on a single-point or
two-point adjustable suspension scaffold, the scaffold shall be equipped with additional independent support lines and automatic locking devices
capable of stopping the fall of the scaffold in the event one or both of the suspension ropes fail. The independent support lines shall be equal in
number and strength to the suspension ropes.
..1926.451(g)(3)(iv)
1926.451(g)(3)(iv) Vertical lifelines, independent support lines, and suspension ropes shall not be attached to
each other, nor shall they be attached to or use the same point of anchorage, nor shall they be attached to the same point on the scaffold or personal
fall arrest system.
1926.451(g)(4) Guardrail systems installed to meet the requirements of this section shall comply with the following
provisions (guardrail systems built in accordance with Appendix A to this subpart will be deemed to meet the requirements of paragraphs (g)(4)(vii),
(viii), and (ix) of this section):
1926.451(g)(4)(i) Guardrail systems shall be installed along all open sides and ends of platforms. Guardrail
systems shall be installed before the scaffold is released for use by employees other than erection/dismantling crews.
1926.451(g)(4)(ii) The top edge height of toprails or equivalent member on supported scaffolds manufactured or
placed in service after January 1, 2000 shall be installed between 38 inches (0.97 m) and 45 inches (1.2 m) above the platform surface. The top edge
height on supported scaffolds manufactured and placed in service before January 1, 2000, and on all suspended scaffolds where both a guardrail and a
personal fall arrest system are required shall be between 36 inches (0.9 m) and 45 inches (1.2 m). When conditions warrant, the height of the top edge
may exceed the 45-inch height, provided the guardrail system meets all other criteria of paragraph (g)(4).
..1926.451(g)(4)(iii)
1926.451(g)(4)(iii) When midrails, screens, mesh, intermediate vertical members, solid panels, or equivalent
structural members are used, they shall be installed between the top edge of the guardrail system and the scaffold platform.
1926.451(g)(4)(iv) When midrails are used, they shall be installed at a height approximately midway between the top
edge of the guardrail system and the platform surface.
1926.451(g)(4)(v) When screens and mesh are used, they shall extend from the top edge of the guardrail system to
the scaffold platform, and along the entire opening between the supports.
1926.451(g)(4)(vi) When intermediate members (such as balusters or additional rails) are used, they shall not be
more than 19 inches (48 cm) apart.
1926.451(g)(4)(vii) Each toprail or equivalent member of a guardrail system shall be capable of withstanding,
without failure, a force applied in any downward or horizontal direction at any point along its top edge of at least 100 pounds (445 n) for guardrail
systems installed on single-point adjustable suspension scaffolds or two-point adjustable suspension scaffolds, and at least 200 pounds (890 n) for
guardrail systems installed on all other scaffolds.
1926.451(g)(4)(viii) When the loads specified in paragraph (g)(4)(vii) of this section are applied in a downward
direction, the top edge shall not drop below the height above the platform surface that is prescribed in paragraph (g)(4)(ii) of this
section.
..1926.451(g)(4)(ix)
1926.451(g)(4)(ix) Midrails, screens, mesh, intermediate vertical members, solid panels, and equivalent structural
members of a guardrail system shall be capable of withstanding, without failure, a force applied in any downward or horizontal direction at any point
along the midrail or other member of at least 75 pounds (333 n) for guardrail systems with a minimum 100 pound toprail capacity, and at least 150
pounds (666 n) for guardrail systems with a minimum 200 pound toprail capacity.
1926.451(g)(4)(x) Suspension scaffold hoists and non-walk-through stirrups may be used as end guardrails, if the
space between the hoist or stirrup and the side guardrail or structure does not allow passage of an employee to the end of the scaffold.
1926.451(g)(4)(xi) Guardrails shall be surfaced to prevent injury to an employee from punctures or lacerations, and
to prevent snagging of clothing.
1926.451(g)(4)(xii) The ends of all rails shall not overhang the terminal posts except when such overhang does not
constitute a projection hazard to employees.
1926.451(g)(4)(xiii) Steel or plastic banding shall not be used as a toprail or midrail.
1926.451(g)(4)(xiv) Manila or plastic (or other synthetic) rope being used for toprails or midrails shall be
inspected by a competent person as frequently as necessary to ensure that it continues to meet the strength requirements of paragraph (g) of this
section.
..1926.451(g)(4)(xv)
1926.451(g)(4)(xv) Crossbracing is acceptable in place of a midrail when the crossing point of two braces is
between 20 inches (0.5 m) and 30 inches (0.8 m) above the work platform or as a toprail when the crossing point of two braces is between 38 inches
(0.97 m) and 48 inches (1.3 m) above the work platform. The end points at each upright shall be no more than 48 inches (1.3 m) apart.
1926.451(h) "Falling object protection."
1926.451(h)(1) In addition to wearing hardhats each employee on a scaffold shall be provided with additional
protection from falling hand tools, debris, and other small objects through the installation of toeboards, screens, or guardrail systems, or through
the erection of debris nets, catch platforms, or canopy structures that contain or deflect the falling objects. When the falling objects are too
large, heavy or massive to be contained or deflected by any of the above-listed measures, the employer shall place such potential falling objects away
from the edge of the surface from which they could fall and shall secure those materials as necessary to prevent their falling.
1926.451(h)(2) Where there is a danger of tools, materials, or equipment falling from a scaffold and striking
employees below, the following provisions apply:
1926.451(h)(2)(i) The area below the scaffold to which objects can fall shall be barricaded, and employees shall
not be permitted to enter the hazard area; or
..1926.451(h)(2)(ii)
1926.451(h)(2)(ii) A toeboard shall be erected along the edge of platforms more than 10 feet (3.1 m) above lower
levels for a distance sufficient to protect employees below, except on float (ship) scaffolds where an edging of 3/4 x 1 1/2 inch (2 x 4 cm) wood or
equivalent may be used in lieu of toeboards;
1926.451(h)(2)(iii) Where tools, materials, or equipment are piled to a height higher than the top edge of the
toeboard, paneling or screening extending from the toeboard or platform to the top of the guardrail shall be erected for a distance sufficient to
protect employees below; or
1926.451(h)(2)(iv) A guardrail system shall be installed with openings small enough to prevent passage of potential
falling objects; or
1926.451(h)(2)(v) A canopy structure, debris net, or catch platform strong enough to withstand the impact forces of
the potential falling objects shall be erected over the employees below.
1926.451(h)(3) Canopies, when used for falling object protection, shall comply with the following
criteria:
1926.451(h)(3)(i) Canopies shall be installed between the falling object hazard and the employees.
..1926.451(h)(3)(ii)
1926.451(h)(3)(ii) When canopies are used on suspension scaffolds for falling object protection, the scaffold shall
be equipped with additional independent support lines equal in number to the number of points supported, and equivalent in strength to the strength of
the suspension ropes.
1926.451(h)(3)(iii) Independent support lines and suspension ropes shall not be attached to the same points of
anchorage.
1926.451(h)(4) Where used, toeboards shall be:
1926.451(h)(4)(i) Capable of withstanding, without failure, a force of at least 50 pounds (222 n) applied in any
downward or horizontal direction at any point along the toeboard (toeboards built in accordance with Appendix A to this subpart will be deemed to meet
this requirement); and
1926.451(h)(4)(ii) At least three and one-half inches (9 cm) high from the top edge of the toeboard to the level of
the walking/working surface. Toeboards shall be securely fastened in place at the outermost edge of the platform and have not more than 1/4 inch (0.7
cm) clearance above the walking/working surface. Toeboards shall be solid or with openings not over one inch (2.5 cm) in the greatest
dimension.
[44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 58 FR 35182 and 35310, June 30, 1993; 61 FR 46025, Aug. 30 1996; 61 FR
59831, Nov. 25, 1996]
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