# Safety Standards for Scaffolds Used in the Construction Industry

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URL: https://www.frixlaw.com/law-library/documents/fr%3A96-21289

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** August 30, 1996
- **Citation:** 61 FR 46026

## Text

SUMMARY: The Occupational Safety and Health Administration (OSHA)
hereby revises the construction industry safety standards which
regulate the design, construction, and use of scaffolds. The final rule
updates the existing scaffold standards and sets performance-oriented
criteria, where possible, to protect employees from scaffold-related
hazards such as falls, falling objects, structural instability,
electrocution and overloading.
In particular, the final rule has been updated to address types of
scaffolds--such as catenary scaffolds, step and trestle ladder
scaffolds, and multi-level suspended scaffolds--not covered by OSHA's
existing scaffold standards. In addition, the final rule allows
employers greater flexibility in the use of fall protection systems to
protect employees working on scaffolds and extends fall protection to
erectors and dismantlers of scaffolds to the extent feasible. Another
area that the final rule strengthens is training for workers using
scaffolds; the conditions under which such employees must be retrained
are also specified in the final rule. Finally, the language of the rule
has been simplified, duplicative and outdated provisions have been
eliminated, overlapping requirements have been consolidated, and the
performance orientation of the rule has been enhanced to allow
employers as much flexibility in compliance as is consistent with
employee protection.

DATES: Effective dates. This standard will become effective on November
29, 1996, except for Sec. 1926.453(a)(2), which will not become
effective until an Office of Management and Budget (OMB) Control number
is received and displayed for this ``collection of information'' in
accordance with the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et
seq.). OSHA will publish a document in the Federal Register announcing
the effective date of Sec. 1926.453(a)(2).
Incorporation by reference. The incorporations by reference of
certain publications listed in this final rule are approved by the
Director of the Federal Register as of November 29, 1996.
Compliance date: Employers are required to comply with the
provisions of paragraphs (e)(9) and (g)(2) of Sec. 1926.451, which
address safe access and fall protection, respectively, for employees
erecting and dismantling supported scaffolds starting on September 2,
1997.
Comments. Written comments on the paperwork requirements of this
final rule must be submitted on or before October 29, 1996.

ADDRESSES: In compliance with 28 U.S.C. 2112(a), the Agency designates
for receipt of petitions for review of the standard, the Associate
Solicitor for Occupational Safety and Health, Office of the Solicitor,
Room S-4004, U.S. Department of Labor, 200 Constitution Avenue, N.W.,
Washington, D.C. 20210.
Suggestions and information regarding the drafting of non-mandatory
Appendix B, ``Criteria for Determining the Feasibility of Providing
Fall Protection and Safe Access for Workers Erecting or Dismantling
Supported Scaffolds'' should be submitted to the Docket Officer, Docket
S-205, U.S. Department of Labor, Room N-2625, 200 Constitution Avenue,
NW., Washington, D.C. 20210.

FOR FURTHER INFORMATION CONTACT: Ms. Anne C. Cyr, Occupational Safety
and Health Administration, Office of Information and Public Affairs,
Room N-3647, U.S. Department of Labor, 200 Constitution Avenue, N.W.,
Washington, D.C. 20210, Telephone: (202) 219-8148.

SUPPLEMENTARY INFORMATION:

I. Background

Congress amended the Contract Work Hours Standards Act (40 U.S.C.
327 et seq.) in 1969 by adding a new section 107 (40 U.S.C. 333) to
provide employees in the construction industry with a safer work
environment and to reduce the frequency and severity of construction
accidents and injuries. The amendment, commonly known as the
Construction Safety Act (CSA), significantly strengthened employee
protection by authorizing the promulgation of construction safety and
health standards for employees of the building trades and construction
industry working on federal and federally-financed or federally-
assisted construction projects. Accordingly, the Secretary of Labor
issued Safety and Health Regulations for Construction in 29 CFR part
1518 (36 FR 7340, April 17, 1971).
The Occupational Safety and Health Act of 1970 (the OSH Act) (29
U.S.C. 651 et seq.) authorized the Secretary of Labor to adopt
established federal standards issued under other statutes, including
the CSA, as occupational safety and health standards. Accordingly, the
Secretary of Labor adopted the Construction Standards, which had been
issued under the CSA, as OSHA standards (36 FR 10466, May 29, 1971).
The Safety and Health Regulations for Construction were subsequently
redesignated as 29 CFR part 1926 (36 FR 25232, December 30, 1971).
Standards addressing scaffolds, Secs. 1926.451 and 1926.452, were
adopted in subpart L of part 1926 as OSHA standards as part of this
process.
Various amendments were made to subpart L during the first two
years of the OSH Act. The amendments revised scaffold provisions that
addressed planking grades, wood pole scaffold construction, overhead
protection, bracket scaffold loading, and plank spans. Also,
substantive provisions concerning pump jack scaffolds, height of catch
platforms, and guardrails were added (37 FR 25712, December 2, 1972).
Based on concerns regarding the effectiveness of the existing
scaffold standards, OSHA began a complete review of subpart L in 1977.
The Agency consulted the Advisory Committee on Construction Safety and
Health (ACCSH) several times regarding draft revisions to subpart L.
The transcripts of these meetings are part of the public record for
this rulemaking (Ex. 3-4). OSHA addresses specific recommendations from
the ACCSH, as well as those submitted by other rulemaking participants,
in the Summary and Explanation section, below.
On November 25, 1986, OSHA issued a notice of proposed rulemaking
(NPRM) on scaffolds used in construction (51 FR 42680). The proposal
set a period, ending February 23, 1987, during which interested parties
could submit written comments or request a hearing. The Agency twice
granted requests for more time to submit comments and hearing requests.
OSHA first extended the comment and hearing request period to June 1,
1987 (52 FR 5790, February 26, 1987) and then extended that period to
August 14, 1987 (52 FR 20616, June 2, 1987). OSHA received 602 comments
on the proposal, along with several hearing requests.
On January 26, 1988, OSHA announced that it would convene an
informal public hearing on March 22, 1988 to elicit additional
information on

[[Page 46027]]

specific issues related to scaffolds, fall protection and stairways and
ladders (53 FR 2048). The informal public hearing was held on March 22-
23, 1988, with Administrative Law Judge Joel Williams presiding. At the
close of the hearing, Judge Williams set a period, ending May 9, 1988,
for the submission of additional comments and information. OSHA
received 31 submissions, including testimony and documentary evidence,
in response to the hearing notice. On August 11, 1988, Judge Williams
certified the rulemaking record, including the hearing transcript and
all written submissions to the docket, thereby closing the record for
this proceeding.
In 1988, the American National Standards Institute (ANSI), an
organization which sets voluntary consensus standards, approved a
revision of ANSI A10.8-1977, Scaffolding, updating its safety
requirements for the use of scaffolds in construction and demolition
operations. Section 6(b)(8) of the OSH Act requires that when an OSHA
standard differs substantially from an existing national consensus
standard, the Secretary must publish ``a statement of the reasons why
the rule as adopted will better effectuate the purposes of the Act than
the national consensus standard.'' In compliance with that requirement,
OSHA has reviewed the requirements of this final rule with reference to
the corresponding provisions of ANSI A10.8-1988. The Agency discusses
the relationship between the provisions of subpart L and corresponding
provisions of ANSI A10.8-1988 in the Summary and Explanation, below.
On March 29, 1993, OSHA reopened the rulemaking record for subpart
L (58 FR 16509) to obtain additional comments and information regarding
fall protection and safe means of access for employees erecting and
dismantling scaffolds; the use of crossbraces in scaffold systems; and
the use of repair bracket scaffolds. The comment period was scheduled
to end on May 28, 1993. On May 26, 1993, the Agency extended the
comment period (58 FR 30131) to June 29, 1993, in response to a request
for additional time to submit comments. OSHA received 46 comments in
response to the March 29 notice. Those comments are discussed below in
relation to the pertinent provisions of the final rule.
On February 1, 1994, OSHA again reopened the rulemaking record (59
FR 4615) to obtain comments and information regarding scaffold
stairways; repair bracket scaffolds; tank builder scaffolds; a NIOSH
study of workplace fatalities; and scaffold-related material
incorporated from the proposed part 1910, subpart D rulemaking. The
comment period, which ended on March 18, 1994, elicited 46 comments.
Those comments are also discussed below in relation to the pertinent
provisions of the final rule.
A wide range of employers, businesses, labor unions, trade
associations, state governments, and other interested parties
contributed to the development of this record. OSHA appreciates these
efforts to help develop a rulemaking record that provides a sound basis
for the promulgation of revised subpart L.
Based on its review of existing subpart L, OSHA believes that
certain provisions in the existing standards are outdated, redundant,
or ambiguous. In addition, some types of scaffolds used in construction
(e.g., catenary scaffolds) are not clearly addressed by the existing
standards, and some provisions cover only certain types of scaffolds
when they should apply to all. The final rule eliminates those
unnecessary, outdated and redundant provisions (e.g., revised subpart L
states the requirement for guardrails once, rather than 19 separate
times as in the existing standard).
OSHA is coordinating the revision of part 1926, subpart L, with the
ongoing rulemakings initiated to revise the General Industry (part
1910, subpart D) and Shipyard (part 1915, subpart N) scaffold
standards, so that those standards will be consistent, where
appropriate.

II. Hazards Involved

Scaffold-related incidents resulting in injuries and fatalities
continue to occur despite the fact that OSHA has had a scaffold
standard (existing subpart L) in place since 1971 (Exs. 1, 2, 3, 42,
43, 44 and 45). However, the Agency believes that compliance with the
standard being published today will be better than it has been in the
past because this standard has been simplified, brought up to date, and
strengthened to provide additional protection.
Although specific accident ratios cannot be projected for the
estimated 3.6 million construction workers currently covered by subpart
L, the Economic Analysis that accompanies this final rule estimates
that, of the 510,500 injuries and illnesses that occur in the
construction industry annually, 9,750 are related to scaffolds. In
addition, of the estimated 924 occupational fatalities occurring
annually, at least 79 are associated with work on scaffolds.
OSHA prepared the following statistical estimates (based on 4.5
million construction workers then covered by subpart L) to support the
1986 proposal for subpart L, based on a review of accident data
prepared by the Bureau of Labor Statistics (BLS) (Ex. 3-1). The revised
scaffold standards contain a number of provisions designed specifically
to address the findings of this analysis.
a. Seventy-two percent of the workers injured in scaffold accidents
covered by the BLS study attributed the accident either to the planking
or support giving way, or to the employee slipping, or being struck by
a falling object. Plank slippage was the most commonly cited cause.
b. About 70 percent of the workers learned of the safety
requirements for installing work platforms, assembling scaffolds, and
inspecting scaffolds through on-the-job training. Approximately 25
percent had no training in these areas.
c. Only 33 percent of scaffolds were equipped with a guardrail.
The following are recent examples, from the OSHA Integrated
Management Information System (IMIS) data, of the types of accidents
that continue to injure and kill employees working on scaffolds.
In July, 1991, two employees were working on a pump jack
scaffold doing roofing work. The scaffold became overloaded and broke.
The employees fell 12 feet to the ground, resulting in one fatality and
one serious injury.
In August, 1992, two workers were erecting an aluminum
pump jack scaffold. As they were raising the second aluminum pole, the
pole apparently contacted an overhead power line. The pole being raised
was 29 feet 10 inches long and the line was 28 feet 10 inches high. The
line was approximately 11 feet from the house. One employee died and
the other suffered severe burns and was hospitalized. The surviving
employee noted that he thought they had enough room to work around the
power lines, which were not de-energized or shielded.
In July, 1993, a foreman climbed up the frame of a 45 foot
high tubular welded frame scaffold to check on an employee who was
sandblasting inside a stack at a steam plant. The scaffold was not
equipped with guardrails and there was no access ladder. After talking
to the employee, the foreman either fell from the unguarded platform or
fell while climbing down the scaffold end frame, resulting in his
death. There were no witnesses to the fall.
Based on its analysis of the available data and its field
experience in enforcing construction standards, the Agency has
determined that employees using scaffolds are exposed to a

[[Page 46028]]

significant risk of harm. Specifically, scaffold related fatalities
still account for approximately 9% of all fatalities in the
construction workplace. In addition, the above data indicate that the
revised final standard would have prevented many of these accidents
more effectively than compliance with the existing scaffold standards.
Consequently, OSHA finds that the revision of its scaffold standards
for construction is necessary to improve employee protection. OSHA has
determined that, as revised, the standard clearly states employers'
duties and the appropriate compliance measures.
For additional discussion of incidence rates, significance of risk,
and the protectiveness of the final rule, see Section IV, Summary of
the Final Economic Analysis.

III. Summary and Explanation of the Final Rule

The following discussion explains how the final rule corresponds to
or differs from the proposed scaffold standard and the existing
standard, and how the comments and testimony presented on each
provision influenced the drafting of the final rule. Except where
otherwise indicated, proposed provisions which did not elicit comment
have been promulgated as proposed, for reasons stated in the preamble
to the proposed rule which is hereby incorporated by reference (51 FR
42680).
Subpart L--Scaffolds. The title of subpart L of OSHA's Construction
standards has been changed from ``Scaffolding'' to ``Scaffolds'', as
proposed. The word ``scaffold'' is used in the title and throughout the
final rule in lieu of the longer word ``scaffolding.'' This change does
not affect the scope of subpart L. OSHA did not receive any comments
concerning the title of the subpart.
Section 1926.450 Scope, application and definitions applicable to
this subpart. Paragraph (a) of Sec. 1926.450 states the scope and
application of subpart L. The final rule will apply to all scaffolds
used in construction, alteration, repair (including painting and
decorating), and demolition operations covered under 29 CFR part 1926,
except that crane or derrick suspended personnel platforms will
continue to be regulated under Sec. 1926.550(g). Language explicitly
excluding these platforms has been added to the final rule. The
relationship between Sec. 1926.550(g), which covers these platforms,
and subpart L is discussed further in relation to Sec. 1926.451(c)(2)
and NPRM Issue 3, below. In addition, aerial lifts are covered
exclusively in Sec. 1926.453, as noted in paragraph (a) of
Sec. 1926.450. Proposed paragraph (a) covered all scaffolds.
A commenter (Ex. 2-38) recommended that OSHA explicitly exempt
personnel platforms suspended by cranes or derricks from this final
rule. The commenter stated ``[t]his would avoid confusion, both for the
Compliance Officer and the employer.'' As noted above, the Agency
recognizes the need for an exemption and has revised paragraph (a)
accordingly.
Another commenter (Ex. 2-18), representing the elevator industry,
suggested that OSHA revise the scope of proposed subpart L to exclude
``False cars used in elevator construction that are equipped with
independent safeties that operate on the guardrails * * *'' The
commenter supported the suggestion as follows: ``An elevator false car
operates on fixed guiderails * * * equipped with safeties that ride on
the guiderails * * * and are operated automatically by the slackening
of the hoisting rope. Past OSHRC (Occupational Safety and Health Review
Commission) decisions have recognized that a false car is a unique tool
and is not a scaffold.'' The commenter did not cite any specific OSHRC
decisions to support its assertion.
OSHA disagrees with this commenter on this point, because the
findings in two enforcement cases involving the Otis Elevator Company
(12 OSHRC 1470 and 12 OSHRC 1513 (1985)) clearly indicate that the
scaffold standards of subpart L cover false cars. In Otis Elevator
Company, 12 OSHRC 1513 (1985), the final order stated:

The evidence in this case showed that the false cars were used
as elevated working space from which employees installed permanent
elevator rails. The ability to raise and lower the false cars by
means of cables from overhead supports does not remove false cars
from the applicability of the scaffold standard, and a false car is
found to be a scaffold within the meaning of 29 CFR 1926.452(b)(27).

The Agency notes that elevator false cars fit the definition of a
``scaffold'' in final rule Sec. 1926.450(b) in that they are temporary
elevated work platforms used for supporting employees. Accordingly,
there are no apparent grounds for disputing that elevator false cars
are properly regulated under part 1926, subpart L. Therefore, OSHA will
continue to regulate temporary elevated work platforms, such as false
cars and go-devils used in elevator shaft construction, as scaffolds.
The Scaffolding, Shoring and Forming Institute (SSFI) (Ex. 2-367)
recommended that OSHA include ``Window cleaning'' within the scope of
subpart L, because ``[w]indow cleaning is a common activity that, for
the overwhelming majority of instances, uses transportable suspended
scaffolds.'' In addition, the Scaffold Industry Association (SIA) (Ex.
2-368) suggested that OSHA add ``scheduled and unscheduled maintenance
(including but not limited to painting and decorating, tuck pointing,
sand blasting, water proofing and window cleaning)'' to the scope of
subpart L, because maintenance is a type of work ``regularly performed
on scaffolds addressed in this subpart and, therefore, should be
included in the scope.''
Another commenter (Ex. 2-462) stated that expanding the scope of
subpart L to include maintenance would create confusion and ``would
greatly reduce the safety standard already in place for Powered
platforms for exterior building maintenance'' (29 CFR 1910.66).
The Agency is not expanding the scope to include building
maintenance because building maintenance (such as window cleaning) is a
general industry activity, addressed under the appropriate scaffold and
powered platform standards of 29 CFR part 1910.
OSHA received a general comment (Ex. 2-29) which noted that
Sec. 1910.66 addressed powered platforms used for exterior building
maintenance in general industry and urged OSHA to ensure that the
corresponding regulatory language in the construction standard for
scaffolds was consistent. As discussed above, the Agency agrees, and is
coordinating its General Industry, Shipyard and Construction rulemaking
activity so that employers in those industries have consistent
regulation, to the extent that workplace conditions permit.
Paragraph (b) of Sec. 1926.450 lists and defines all major terms
used in subpart L. Proposed terms and definitions which elicited no
comments and which have been promulgated unchanged or with only minor
editorial revisions are not addressed below. Those terms include
``adjustable suspension scaffold'', ``boatswains' chair'', ``body
belt'', ``body harness'', `` brace'', ``cleat'', ``coupler'',
``crawling board'', ``double pole scaffold'', ``exposed power lines'',
``fabricated decking and planking'', ``float (ship) scaffold'', ``form
scaffold'', ``hoist'', ``interior hung scaffold'', ``ladder stand'',
``lean-to scaffold'', ``lower level'', ``mobile scaffold'', ``multi-
level suspension scaffold'', ``multi-point adjustable scaffold'',
``open sides and edges'', ``overhand bricklaying'', ``platform'',
``pole scaffold'', ``pump jack scaffolds'', ``roof bracket scaffold'',
``runner'', ``self-

[[Page 46029]]

contained adjustable scaffold'', ``shore scaffold'', ``single-point
adjustable suspension scaffold'', ``single pole scaffold'', ``step
platform and trestle ladder scaffold'', ``stone setter multi-point
adjustable suspension scaffold'', ``supported scaffold'', ``suspension
scaffold'', ``tube and coupler scaffolds'', ``tubular welded frame
scaffold'', ``two-point suspension scaffold'', ``unstable objects'',
``vertical pickup'', ``walkway'', and ``window jack scaffold''.
As proposed, OSHA is revising its definitions for particular types
of scaffolds by specifying whether a particular type of scaffold is a
``supported'' or a ``suspension scaffold.'' OSHA believes that adding
this information will make it easier for employers to identify the
appropriate general requirements in final rule Sec. 1926.451.
In addition, the Agency has revised subpart L definitions by
deleting language that limits the use of a particular type of scaffold.
Such substantive limitations are more appropriately placed in
regulatory text. Accordingly, for example, OSHA has revised the
definition for ``bricklayers' square scaffolds'' (a scaffold composed
of framed wood squares which support a platform, limited to light and
medium duty) by deleting the words ``limited to light and medium
duty''. Similarly, OSHA has revised the definition for ``coupler'' to
be ``a device for locking together the component tubes of a tube and
coupler scaffold'', deleting language addressing the material used for
the coupler because such requirements are more properly located in
Secs. 1926.451 or 1926.452.
The following discussion covers the terms for which definitions are
being added or revised in this final rule and those proposed terms
which elicited comments.
``Bearer (Putlog).'' This definition is the same as the definition
proposed except that the word ``Putlog,'' an industry-used term, has
been added to the definition. A commenter (Ex. 2-29) suggested putlog
should be included in the proposed definition ``to show a close or
synonymous relationship to the term `bearer' '' and because ``it is a
widely used and understood term.'' The Agency agrees with the commenter
and has revised the proposed definition accordingly.
``Bricklayers' Square Scaffold'' is defined in existing
Sec. 1926.452(b) and the proposed definition is substantively unchanged
in the final rule. The definition deletes the existing Sec. 1926.452(b)
requirements that bricklayers' square scaffolds be constructed of
``wood'' and that the platform capacity be limited to ``light and
medium duty.'' The revised definition recognizes that bricklayers'
square scaffolds can be constructed of materials other than ``wood''
and that their capacity is not limited to ``light and medium duty'' as
long as they can meet the capacity requirements set forth in final rule
Sec. 1926.451(a)(1).
A commenter (Ex. 2-23) suggested that OSHA adopt the ANSI A10.8-
1977 definition for Bricklayers' Square Scaffold which specifies the
use of ``wood'' and the ability to sustain light to medium loads. As
stated above, OSHA believes it would be inappropriate to limit
technological advances that would provide for the use of other
materials with greater capacities. Therefore, the Agency has not made
the suggested revision.
``Carpenters' bracket scaffold.'' This term means a supported
scaffold consisting of a platform supported by brackets attached to
building or structural walls. The final rule is identical to the
proposal. The SIA (Ex. 2-368) suggested that because different trades
(i.e., cement finishers) use this type scaffold, the term be renamed
``bracket scaffold'' exclusively. OSHA recognizes that this type of
scaffold is used by several trade groups. However, OSHA believes that
it is widely recognized in the construction industry that ``carpenters'
bracket scaffolds'' are not used only by carpenters. Therefore, the
Agency is not making the suggested revision.
``Catenary scaffold.'' This type of scaffold is not specifically
addressed in OSHA's existing rule but is covered in final rule
Sec. 1926.452(r). This term refers to a suspension scaffold consisting
of a platform supported by two essentially horizontal and parallel
ropes which are secured to structural members and may be supported by
vertical pickups. The proposed definition has been changed to replace
the language ``fastened to'' with ``supported by'' and a phrase has
been added explaining that horizontal ropes ``may be supported by
vertical pickups.''
One commenter (Ex. 2-23) suggested that OSHA insert the word
``wire'' between the words ``parallel'' and ``rope.''
However, OSHA does not intend to restrict the type of material used
for suspension scaffold rope as long as it is ``capable of supporting
without failure six times the maximum intended load'' as set forth in
final rule Sec. 1926.451(a)(3).
Two commenters (Exs. 2-23 and 2-368) suggested OSHA replace the
words ``fastened to'' with ``supported by'' in this definition. OSHA
agrees that the suggested words more accurately describe the function
of the horizontal ropes with relation to the platform and is revising
the proposed definition accordingly.
In addition, the SIA (Ex. 2-368) suggested that OSHA add the phrase
``and may be supported by vertical pickups''. OSHA agrees with the
commenter. Vertical pick-ups can act as supports for sagging horizontal
ropes. Also, because final rule Sec. 1926.452(r)(1) refers to vertical
pickups, OSHA believes that it is appropriate to include this phrase in
the definitions.
``Chimney hoist.'' This term is being added to recognize a specific
type of multi-point adjustable suspension scaffold used to gain access
to worksites inside chimneys.
``Competent person.'' This term is being added to the final rule as
a matter of convenience for users. The definition is identical to that
found in Sec. 1926.32.
``Continuous run scaffold (run scaffold)'' means a two-point or
multi-point adjustable suspension scaffold constructed using a series
of interconnected braced scaffold members or supporting structures
erected to form a continuous scaffold. This term is being added to
recognize this type of system. The Agency notes that the key element
here is that the scaffold members must be interconnected so that the
erected scaffold acts as a single unit. This would preclude planking
across two independent scaffolds without joining them so the resulting
scaffold acts as one unit. This system allows erecting a lengthy
scaffold without requiring a continuous planked platform, as long as
the smaller platform is properly guarded.
``Deceleration device.'' This term means any mechanism, such as a
rope grab, rip stitch lanyard, specially-woven lanyard, tearing or
deforming lanyard, automatic self-retracting lifelines/lanyard, 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. The proposed definition, which was effectively identical,
has been editorially revised for the sake of clarity.
Three commenters (Exs. 2-13, 2-368 and 2-516) suggested that rope
grabs and some self-retracting lifelines are not ``deceleration
devices'' but are actually fall arrest devices. OSHA notes, however,
that it is difficult to differentiate clearly between system
components, as suggested, because fall arrest (stopping) and energy
absorption (braking) are closely related. The Agency also observes that
the performance criteria for personal fall arrest equipment address the
entire system, not just ``fall arresters'' or

[[Page 46030]]

``energy absorbers''. Accordingly, OSHA has not made the suggested
change.
``Equivalent.'' This term is used in the final rule to allow
alternative means of complying with the standard. The definition
provides that the employer must be able to demonstrate that the
alternative means of compliance will provide an equal or greater degree
of safety than that attained by using the method or item specified in
the standard. The final definition is identical to the proposed
definition, except that minor editorial changes have been made for the
sake of clarity. The final rule definition is consistent with the
corresponding definitions in Sec. 1910.66 and in part 1926, subparts M
and X.
The SIA (Ex. 2-368) suggested that OSHA not require the employer to
``demonstrate whether or not the scaffold is of `equal or greater
degree of safety' because the employer is too many steps removed from
the manufacturer'' and because requiring the employer to test for
equivalency would create a significant danger that failure would occur.
However, the proposed language reflects the Agency's longstanding
position that employers who choose to deviate from criteria set in OSHA
standards must be able to demonstrate that employee protection has not
been adversely affected. The employer has the flexibility to establish
equivalence by any effective means, including information available
from equipment suppliers and taking into account the specific
circumstances of the work to be done.
``Eye'' or ``eye splice'' means a loop with or without a thimble at
the end of a wire rope. This term is being added to the final rule to
clarify the Agency's intent that this type of connection is an
acceptable way to connect wire ropes without significantly affecting
their strength or capacities. The term is used in final rule
Sec. 1926.451(d) (8) and (9).
``Fabricated frame scaffold'' means a supported or suspended frame
scaffold consisting of platform(s) supported on fabricated end frames
with integral posts, horizontal bearers, and intermediate members. This
is the term for the type of scaffold presently identified as ``tubular
welded frame scaffold.'' OSHA has determined that the current term is
too restrictive because the words ``tubular'' means round and
``welded'' means that metal components are involved. The provisions of
final rule Sec. 1926.452(c), Fabricated frame scaffolds, are not
subject to such limitations. They address fabricated frames and related
scaffold components whether the component parts are square or round, or
made of metal, plastic, wood, or some other material. The final rule
definition is identical to that in the proposed rule.
Two commenters (Exs. 2-13 and 2-320) suggested using the existing
term ``tubular welded frame'' and one commenter (Ex. 2-23) suggested
using the term ``Fabricated tubular frame (Tubular welded frame
scaffold)'' instead of the proposed term. However, as explained above,
OSHA does not intend to restrict this term to ``tubular'' or ``welded''
components.
``Failure.'' This term is used in performance-oriented paragraphs
such as Secs. 1926.451 (a)(1) and (a)(3), which address scaffold
capacity. Because the word might otherwise be interpreted to mean only
breakage or a physical separation of scaffold components, the final
rule definition clearly indicates that load refusal (the point where
the ultimate strength of a component is exceeded) is also considered to
be failure. This is the point where structural members lose their
ability to carry loads although they have not broken or separated. The
term is the same as the term defined in Subpart X of Part 1926, Ladders
and Stairways. The definition for ``failure'' in the final rule is the
same as proposed.
One commenter (Ex. 2-40) suggested that the term ``ultimate
strength'' was not clearly defined. Another commenter (Ex. 2-38)
suggested deleting the last sentence of the proposed definition (Load
refusal is the point where the ultimate strength is exceeded) to avoid
confusion between ``ultimate strength'' and ``overloading without
breaking.'' As OSHA stated above, ``ultimate strength'' may be exceeded
without component parts breaking or separating. Therefore, the Agency
believes the suggested changes are unnecessary.
``Guardrail system.'' This term refers to perimeter protection
composed of vertical barriers which are erected to prevent employees
from falling. The final rule definition is essentially identical to the
proposed definition. This term replaces the definition of ``guardrail''
in the existing rule, which appeared at Sec. 1926.452(b)(10). The old
definition was rail secured to uprights and erected along the exposed
sides and ends of platforms. OSHA believes that this definition did not
adequately reflect the manner in which toprails, midrails and other
intermediate members, and toeboards combine to provide effective fall
protection. The final rule definition of guardrail clearly indicates
that the entire system, including toprail, midrail (or other
intermediate protection), and uprights, is covered when guardrails are
addressed in final rule Sec. 1926.451(e). The definition of guardrail
system used in the proposed rule stated that a guardrail system was ``a
vertical barrier erected to prevent employees from falling from an open
side or edge of a scaffold platform or walkway''. The proposed
definition also distinguished between ``Type I guardrails'', which were
capable of providing fall protection without the use of personal fall
arrest systems, and ``Type II guardrails'', which would need to be
supplemented by personal fall arrest systems (as explained below, OSHA
has not maintained this distinction in the final rule).
The SIA (Ex. 2-368) suggested replacing the word ``prevent'' with
the word ``protect'' in the proposed definition of ``guardrail
system''. According to standard dictionary meanings of both words,
``prevent'' more accurately describes the function of the guardrail
system, which is to keep the employee from going past the perimeter of
the scaffold in the first place. Therefore, the Agency is not making
the suggested change.
Three commenters (Exs. 2-13, 2-53 and 2-370) recommended that OSHA
retain the guardrail rules in the existing scaffold standard and
eliminate the concept of ``Type I'' and ``Type II'' from the proposed
definition of guardrail systems. The commenters suggested that the old
rule's definition of guardrail protection would provide more fall
protection than the definition used in the proposed rule. For reasons
discussed further below, OSHA finds that the final rule's requirements
for guardrail systems, which are essentially identical to those in the
proposed rule, provide more protection than the requirements in the
existing rule. However, OSHA has deleted the discussion of ``Type I''
and ``Type II'' guardrails from the final rule for the sake of clarity
and has added specific criteria for guardrails to final rule
Sec. 1926.451(g).
``Horse scaffold'' means a supported scaffold consisting of a
platform supported by construction horses. Horse scaffolds made of
metal are sometimes known as trestle scaffolds. The proposed definition
was similar except that it did not include the term ``trestle
scaffold.'' The SIA (Ex. 2-368) suggested revising the definition to
specify that horse scaffolds ``may be constructed of wood, metal, or a
combination of both. The metal horses may be referred to as `trestle
horses'.'' Under OSHA's performance-oriented approach to subpart L, an
employer may use any construction materials (e.g., wood or metal) that
enable the scaffold to comply with the capacity requirement set forth
in Sec. 1926.451(a)(1). However,

[[Page 46031]]

the Agency agrees that it would be useful to indicate that some horse
scaffolds constructed of metal are known as trestle scaffolds. OSHA has
revised the definition accordingly.
``Ladder jack scaffold.'' The final rule definition, which is
identical to that in the proposed rule, states that this type of
scaffold is a supported scaffold consisting of a platform supported by
brackets attached to ladders.
A commenter (Ex. 2-23) stated that the capacity of this type of
scaffold should be limited to ``light duty'' and that the words ``light
duty'' should be included in this definition. As discussed above, OSHA
believes it is inappropriate for definitions to include substantive
requirements. In any event, the Agency has determined that a ladder
jack scaffold which complies with the capacity criteria of
Sec. 1926.451(a)(1) and the other pertinent subpart L requirements will
be considered acceptable. Accordingly, OSHA has not made the suggested
change.
``Landing.'' This new term, which has been added to ensure that the
requirements of final rule Sec. 1926.451(e)(4) are clearly understood,
refers to a platform at the end of a flight of stairs.
``Large area scaffold'' means a pole scaffold, tube and coupler
scaffold, systems scaffold, or fabricated frame scaffold erected over
substantially the entire work area, for example; A scaffold erected
over the entire floor area of a room. The Agency has added this term
and definition, along with final rule Sec. 1926.452(d), to provide a
reference point in the standard for this widely used type of scaffold.
``Lifeline'' means a component consisting of a flexible line for
connection to an anchorage at one end to hang vertically (vertical
lifeline) or for connection to anchorages 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
anchorage. A vertical lifeline is sometimes known as a dropline. A
horizontal lifeline is sometimes known as a trolley line. This
definition, which was not part of the proposed rule, has been added for
the sake of clarity. The definition in part 1926, subpart M, Fall
Protection, is consistent with the definition in final subpart L. The
proposed terms ``dropline'' and ``trolley line'', along with their
definitions, have been deleted as separate definitions and have been
incorporated into this final rule definition.
One commenter (Ex. 2-57) stated that a ``trolley line'' was a
``horizontal lifeline'' and suggested that OSHA set ``strength
requirements.'' While final rule subpart L does not set numerical load
requirements for ``horizontal lifelines'', criteria for such equipment
are provided in Sec. 1926.502(d), subpart M, as referenced by a note to
final rule Sec. 1926.451(g)(3).
``Masons' adjustable supported scaffold.'' OSHA proposed this term,
which was not defined in existing subpart L, so employers who used
``self-contained adjustable scaffolds'' in masonry operations would
have a clear reference point in revised subpart L. The final rule is
identical to the proposed rule definition.
One commenter (Ex. 2-23) suggested replacing the parenthetical
reference to self contained adjustable scaffolds with the definition
for such scaffolds in ANSI A10.8-1977. However, to limit redundancy and
confusion, OSHA does not believe that this term should be defined by
the format suggested by the commenter.
``Masons' multi-point adjustable suspension scaffold.'' This term
replaces the term ``Masons' adjustable multiple-point suspension
scaffold'' in the existing standard. The term means a two-point or
multi-point adjustable suspension scaffold designed and used for
masonry operations. The final rule definition is the same as that
proposed.
One commenter (Ex. 2-23) suggested OSHA adopt the definition for
this term from ANSI A10.8-1977, which contains the language
``continuous platform.'' However, it is not OSHA's intent to limit this
type of scaffold to a single ``continuous platform.'' All types of
multi-point suspension scaffolds covered by subpart L may consist of
more than one platform. Multi-point scaffolds are not limited by the
number of suspension wires, platforms, or the location of attachment of
the suspension wires to the platform or platforms (Example: A multi-
point scaffold may consist of one platform suspended by four wires or
it may consist of two platforms suspended by four wires). Additionally
the definition suggested by the commenter did not include the words
``masonry operations.'' OSHA is including the words ``masonry
operations'' in this definition so it applies specifically to such
scaffolds used in the masonry trade.
``Maximum intended load'' means the total load of all persons,
equipment, tools, materials, transmitted loads, and other loads
reasonably anticipated to be applied to a scaffold or scaffold
component at any one time. This term replaces the existing terms
``maximum rated load'' and ``workload''. The term addresses the types
of loads which are to be included when determining the maximum load.
OSHA has been concerned that the word ``rated'' in the existing term
``maximum rated load'' does not clearly express how the safety factor
of four (existing rule paragraph 1926.451(a)(7)) or six (existing rule
paragraph 1926.451(a)(2)) is to be incorporated into the determination
of the maximum load. The final rule definition and final rule
Sec. 1926.451(a)(1) clearly indicate that the maximum intended load is
determined without regard to safety factors. Once the maximum intended
load is determined, the employer then applies the pertinent safety
factor to determine the requisite strength for the system in question.
The final rule definition is the same as in the proposed rule
except the word ``employees'' has been replaced with the word
``persons''. The SIA (Ex. 2-368) suggested this change because
``[p]ersons other than employees might be on a scaffold thus
overloading it.'' OSHA agrees that the weight of all ``persons'' needs
to be considered when calculating the maximum intended load.
One commenter (Ex. 2-23) suggested that OSHA add the closely
related term ``scaffold load rating'' which includes definitions for
the words ``heavy-duty loading,'' ``medium-duty loading,'' ``light-duty
loading'' and ``special loading.'' The Agency provides examples of
appropriate measures for ``heavy-duty,'' ``medium-duty'' and ``light-
duty'' scaffold in non-mandatory Appendix A of final rule subpart L.
Accordingly, the Agency believes the appropriate information is
available and no further changes are necessary.
Two comments (Exs. 2-13 and 2-320) suggested replacing the proposed
term and definition of maximum intended load with the term ``Maximum
Rated Load.'' The commenters suggested that the term ``Maximum Rated
Load'' takes into account safety factors established by the designer or
manufacturer.
OSHA agrees that the term ``Maximum Rated Load'' does include
built-in safety factors. As stated above, by not including the words
``safety factor'' in this definition or replacing the proposed term
with ``Maximum Rated Load,'' which implies built-in safety factors,
OSHA clearly indicates that the minimum safety factor of 4:1 as set
forth in final rule Sec. 1926.451(a)(1) applies. The Agency believes it
is appropriate to take into account the ``expected'' burden as well as
the burden a scaffold ``can'' support without failure.
``Needle beam scaffold'' means a suspension scaffold supported by
needle beams. The final rule definition is the same as the proposed
definition. One commenter (Ex. 2-23) suggested

[[Page 46032]]

that OSHA limit the use of this type of scaffold to ``light-duty''.
However, as discussed earlier, the Agency does not intend to limit the
capacity of a scaffold as long as it meets the pertinent requirements
of Sec. 1926.451(a). OSHA has provided examples of measures that would
enable a scaffold to comply with these requirements in non-mandatory
Appendix A.
``Outrigger.'' This term means the structural member of a supported
scaffold used to increase the base width of a scaffold in order to
provide support and stability for the scaffold. The terms, ``outrigger
beam'' and ``outrigger scaffold'' are new definitions provided to
explain the difference between these three similar terms. The final
rule differs from the proposal, which defined outrigger as ``the
structural member of a supported scaffold used to increase the base
width of a scaffold in order to provide greater stability for the
scaffold.'' The wording change was made in response to a comment from
the SIA (Ex. 2-368), suggesting that OSHA replace the word ``greater''
with the words ``support and increased.'' OSHA agrees that the
suggested wording more accurately expresses the Agency's intent.
``Personal fall arrest system.'' This term, which replaces the
proposed term ``body belt/harness system'', refers to a system used to
arrest the fall of an employee from a working level. It consists of an
anchorage, connectors, and a body belt or body harness and may include
a lanyard, deceleration device, lifeline, or suitable combinations of
these. The final rules on fall protection (part 1926, subpart M) and
powered platforms (Sec. 1910.66) also define ``personal fall arrest
system'' in this manner. The final rule definition is essentially the
same as that proposed for ``body belt/harness systems'', and the phrase
``personal fall arrest systems'' appears in the final rule wherever the
phase ``body belt/harness systems'' was used in the proposed rule. A
commenter (Ex. 2-13) suggested that the definition be reworded to
indicate clearly that lifelines and deceleration devices are not always
included as a part of a body belt/harness system. OSHA agrees and has
clarified this point in the revised definition.
OSHA has deleted the proposed term ``platform unit'' and has
incorporated the proposed definition language into final rule
Sec. 1926.451(b)(1)(i), which addresses the construction of scaffold
platforms.
``Power operated hoists.'' This new term refers to hoists which are
powered by other than human energy. The final rule language differs
from the proposed language, which used the term ``mechanically-powered
hoists''. OSHA has revised the terms ``mechanically powered'' and
``manually powered'' hoists to read ``power operated hoists and
manually operated hoists'', because the Agency has determined that the
language should be consistent with ANSI A10.8-1988, paragraph 6.
``Qualified.'' This term is being added to the final rule as a
matter of convenience for users. The definition is identical to that
found in Sec. 1926.32.
``Rated load.'' This new term addresses the maximum load that a
hoist is allowed to lift. The discussion of final rule
Sec. 1926.451(a)(1), below, addresses the use of this term.
``Repair bracket scaffold.'' This new term has been added to
address the type of scaffold addressed by final rule Sec. 1926.452(x).
This term is discussed below in conjunction with the discussion of that
paragraph.
``Scaffold.'' This term refers to a temporary elevated platform
(supported or suspended) and its supporting structure, including points
of anchorage, used for supporting employees or materials or both. The
definition also clearly indicates that crane or derrick suspended
personnel platforms are not scaffolds. The Agency has added the phrase
``including points of anchorage'' to the definition of scaffold in the
final rule to indicate clearly that points of anchorage are considered
to be part of a scaffold.
``Stair tower (Scaffold stairway/tower).'' This new term has been
added to describe the means of access addressed by final rule
Sec. 1926.451(e)(4). This term is addressed in relation to that
provision below.
``Stall load.'' This new term has been added to identify the
maximum load that a hoist can lift without stalling or shutting down.
The use of this term is discussed in relation to final rule
Sec. 1926.451(a)(2), below.
``Stilts'' mean a pair of poles or similar supports with raised
footrests, used to permit walking above the ground or working surface.
This term and definition has been added to recognize this type of
scaffold, which is used by many trades in the construction industry to
allow employees to walk elevated above the ground or working surface.
Final rule paragraph Sec. 1926.452(y) addresses the safe use of this
type of scaffold both as a scaffold itself, and on other types of
scaffolds (large area scaffolds).
``System scaffold'' means a scaffold consisting of posts with fixed
connection points that accept runners, bearers, and diagonals that can
be interconnected at predetermined levels. This new term has been added
to the final rule to recognize the existence and acceptance of this
type of scaffold. The definition is identical to the definition for the
same term found in ANSI A10.8-1988.
``Tank builders' scaffold'' means a supported scaffold consisting
of a platform supported by brackets that are either directly attached
to a cylindrical tank or are attached to devices that are attached to
such a tank. In the February 1, 1994 notice of record reopening (59 FR
4618), OSHA suggested a definition of ``tank builders' scaffold'' for
consideration. That definition was very similar to the final rule
definition except that the reopening notice definition did not
specifically refer to cylindrical tanks and did specify that the
platform was welded to the steel plates of the tank.
The commenters (Exs. 43-19, 43-23, 43-33, 43-34, 43-35, 43-39, 43-
40, 43-42, and 43-43) who responded to the proposed definition for tank
builders' scaffold stated:

A ``tank'' is not necessarily a cylinder. The scaffold is used
on structures that can be cylindrical, rectangular, conical,
spherical, spheroidal, or elliptical. Also, ``tanks'' are
constructed of material other than metal; e.g., fiberglass, wood,
etc. Some tanks have vertical walls that are so thin that a bracket
could not be welded to it; rather, the bracket would have to be
bolted. We would further comment that the bracket is often inserted
into a device which is welded to the steel plate. So we would
suggest not referencing the bracket being attached to the structure,
but rather the bracket being attached to a device that is affixed to
the structure.

In addition, eleven commenters (Exs. 43-19, 43-21, 43-23, 43-27,
43-33, 43-34, 43-35, 43-39, 43-40, 43-42, and 43-43) stated that the
criteria of an April 4, 1975 variance (40 FR 15139), which addressed
tank builder scaffolds, would be adequately addressed by general
provisions of the final rule and the definition of ``tank builders'
scaffold''.
The 1975 variance order stated:

The applicants' business, which is part of the tank building
industry, involves the erection of relatively large steel plate
segments of circumferential rings. Due to the unique nature of the
construction involved, special procedures, including special
scaffolding, have been developed. For example, as opposed to more
conventional scaffolds, tank scaffolds must be highly portable and
have a relatively low density of occupancy by [workers]. These
scaffolds are raised up the shell of the tank as new rings of steel
are added and work is completed at the level below.
Most plate structures are fabricated from standard length plates
* * * each approximately 31.416 feet (9.42 m.) long, [with] brackets
[normally] welded to them while they are on the ground prior to
being

[[Page 46033]]

placed into position on the tank wall. Scaffolding and guardrail
supports are then attached to these brackets. If the applicants were
to comply with [requirements] that [the maximum spacing for supports
be no more than 8 feet (2.4 m.) for guardrails or 10 feet (3.0 m.)
for planking], they assert it would be necessary to lay out each
steel plate into sections with the brackets located approximately
7.854 feet (2.36 m.) apart. Instead, the applicants wish to lay out
the plates into three equal sections with brackets located
approximately 10' 6'' (3.15 m.) apart.
* * * Because the contour of the steel plates of the tank face
is curved and the adjacent edge of the scaffold platform is
straight, there is an open space between them. As a result,
applicants have installed taut wire rope on the scaffold brackets
that extends midway between the innermost edge of the scaffold
platform and the curved plate structure of the tank face to serve as
a safety line in lieu of an inner guardrail assembly.

Since the information submitted to OSHA in relation to the variance
addressed scaffolds used on cylindrical steel tanks, the Agency is
applying the criteria of the variance only to structures that are
approximately cylindrical. The Agency believes that non-cylindrical
structures should be addressed on a case-by-case basis under the
general provisions of the final rule. OSHA notes that 9 of the 11
commenters (Exs. 43-19, 43-23, 43-33, 43-34, 43-35, 43-39, 43-40, 43-
42, and 43-43) mentioned above also stated ``[t]ank builders place the
scaffold inside of a cylinder, traditionally, to erect the tank.''
However, the Agency believes that the requirements of the variance, as
modified in Appendix A of the final rule, can reasonably be applied to
cylindrical tanks that are constructed of materials other than steel.
The final rule definition for ``tank builders' scaffold'' has been
worded accordingly.
OSHA has not promulgated specific requirements for tank builders'
scaffolds in the final rule because the Agency believes that the
requirements for those scaffolds are adequately addressed in the
general provisions of the final rule. The Agency notes that it has
placed several provisions (some of which have been editorially
modified) of the variance in Appendix A for the benefit of employers
who use tank builders' scaffolds, and that the introductory text to the
Appendix clearly indicates that following the Appendix will be
considered to constitute compliance with the requirements of this
standard with regard to scaffolds used in the construction of
cylindrical tanks. However, employers choosing not to follow the
Appendix must still comply with the applicable requirements of
Sec. 1926.451, particularly paragraphs (a) and (f).
``Top plate bracket scaffold.'' This term is being added to the
final rule to recognize a type of scaffold which is similar to
carpenters' bracket scaffolds and form scaffolds. This type of scaffold
consists of a platform supported by brackets that hook over or are
attached to the top plate of a wall. Such scaffolds are used in
residential construction when employees are setting roof trusses.
OSHA has deleted the following terms, which are defined in the old
scaffold standard, from the definition section of the final rule,
because those terms are now defined in other subparts or because the
final rule no longer uses the terms in question: ``heavy duty
scaffold,'' ``light duty scaffold,'' ``medium duty scaffold,''
``midrail,'' ``toeboard,'' and ``working load.'' In addition, the
proposed definitions for ``drop lines'', and ``trolley line'' have been
deleted from this final rule, since they have been incorporated into
the definition of ``lifeline''.
Under Issue L-12 in the preamble of the proposed rule, OSHA
solicited testimony and related information on a suggestion by the
ACCSH (Tr. 206, 6-9-87) that definitions for ``ramp'' and ``runway'' be
added to the standard. The ACCSH indicated that the added definitions
would facilitate clear understanding of the requirements in proposed
Sec. 1926.451(c)(4) (final rule Sec. 1926.451(e)(4)). As noted under
the discussion of the Issue, a member of the ACCSH recommended that the
Agency use the definition of ramp developed by the National Safety
Council.
The one comment (Ex. 2-593) OSHA received addressing the Issue
supported defining the two terms. The commenter did not provide any
suggested wording but indicated that the definitions should be ``clear
and consistent with existing OSHA and ANSI definitions.''
In the final rule, OSHA has replaced the proposed term ``runway''
with the term ``walkway'', to indicate the Agency's regulatory intent
clearly . However, the Agency believes that ``ramp'' is a commonly
understood term and does not require a specific OSHA definition.
Accordingly, OSHA has not added a definition for ``ramp'' to the final
rule.

Paragraph 1926.451(a) Capacity

Final rule paragraph (a) sets the minimum strength criteria for all
scaffold components and connections. The final rule sets scaffold
capacity requirements that are substantively the same as those in
existing subpart L, while eliminating ambiguities and apparent
inconsistencies. The introductory text of the proposed paragraph, which
stated that ``the following requirements applied to all types of
scaffolds except as indicated:'', has been deleted in the final rule
because the Agency has determined that it is too similar to the
introductory text of paragraph (a)(1) and, therefore, is unnecessary.
Paragraph (a)(1) requires that each scaffold and scaffold component
be capable of supporting, without failure, its own weight and at least
4 times the maximum intended load applied or transmitted to it.
Paragraphs (a)(2), (a)(3), (a)(4), (a)(5) and (g) of Sec. 1926.451
provide exceptions to this general rule, and are discussed below. This
provision is based on existing Sec. 1926.451(a)(7), which requires that
scaffolds and scaffold components ``be capable of supporting without
failure at least four times the maximum intended load''.
The final rule clearly provides that the 4 to 1 factor for a
component applies only to the load which is actually applied or
transmitted to that component, and not to the total load placed on the
scaffold. Existing Sec. 1926.451(a)(7), taken literally, could be read
to require that each separate scaffold component be able to support
four times the maximum intended load (MIL) of the entire scaffold. For
example, the existing provision could be interpreted to require that a
crossbrace on a supported scaffold be capable of supporting the same
load as a scaffold leg, that is, be sized to support four times the
entire MIL regardless of where the load is placed on the scaffold and
regardless of the fact that the function of a brace is to prevent sway
and not directly to support the MIL. Such an approach was not OSHA's
intent. The Agency intended that each component be adequate to meet the
4 to 1 factor, but only for the portion of the MIL applied or
transmitted to that component. The MIL for each component depends on
the type and configuration of the scaffold system. Final rule paragraph
(a)(1), which is effectively identical to the corresponding language in
proposed paragraph (a)(1), clearly expresses the Agency's intent. The
proposed provision has been editorially revised and reorganized for the
sake of clarity. In particular, the exceptions to proposed paragraph
(a)(1), which provide different coverage for suspension scaffolds, have
been clearly delineated as separate paragraphs (a)(2) through (a)(6) in
the final rule.
Paragraph (a)(2) of the final rule requires that direct connections
to roofs and floors and counterweights used to balance adjustable
suspension scaffolds be capable of resisting at least 4 times the
tipping moment imposed by the scaffold operating at either the rated

[[Page 46034]]

load of the hoist or at 1.5 (minimum) times the tipping moment imposed
by the scaffold operating at the stall load of the hoist, whichever is
greater. Proposed paragraph (a)(2) simply required that direct
connections to roofs and floors, and counterweights used to support
suspension scaffolds, be capable of providing a resisting moment of at
least four times the tipping moment. The proposed provision was
intended to clarify that the safety factor of four to one also applies
to direct connections to floors and roofs and to counterweight systems.
These areas are as integral to the scaffold system as the scaffold
platform itself. OSHA has revised the proposed provision to account for
the need to base the factor of safety for adjustable suspension
scaffolds on the rated load of the hoist and the stall load of the
hoist.
Several commenters (Exs. 2-8, 2-28, 2-64, 2-367, and 2-516)
indicated that the factors of safety for adjustable suspension
scaffolds should be based on the rated load of the hoist. Four of those
commenters (Exs. 2-28, 2-64, 2-367 and 2-516) and the SIA (Ex. 2-368)
recommended that the stall capacity of the hoist be considered in the
factors of safety.
One of these commenters (Ex. 2-28) stated that many suspended
scaffolds are rigged by inexperienced persons who do not realize that
if the scaffold catches on an obstruction, the maximum lifting power
(stall load) of the hoist can be developed and transmitted to the
counterweights and anchorages. This commenter suggested adding one of
the following requirements to proposed Sec. 1926.451(a)(2) as an
alternative to four times the tipping moment: (1) or 4,000 pounds,
whichever is greater; (2) or 150 % of the maximum pulling power of the
hoist, whichever is greater; or 4 times the rated load of the hoist,
whichever is greater. The SIA (Ex. 2-368) recommended changing the
resisting moment of proposed Sec. 1926.451(a)(2) to ``at least 1.5
times the stall capacity of the hoist or four times the maximum
intended load, whichever is greater.''
Three commenters (Exs. 2-8, 2-28, and 2-516) indicated that
Underwriters Laboratories (U.L.) standard 1323 (Standard for Scaffold
Hoists) limits the maximum output of a scaffold hoist to 3 times the
rated working load of the hoist. One commenter (Ex. 2-64) recommended
that OSHA limit the stall load of a hoist to no more than three times
the rated load of the hoist. Another commenter (Ex. 2-8) stated that if
the safety factor for suspended scaffolds is not based upon the highest
rated working load of any component, normally the hoist, failure can
occur.
Two commenters (Exs. 2-8 and 2-516) presented examples of the
relationship between the stall load of a hoist and the rated load of
the same hoist. One commenter (Ex. 2-8) provided the following example:

A typical hoist with a ``rated working load'' of 1000 lbs. can
exert a pulling force of 3000 lbs. if an obstruction is encountered
such as a window ledge or air conditioner while ascending. If one
designs for a maximum intended load of only 500 lbs. because of a
short light scaffold platform or a work cage and the counterweight
or suspension system is designed for 4:1 MIL then the ultimate load
that the suspension can support is 4 x 500 lbs. MIL or 2000 lbs. A
3000 lb. hoist pull can cause failure or even wire rope failure if 6
x MIL is used. No one intends to stall a hoist on an obstruction
but it does occur. Therefore, a suspended scaffold should be
designed for safety factors based upon MIL or rated working load of
the hoist whichever is greater.

OSHA agrees that the safety factors for the counterweights,
riggings, direct connections to roofs and floors, and suspension ropes
of adjustable suspension scaffolds should be related to the rated load
of the hoist and the stall load of the hoist, and not be based on the
maximum intended load. OSHA agrees with the commenters who stated that
failure can result if the factors of safety are based on the maximum
intended load. Furthermore, the Agency also agrees with the commenters
(Exs. 2-28 and 2-368) who indicated that these factors of safety should
be based on 1.5 times the stall load of the hoist.
The Agency notes that the stall load of a hoist is equal to three
times the rated load of that hoist. When one applies the 4 to 1 safety
factor required (4 x rated load = 4/3 x stall load) the result
would be 1.33 times the stall load. However, while using 1.33 times the
stall load would provide the required safety factor, OSHA is using 1.5
times the stall load based on the above comments. The Agency believes
that such a requirement reduces the possibility of failure due to
improperly installed equipment as well as the dynamic loads that can be
developed when an obstruction is encountered. Accordingly, the Agency
has changed the final rule language so that it requires a factor of
safety of four times the maximum rated load of the hoist or 1.5 times
the stall load of the hoist, whichever is greater.
Paragraph (a)(3) of the final rule provides that ``[e]ach
suspension rope, including its 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.'' This is the same requirement as the
proposed rule except that final rule paragraph (a)(3) applies only to
non-adjustable suspension scaffolds, while the requirements for
adjustable suspension scaffolds have been placed in final rule
paragraph (a)(4), below. The proposed rule did not distinguish between
these two types of scaffolds. Proposed paragraph (a)(4)(i) has been
redesignated to Sec. 1926.451(f)(11) of the final rule, to consolidate
all requirements for wire rope used with suspension scaffolds. In
addition, proposed paragraphs (a)(4)(ii) and (iii) have been moved to
non-mandatory Appendix A, so that examples of measures that would
comply with final paragraph (a) are consolidated in one place.
Paragraph (a)(4) of the final rule provides that ``[e]ach
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 (a) The rated load of
the hoist, or (b) 2 (minimum) times the stall load of the hoist,
whichever is greater''.
This provision addresses adjustable suspended scaffolds and is
similar to proposed paragraph (a)(3) except that the proposed paragraph
contained the language ``maximum intended load applied or transmitted
to the rope'' instead of ``rated load of the hoist (or at least 2 times
the stall load of the hoist, whichever is greater)''. The proposed rule
was based on existing Sec. 1926.451(a)(19).
Three commenters (Exs. 2-8, 2-64, and 2-516) recommended that OSHA
use ``rated capacity of the hoist'' instead of ``maximum intended
load.'' This recommendation was based on the belief that the safety
factor for adjustable suspended scaffolds should be based on the
highest rated work load of any component, normally the hoist. The
Agency agrees and has modified the proposed rule accordingly. In
addition, the Agency has included language that accounts for the stall
load of the hoist in the factor of safety for the same reasons that
were discussed in regard to final rule Sec. 1926.451(a)(2), except that
the factor to be applied to the stall load has been increased from 1.5
to 2 in order to account for the 6:1 factor of safety applied to
suspension ropes. This factor of safety does not include an added
margin as does the factor of safety in paragraph (a)(2). One commenter
(Ex. 2-516) recommended an 8:1 factor of safety for suspension ropes on
adjustable suspension scaffolds. This recommendation was based on
several factors that can reduce the effective

[[Page 46035]]

strength of a rope: (1) A termination rating of 80% of the wire rope
design strength; (2) time-use of the rope; (3) energy applied to the
system when the overspeed brake is actuated; and (4) failure of the
brake to set or the loss of one end of the platform rigging. The
commenter concluded that these factors can reduce the factor of safety
from 6:1 to 1.15:1, with failure occurring if anything else goes wrong
such as the free end of the platform swinging through its arc.
OSHA notes that this commenter addresses a worst case scenario
which would involve violations of other provisions of the final rule.
The Agency believes that each of the elements of the scenario will be
prevented by compliance with the final rule. For example, final rule
Sec. 1926.451(d)(6) requires winding drum hoists to contain not less
than four wraps of the suspension rope at the lowest point of scaffold
travel, thereby reducing the force applied to the termination at the
winding drum. In addition, final rule Sec. 1926.451(d)(12)(v) prohibits
the use of U-bolt clips at the point of suspension for any scaffold
hoist. Also, final rule Sec. 1926.451(a)(3) requires that suspension
rope connections be considered part of the rope and that they be taken
into account when determining whether a rope is capable of withstanding
without failure at least six times the loads imposed upon it.
Further, final rule Sec. 1926.451(d)(10) requires that a competent
person inspect suspension ropes prior to each workshift or after any
occurrence which could affect a rope's structural integrity. Paragraph
1926.451(d)(10) also requires that defective or damaged ropes be
removed from service. For these reasons, OSHA believes that the final
rule adequately addresses the commenter's concerns.
The third commenter (Ex. 2-29) recommended that OSHA include the
weight of the scaffold and all its components in calculating maximum
intended load. The Agency believes the above described changes made to
proposed paragraph (a) resolve the concerns raised by this comment.
Paragraph (a)(5) of the final rule, which was not part of the
proposed rule, requires that the stall load of any scaffold hoist not
exceed 3 times its rated load. OSHA finds that this requirement is
reasonably necessary to prevent accidental overloading of suspension
scaffold support systems. OSHA notes that U.L. standard 1323 limits the
output force of a scaffold hoist to three times the rated load of the
hoist. As far as OSHA has been able to determine, the other
laboratories which test and list scaffold hoists adhere to the
requirements of U.L. 1323.
A commenter (Ex. 2-64) recommended that OSHA limit the stall load
of scaffold hoists to three times the rated load of the hoist. The
Agency agrees that it is appropriate to add the suggested provision,
for the reasons described above.
Final rule paragraph (a)(6) requires that scaffolds be designed by
a qualified person and constructed and loaded in accordance with that
design. The provision also indicates that non-mandatory Appendix A
provides examples of criteria, including design specifications, that
will enable the employer to comply with paragraph (a) of this section.
Proposed paragraph (a)(1), which focused on supported scaffolds, also
referenced Appendix A for acceptable criteria.
Non-mandatory Appendix A provides examples of design and
construction measures that employers can use to comply with final rule
Sec. 1926.451(a). This Appendix is based on the requirements set by
existing Secs. 1926.451(c)(1)-(4) and by Tables L-3 through L-19. OSHA
has recognized that employers can design and construct scaffolds which
satisfy the performance requirements of the final rule without
following the specifications set by the existing rule, and drafted both
the proposed and final rule Sec. 1926.451(a) accordingly. The Agency
believes that the above-cited specifications could assist an employer
in complying with the capacity requirements of the final rule, so OSHA
has relocated that language to non-mandatory Appendix A.
In Issue 5 of the preamble to the NPRM, OSHA requested comment on
whether or not all scaffold units (such as planks and decks) should
have their capabilities or grades marked on them. Some commenters (Exs.
2-41, 2-46, 2-51, 2-54, 2-73, 2-367, 2-495, 2-512, 2-516, and 2-534)
indicated they favored the requirements for such markings. Two
commenters (Exs. 2-495 and 2-534) stated ``very few people would know
which grade for any species of wood qualifies that plank as scaffold
grade.'' Those commenters recognized that there was a lack of consensus
concerning the maximum safe loads on certain plank spans, stating that
``[a]t the same time, we believe it may be premature to require that
all planks be so marked since agreement on methodology of determining
load displacement has not been reached by the engineering profession.''
Another commenter (Ex. 2-54) indicated that marks would not wear
off platform units because ``[i]n most instances, planks are placed and
not moved [and are] generally not rubbed against each other
constantly.'' Another commenter (Ex. 2-516) stated ``[i]f it is so worn
that the mark is lost, it probably needs retesting anyway.''
One commenter (Ex. 2-51) stated that while grade marks would wear
off, it seems unlikely ``that every plank on an entire job would
simultaneously suffer such a fate. We believe that invariably, there
would be some plank where grade stamping was legible if grade stamping
ever existed.''
Another commenter (Ex. 2-41) stated ``[k]nowledge of the capacity
of each [piece of] equipment is basic to implementation of this
proposal.''
In addition, the SSFI (Ex. 2-367) pointed out that fabricated plank
stages and platforms are currently marked as to their capacity. They
stated that this ``practice should be continued for fabricated planks,
stages, and platforms, as these are designed for unique applications.''
The commenter also stated ``there is no common practice within the
industry to have solid sawn lumber marked as to their load capacity.''
The SSFI recommended ``that the solid sawn lumber or laminated veneer
be repeatedly and continuously grade[-]stamped along the side edge of
the material at the time the plank is initially purchased.''
Another commenter (Ex. 2-51) stated that ``[s]ince 1980, Timber
Products Inspection has been involved in five cases where plank failure
has resulted in injury and litigation. In all five cases the planks
that failed were purchased as rough Canadian Spruce #1 and better or #2
and better. None of the planks were grade-stamped and one plank was
identified as Lodge pole pine instead of spruce.''
Another commenter (Ex. 2-35) recommended that OSHA adopt the
language of the ANSI A10.8 draft scaffold standard that requires
``solid sawn scaffold plank to bear the grade stamp of a grading agency
approved by the American Lumber Standards Committee.'' The commenter
also stated ``it is essential to assure use of scaffold members of
adequate strength and stiffness.''
In addition, a commenter (Ex. 2-534) stated:

We are strong advocates of requiring that all plank to be used
as scaffold plank be required to be stamped or embossed as
``SCAFFOLD PLANK''. To most people, all planks look alike. Very few
people would know which grade for any species of wood qualifies that
plank as scaffold grade unless the grade stamp is explicit for
flatwise use as ``Scaffold Plank''.
* * * There is everything to gain, and nothing to lose, by
requiring marks that

[[Page 46036]]

communicate to answer the bottom line question, ``Is this plank OK
as a scaffold plank?''

In addressing Issue 5, the ACCSH recommended (Tr. 6/9/87, pp. 64-
65) that all planking and decks, etc., be properly marked as scaffold
materials. The Advisory Committee indicated that a performance
standard, which would allow employers to determine how they wanted to
mark these materials, would be appropriate. Among the options
envisioned by the ACCSH to distinguish the materials intended solely
for scaffold system use were color-coding systems, stamping, and
tagging.
On the other hand, some commenters expressed the view that a
marking requirement would be impractical (Exs. 2-15, 2-20, 2-22, 2-368,
and 2-390). In addition, commenters (Exs. 2-20, 2-53, 2-55, and 2-390)
stated that the requisite costs would be burdensome, and others (Exs.
2-13, 2-15, 2-69, and 2-368) stated that, while manufactured or
fabricated planks or platforms were often or usually marked, carrying
this over to wooden components was inadvisable, citing anticipated
problems with the volume of planks to be marked and the marks wearing
off. Several commenters (Exs. 2-20, 2-55, 2-70, and 2-390) pointed out
the marks would lend a possibly false sense of security or safety, and
some (Exs. 2-20, 2-55, 2-69, and 2-390) added that maintaining the
marks would be neither feasible nor economical. One commenter (Ex. 2-
70) stated ``The user of platform units can calculate the maximum load
that can be placed on a scaffold and it is up to management personnel
to ensure that the scaffolding is not overloaded. I feel that the
marking of platform units does not, in itself, insure a safe
scaffolding.''
After careful evaluation of the above comments, the Agency has
decided not to require marking of platform units. OSHA has determined
that, while markings can increase confidence in and use of appropriate
platform units, they do not add to the inherent safety of the scaffold.
Furthermore, the absence of markings does not establish a lack of
quality.
In addition, materials quality is only one of several factors which
must be considered when erecting a scaffold platform. Other significant
elements include unit size, span, and load applied. A platform unit,
whether wood or metal, solid sawn or prefabricated, which is marked as
appropriate for use as a plank, may be appropriate for use in one set
of conditions but not in another (i.e., longer span or higher load).
Similarly, a platform unit which does not have the quality
characteristics to allow its use in one situation may be acceptable for
use in another (i.e., shorter span or lighter load) whether or not it
is marked. The important consideration in all situations is that the
platform be capable of supporting the load with a design factor of
four.
OSHA believes the grading rules of recognized independent
inspection agencies, such as the American Lumber Standards Committee
(ALSC), provide useful information about wood plank selection and use.
Planks that are marked and used in accordance with pertinent grading
rules of the ALSC or other recognized independent inspection agency
will be deemed to meet the four-to-one requirement. Therefore, given
the extent to which the private sector has voluntarily adopted plank
grading and marking programs, the Agency has concluded that any benefit
resulting from the addition of marking requirements would be minimal.
Wood products such as Canadian spruce, which are alleged to be
unacceptably inferior in some applications, could have standards
developed for their use by a recognized grading agency. OSHA believes
there are combinations of thickness, quality, span, loads, and other
factors that can be established for all species of wood used for
platforms.
Issue 17 of the preamble to the NPRM asked whether the Agency
should specify a minimum slippage capacity of 4,000 pounds and a
minimum breakage capacity of 16,000 pounds for couplers used on tube
and coupler type scaffolds. The SSFI and SIA (Exs. 2-367 and 2-368)
opposed such a requirement, stating that ``the entire scaffold
structure should be required to withstand the specified design loads.''
They also noted that this special component requirement was unlike
other OSHA requirements. The SIA (Ex. 2-368) also stated:

It is redundant and unnecessary to specify a quantitative value
for clamp strength since the required safety factors already in
existence provide the proper strength for the intended load. There
may be cases where the clamps should be of higher value or lower
value, depending on usage. Consequently, requiring a numerical value
may produce the catastrophe which the proposed rule is trying to
avoid in the first place. Existing rules require design by competent
individuals, which provides the proper safeguards against abuse and
eliminates the need for the proposed rule.

Also, a commenter (Ex. 2-15) indicated that a British standard (BS
1129) recognizing 2800 lb. has been in place for 20 years ``with
satisfactory results.'' The commenter stated that most American clamps
are built to BS1129, and went on to indicate that the same 2800 lb.
figure is generally sufficient, except for possible heavy-duty
applications in a specific configuration. The commenter further felt
that specifying a 4,000 lb. minimum slippage capacity would ``outlaw''
many clamps.
One commenter (Ex. 2-22) stated that both slippage and minimum
breakage capacities ``should be equivalent to that required on the
other parts of the scaffold.''
Another commenter (Ex. 2-128) stated ``couplers for tube and clamp
[scaffolds] should be rated by the manufacturer in accordance with a
recognized testing standard [and] certified by an engineer.'' In
addition, a commenter (Ex. 2-13) expounded on the relationship between
the torque applied to tighten a coupler and the slippage capacity, and
noted that proper torque values needed to be determined by tests or
calculations.
The ACCSH (Tr. 6/9/87, pp. 138-147) recommended that OSHA specify
both minimum slippage and breakage capacities and should require
employers to obtain manufacturer's specifications and/or certifications
that a scaffold meets minimum standards. However, the ACCSH did not
endorse the suggested 4000 and 16,000 pound limits and did not propose
any other limits.
After a careful review of the above comments, OSHA has determined
that the capacity provisions set out in final rule Sec. 1926.451(a)
will appropriately address the concerns regarding scaffold strength and
that additional specifications would be redundant.
Issue 21 of the preamble to the NPRM requested public comment on
appropriate field test procedures or certifications for determining the
capacity of scaffolds and scaffold components such as planks and ropes.
As noted above, existing Sec. 1926.451(a)(7) and proposed
Sec. 1926.451(a)(1) require scaffolds to be capable of supporting,
without failure, at least four times the maximum intended load. OSHA
has recognized, however, that field testing of scaffolds and scaffold
components with loads four times greater than the maximum intended load
could cause damage that would render the scaffold and scaffold
components unusable.
One commenter (Ex. 2-54) mentioned reliance on testing laboratories
to ensure that rope and planks meet industry standards. Another
commenter (Ex. 2-64) stated that scaffolds' and support systems' rated
capacities should be marked when manufactured and that any field
testing beyond that set forth in a manufacturer's instructions would be
superfluous and could conflict with those instructions.

[[Page 46037]]

The SSFI (Ex. 2-367) and the SIA (Ex. 2-368) both stated that field
testing of supported scaffolds would permanently damage equipment or
render it useless, and that a visual check of the scaffolding before
use should ensure safety ``as the manufacturer already warrants the
appropriate safety factors.'' The SIA also stated that current testing
methods ``are not suitable for checking the ultimate capacity of
scaffold components.'' The SIA further stated that for metal
components, visual inspection is the only practical method available.
For wooden components, the SIA stated that inherent material variables
make obtaining repeatable results from a suitable bending test
impossible. On the other hand, the SIA recommended that suspension
scaffolds be field tested with the intended load.
Two other commenters (Ex. 2-495 and 2-534) agreed with the SIA that
it is impossible to obtain repeatable results from a bending test.
However, they stated that a minimum threshold design value for flat-
wise bending of planks could be derived from available information for
flat-wise bending for any specie of plank. Those commenters also stated
that field testing would not necessarily permanently damage or render a
plank useless. They stated that strength testing of used planks could
be accomplished by combining visual inspections with deflection testing
using a safe load and deflection testing machines that are currently
available.
One commenter (Ex. 2-516) indicated that a reasonable level of load
testing for scaffold machinery might be found ``somewhere near 1.25
times [the] rated load'' and that ``any field tests should be a ratio
of rated load, not failure load.'' The commenter assumed different
safety factors for moving equipment, suspended scaffold hoists, and
fixed structures. The commenter also questioned whether the safety
factor referred to in Issue 21 was for static, dynamic, or shock loads,
and noted that 4 to 1 is not an engineering safety factor but a gross
factor. In addition, the commenter stated:

Any device or mechanism designed for a structural safety factor
of four-to-one certainly can be tested at some level less than four-
to-one without structural failure. * * * It is difficult to
comprehend the rationale of prohibiting testing of a structure using
1\1/2\ times rated load for fear it will collapse, when the
structure must not collapse at 4 times rated load. There would then
be doubt in my mind as to its ability to meet that 4-to-1 criterion.

Also, the commenter (Ex. 2-516) pointed out that any test of wood
components should consider the effects of aging material, and he listed
a number of variables for which some testing adjustments would be
required. These variables included ``fatigue, finish,'' and ``material
test scales.''
Two commenters (Exs. 2-13 and 2-69) indicated there would be no
need for field testing since scaffolds should be designed for their
intended load with an added safety factor. In particular, one of those
commenters (Ex. 2-13) stated ``[t]here are no appropriate field tests
for such items as planks and ropes. A simple visual inspection is all
that is required by a competent person.''
The ACCSH (Tr. pp. 163-174, 6-9-87) recommended that the
manufacturer's design specifications be recognized as sufficient for
manufactured scaffolds. The ACCSH also recommended that specifications
or testing procedures be specified for job-made scaffolds.
After carefully considering the above comments, OSHA has decided
not to require field testing of scaffolds. Based on the comments
received, the Agency has determined that such testing is not needed and
that, given the inspection and capacity requirements, it would be
difficult or impossible to implement effectively for the range of
materials in question.
Issue 23 of the preamble to the NPRM solicited comments on whether
or not the Agency should revise paragraph 1.(b) of proposed non-
mandatory Appendix A, which provides for selection of wood scaffold
planks according to the grading rules established by a recognized
independent inspection agency. In particular, OSHA asked if the
language should be more specific and, if so, what that language should
be.
Four commenters (Exs. 2-13, 2-22, 2-29, and 2-53) responded that
the proposed Appendix A language was adequate. One commenter (Ex. 2-13)
added ``it should be mandatory that the employer visually check all
scaffold planks before they are used.'' Another commenter (Ex. 2-54)
stated that scaffold planks ``should have identification'' to indicate
that they are scaffold grade.
However, a commenter (Ex. 2-534) noted that ``it may be premature
to require that all planks be so marked since agreement on methodology
of determining load displacement has not been reached by the
engineering profession.''
The SSFI (Ex. 2-367) recommended that scaffold planks be marked,
and noted that the most plank failures are inspection related. The SIA
(Ex. 2-368) recommended that OSHA revise paragraph (b) of proposed
Appendix A to read, in part, as follows:

All solid sawn planking shall be `SCAFFOLD GRADE' plank and
grade stamped as appropriate per the published grading rules of the
recognized independent inspection agency and as approved by the
Board of Review of the American Lumber Standards Committee. The
maximum permissible spans for 2 x 10 inch (nominal 1\1/2\'' x
9\1/4\'' minimum dressed (S4S), 1\5/8\'' x 9\1/2\'' minimum rough
or 2'' x 10'' minimum rough, solid sawn wood planks shall be as
shown in the following table.
Paragraph 1(b) of Appendix A should be expanded and clarified to
eliminate the confusion that exists over the use of nominal
thickness scaffold grade planks on 10 ft. spans for light trades.
This could be achieved by defining a scaffold grade plank in the
manner done in Cal-OSHA standards.
Cal-OSHA Section 1637(e) requires what it calls a ``structural
plank'' for scaffold platforms as follows:
``Except as specified in certain other Orders, all planking
shall be 2-inch (nominal) material selected for scaffold grade plank
as defined in Section 1504 under the heading Lumber--`Structural
Plank'.''

The ACCSH, in its June 9, 1987 (Tr. pp. 175-180), meeting,
recommended that a competent person be responsible for the selection
and use of scaffold materials, where scaffolding materials are not
certified by the manufacturer.
After carefully considering the above comments, OSHA has decided to
modify paragraph 1.(b) of non-mandatory Appendix A to the final rule to
provide for identification of scaffold planks by the grade stamp of the
recognized lumber grading association or independent lumber grading
inspection agency under whose grading rules the planks were selected.
OSHA is also modifying proposed Appendix A to provide that the
association or agency under which the wood is graded should be
certified by the Board of Review, American Lumber Standard Committee as
set forth in the American Softwood Lumber Standard of the U.S.
Department of Commerce. This added language clearly indicates what
constitutes a ``recognized'' inspection agency.
As a separate matter, OSHA is modifying Appendix A to the final
rule to provide that allowable spans of scaffold planks, other than 2 x
10 inch (nominal) or 2 x 9 inch (rough) solid sawn planks which are
addressed in the table in paragraph 1 (b), shall be determined in
accordance with the National Design Specification For Wood Construction
published by the National Forest Products Association or with ANSI
A10.8-1988, paragraph 5. OSHA notes that Appendix A is intended to help
the employer comply with the scaffolding rules. The Agency believes
that the above modifications will facilitate compliance with those
rules.

[[Page 46038]]

Paragraph (a)(6) of the final rule, which was not part of the
proposed rule, requires that scaffolds be designed by a qualified
person and must be constructed and loaded in accordance with that
design. OSHA believes that a ``qualified'' person can design a scaffold
which satisfies the criteria of Sec. 1926.451(a). This provision also
notes that non-mandatory Appendix A contains examples of criteria that
will enable employers to comply with paragraph (a) of this section.
Issue 24 of the preamble of the NPRM noted that existing
Secs. 1926.451(b)(16), (c)(4), (c)(5), (d)(9) and (g)(3) and proposed
Sec. 1926.451(b)(18)(i) and Secs. 1926.452(a)(10), (b)(10), (c)(6) and
(i)(8) require that an engineer design specified scaffold types and/or
components that are not built or loaded in accordance with Tables L-4
through L-13 of existing Sec. 1926.451 or proposed Sec. 1926.451
Appendix A, respectively. OSHA asked for comments regarding the extent
to which the services of an engineer or of a qualified person would be
needed to design scaffolds in accordance with the provisions of
Appendix A or to design scaffolds that, while not in accordance with
Appendix A, would comply with Sec. 1926.451(a).
Two commenters (Exs. 2-69 and 2-437) responded that employers
should be allowed to assess whether individual employees with several
years of hands-on experience are capable of designing and modifying
scaffolds or an engineer's services are required. Also, a commenter
(Ex. 2-22) expressed the view that there was no need for further
licensing and determinations because employers are responsible for
ensuring that scaffolds meet regulations for capacity and that
alterations of scaffold designs are made by qualified individuals. The
AGC commenters (Exs. 2-20, 2-55, and 2-390) stated ``there are many
individuals in the construction industry with many years of experience
who are quite capable of scaffold design and modification. Employers
should be permitted the flexibility to determine if such individuals
are capable or if they should seek the services of an engineer.''
Another commenter (Ex. 2-54) noted that not all engineers are
capable of designing scaffolds and that a good many people who work
with scaffolds do not know all the scaffold limits or strengths. The
commenter acknowledged that complicated scaffold designs require the
skills of an engineer familiar with the equipment available. However,
the commenter added that a competent worker who has followed an
engineer's drawings to erect a scaffold can at times recall and use
that experience in another situation requiring a complicated scaffold
structure.
In addition, a commenter (Ex. 2-21) stated that no additional
specification requiring the use of engineering services was warranted.
The commenter explained that ``[c]onditions on most construction jobs
change daily and can best be handled by qualified foremen or
supervisors on the job.'' Also, a commenter (Ex. 2-31), addressing
pumpjack scaffolds specifically, responded that although he was not an
engineer himself, he knew at least as much as anyone else about
pumpjack scaffolds. He felt that an engineer could be supplanted by
someone with recognized expertise but added that he did not believe a
specific definition of someone qualified to design a scaffold system
could be made.
Both the SSFI (Ex. 2-367) and the SIA (Ex. 2-368) recommended that
a ``qualified person,'' as defined in proposed ANSI A10.8, be allowed
to design those scaffolds that would not require the services of a
registered engineer. They quoted the proposed ANSI definition as
follows:

A term describing one who, by possession of a recognized degree,
certificate, or professional standing, or who by extensive
knowledge, training, and experience, has successfully demonstrated
the ability to solve or resolve problems relating to the subject
matter, the work, or the project.

The suggested definition is identical to the definition of
``qualified'' in Sec. 1926.32(l).
Two Saf-t-Green commenters (Exs. 2-14 and 2-15) stated that people
other than engineers were capable of designing scaffolds. In
particular, one commenter (Ex. 2-15) stated ``There are many good,
practical scaffold designers who are not engineers. They should not be
excluded.''
On the other hand, some responses to Issue 24 stated that the
services of a registered or professional engineer were needed (Exs. 2-
3, 2-9, 2-13, 2-70, 2-128, and 2-516). One such commenter (Ex. 2-13)
stated that he backed using registered professional engineers ``with
the knowledge and training required for [designing] a life support
system'' and queried where ``an equivalent qualified responsible person
could be found?'' One commenter (Ex. 2-70) offered a brief response,
``when in doubt, consult an engineer.'' Another commenter (Ex. 2-516)
responded:

I would rather take my chances with the engineer [-designed
scaffold system]. At least he knows some limits. Any other
definition lets anyone determine by themselves that they are
eminently qualified. All it then takes to be qualified is a big ego,
a little knowledge, and a pile of frame scaffold.

A comment from Aluma-Systems, Incorporated (Ex. 2-128) expressed
the belief that an engineer's services should be required for all but
the simplest of scaffold structures. The commenter indicated that the
Province of Ontario requires that a professional engineer design any
scaffold which exceeds 15 meters in height (approximately 50 feet), any
suspension scaffold where the scaffold consists of more than one
platform, or any suspension scaffold where the weight of the platform
and its components exceed 363 kg.
In addition, two commenters (Exs. 2-12 and 2-53) responded that the
existing regulations were sufficient or adequate. One of the two (Ex.
2-12) stated that there was already sufficient regulation and
questioned whether rules could be made to cover all situations.
In its June 9, 1987, meeting, the ACCSH (Tr. pp. 180-183)
recommended that OSHA authorize a competent person, rather than a
qualified person, to follow Appendix A for scaffold design, but that a
registered professional engineer be required to design scaffolds where
conditions are not covered by Appendix A. The Agency notes that a
competent person, as defined in Sec. 1926.32(f) and in the final rule
for subpart L, is able to detect hazards and has the authority to have
hazards corrected. On the other hand, ``qualified'', as defined in
Sec. 1926.32(m) and in the final rule for subpart L, refers to a person
who has the ability to solve or resolve safety and health problems.
After carefully considering the above comments, OSHA believes that
the proposed rule adequately addressed the conditions under which a
scaffold must be designed by an engineer. Accordingly, the above-listed
proposed requirements (Sec. 1926.451(b)(18)(i) [now final rule
Sec. 1926.451(d)(3)(i)] and Secs. 1926.452(a)(10), (b)(10), (c)(6), and
(i)(8)) have been promulgated in the final rule. As discussed below,
proposed rules Sec. 1926.452(a)(10) and (b)(10) have been revised to
distinguish more clearly between those circumstances where the employer
would need the services of a registered professional engineer and those
situations where the services of a qualified person, who could refer to
non-mandatory Appendix A, would be sufficient.
The Agency believes that there are qualified persons who can
properly design scaffolds without reference to Appendix A. The Agency
also believes that there will be circumstances where the ``qualified
person'' retained to comply with paragraph (a)(6) will need to be a
registered professional engineer.

[[Page 46039]]

Paragraph 1926.451(b) Scaffold Platform Construction

Paragraph 1926.451(b) of this final rule provides criteria for the
construction of scaffolds. Paragraph (b)(1) requires all platforms,
except walkways and those platforms used by employees performing
scaffold erection and dismantling operations, to be fully decked or
planked. In addition, paragraph (b)(1)(i) requires that platform units
be placed so that spaces between units do not exceed 1-inch, except
where employers establish that more space is needed. For example, this
would be necessary to fit around uprights when using side brackets to
extend platform width. Paragraph (b)(1)(ii) provides that, where the
exception created by paragraph (b)(1)(i) applies, employers shall place
platform units as close together as possible, with the space between
the platform and uprights not to exceed 9\1/2\ inches. OSHA set 9\1/2\
inches as the maximum space allowed, because the minimum width for
scaffold units that could be expected to sustain a working load is just
over 9\1/2\ inches. This provision, which is effectively identical to
the provision in the proposed rule, codifies the Agency's longstanding
interpretation of existing Sec. 1926.451(a)(4), which addresses
guardrails on scaffolds, to require that guardrails be erected as close
as possible to the platform planking. Because guardrails normally can
be conveniently attached only at the scaffold uprights, OSHA has
required the platforms to be sized such that there is no gap between
the outermost plank edge and the guardrail. However, most prefabricated
end frames do not have a lateral spacing between uprights which can
accommodate an integral number of commercially-available planks. In
order to comply with the existing rule, some employers have modified
the last plank (notched, slanted, or cut it to size). This can lead to
a significant reduction in plank strength, and possibly cause tipping
of the plank (sideways) if eccentrically loaded. Therefore, to deal
with this problem, proposed and final rule paragraph (b)(1) have
modified the corresponding requirement of the existing standard by
requiring the span between uprights to be planked or decked as fully as
possible, but allowing up to 9\1/2\ inches between the planking or
decking and the guardrail supports. As explained above, 9\1/2\ inches
is the maximum allowable open space.
One commenter (Ex. 2-29) stated that the 1-inch opening allowed by
proposed paragraph (b)(1)(i) would be large enough to ``allow many
tools and small materials to fall through'', and recommended a maximum
space of \1/4\ inch between units. OSHA, however, finds that such a
small maximum space would pose unreasonable compliance burdens, and is
retaining the 1-inch maximum.
The SSFI and the SIA (Exs. 2-367 and 2-368) stated that compliance
with proposed paragraph (b)(1) would be impossible when erecting or
dismantling scaffolds. In particular, the SIA (Ex. 2-368) stated:

For example: On a multi-level supported scaffold where
construction work is to be performed only at the top level, lower
levels would not be planked. Erectors would only use sufficient
planks required to construct the scaffold.
Load requirements limit the number of levels that can be planked
on many installations. The additional cost in labor and material
would be staggering. In addition, the fatigue factor created by
installing full planking from one level to the next would create a
greater hazard to the erectors.

The Agency agrees with the SIA comments and acknowledges that a
requirement to fully plank under these conditions would unreasonably
interfere with the erection and dismantling process. The Agency also
agrees that a requirement to fully plank every intermediate platform
level, where no work other than scaffold erection or dismantling
operations will occur, is overly burdensome. Therefore, OSHA has
revised proposed paragraph (b)(1), which already excepted walkways from
the requirement for full planking or decking, to add an exception to
the final rule to the planking requirements for erection or dismantling
operations. In a situation where no work, other than erecting or
dismantling the scaffold, is being done at intermediate levels, the
final rule requires only that the planking established by the employer
as necessary to provide safe working conditions for employees erecting
or dismantling the scaffold be used. On the other hand, if scaffold
erection or dismantling is being performed from an intermediate level
platform that is being or will be used as a work area, that platform
must be fully planked in accordance with paragraph (b)(1).
Paragraph (b)(2) of the final rule requires that all scaffold
platforms and walkways be at least 18 inches (46 cm) wide, with lesser
widths allowed for ladder jack scaffolds, top plate bracket scaffolds,
pump jack scaffolds, roof bracket scaffolds, and boatswains' chairs,
and for scaffolds in areas shown to be too narrow to accommodate an 18-
inch wide surface. Proposed paragraph (b)(2) also required a minimum
18-inch width, with exceptions for ladder jack scaffolds (12 inches)
and boatswains' chairs (any width). The rationale for setting a 12-inch
minimum width for ladder jack scaffolds, as discussed in the preamble
of the proposal (51 FR 42684-85), was the difficulty of handling one
18-inch wide plank or two 9-inch planks on a ladder, which the Agency
considered more hazardous than working on a 12-inch wide plank. In the
final rule, OSHA has also included pump jack scaffolds in the exception
to paragraph (b)(2) for which a minimum platform width of 12 inches is
permitted, based on a commenter's statement (Ex. 2-31) that OSHA's
performance criteria for pump jack scaffolds enable employees to work
safely on platforms that are 12 inches or 14 inches wide. The commenter
also indicated that requiring pump jack scaffold platforms to be at
least 18 inches, instead of 12 inches, wide would create ``an economic
hardship * * * for this very prevalent size aluminum platform.'' OSHA
agrees that pump jack scaffolds with platforms as narrow as 12 inches
can satisfy the performance criteria of the final rule and has revised
paragraph (b)(2) accordingly.
In addition, the Agency is recognizing top plate bracket scaffolds
and adding them to the list of scaffolds which are permitted to have
platforms not less than 12 inches in width. As discussed above in the
definition section, these are supported scaffolds, similar to
carpenters' bracket scaffolds and form scaffolds, which consist of a
platform supported by brackets that hook over or are attached to the
top plate of a wall. These scaffolds are used in residential
construction for setting trusses, usually for high ceiling situations
(e.g., cathedral ceilings, atria). The Agency has determined that use
of this type of scaffold, even with a 12-inch wide platform, provides
greater protection for employees setting trusses than the use of
ladders, makeshift scaffolds or walking the top plate. OSHA concludes
that it would be less safe to require wider platforms for top plate
scaffolds because setting up this type of scaffold would then require
handling and positioning an 18-inch wide platform or two nine-inch wide
platforms, and handling and positioning larger, heavier brackets, which
is usually done from ladders. OSHA finds that this would be more
hazardous than working on one 12-inch wide platform equipped with fall
protection.
As proposed, OSHA is deleting the requirement that appeared in the
existing scaffold rule at Sec. 1926.451(l)(1), which sets the minimum
dimensions of

[[Page 46040]]

a boatswains' chair at 12 inches by 24 inches, because, with the advent
of slings and molded seats, the Agency believes that setting minimum
dimensions is overly restrictive. This performance-oriented approach is
reflected by the inclusion of language in paragraph (b)(2)(i) which
specifically exempts boatswains' chairs from any width requirements.
The SIA (Ex. 2-368) suggested that platforms as narrow as 12 inches
wide be allowed in areas where entryways are restricted. Another
commenter (Ex. 2-64) suggested that suspension scaffolds designed for
special applications (e.g., to fit through manholes) be permitted to be
as narrow as 12 inches. OSHA realizes that there may be instances where
the nature of the work being performed makes it impossible to make
platforms and walkways at least 18 inches wide. Where the employer can
establish that such a situation exists, the Agency will accept
platforms and walkways that are less than 18 inches wide, provided both
that such platforms and walkways are as wide as is feasible and that
employees are adequately protected from fall hazards by the use of
guardrails and/or personal fall arrest systems, as required by
paragraph (g).
Final rule paragraph (b)(3) (proposed as paragraph (b)(4)) sets the
requirements for the space between the front edge of a platform and the
face of the structure where the scaffold is being used. Paragraph
(b)(3) requires that, except as provided in paragraphs (b)(3)(i) and
(b)(3)(ii), the front edge of all platforms must be no more than 14
inches from the face of the structure, unless the employer implements
guardrail systems or personal fall arrest systems that comply with
paragraph (g) of the final rule to protect employees from falling
between the platform and the structure. Final rule paragraph (b)(3)(i)
requires that the front edges of outrigger scaffolds be no more than
three inches from the face of the structure, as is required by
Sec. 1926.451(g)(4) of OSHA's existing standard. Final rule paragraph
(b)(3)(ii) requires that the front edges of scaffolds used for
plastering and lathing operations be no more than 18 inches from the
face of the structure.
The 18-inch dimension was developed from data collected by Wang
Associates (Ex. 5) which show that a shorter distance between the
scaffold platform and the wall is not feasible for the operators of
plastering and lathing equipment because of interference with the tools
used during such operations. However, these same operations cause the
employee to stand back from the edge and the hazard of falling is
correspondingly reduced. The SIA (Ex. 2-368) supported the 18-inch
provision as being necessary for the types of work covered, while
acknowledging that in some cases 14 inches would be adequate.
Final rule paragraph (b)(3) is effectively identical to proposed
paragraph (b)(4), except that the proposed provision specified ``Type
I'' guardrails instead of requiring compliance with paragraph (g). OSHA
has deleted the designations ``Type I'' and ``Type II'' from the final
rule for subpart L, as discussed above in relation to the definition of
``Guardrail system''.
Existing Sec. 1926.451(a)(4) requires guardrails on all open sides
and ends of a scaffold platform, but does not specify how far away a
scaffold platform may be from a building before the side facing the
building is considered to be an ``open side.'' OSHA's existing scaffold
rule has often been interpreted to mean that no open space is allowed.
However, zero clearance during all phases of construction is not
feasible. The 14-inch limit in proposed paragraph (b)(4) recognized
that during construction the face of the wall being built often moves
out toward the scaffolds. There must be sufficient space at the
beginning of work to allow for the installation of insulation, lathing,
plaster, masonry units, ledges, facings and other architectural or
structural additions. The spacing must be allowed for from the start,
because it is not practical to move large scaffolds away from the wall
as wall construction progresses outward. When the initial set back
distance must be more than 14 inches, the platform can often still be
kept within 14 inches of the building by the use of side brackets or
extensions on supported scaffolds, and by angulated roping, static
lines, or equivalent means on suspension scaffolds.
Two commenters (Exs. 2-41 and 2-465) questioned the use of 14
inches in this provision, suggesting that a maximum of 12 inches be
allowed. While OSHA recognizes that the suggested 12-inch spacing could
be marginally more protective, the Agency also recognizes that, as
discussed above, in many cases an unobstructed working space of at
least 14 inches is necessary. OSHA also notes that ANSI A10.8-1988,
paragraph 4.5.9, allows up to a 16-inch space for supported scaffolds
and a 12-inch space for suspended scaffolds. In support of OSHA's
position, the SIA (Ex. 2-368) endorsed the proposed language as the
proper solution to the problem, while noting that it would prefer 18
inches. The Agency believes that the 14-inch space appropriately
addresses both the safety concerns and the need to allow necessary room
for many of the jobs normally performed from scaffolds.
Final rule paragraph (b)(4) requires each end of a platform unit,
unless cleated or otherwise restrained by hooks or equivalent means, to
extend over the center line of its support at least six inches (15 cm).
This provision is virtually identical to proposed paragraph (b)(5),
which was based on existing Sec. 1926.451(a)(14). The use of cleats,
hooks, and similar securing devices would also be allowed as
alternatives to the six inch extension in the proposed and final rules,
because of their ability to restrain movement of platform units.
OSHA received one comment (Ex. 2-40) on this provision, which
stressed the importance of securing platform units against movement.
Final rule paragraph (b)(5) (proposed paragraph (b)(6)) addresses
the maximum distance platform units may extend over their supports. In
particular, paragraph (b)(5)(i) provides that each end of a platform
unit 10 feet (3 m) or less in length shall not extend over its support
more than 12 inches (30 cm) unless the unit is designed, and installed
so that the cantilevered portion of the unit is able to support
employees or material without tipping or has guardrails which prevent
employee access to the cantilevered end. In addition, paragraph
(b)(5)(ii) provides that each platform unit greater than 10 feet in
length shall not extend over its support more than 18 inches (46 cm),
unless the unit is designed and installed so that the cantilevered
portion of the unit is able to support employees without tipping, or
that the unit has guardrails which block employee access to the
cantilevered end.
OSHA proposed to change the maximum overhang allowed by existing
Sec. 1926.451(a)(14) from 12 inches to 18 inches because many planks in
use are 10 feet long, and are used to span eight foot distances. OSHA
also notes that ANSI A10.8-1988, paragraph 4.17, limits planks from
extending more than 18 inches over their supports, without regard to
the length of the plank.
OSHA's thinking at the time of the proposal was that the existing
requirement was unnecessarily restrictive, and that strict adherence to
the existing maximum overhang limit would require platform units to be
cut if they extended beyond the 12-inch limit.
Although no comments were received on this provision, OSHA has
concluded, upon further consideration of this matter, that the maximum
overhang allowed, unless the above specified

[[Page 46041]]

measures have been taken, should be limited to 12 inches for planks 10
feet or less in length, and 18 inches for planks greater than 10 feet
in length. The Agency concludes that allowing an 18-inch overhang as a
matter of course would be unsafe, because the weight of an employee on
an 18-inch overhang could easily tip a 10-foot plank. However, an 18-
inch overhang on a plank that is longer than 10 feet would be
permissible because the additional weight of the longer platform would
offset the weight of the employee on the overhang. In addition, an
employer who seeks to use platform units that overhang the supports
more than the prescribed distance would be required to satisfy the
performance criteria of paragraph (b)(5) of the final rule.
Under final rule paragraph (b)(6), where platform units are abutted
to create a long platform, each abutted end shall rest on a separate
support surface. Abutted platform units do not rest one on another, but
instead are end-to-end. Consequently, one unit does not support the
other, and proper support can only be provided by separate support
surfaces. This provision is virtually identical to proposed paragraph
(b)(7), except that the final rule has deleted the words ``butt plate
or equivalent means of support'', because those words add nothing to
the requirement for ``separate support.'' This provision is based on
existing Sec. 1926.451(b)(12), which currently applies only to wood
pole scaffolds. OSHA has determined that all scaffolds need proper
platform support and, accordingly, has promulgated this provision.
The Agency has also added a note to this provision stating that
common support members such as ``T'' sections or hook-on platforms
designed to rest on common supports are not prohibited by this
provision. The Agency is doing this to prevent confusion since these
commonly used support members might be considered not to meet the
requirements of this provision.
Final rule paragraph (b)(7) provides that 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. This provision is virtually identical to proposed paragraph
(b)(8) which was based on existing Sec. 1926.451(a)(12).
Final rule paragraph (b)(8) requires that 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. This provision is virtually identical to proposed paragraph
(b)(9), which was based on existing Sec. 1926.451(b)(13). While this
provision in OSHA's existing standard addresses only wood pole
scaffolds, OSHA has determined, as with final rule paragraph (b)(6),
that the existing requirement is appropriately applied to the
construction of all scaffold platforms.
Final rule paragraph (b)(9) provides that wood platforms shall not
be covered with opaque finishes, except that platform edges may be
covered or marked for purposes of identification. Platforms may be
coated periodically with wood preservatives, fire-retardant finishes,
and slip-resistant finishes, but the coating may not obscure the top or
bottom wood surfaces. This paragraph is intended to ensure that
structural defects in platforms are not covered from view by the use of
an opaque coating or finish. Hairline cracks can significantly reduce
the strength of a wood member, so early detection of structural defects
is important. Opaque finishes can cover such cracks and make them
difficult to discover. The edges of platform units are excepted from
this rule to allow identification marks, grading marks, or other
similar type of marks to be placed on the unit edges.
This provision is virtually identical to proposed paragraph
(b)(10). The proposal addressed the use of wood preservatives, fire
retardant finishes and slip-resistant finishes in a ``note'', while the
final rule has incorporated the pertinent language directly into the
regulatory text. In short, those finishes may be used as long as they
do not obscure the top or bottom wood surfaces.
Final rule paragraph (b)(10) requires that scaffold components
manufactured by different manufacturers not be intermixed unless the
component parts fit together without force and the resulting 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 the resulting scaffold is determined by a
competent person to be structurally sound. OSHA expects that the
competent person who evaluates the scaffold will have the appropriate
knowledge, skill and experience regarding scaffold systems and
components.
This provision is identical to proposed paragraph (b)(11), except
that the proposal did not contain the phrase ``and the resulting
scaffold's structural integrity is maintained by the user''. The SIA
(Ex. 2-368) suggested the added language, citing the ``latest ANSI
A10.8 draft.'' The Agency acknowledges that a scaffold may lack the
requisite structural integrity even though the intermixed components
``fit together without force.'' OSHA agrees that the requirement to
maintain structural integrity should be clearly stated in this
provision and has revised the final rule accordingly.
One commenter (Ex. 2-29) stated ``[m]any, if not all, scaffold
manufacturers void any liability if their scaffold components are
intermixed * * * A standard requirement should not result in a lesser
degree of safety; neither should it encourage an employer to take a
course of action that could increase his liability.'' The SSFI (Ex. 2-
367) stated ``[i]t would be the Institute's recommendation that
scaffold components not be intermixed even though they may re[a]dily
fit together without force. Many times the capacity or bracing
alignment would not be the same as other types of scaffold, thus
creating a hazardous situation.'' OSHA agrees that an unsafe condition
could exist when parts are intermixed, unless adequate precautions are
taken, and believes that paragraph (b)(10), as modified, in conjunction
with Sec. 1926.451(a), provides for adequate precautions to be taken by
the employer to ensure against this eventuality.
Paragraph (b)(11) of the final rule provides t

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A96-21289. Public record. Not legal advice.