[Federal Register Volume 88, Number 47 (Friday, March 10, 2023)]
[Notices]
[Pages 15080-15090]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-04883]


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DEPARTMENT OF LABOR

Occupational Safety and Health Administration

[Docket No. OSHA-2022-0007]


McNally/Kiewit Joint Venture: Grant of Permanent Variance

AGENCY: Occupational Safety and Health Administration (OSHA), Labor.

ACTION: Notice of permanent variance.

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SUMMARY: In this notice, OSHA grants a permanent variance to McNally/
Kiewit Joint Venture (McNally) related to work in compressed-air 
environments.

DATES: The permanent variance specified by this notice becomes 
effective on March 10, 2023 and shall remain in effect until the 
completion of the Shoreline Storage Tunnel project or until modified or 
revoked by OSHA.

FOR FURTHER INFORMATION CONTACT: Information regarding this notice is 
available from the following sources:
    Press inquiries: Contact Mr. Frank Meilinger, Director, OSHA Office 
of Communications, phone: (202) 693-1999; email: 
[email protected].
    General and Technical Information: Contact Kevin Robinson, 
Director, Office of Technical Programs and Coordination Activities, 
Directorate of Technical Support and Emergency Management, Occupational 
Safety and Health Administration, U.S. Department of Labor; phone: 
(202) 693-2110 or email: [email protected].

SUPPLEMENTARY INFORMATION: 
    Copies of this Federal Register notice: Electronic copies of this 
Federal Register notice are available at http://www.regulations.gov. 
This Federal Register notice and other relevant information are also 
available at OSHA's web page at http://www.osha.gov.

I. Overview

    On November 12, 2021, OSHA received a variance application 
submitted by letter from McNally/Kiewit joint venture (``McNally'' or 
``the applicant'') regarding the Shoreline Storage Tunnel project, 
which consists of boring a 12-foot diameter tunnel under a subaqueous 
roadway in Cleveland, Ohio. McNally requested a permanent variance from 
several provisions of 29 CFR 1926.803, the OSHA standard that regulates 
construction work in compressed air environments. Specifically, McNally 
sought a variance from the provisions of the standard that: (1) 
prohibit compressed-air worker exposure to pressures exceeding 50 
pounds per square inch (p.s.i.) except in an

[[Page 15081]]

emergency (29 CFR 1926.803(e)(5)); \1\ (2) require the use of the 
decompression values specified in decompression tables in Appendix A of 
the compressed-air standard for construction (29 CFR 1926.803(f)(1)); 
and (3) require the use of automated operational controls and a special 
decompression chamber (29 CFR 1926.803(g)(1)(iii) and .803(g)(1)(xvii), 
respectively). McNally also requested an interim order pending OSHA's 
decision on the application for a variance (Document ID No. OSHA-2022-
0007-0002).
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    \1\ The decompression tables in Appendix A of subpart S express 
the maximum working pressures as pounds per square inch gauge 
(p.s.i.g.), with a maximum working pressure of 50 p.s.i.g. 
Therefore, throughout this notice, OSHA expresses the 50 p.s.i. 
value specified by 29 CFR 1926.803(e)(5) as 50 p.s.i.g., consistent 
with the terminology in Appendix A, Table 1 of subpart S.
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    OSHA reviewed McNally's application for a permanent variance and 
interim order and determined that it was appropriately submitted in 
compliance with the applicable variance procedures in Section 6(d) of 
the Occupational Safety and Health Act of 1970 (OSH Act; 29 U.S.C. 655) 
and OSHA's regulations at 29 CFR 1905.11 (variances and other relief 
under section 6(d)), including the requirement that the applicant 
inform workers and their representatives of their rights to petition 
the Assistant Secretary of Labor for Occupational Safety and Health for 
a hearing on the variance application.
    OSHA reviewed the alternative procedures in McNally's application 
and preliminarily determined that the applicant's proposed alternatives 
on the whole, subject to the conditions in the request and imposed by 
the interim order, provide measures that are as safe and healthful as 
those required by the cited OSHA standards. On September 26, 2022, OSHA 
published a Federal Register notice announcing McNally's application 
for permanent variance, stating the preliminary determination along 
with the basis of that determination, and granting the interim order 
(87 FR 58379). OSHA requested comments on each.
    OSHA did not receive any comments or other information disputing 
the preliminary determination that the alternatives were at least as 
safe as OSHA's standard, nor any objections to OSHA granting a 
permanent variance. Accordingly, through this notice OSHA grants a 
permanent variance, subject to the conditions set out in this document.

A. Background

    The information that follows about McNally, its methods, and its 
project comes from McNally's variance application.
    McNally (the applicant) is a contractor that works on complex 
tunnel projects using innovations in tunnel-excavation methods and is 
the contractor for the Shoreline Storage Tunnel Project (the project). 
The applicant's workers engage in the construction of tunnels using 
advanced shielded mechanical excavation techniques in conjunction with 
an earth pressure balanced tunnel boring machine (TBM). Using shielded 
mechanical excavation techniques, in conjunction with precast concrete 
tunnel liners and backfill grout, TBMs provide methods to achieve the 
face pressures required to maintain a stabilized tunnel face through 
various geologies and isolate that pressure to the forward section (the 
working chamber) of the TBM.
    McNally asserts that it bores tunnels using a TBM at levels below 
the water table through soft soils consisting of clay, silt, and sand. 
TBMs are capable of maintaining pressure at the tunnel face, and 
stabilizing existing geological conditions, through the controlled use 
of a mechanically driven cutter head, bulkheads within the shield, 
ground-treatment foam, and a screw conveyor that moves excavated 
material from the working chamber. The forward-most portion of the TBM 
is the working chamber, and this chamber is the only pressurized 
segment of the TBM. Within the shield, the working chamber consists of 
two sections: the forward working chamber and the staging chamber. The 
forward working chamber is immediately behind the cutter head and 
tunnel face. The staging chamber is behind the forward working chamber 
and between the man-lock door and the entry door to the forward working 
chamber.
    The TBM has twin man-locks located between the pressurized working 
chamber and the non-pressurized portion of the machine. Each man-lock 
has two compartments. This configuration allows workers to access the 
man-locks for compression and decompression, and medical personnel to 
access the man-locks if required in an emergency.
    McNally's Hyberbaric Operations Manual (HOM) for the Shoreline 
Storage Tunnel Project indicated that the maximum pressure to which it 
is likely to expose workers during project interventions for the 
Shoreline Storage Tunnel Project is 55 p.s.i. Therefore, to work 
effectively, McNally must perform hyperbaric interventions in 
compressed air at pressures nearly 10% higher than the maximum pressure 
specified by the existing OSHA standard, 29 CFR 1926.803(e)(5), which 
states: ``No employee shall be subjected to pressure exceeding 50 
p.s.i. except in emergency'' (see footnote 1).
    McNally employs specially trained personnel for the construction of 
the tunnel. To keep the machinery working effectively, McNally asserts 
that these workers must periodically enter the excavation working 
chamber of the TBM to perform hyperbaric interventions during which 
workers would be exposed to air pressures up to 55 p.s.i., which 
exceeds the maximum pressure specified by the existing OSHA standard at 
29 CFR 1926.803(e)(5). These interventions consist of conducting 
inspections or maintenance work on the cutter-head structure and 
cutting tools of the TBM, such as changing replaceable cutting tools 
and disposable wear bars, and, in rare cases, repairing structural 
damage to the cutter head. These interventions are the only time that 
workers are exposed to compressed air. Interventions in the working 
chamber (the pressurized portion of the TBM) take place only after 
halting tunnel excavation and preparing the machine and crew for an 
intervention.
    During interventions, workers enter the working chamber through one 
of the twin man-locks that open into the staging chamber. To reach the 
forward part of the working chamber, workers pass through a door in a 
bulkhead that separates the staging chamber from the forward working 
chamber. The man-locks and the working chamber are designed to 
accommodate three people, which is the maximum crew size allowed under 
the permanent variance. When the required decompression times are 
greater than work times, the twin man-locks allow for crew rotation. 
During crew rotation, one crew can be compressing or decompressing 
while the second crew is working. Therefore, the working crew always 
has an unoccupied man-lock at its disposal.
    McNally asserts that these innovations in tunnel excavation have 
greatly reduced worker exposure to hazards of pressurized air work 
because they have eliminated the need to pressurize the entire tunnel 
for the project and would thereby reduce the number of workers exposed, 
as well as the total duration of exposure, to hyperbaric pressure 
during tunnel construction. These advances in technology substantially 
modified the methods used by the construction industry to excavate 
subaqueous tunnels compared to the caisson work regulated by the 
current OSHA compressed-air standard for construction at 29 CFR 
1926.803.

[[Page 15082]]

    In addition to the reduced exposures resulting from the innovations 
in tunnel-excavation methods, McNally asserts that innovations in 
hyperbaric medicine and technology improve the safety of decompression 
from hyperbaric exposures. These procedures, however, would deviate 
from the decompression process that OSHA requires for construction in 
29 CFR 1926.803(e)(5) and (f)(1) and the decompression tables in 
Appendix A of 29 CFR 1926, subpart S. Nevertheless, according to 
McNally, their use of decompression protocols incorporating oxygen is 
more efficient, effective, and safer for tunnel workers than compliance 
with the decompression tables specified by the existing OSHA standard.
    McNally contends that the alternative safety measures included in 
the application provide McNally's workers with a place of employment 
that is at least as safe under its proposed alternatives as they would 
be under OSHA's compressed-air standard for construction. McNally also 
provided OSHA a project-specific HOM, (OSHA-2022-0007-0003) that 
requires specialized medical support and hyperbaric supervision to 
provide assistance to a team of specially trained man-lock attendants 
and hyperbaric or compressed-air workers to support their assertions of 
equivalency in worker protection.
    OSHA included all of the above information in the Federal Register 
notice regarding McNally's variance application and did not receive any 
comments disputing any of that information, including the safety 
assertions made by McNally in the Variance application.

II. The Variance Application

    Pursuant to the requirements of OSHA's variance regulations (29 CFR 
1905.11), the applicant has certified that it notified its workers \2\ 
of the variance modification application and request for interim order 
by posting, at prominent locations where it normally posts workplace 
notices, a summary of the application and information specifying where 
the workers can examine a copy of the application. In addition, the 
applicant has certified that it informed its workers of their right to 
petition the Assistant Secretary of Labor for Occupational Safety and 
Health for a hearing on the variance modification application.
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    \2\ See the definition of ``Affected employee or worker'' in 
section VII.C. of this Notice.
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III. OSHA History of Approval of Nearly Identical Variance Requests

    OSHA has previously approved several nearly identical variances 
involving the same types of tunneling equipment used for similar 
projects (tunnel construction variances). OSHA notes that it granted 
five subaqueous tunnel construction permanent variances from the same 
provisions of OSHA's compressed-air standard (29 CFR 1926.803(e)(5), 
(f)(1), (g)(1)(iii), and (g)(1)(xvii)) that are the subject of the 
present application: (1) Impregilo, Healy, Parsons, Joint Venture (IHP 
JV) for the completion of the Anacostia River Tunnel in Washington, DC 
(80 FR 50652 (August 20, 2015)); (2) Traylor JV for the completion of 
the Blue Plains Tunnel in Washington, DC (80 FR 16440 (March 27, 
2015)); (3) Tully/OHL USA Joint Venture for the completion of the New 
York Economic Development Corporation's New York Siphon Tunnel project 
(79 FR 29809 (May 23, 2014)); (4) Salini/Impregilo/Healy Joint Venture 
for the completion of the Northeast Boundary Tunnel in Washington, DC 
(85 FR 27767 (May 11, 2020)); and (5) Ballard Marine Construction for 
the completion of the Suffolk County Tunnel Project in Suffolk, New 
York (86 FR 5253 (January 19, 2021)). OSHA has also granted interim 
orders to two applicants, Ballard Marine for the Suffolk County Outfall 
Tunnel project in West Babylon, New York (86 FR 5253 (January 19, 
2021)) and Traylor Shea Joint Venture for the Alexandria RiverRenew 
Tunnel Project in Alexandria, Virginia and Washington, DC (87 FR 54536 
(September 6, 2022)). The proposed alternate conditions in this notice 
are nearly identical to the alternate conditions of the previous 
permanent variances.\3\ OSHA is not aware of any injuries or other 
safety issues that arose from work performed under these conditions in 
accordance with the previous variances.
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    \3\ The previous tunnel construction variances allowed further 
deviation from OSHA standards by permitting employee exposures above 
50 p.s.i. based on the composition of the soil and the amount of 
water that will be above the tunnel for various sections of this 
project. The current proposed variance includes substantively the 
same safeguards as the variances that OSHA granted previously even 
though employees will not be exposed to pressures higher than 55 
p.s.i.g.
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IV. Applicable OSHA Standard and the Relevant Variances

A. Variance From Paragraph (e)(5) of 29 CFR 1926.803, Prohibition of 
Exposure to Pressure Greater Than 50 p.s.i.g. (See Footnote 1)

    The applicant states that it may perform hyperbaric interventions 
at pressures up to 55 p.s.i.g. in the working chamber of the TBM; this 
pressure exceeds the pressure limit of 50 p.s.i. specified for 
nonemergency purposes by 29 CFR 1926.803(e)(5). The TBM has twin man-
locks, with each man-lock having two compartments. This configuration 
allows workers to access the man-locks for compression and 
decompression, and medical personnel to access the man-locks if 
required in an emergency.
    TBMs are capable of maintaining pressure at the tunnel face, and 
stabilizing existing geological conditions, through the controlled use 
of a mechanically driven cutter head, bulkheads within the shield, 
ground-treatment foam, and a screw conveyor that moves excavated 
material from the working chamber. As noted earlier, the forward-most 
portion of the TBM is the working chamber, and this chamber is the only 
pressurized segment of the TBM. Within the shield, the working chamber 
consists of two sections: the staging chamber and the forward working 
chamber. The staging chamber is the section of the working chamber 
between the man-lock door and the entry door to the forward working 
chamber. The forward working chamber is immediately behind the cutter 
head and tunnel face.
    McNally will pressurize the working chamber to the level required 
to maintain a stable tunnel face. Pressure in the staging chamber 
ranges from atmospheric (no increased pressure) to a maximum pressure 
equal to the pressure in the working chamber. The applicant asserts 
that they may have to perform interventions at pressures up to 55 
p.s.i.
    During interventions, workers enter the working chamber through one 
of the twin man-locks that open into the staging chamber. To reach the 
forward part of the working chamber, workers pass through a door in a 
bulkhead that separates the staging chamber from the forward working 
chamber. The maximum crew size allowed in the forward working chamber 
is three. At certain hyperbaric pressures (i.e., when decompression 
times are greater than work times), the twin man-locks allow for crew 
rotation. During crew rotation, one crew can be compressing or 
decompressing while the second crew is working. Therefore, the working 
crew always has an unoccupied man-lock at its disposal.
    Further, McNally has developed a project-specific HOM (OSHA-2022-
0007-0003) that describes in detail the hyperbaric procedures, the 
required medical examination used during the tunnel-construction 
project, the standard operating procedures and the

[[Page 15083]]

emergency and contingency procedures. The procedures include using 
experienced and knowledgeable man-lock attendants who have the training 
and experience necessary to recognize and treat decompression illnesses 
and injuries. The attendants are under the direct supervision of the 
hyperbaric supervisor (a competent person experienced and trained in 
hyperbaric operations, procedures and safety) and attending physician. 
In addition, procedures include medical screening and review of 
prospective compressed-air workers (CAWs). The purpose of this 
screening procedure is to vet prospective CAWs with medical conditions 
(e.g., deep vein thrombosis, poor vascular circulation, and muscle 
cramping) that could be aggravated by sitting in a cramped space (e.g., 
a man-lock) for extended periods, or by exposure to elevated pressures 
and compressed gas mixtures. A transportable recompression chamber 
(shuttle) is available to extract workers from the hyperbaric working 
chamber for emergency evacuation and medical treatment; the shuttle 
attaches to the topside medical lock, which is a large recompression 
chamber. The applicant believes that the procedures included in the HOM 
provide safe work conditions when interventions are necessary, 
including interventions above 50 p.s.i. or 50 p.s.i.g.
    OSHA comprehensively reviewed the project-specific HOM and 
determined that the safety and health instructions and measures it 
specifies are appropriate, conform with the conditions in the variance, 
and adequately protect the safety and health of the CAWs.

B. Variance From Paragraph (f)(1) of 29 CFR 1926.803, Requirement To 
Use OSHA Decompression Tables

    OSHA's compressed-air standard for construction requires 
decompression in accordance with the decompression tables in Appendix A 
of 29 CFR 1926, subpart S (29 CFR 1926.803(f)(1)). As an alternative to 
the OSHA decompression tables, the applicant proposes to use newer 
decompression schedules (the 1992 French Decompression Tables) that 
rely on staged decompression and supplement breathing air used during 
decompression with air or oxygen (as appropriate).\4\ The applicant 
asserts decompression protocols using the 1992 French Decompression 
Tables for air or oxygen as specified by the Shoreline Storage Tunnel-
specific Hyperbaric Operations Manual (HOM) are safer for tunnel 
workers than the decompression protocols specified in Appendix A of 29 
CFR 1926, subpart S. Accordingly, the applicant commits to following 
the decompression procedures described in that HOM, which would require 
it to follow the 1992 French Decompression Tables to decompress CAWs 
after they exit the hyperbaric conditions in the working chamber.
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    \4\ In 1992, the French Ministry of Labour replaced the 1974 
French Decompression Tables with the 1992 French Decompression 
Tables, which differ from OSHA's decompression tables in Appendix A 
by using: (1) staged decompression as opposed to continuous (linear) 
decompression; (2) decompression tables based on air or both air and 
pure oxygen; and (3) emergency tables when unexpected exposure times 
occur (up to 30 minutes above the maximum allowed working time).
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    Depending on the maximum working pressure and exposure times, the 
1992 French Decompression Tables provide for air decompression with or 
without oxygen. McNally asserts that oxygen decompression has many 
benefits, including (1) keeping the partial pressure of nitrogen in the 
lungs as low as possible; (2) keeping external pressure as low as 
possible to reduce the formation of bubbles in the blood; (3) removing 
nitrogen from the lungs and arterial blood and increasing the rate of 
nitrogen elimination; (4) improving the quality of breathing during 
decompression stops so that workers are less tired and to prevent bone 
necrosis; (5) reducing decompression time by about 33 percent as 
compared to air decompression; and (6) reducing inflammation.
    In addition, the project-specific HOM requires a physician, 
certified in hyperbaric medicine, to manage the medical condition of 
CAWs during hyperbaric exposures and decompression. A trained and 
experienced man-lock attendant also will be present during hyperbaric 
exposures and decompression. This man-lock attendant will operate the 
hyperbaric system to ensure compliance with the specified decompression 
table. A hyperbaric supervisor, trained in hyperbaric operations, 
procedures, and safety, directly oversees all hyperbaric interventions, 
and ensures that staff follow the procedures delineated in the HOM or 
by the attending physician.

C. Variance From Paragraph (g)(1)(iii) of 29 CFR 1926.803, 
Automatically Regulated Continuous Decompression

    McNally is applying for a permanent variance from the OSHA standard 
at 29 CFR 1926.803(g)(1)(iii), which requires automatic controls to 
regulate decompression. As noted above, the applicant is committed to 
conducting the staged decompression according to the 1992 French 
Decompression Tables under the direct control of the trained man-lock 
attendant and under the oversight of the hyperbaric supervisor.
    Breathing air under hyperbaric conditions increases the amount of 
nitrogen gas dissolves in a CAW's tissues. The greater the hyperbaric 
pressure under these conditions and the more time spent under the 
increased pressure, the greater the amount of nitrogen gas dissolved in 
the tissues. When the pressure decreases during decompression, tissues 
release the dissolved nitrogen gas into the blood system, which then 
carries the nitrogen gas to the lungs for elimination through 
exhalation. Releasing hyperbaric pressure too rapidly during 
decompression can increase the size of the bubbles formed by nitrogen 
gas in the blood system, resulting in decompression illness (DCI), 
commonly referred to as ``the bends.'' This description of the etiology 
of DCI is consistent with current scientific theory and research on the 
issue (see footnote 16 in this notice discussing a 1985 NIOSH report on 
DCI).
    The 1992 French Decompression Tables, proposed for use by the 
applicant provide for stops during worker decompression (i.e., staged 
decompression) to control the release of nitrogen gas from tissues into 
the blood system. Studies show that staged decompression, in 
combination with other features of the 1992 French Decompression Tables 
such as the use of oxygen, result in a lower incidence of DCI than the 
use of automatically regulated continuous decompression.\5\ In 
addition, the applicant asserts that staged decompression administered 
in accordance with its HOM is at least as

[[Page 15084]]

effective as an automatic controller in regulating the decompression 
process because the HOM includes a hyperbaric supervisor who directly 
supervises all hyperbaric interventions and ensures that the man-lock 
attendant, who is a competent person in the manual control of 
hyperbaric systems, follows the schedule specified in the decompression 
tables, including stops.
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    \5\ See, e.g., Dr. Eric Kindwall, EP (1997), Compressed air 
tunneling and caisson work decompression procedures: development, 
problems, and solutions. Undersea and Hyperbaric Medicine, 24(4), 
pp. 337-345. This article reported 60 treated cases of DCI among 
4,168 exposures between 19 and 31 p.s.i.g. over a 51-week contract 
period, for a DCI incidence of 1.44% for the decompression tables 
specified by the OSHA standard. Dr. Kindwall notes that the use of 
automatically regulated continuous decompression for compressed-air 
work was in some cases at the insistence of contractors and the 
union, and against the advice of the expert who calculated the 
decompression table and recommended using staged decompression. Dr. 
Kindwall then states, ``Continuous decompression is inefficient and 
wasteful. For example, if the last stage from 4 p.s.i.g. . . . to 
the surface took 1h, at least half the time is spent at pressures 
less than 2 p.s.i.g. . . ., which provides less and less meaningful 
bubble suppression . . . .'' In addition, Dr. Kindwall addresses the 
continuous-decompression protocol in the OSHA compressed-air 
standard for construction, noting that ``[a]side from the tables for 
saturation diving to deep depths, no other widely used or officially 
approved diving decompression tables use straight line, continuous 
decompressions at varying rates. Stage decompression is usually the 
rule, since it is simpler to control.''
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D. Variance From Paragraph (g)(1)(xvii) of 29 CFR 1926.803, Requirement 
of Special Decompression Chamber

    The OSHA compressed-air standard for construction requires 
employers to use a special decompression chamber of sufficient size to 
accommodate all CAWs being decompressed at the end of the shift when 
total decompression time exceeds 75 minutes (see 29 CFR 
1926.803(g)(1)(xvii)). Use of the special decompression chamber enables 
CAWs to move about and flex their joints to prevent neuromuscular 
problems during decompression.
    Space limitations in the TBM do not allow for the installation and 
use of an additional special decompression lock or chamber. The 
applicant proposes that it be permitted to rely on the man-locks and 
staging chamber in lieu of adding a separate, special decompression 
chamber. Because only a few workers out of the entire crew are exposed 
to hyperbaric pressure, the man-locks (which, as noted earlier, connect 
directly to the working chamber) and the staging chamber are of 
sufficient size to accommodate all exposed workers during 
decompression. The applicant uses the existing man-locks, each of which 
adequately accommodates a three-member crew for this purpose when 
decompression lasts up to 75 minutes. When decompression exceeds 75 
minutes, crews can open the door connecting the two compartments in 
each man-lock (during decompression stops) or exit the man-lock and 
move into the staging chamber where additional space is available. The 
applicant asserts that this alternative arrangement is as effective as 
a special decompression chamber in that it has sufficient space for all 
the CAWs at the end of a shift and enables the CAWs to move about and 
flex their joints to prevent neuromuscular problems.

V. Decision

    After reviewing the proposed alternatives, OSHA has determined that 
the applicant's proposed alternatives on the whole, subject to the 
conditions in the variance request and imposed by the permanent 
variance, provide measures that are as safe and healthful as those 
required by the cited OSHA standards addressed in section II of this 
notice.
    In addition, OSHA has determined that each of the following 
alternatives are at least as effective as the specified OSHA 
requirements:

A. 29 CFR 1926.803(e)(5)

    McNally has developed, and proposed to implement, effective 
alternative measures to the prohibition of using compressed air under 
hyperbaric conditions exceeding 50 p.s.i. The alternative measures 
include use of engineering and administrative controls of the hazards 
associated with work performed in compressed-air conditions exceeding 
50 p.s.i. while engaged in the construction of a subaqueous tunnel 
using advance shielded mechanical-excavation techniques in conjunction 
with the TBM. Prior to conducting interventions in the TBM's 
pressurized working chamber, McNally halts tunnel excavation and 
prepares the machine and crew to conduct the interventions. 
Interventions involve inspection, maintenance, or repair of the 
mechanical-excavation components located in the working chamber.

B. 29 CFR 1926.803(f)(1)

    The applicant has proposed to implement equally effective 
alternative measures to the requirement in 29 CFR 1926.803(f)(1) for 
compliance with OSHA's decompression tables. The HOM specifies the 
procedures and personnel qualifications for performing work safely 
during the compression and decompression phases of interventions. The 
HOM also specifies the decompression tables the applicant proposes to 
use (the 1992 French Decompression Tables). Depending on the maximum 
working pressure and exposure times during the interventions, the 
tables provide for decompression using air, pure oxygen, or a 
combination of air and oxygen. The decompression tables also include 
delays or stops for various time intervals at different pressure levels 
during the transition to atmospheric pressure (i.e., staged 
decompression). In all cases, a physician certified in hyperbaric 
medicine will manage the medical condition of CAWs during 
decompression. In addition, a trained and experienced man-lock 
attendant, experienced in recognizing decompression sickness or 
illnesses and injuries, will be present. Of key importance, a 
hyperbaric supervisor, trained in hyperbaric operations, procedures, 
and safety, will directly supervise all hyperbaric operations to ensure 
compliance with the procedures delineated in the project-specific HOM 
or by the attending physician.
    Prior to granting the five previous permanent variances to IHP JV, 
Traylor JV, Tully JV, Salini-Impregilo Joint Venture, and Ballard, OSHA 
conducted a review of the scientific literature and concluded that the 
alternative decompression method (i.e., the 1992 French Decompression 
Tables) McNally proposed would be at least as safe as the decompression 
tables specified by OSHA when applied by trained medical personnel 
under the conditions outlined in this variance application.
    Some of the literature indicates that the alternative decompression 
method may be safer, concluding that decompression performed in 
accordance with these tables resulted in a lower occurrence of DCI than 
decompression conducted in accordance with the decompression tables 
specified by the standard. For example, H. L. Anderson studied the 
occurrence of DCI at maximum hyperbaric pressures ranging from 4 
p.s.i.g. to 43 p.s.i.g. during construction of the Great Belt Tunnel in 
Denmark (1992-1996).\6\ This project used the 1992 French Decompression 
Tables to decompress the workers during part of the construction. 
Anderson observed 6 DCI cases out of 7,220 decompression events and 
reported that switching to the 1992 French Decompression tables reduced 
the DCI incidence to 0.08% compared to a previous incidence rate of 
0.14%. The DCI incidence in the study by H. L. Andersen is 
substantially less than the DCI incidence reported for the 
decompression tables specified in Appendix A.
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    \6\ Anderson HL (2002). Decompression sickness during 
construction of the Great Belt tunnel, Denmark. Undersea and 
Hyperbaric Medicine, 29(3), pp. 172-188.
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    OSHA found no studies in which the DCI incidence reported for the 
1992 French Decompression Tables were higher than the DCI incidence 
reported for the OSHA decompression tables.\7\
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    \7\ Le P[eacute]chon JC, Barre P, Baud JP, Ollivier F (September 
1996). Compressed air work--French Tables 1992--operational results. 
JCLP Hyperbarie Paris, Centre Medical Subaquatique Interentreprise, 
Marseille: Communication a l'EUBS, pp. 1-5 (see Ex. OSHA-2012-0036-
0005).
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    OSHA's experience with the previous five variances, which all 
incorporated nearly identical decompression plans and did not result in 
safety issues, also provide evidence that the alternative procedure as 
a whole is at least as effective for this type of tunneling project as 
compliance with OSHA's decompression tables. The experience of State 
Plans \8\ that either granted

[[Page 15085]]

variances (Nevada, Oregon and Washington) \9\ or promulgated a new 
standard (California) \10\ for hyperbaric exposures occurring during 
similar subaqueous tunnel-construction work, provide additional 
evidence of the effectiveness of this alternative procedure.
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    \8\ Under Section 18 of the OSH Act, Congress expressly provides 
that States and U.S. territories may adopt, with Federal approval, a 
plan for the development and enforcement of occupational safety and 
health standards. OSHA refers to such States and territories as 
``State Plans.'' Occupational safety and health standards developed 
by State Plans must be at least as effective in providing safe and 
healthful employment and places of employment as the Federal 
standards (29 U.S.C. 667).
    \9\ These state variances are available in the docket for the 
2015 Traylor JV variance: Exs. OSHA-2012-0035-0006 (Nevada), OSHA-
2012-0035-0005 (Oregon), and OSHA-2012-0035-0004 (Washington).
    \10\ See California Code of Regulations, Title 8, Subchapter 7, 
Group 26, Article 154, available at http://www.dir.ca.gov/title8/sb7g26a154.html.
---------------------------------------------------------------------------

C. 29 CFR 1926.803(g)(1)(iii)

    The applicant developed, and proposed to implement, an equally 
effective alternative to 29 CFR 1926.803(g)(1)(iii), which requires the 
use of automatic controllers that continuously decrease pressure to 
achieve decompression in accordance with the tables specified by the 
standard. The applicant's alternative includes using the 1992 French 
Decompression Tables for guiding staged decompression to achieve lower 
occurrences of DCI, using a trained and competent attendant for 
implementing appropriate hyperbaric entry and exit procedures, and 
providing a competent--and attending physician certified in hyperbaric 
medicine to oversee all hyperbaric operations.
    In reaching this preliminary conclusion, OSHA again notes the 
experience of previous nearly identical tunneling variances, the 
experiences of State Plan States, and a review of the literature and 
other information noted earlier.

D. 29 CFR 1926.803(g)(1)(xvii)

    The applicant developed, and proposed to implement, an effective 
alternative to the use of the special decompression chamber required by 
29 CFR 1926.803(g)(1)(xvii). The TBM's man-lock and working chamber 
appear to satisfy all of the conditions of the special decompression 
chamber, including that they provide sufficient space for the maximum 
crew of three CAWs to stand up and move around, and safely accommodate 
decompression times exceeding 75 minutes. Therefore, again noting 
OSHA's previous experience with nearly identical variances including 
the same alternative, OSHA preliminarily determined that the TBM's man-
lock and working chamber function as effectively as the special 
decompression chamber required by the standard.
    Based on a review of available evidence, the experience of State 
Plans that either granted variances (Nevada, Oregon, and Washington) 
\11\ or promulgated a new standard (California) \12\ for hyperbaric 
exposures occurring during similar subaqueous tunnel-construction work, 
and the information provided in the applicant's variance application, 
OSHA is granting the permanent variance.
---------------------------------------------------------------------------

    \11\ These state variances are available in the application 
docket for the original Traylor variance application: Exs. OSHA-
2012-0035-0006 (Nevada), OSHA-2012-0035-0007 (Oregon), and OSHA-
2012-0035-0008 (Washington).
    \12\ See California Code of Regulations, Title 8, Subchapter 7, 
Group 26, Article 154, available at http://www.dir.ca.gov/title8/sb7g26a154.html.
---------------------------------------------------------------------------

    Pursuant to Section 6(d) of the Occupational Safety and Health Act 
of 1970 (29 U.S.C. 655), and based on the record discussed above, the 
agency finds that when the McNally complies with the conditions of the 
following order, the working conditions of the McNally's workers are at 
least as safe and healthful as if it complied with the working 
conditions specified by paragraphs (e)(5), (f)(1), (g)(1)(iii), and 
(g)(1)(xvii) of 29 CFR 1926.803. Therefore, McNally must: (1) comply 
with the conditions listed below under ``Conditions Specified for the 
Permanent Variance'' for the period between the date of this notice and 
completion of the Shoreline Storage Tunnel Project; (2) comply fully 
with all other applicable provisions of 29 CFR part 1926; and (3) 
provide a copy of this Federal Register notice to all employees 
affected by the conditions, including the affected employees of other 
employers, using the same means it used to inform these employees of 
the application for a permanent variance. Additionally, this order will 
remain in effect until one of the following conditions occurs: (1) 
completion of the Shoreline Storage Tunnel Project; or (2) OSHA 
modifies or revokes this final order in accordance with 29 CFR 1905.13.

VI. Description of the Conditions Specified for the Permanent Variance

    The conditions for the variance are set out in the Order at the end 
of this document. This section provides additional detail regarding the 
conditions in the Order.

Condition A: Scope

    The scope of the permanent variance limits coverage to the work 
situations specified under this condition. Clearly defining the scope 
of the permanent variance provides McNally, their employees, potential 
future applicants, other stakeholders, the public and OSHA with 
necessary information regarding the work situations in which the 
permanent variance applies. To the extent that McNally exceeds the 
defined scope of this variance, it will be required to comply with 
OSHA's standards. This permanent variance applies only to McNally, and 
only to the remainder of the Cleveland Storage Tunnel Project.

Condition B: List of Abbreviations

    Condition B defines a number of abbreviations used in the permanent 
variance. OSHA believes that defining these abbreviations serves to 
clarify and standardize their usage, thereby enhancing the applicant's 
and their employees' understanding of the conditions specified by the 
permanent variance.

Condition C: Definitions

    Condition C defines a series of terms, mostly technical terms, used 
in the permanent variance to standardize and clarify their meaning. 
Defining these terms serves to enhance the applicant's and their 
employees' understanding of the conditions specified by the permanent 
variance.

Condition D: Safety and Health Practices

    This condition requires the applicant to develop and submit to OSHA 
an HOM specific to the Shoreline Storage Tunnel at least six months 
before using the TBM, proof that the TBM's hyperbaric chambers have 
been designed, fabricated, inspected, tested marked, and stamped in 
accordance with the requirements for ASME PVHO-1-2019 (or the most 
recent edition of Safety Standards for Pressure Vessels for Human 
Occupancy). These requirements ensure that the applicant develops 
hyperbaric safety and health procedures suitable for the project.
    The submission of the HOM to OSHA, which McNally has already 
completed, enables OSHA to determine that the specific safety and 
health instructions and measures it specifies are appropriate to the 
field conditions of the tunnel (including expected geological 
conditions), conform to the conditions of the variance, and adequately 
protect the safety and health of the CAWs. It also facilitates OSHA's 
ability to ensure that the applicant is complying with these 
instructions and measures. The requirement for proof of compliance with 
ASME PVHO-1-2019 is intended

[[Page 15086]]

to ensure that the equipment is structurally sound and capable of 
performing to protect the safety of the employees exposed to hyperbaric 
pressure.
    Additionally, the condition includes a series of related hazard 
prevention and control requirements and methods (e.g., decompression 
tables, job hazard analysis (JHA), operations and inspections 
checklists, incident investigation, and recording and notification to 
OSHA of recordable hyperbaric injuries and illnesses) designed to 
ensure the continued effective functioning of the hyperbaric equipment 
and operating system.

Condition E: Communication

    Condition E requires the applicant to develop and implement an 
effective system of information sharing and communication. Effective 
information sharing and communication ensures that affected workers 
receive updated information regarding any safety-related hazards and 
incidents, and corrective actions taken, prior to the start of each 
shift. The condition also requires McNally to ensure that reliable 
means of emergency communications are available and maintained for 
affected workers and support personnel during hyperbaric operations. 
Availability of such reliable means of communications enables affected 
workers and support personnel to respond quickly and effectively to 
hazardous conditions or emergencies that may develop during TBM 
operations.

Condition F: Worker Qualification and Training

    This condition requires the applicant to develop and implement an 
effective qualification and training program for affected workers. The 
condition specifies the factors that an affected worker must know to 
perform safely during hyperbaric operations, including how to enter, 
work in, and exit from hyperbaric conditions under both normal and 
emergency conditions. Having well-trained and qualified workers 
performing hyperbaric intervention work ensures that they recognize, 
and respond appropriately to, hyperbaric safety and health hazards. 
These qualification and training requirements enable affected workers 
to cope effectively with emergencies, as well as the discomfort and 
physiological effects of hyperbaric exposure, thereby preventing worker 
injury, illness, and fatalities.
    Paragraph (2)(e) of this condition also requires the applicant to 
provide affected workers with information they can use to contact the 
appropriate healthcare professionals if they believe they are 
developing hyperbaric-related health effects. This requirement provides 
for early intervention and treatment of DCI and other health effects 
resulting from hyperbaric exposure, thereby reducing the potential 
severity of these effects.

Condition G: Inspections, Tests, and Accident Prevention

    Condition G requires the applicant to develop, implement, and 
operate a program of frequent and regular inspections of the TBM's 
hyperbaric equipment and support systems, and associated work areas. 
This condition helps to ensure the safe operation and physical 
integrity of the equipment and work areas necessary to conduct 
hyperbaric operations. The condition also enhances worker safety by 
reducing the risk of hyperbaric-related emergencies.
    Paragraph (3) of this condition requires the applicant to document 
tests, inspections, corrective actions, and repairs involving the TBM, 
and maintain these documents at the job site for the duration of the 
job. This requirement provides the applicant with information needed to 
schedule tests and inspections to ensure the continued safe operation 
of the equipment and systems, and to determine that the actions taken 
to correct defects in hyperbaric equipment and systems were 
appropriate, prior to returning them to service.

Condition H: Compression and Decompression

    This condition requires the applicant to consult with a designated 
medical advisor regarding special compression or decompression 
procedures appropriate for any unacclimated CAW and then implement the 
procedures recommended by the medical advisor. This provision ensures 
that the applicant consults with the medical advisor, and involves the 
medical advisor in the evaluation, development, and implementation of 
compression or decompression protocols appropriate for any CAW 
requiring acclimation to the hyperbaric conditions encountered during 
TBM operations. Accordingly, CAWs requiring acclimation have an 
opportunity to acclimate prior to exposure to these hyperbaric 
conditions. OSHA believes this condition will prevent or reduce adverse 
reactions among CAWs to the effects of compression or decompression 
associated with the intervention work they perform in the TBM.

Condition I: Recordkeeping

    Under OSHA's existing recordkeeping requirements in 29 CFR part 
1904 regarding Recording and Reporting Occupational Injuries and 
Illnesses, the employer must maintain a record of any recordable 
injury, illness, or fatality (as defined by 29 CFR part 1904) resulting 
from exposure of an employee to hyperbaric conditions by completing the 
OSHA Form 301 Incident Report and OSHA Form 300 Log of Work-Related 
Injuries and Illnesses. The applicant did not seek a variance from this 
standard and therefore McNally must comply fully with those 
requirements.
    Examples of important information to include on the OSHA Form 301 
Injury and Illness Incident Report (along with the corresponding 
question on the form) are:
Q14
     the task performed;
     the composition of the gas mixture (e.g., air or oxygen);
     an estimate of the CAW's workload;
     the maximum working pressure;
     temperature in the work and decompression environments;
     unusual occurrences, if any, during the task or 
decompression
Q15
     time of symptom onset;
     duration between decompression and onset of symptoms
Q16
     type and duration of symptoms;
     a medical summary of the illness or injury
Q17
     duration of the hyperbaric intervention;
     possible contributing factors;
     the number of prior interventions completed by the injured 
or ill CAW; and the pressure to which the CAW was exposed during those 
interventions.\13\
---------------------------------------------------------------------------

    \13\ See 29 CFR 1904 Recording and Reporting Occupational 
Injuries and Illnesses (http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9631); recordkeeping 
forms and instructions (http://www.osha.gov/recordkeeping/RKform300pkg-fillable-enabled.pdf); and OSHA Recordkeeping Handbook 
(http://www.osha.gov/recordkeeping/handbook/index.html).
---------------------------------------------------------------------------

    Condition I adds additional reporting responsibilities, beyond 
those already required by the OSHA rule. McNally is required to 
maintain records of specific factors associated with each hyperbaric 
intervention. The information gathered and recorded under this 
provision, in concert with the information provided under Condition J 
(using OSHA's Form

[[Page 15087]]

301 Injury and Illness Incident Report to investigate and record 
hyperbaric recordable injuries as defined by 29 CFR 1904.4, 1904.7, and 
1904.8-.12), enables McNally and OSHA to assess the effectiveness of 
the permanent variance in preventing DCI and other hyperbaric-related 
effects.

Condition J: Notifications

    Under the notification condition, the applicant is required, within 
specified periods of time, to notify OSHA of: (1) any recordable 
injury, illness, in-patient hospitalization, amputation, loss of an 
eye, or fatality that occurs as a result of hyperbaric exposures during 
TBM operations; (2) provide OSHA a copy of the hyperbaric exposures 
incident investigation report (using OSHA Form 301 Injury and Illness 
Incident Report) of these events within 24 hours of the incident; (3) 
include on OSHA Form 301 Injury and Illness Incident Report information 
on the hyperbaric conditions associated with the recordable injury or 
illness, the root-cause determination, and preventive and corrective 
actions identified and implemented; (4) provide the certification that 
affected workers were informed of the incident and the results of the 
incident investigation; (5) notify OSHA's Office of Technical Programs 
and Coordination Activities (OTPCA) and the Cleveland OSHA Area Office 
within 15 working days should the applicant need to revise the HOM to 
accommodate changes in its compressed-air operations that affect 
McNally's ability to comply with the conditions of the modified 
permanent variance; and (6) provide OTPCA and the Cleveland Ohio OSHA 
Area Office, at the end of the project, with a report evaluating the 
effectiveness of the decompression tables.
    It should be noted that the requirement for completing and 
submitting the hyperbaric exposure-related (recordable) incident 
investigation report (OSHA 301 Injury and Illness Incident Report) is 
more restrictive than the current recordkeeping requirement of 
completing OSHA Form 301 Injury and Illness Incident Report within 7 
calendar days of the incident (1904.29(b)(3)). This modified, more 
stringent incident investigation and reporting requirement is 
restricted to intervention-related hyperbaric (recordable) incidents 
only. Providing rapid notification to OSHA is essential because time is 
a critical element in OSHA's ability to determine the continued 
effectiveness of the variance conditions in preventing hyperbaric 
incidents, and the applicant's identification and implementation of 
appropriate corrective and preventive actions.
    Further, these notification requirements also enable the applicant, 
its employees, and OSHA to assess the effectiveness of the modified 
permanent variance in providing the requisite level of safety to the 
applicant's workers and, based on this assessment, whether to revise or 
revoke the conditions of the modified permanent variance. Timely 
notification permits OSHA to take whatever action may be necessary and 
appropriate to prevent possible further injuries and illnesses. 
Providing notification to employees informs them of the precautions 
taken by the applicant to prevent similar incidents in the future.
    Additionally, this condition requires the applicant to notify OSHA 
if it ceases to do business, has a new address or location for the main 
office, or transfers the operations covered by the modified permanent 
variance to a successor company. In addition, the condition specifies 
that the transfer of the modified permanent variance to a successor 
company must be approved by OSHA. These requirements allow OSHA to 
communicate effectively with the applicant regarding the status of the 
modified permanent variance and expedite the agency's administration 
and enforcement of the modified permanent variance. Stipulating that an 
applicant is required to have OSHA's approval to transfer a variance to 
a successor company provides assurance that the successor company has 
knowledge of, and will comply with, the conditions specified by 
modified permanent variance, thereby ensuring the safety of workers 
involved in performing the operations covered by the modified permanent 
variance.

VII. Order

    As of the effective date of this final order, OSHA is revoking the 
interim order granted to the employer on September 26, 2022 and 
replacing it with a permanent variance order. Note that there are not 
any substantive changes in the conditions between interim order and the 
final order.
    OSHA issues this final order authorizing McNally to comply with the 
following conditions instead of complying with the requirements of 29 
CFR 1926.803(e)(5), (f)(1), (g)(1)(iii), and (g)(1)(xvii). These 
conditions are:

A. Scope

    The permanent variance applies only when McNally stops the tunnel-
boring work, pressurizes the working chamber, and the CAWs either enter 
the working chamber to perform an intervention (i.e., inspection, 
maintain, or repair the mechanical-excavation components), or exit the 
working chamber after performing interventions.
    The permanent variance applies only to work:
    1. That occurs in conjunction with construction of the Shoreline 
Storage Tunnel Project in Cleveland, Ohio, a subaqueous tunnel 
constructed using advanced shielded mechanical-excavation techniques 
and involving operation of an TBM;
    2. In the TBM's forward section (the working chamber) and 
associated hyperbaric chambers used to pressurize and decompress 
employees entering and exiting the working chamber; and
    3. Performed in compliance with all applicable provisions of 29 CFR 
1926 except for the requirement specified by 29 CFR 1926.803(e)(5), 
(f)(1), (g)(1)(iii), and (g)(1)(xvii).
    4. This order will remain in effect until one of the following 
conditions occurs: (1) completion of the Shoreline Storage Tunnel 
Project; or (2) OSHA modifies or revokes this final order in accordance 
with 29 CFR 1905.13.

B. List of Abbreviations

    Abbreviations used throughout this permanent variance include the 
following:

1. COAO--Cleveland, Ohio OSHA Area Office
2. CAW--Compressed-air worker
3. CFR--Code of Federal Regulations
4. DCI--Decompression Illness
5. TBM--Earth Pressure Balanced Moving Tunnel Boring Machine
6. HOM--Hyperbaric Operations and Safety Manual
7. JHA--Job hazard analysis
8. OSHA--Occupational Safety and Health Administration
9. OTPCA--Office of Technical Programs and Coordination Activities

C. Definitions

    The following definitions apply to this permanent variance. These 
definitions supplement the definitions in McNally's project-specific 
HOM.
    1. Affected employee or worker--an employee or worker who is 
affected by the conditions of this permanent variance, or any one of 
his or her authorized representatives. The term ``employee'' has the 
meaning defined and used under the Occupational Safety and Health Act 
of 1970 (29 U.S.C. 651 et seq.)
    2. Atmospheric pressure--the pressure of air at sea level, 
generally 14.7 p.s.i.a., 1 atmosphere absolute, or 0 p.s.i.g.

[[Page 15088]]

    3. Compressed-air worker--an individual who is specially trained 
and medically qualified to perform work in a pressurized environment 
while breathing air at pressures not exceeding 55 p.s.i.g.
    4. Competent person--an individual who is capable of identifying 
existing and predictable hazards in the surroundings or working 
conditions that are unsanitary, hazardous, or dangerous to employees, 
and who has authorization to take prompt corrective measures to 
eliminate them.\14\
---------------------------------------------------------------------------

    \14\ Adapted from 29 CFR 1926.32(f).
---------------------------------------------------------------------------

    5. Decompression illness (also called decompression sickness or the 
bends)--an illness caused by gas bubbles appearing in body compartments 
due to a reduction in ambient pressure. Examples of symptoms of 
decompression illness include (but are not limited to): joint pain 
(also known as the ``bends'' for agonizing pain or the ``niggles'' for 
slight pain); areas of bone destruction (termed ``dysbaric 
osteonecrosis''); skin disorders (such as cutis marmorata, which causes 
a pink marbling of the skin); spinal cord and brain disorders (such as 
stroke, paralysis, paresthesia, and bladder dysfunction); 
cardiopulmonary disorders, such as shortness of breath; and arterial 
gas embolism (gas bubbles in the arteries that block blood flow).\15\
---------------------------------------------------------------------------

    \15\ See Appendix 10 of ``A Guide to the Work in Compressed Air 
Regulations 1996,'' published by the United Kingdom Health and 
Safety Executive and available from NIOSH at http://www.cdc.gov/niosh/docket/archive/pdfs/NIOSH-254/compReg1996.pdf.

    Note:  Health effects associated with hyperbaric intervention, 
but not considered symptoms of DCI, can include: barotrauma (direct 
damage to air-containing cavities in the body such as ears, sinuses, 
and lungs); nitrogen narcosis (reversible alteration in 
consciousness that may occur in hyperbaric environments and caused 
by the anesthetic effect of certain gases at high pressure); and 
oxygen toxicity (a central nervous system condition resulting from 
the harmful effects of breathing molecular oxygen (O2) at 
---------------------------------------------------------------------------
elevated partial pressures).

    6. Diver Medical Technician--Member of the dive team who is 
experienced in first aid.
    7. Earth Pressure Balanced Moving Tunnel Boring Machine--the 
machinery used to excavate the tunnel.
    8. Hot work--any activity performed in a hazardous location that 
may introduce an ignition source into a potentially flammable 
atmosphere.\16\
---------------------------------------------------------------------------

    \16\ Also see 29 CFR 1910.146(b).
---------------------------------------------------------------------------

    9. Hyperbaric--at a higher pressure than atmospheric pressure.
    10. Hyperbaric intervention--a term that describes the process of 
stopping the TBM and preparing and executing work under hyperbaric 
pressure in the working chamber for the purpose of inspecting, 
replacing, or repairing cutting tools and/or the cutterhead structure.
    11. Hyperbaric Operations Manual--a detailed, project-specific 
health and safety plan developed and implemented by the McNally for 
working in compressed air during the Shoreline Storage Tunnel.
    12. Job hazard analysis--an evaluation of tasks or operations to 
identify potential hazards and to determine the necessary controls.
    13. Man lock--an enclosed space capable of pressurization, and used 
for compressing or decompressing any employee or material when either 
is passing into or out of a working chamber.
    14. Medical Advisor--medical professional experience in the 
physical requirements of compressed air work and the treatment of 
decompression illness.
    15. Pressure--a force acting on a unit area; usually expressed as 
pounds per square inch (p.s.i.).
    16. p.s.i.--pounds per square inch, a common unit of measurement of 
pressure; a pressure given in p.s.i. corresponds to absolute pressure.
    17. p.s.i.a--pounds per square inch absolute, or absolute pressure, 
is the sum of the atmospheric pressure and gauge pressure. At sea 
level, atmospheric pressure is approximately 14.7 p.s.i. Adding 14.7 to 
a pressure expressed in units of p.s.i.g. will yield the absolute 
pressure, expressed as p.s.i.a.
    18. p.s.i.g.--pounds per square inch gauge, a common unit of 
pressure; pressure expressed as p.s.i.g. corresponds to pressure 
relative to atmospheric pressure. At sea level, atmospheric pressure is 
approximately 14.7 p.s.i. Subtracting 14.7 from a pressure expressed in 
units of p.s.i.a. yields the gauge pressure, expressed as p.s.i.g.
    19. Qualified person--an individual who, by possession of a 
recognized degree, certificate, or professional standing, or who, by 
extensive knowledge, training, and experience, successfully 
demonstrates an ability to solve or resolve problems relating to the 
subject matter, the work, or the project.\17\
---------------------------------------------------------------------------

    \17\ Adapted from 29 CFR 1926.32(m).
---------------------------------------------------------------------------

    20. Working chamber--an enclosed space in the TBM in which CAWs 
perform interventions, and which is accessible only through a man lock.

D. Safety and Health Practices

    1. McNally must implement the project-specific HOM submitted to 
OSHA as part of the variance application (see OSHA-2022-0007-0003). The 
HOM provides the minimum requirements regarding expected safety and 
health hazards (including anticipated geological conditions) and 
hyperbaric exposures during the tunnel-construction project.
    2. McNally must demonstrate that the TBM on the project is 
designed, fabricated, inspected, tested, marked and stamped in 
accordance with the requirements of ASME PVHO-1.2019 (or most recent 
edition of Safety Standards for Pressure Vessels for Human Occupancy) 
for the TBM's hyperbaric chambers.
    3. McNally must implement the safety and health instructions 
included in the manufacturer's operations manuals for the TBM, and the 
safety and health instructions provided by the manufacturer for the 
operation of decompression equipment.
    4. McNally must ensure that there are no exposures to pressures 
greater than 55 p.s.i.g.
    5. McNally must ensure that air or oxygen as the only breathing gas 
in the working chamber.
    6. McNally must follow the 1992 French Decompression Tables for 
air, air-oxygen, and oxygen decompression specified in the HOM, 
specifically the tables titled ``French Regulation Air Standard 
Tables.''
    7. McNally must equip man-locks used by their employees with an 
oxygen-delivery system as specified by the HOM. McNally is prohibited 
from storing in the tunnel any oxygen or other compressed gases used in 
conjunction with hyperbaric work.
    8. Workers performing hot work under hyperbaric conditions must use 
flame-retardant personal protective equipment and clothing.
    9. In hyperbaric work areas, McNally must maintain an adequate 
fire-suppression system approved for hyperbaric work areas.
    10. McNally must develop and implement one or more Job Hazard 
Analyses (JHA) for work in the hyperbaric work areas, and review, 
periodically and as necessary (e.g., after making changes to a planned 
intervention that affects their operation), the contents of the JHAs 
with affected employees. The JHAs must include all the job functions 
that the risk

[[Page 15089]]

assessment \18\ indicates are essential to prevent injury or illness.
---------------------------------------------------------------------------

    \18\ See ANSI/AIHA Z10-2012, American National Standard for 
Occupational Health and Safety Management Systems, for reference.
---------------------------------------------------------------------------

    11. McNally must develop a set of checklists to guide compressed-
air work and ensure that employees follow the procedures required by 
this permanent variance (including all procedures required by the HOM, 
which this permanent variance incorporates by reference). The 
checklists must include all steps and equipment functions that the risk 
assessment indicates are essential to prevent injury or illness during 
compressed-air work.
    12. McNally must ensure that the safety and health provisions of 
this project-specific HOM adequately protect the workers of all 
contractors and subcontractors involved in hyperbaric operations for 
the project to which the HOM applies.\19\
---------------------------------------------------------------------------

    \19\ See ANSI/ASSE A10.33-2011, American National Standard for 
Construction and Demolition Operations--Safety and Health Program 
Requirements for Multi-Employer Projects, for reference.
---------------------------------------------------------------------------

E. Communication

    1. Prior to beginning a shift, McNally must implement a system that 
informs workers exposed to hyperbaric conditions of any hazardous 
occurrences or conditions that might affect their safety, including 
hyperbaric incidents, gas releases, equipment failures, earth or 
rockslides, cave-ins, flooding, fires, or explosions.
    2. McNally must provide a power-assisted means of communication 
among affected workers and support personnel in hyperbaric conditions 
where unassisted voice communication is inadequate.
    (a) McNally must use an independent power supply for powered 
communication systems, and these systems must operate such that use or 
disruption of any one phone or signal location will not disrupt the 
operation of the system from any other location.
    (b) McNally must test communication systems at the start of each 
shift and as necessary thereafter to ensure proper operation.

F. Worker Qualification and Training

    McNally must:
    1. Ensure that each affected worker receives effective training on 
how to safely enter, work in, exit from, and undertake emergency 
evacuation or rescue from, hyperbaric conditions, and document this 
training.
    2. Provide effective instruction, before beginning hyperbaric 
operations, to each worker who performs work, or controls the exposure 
of others, in hyperbaric conditions, and document this instruction. The 
instruction must include topics such as:
    (a) The physics and physiology of hyperbaric work;
    (b) Recognition of pressure-related injuries;
    (c) Information on the causes and recognition of the signs and 
symptoms associated with decompression illness, and other hyperbaric 
intervention-related health effects (e.g., barotrauma, nitrogen 
narcosis, and oxygen toxicity).
    (d) How to avoid discomfort during compression and decompression; 
and
    (e) Information the workers can use to contact the appropriate 
healthcare professionals should the workers have concerns that they may 
be experiencing adverse health effects from hyperbaric exposure; and
    (f) Procedures and requirements applicable to the employee in the 
project-specific HOM.
    3. Repeat the instruction specified in paragraph (2) of this 
condition periodically and as necessary (e.g., after making changes to 
their hyperbaric operations).
    4. When conducting training for their hyperbaric workers, make this 
training available to OSHA personnel and notify OTPCA the Cleveland, 
Ohio OSHA Area Office before the training takes place.

G. Inspections, Tests, and Accident Prevention

    1. McNally must initiate and maintain a program of frequent and 
regular inspections of the TBM's hyperbaric equipment and support 
systems (such as temperature control, illumination, ventilation, and 
fire-prevention and fire-suppression systems), and hyperbaric work 
areas, as required under 29 CFR 1926.20(b)(2), including:
    (a) Developing a set of checklists to be used by a competent person 
in conducting weekly inspections of hyperbaric equipment and work 
areas; and
    (b) Ensuring that a competent person conducts daily visual checks, 
as well as weekly inspections of the TBM.
    2. Remove from service any equipment that constitutes a safety 
hazard until it corrects the hazardous condition and has the correction 
approved by a qualified person.
    3. McNally must maintain records of all tests and inspections of 
the TBM, as well as associated corrective actions and repairs, at the 
job site for the duration of the job.

H. Compression and Decompression

    McNally must consult with their attending physician concerning the 
need for special compression or decompression exposures appropriate for 
CAWs not acclimated to hyperbaric exposure.

I. Recordkeeping

    In addition to completing OSHA Form 301 Injury and Illness Incident 
Report and OSHA Form 300 Log of Work-Related Injuries and Illnesses, 
McNally must maintain records of:
    1. The date, times (e.g., time compression started, time spent 
compressing, time performing intervention, time spent decompressing), 
and pressure for each hyperbaric intervention.
    2. The names of all supervisors and DMTs involved for each 
intervention.
    3. The name of each individual worker exposed to hyperbaric 
pressure and the decompression protocols and results for each worker.
    4. The total number of interventions and the amount of hyperbaric 
work time at each pressure.
    5. The results of the post-intervention physical assessment of each 
CAW for signs and symptoms of decompression illness, barotrauma, 
nitrogen narcosis, oxygen toxicity or other health effects associated 
with work in compressed air for each hyperbaric intervention.

J. Notifications

    1. To assist OSHA in administering the conditions specified herein, 
the McNally must:
    (a) Notify the OTPCA and the Cleveland Ohio OSHA Area Office of any 
recordable injury, illness, or fatality (by submitting the completed 
OSHA's Form 301 Injury and Illness Incident Report form) \20\ resulting 
from exposure of an employee to hyperbaric conditions, including those 
exposures that do not require recompression treatment (e.g., nitrogen 
narcosis, oxygen toxicity, barotrauma), but still meet the recordable 
injury or illness criteria of 29 CFR 1904. The employer shall provide 
the notification within 8 hours of the incident or 8 hours after 
becoming aware of a recordable injury, illness, or fatality, and submit 
a copy of the incident investigation (OSHA's Form 301 Injury and 
Illness Injury Reporting Form) within 24 hours of the incident or 24 
hours after becoming aware of a recordable injury, illness, or 
fatality. In addition to the information

[[Page 15090]]

required by the OSHA's Form 301 Injury and Illness Injury Reporting 
Form, the incident-investigation report must include a root-cause 
determination, and the preventive and corrective actions identified and 
implemented.
---------------------------------------------------------------------------

    \20\ See 29 CFR 1904 (Recording and Reporting Occupational 
Injuries and Illnesses) (http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9631); recordkeeping 
forms and instructions (http://www.osha.gov/recordkeeping/RKform300pkg-fillable-enabled.pdf); and the OSHA Recordkeeping 
Handbook (http://www.osha.gov/recordkeeping/handbook/index.html).
---------------------------------------------------------------------------

    (b) Provide certification within 15 days of the incident that the 
employer informed affected workers of the incident and the results of 
the incident investigation (including the root-cause determination and 
preventive and corrective actions identified and implemented).
    (c) Notify the OTPCA and the Cleveland Ohio OSHA Area Office within 
15 working days in writing of any change in the compressed-air 
operations that affects the employer's ability to comply with the 
conditions specified herein.
    (d) Upon completion of the Shoreline Storage Tunnel, evaluate the 
effectiveness of the decompression tables used throughout the project, 
and provide a written report of this evaluation to the OTPCA and the 
Cleveland Ohio OSHA Area Office.

    Note: The evaluation report is to contain summaries of: (1) the 
number, dates, durations, and pressures of the hyperbaric 
interventions completed; (2) decompression protocols implemented 
(including composition of gas mixtures (air and/or oxygen), and the 
results achieved; (3) the total number of interventions and the 
number of hyperbaric incidents (decompression illnesses and/or 
health effects associated with hyperbaric interventions as recorded 
on OSHA's Form 301 Injury and Illness Incident Report and OSHA's 
Form 300 Log of Work-Related Injuries and Illnesses, and relevant 
medical diagnoses and treating physicians' opinions); and (4) root 
causes of any hyperbaric incidents, and preventive and corrective 
actions identified and implemented.

    (e) To assist OSHA in administering the conditions specified 
herein, inform the OTPCA and the Cleveland Ohio OSHA Area Office as 
soon as possible after it has knowledge that it will:
    i. Cease to do business;
    ii. Change the location and address of the main office for managing 
the tunneling operations specified herein; or
    iii. Transfer the operations specified herein to a successor 
company.
    (f) Notify all affected employees of this permanent variance by the 
same means required to inform them of the application for a variance.
    (g) This permanent variance cannot be transferred to a successor 
company without OSHA approval.
    OSHA hereby grants a permanent variance to McNally to the 
provisions of 29 CFR 1926.803 outlined in this notice.

VIII. Authority and Signature

    James S. Frederick, Deputy Assistant Secretary of Labor for 
Occupational Safety and Health, 200 Constitution Avenue NW, Washington, 
DC 20210, authorized the preparation of this notice. Accordingly, the 
agency is issuing this notice pursuant to 29 U.S.C. 655(d), Secretary 
of Labor's Order No. 8-2020 (85 FR 58393, Sept. 18, 2020), and 29 CFR 
1905.11.

    Signed at Washington, DC, on March 6, 2023.
James S. Frederick,
Deputy Assistant Secretary of Labor for Occupational Safety and Health.
[FR Doc. 2023-04883 Filed 3-9-23; 8:45 am]
BILLING CODE 4510-26-P


