
[Federal Register Volume 88, Number 227 (Tuesday, November 28, 2023)]
[Notices]
[Pages 83152-83161]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-26179]



[[Page 83152]]

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DEPARTMENT OF LABOR

Occupational Safety and Health Administration

[Docket No. OSHA-2023-0004]


Traylor-Sundt Joint Venture: Grant of Permanent Variance

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

ACTION: Notice.

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

DATES: The permanent variance specified by this notice becomes 
effective on November 28, 2023 and shall remain in effect until the 
completion of the Integrated Pipeline 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, U.S. Department of Labor; telephone: (202) 693-1999; 
email: [email protected].
    General and technical information: Contact Mr. 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; telephone: 
(202) 693-2110; email: [email protected].
    Copies of this Federal Register notice. Electronic copies of this 
Federal Register notice are available at http://www.regulations.gov. 
This Federal Register notice, as well as news releases and other 
relevant information, also are available at OSHA's web page at http://www.osha.gov.

SUPPLEMENTARY INFORMATION:

I. Overview

    On April 20, 2022, Traylor Bros., Inc. (Traylor) submitted an 
application by letter to modify the permanent variance granted to 
Traylor on March 11, 2016 (2016 Variance) (81 FR 12954), to include an 
additional employer, the Traylor-Sundt Joint Venture (SUNDTJV), which 
is a joint venture made up of two construction companies; Traylor and 
Sundt Construction, Inc. (Sundt). SUNDTJV was awarded the tunneling 
contract for the Integrated Pipeline Tunnel Project in Dallas, Texas 
(OSHA-2023-0004-0002). The Integrated Pipeline Tunnel Project includes 
two tunnels, the Cedar Creek Tunnel, and the Hollywood Lake Tunnel, 
which require two separate tunnel drives. SUNDTJV also requested an 
interim order while OSHA evaluates the application (OSHA-2023-0004-
0003). Because the joint venture includes an additional employer not 
covered by the previously issued permanent variance, OSHA has evaluated 
the modification request as an application by SUNDTJV for a new 
permanent variance. This notice covers the Integrated Pipeline Tunnel 
Project only and is not applicable to future tunneling projects by 
Traylor, Sundt, or SUNDTJV.
    This notice addresses the application by SUNDTJV (the applicant) 
for a permanent variance and interim order from the provisions of the 
standard governing compressed air work that: (1) prohibit compressed-
air worker exposure to pressures exceeding 50 pounds per square inch 
(p.s.i.) except in an 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 (g)(1)(xvii), respectively).
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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 SUNDTJV's application for the variance and interim 
order and determined that they were 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 SUNDTJV'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 May 1, 2023, OSHA 
published a Federal Register notice announcing SUNDTJV's application 
for permanent variance, stating the preliminary determination along 
with the basis of that determination, and granting the interim order 
(88 FR 26600). 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 SUNDTJV, its methods, and the 
Integrated Pipeline Tunnel Project comes from the SUNDTJV variance 
application.
    SUNDTJV is a contractor for the Integrated Pipeline Tunnel Project 
(the project), that works on complex tunnel projects using innovations 
in tunnel-excavation methods. The applicant's workers engage in the 
construction of tunnels using advanced shielded mechanical excavation 
techniques in conjunction with an earth pressure balance 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.
    SUNDTJV 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

[[Page 83153]]

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.
    SUNDTJV's Hyperbaric Operations Manual (HOM) for the Integrated 
Pipeline Tunnel Project indicates that the maximum pressure to which it 
is likely to expose workers during project interventions for the 
Integrated Pipeline Tunnel Project is 58 p.s.i. Therefore, to work 
effectively, SUNDTJV must perform hyperbaric interventions in 
compressed air at pressures nearly 15% 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).
    SUNDTJV employs specially trained personnel for the construction of 
the tunnel. To keep the machinery working effectively, SUNDTJV 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 58 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.
    SUNDTJV 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.
    In addition to the reduced exposures resulting from the innovations 
in tunnel-excavation methods, SUNDTJV asserts that innovations in 
hyperbaric medicine and technology improve the safety of decompression 
from hyperbaric exposures. These procedures, however, 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 SUNDTJV, 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.
    SUNDTJV contends that the alternative safety measures included in 
the application provide SUNDTJV'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. SUNDTJV also 
provided OSHA a project-specific HOM, (OSHA-2023-0004-0004) 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 announcing SUNDTJV's variance application and did not receive 
any comments disputing any of that information, including the safety 
assertions made by SUNDTJV 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 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 application.
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    \2\ See the definition of ``Affected employee or worker'' in 
section VI.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 
several 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)); (5) McNally/Kiewit SST 
Joint Venture for the completion of the Shoreline Storage Tunnel 
Project in Cleveland, Ohio (88 FR 15080, March 10, 2023); and (6) 
Traylor-Shea Joint Venture for the completion of the Alexandria 
RiverRenew Tunnel Project in Alexandria Virginia and Washington DC (88 
FR 15080, March 10, 2023). OSHA also granted an interim order to 
Ballard Marine for the Suffolk County Outfall Tunnel project in West 
Babylon, New York (86 FR 5253 (January 19, 2021)). The proposed 
alternate conditions in this notice are nearly identical to the 
alternate conditions of the previous permanent variances.\3\ OSHA is 
not

[[Page 83154]]

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 permanent variance includes substantively the 
same safeguards as the variances that OSHA granted previously even 
though employees will not be exposed to pressures higher than 58 
p.s.i.g.
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IV. Applicable OSHA Standard and the Relevant Variance

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

    The applicant states that it may perform hyperbaric interventions 
at pressures greater than 50 p.s.i. 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.
    SUNDTJV 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 58 
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, SUNDTJV has developed a project-specific HOM (OSHA-2023-
0004-0004) that describes in detail the hyperbaric procedures, the 
required medical examination used during the tunnel-construction 
project, the standard operating procedures and the 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 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 (see 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 Integrated 
Pipeline Tunnel Project-specific 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 requires SUNDTJV 
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. SUNDTJV 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 is also required to be present during 
hyperbaric exposures and decompression. This man-lock attendant is to 
operate the hyperbaric system to ensure compliance with the specified 
decompression table. A hyperbaric supervisor, who is trained in 
hyperbaric operations, procedures, and safety, directly oversees all 
hyperbaric interventions and ensures

[[Page 83155]]

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

    SUNDTJV seeks 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 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 dissolved 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 effective as an automatic 
controller in regulating the decompression process because the HOM 
requires 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 in the Washington 
State safety standards for compressed-air work (from which OSHA 
derived its decompression tables) was 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 of the 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 request and imposed by this permanent variance, 
provide measures that are as safe and healthful as those required by 
the cited OSHA standards addressed in section IV 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)

    The applicant 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, SUNDJV 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

[[Page 83156]]

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 six previous permanent variances to IHP JV, 
Traylor JV, Tully JV, Salini-Impregilo Joint Venture, Ballard, and 
Traylor TSJV, OSHA conducted a review of the scientific literature and 
concluded that the alternative decompression method (i.e., the 1992 
French Decompression Tables) SUNDTJV proposed would be at least as safe 
as the decompression tables specified by OSHA when applied by trained 
medical personnel under the conditions imposed by the permanent 
variance.
    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 Docket ID. OSHA-
2012-0036-0005).
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    OSHA's experience with the previous six variances, which all 
incorporated nearly identical decompression plans and did not result in 
safety issues, also provides 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 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.
---------------------------------------------------------------------------

    \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 Plan States'' Occupational safety and health standards 
developed by State Plan States 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: Docket ID. 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 hyperbaric supervisor and attending physician 
certified in hyperbaric medicine to oversee all hyperbaric operations.
    In reaching this 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 up to 360 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 docket: Docket 
ID. 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(d)), and based on the record discussed above, 
the agency finds that when SUNDTJV complies with the conditions of the 
following order, the working conditions of the 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, SUNDTJV 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 Integrated Pipeline 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

[[Page 83157]]

permanent variance. Additionally, this order will remain in effect 
until one of the following conditions occurs: (1) completion of the 
Integrated Pipeline Tunnel Project; or (2) OSHA modifies or revokes 
this final order in accordance with 29 CFR 1905.13.

VI. Description of the Specified Conditions 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. Clearly defining the scope of the permanent 
variance provides SUNDTJV, SUNDTJV's 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 SUNDTJV exceeds the defined scope 
of this variance, it will be required to comply with OSHA's standards. 
This permanent variance applies only to the applicant, SUNDTJV, and 
only to the remainder of construction work on the Integrated Pipeline 
Tunnel Project.

Condition B: List of Abbreviations

    Condition B defines 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 its 
employees' understanding of the conditions specified by the permanent 
variance.

Condition C: Definitions

    The condition defines a series of terms, mostly technical terms, 
used in the permanent variance to standardize and clarify their 
meaning. OSHA believes that defining these terms serves to enhance the 
applicant's and its 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 Integrated Pipeline Tunnel Project at least six 
months before using the TBM for tunneling operations. The applicant 
must also submit, 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 of 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 enables OSHA to determine whether the 
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 to ensure that the 
equipment is structurally sound and capable of performing to protect 
the safety of the employees exposed to hyperbaric pressure. The 
applicant has submitted the HOM and proof of compliance with ASME PVHO-
1.2019.
    Additionally, the condition includes a series of related hazard 
prevention and control requirements and methods (e.g., decompression 
tables, job hazard analyses (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

    This condition requires the applicant to develop and implement an 
effective system of information sharing and communication. Effective 
information sharing and communication are intended to ensure 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 the applicant 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 is intended to ensure 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 requires the applicant to 
provide affected workers with information they can use to contact the 
appropriate healthcare professionals if the workers 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 jobsite 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.

[[Page 83158]]

Condition H: Compression and Decompression

    This condition requires the applicant to consult with the 
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 
proposed 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 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 SUNDTJV 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 
questions 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 J below adds additional reporting responsibilities, 
beyond those already required by the OSHA standard. The applicant is 
required to maintain records of specific factors associated with each 
hyperbaric intervention. The information gathered and recorded under 
Condition J, in concert with the information provided under Condition I 
(using OSHA Form 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 the applicant and OSHA to assess the 
effectiveness of the permanent variance in preventing DCI and other 
hyperbaric-related effects.

Condition J: Notifications

    Under the notifications 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 within 8 hours; (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 OSHA Area Office in Dallas, Texas within 15 working days should 
the applicant need to revise the HOM to accommodate changes in its 
compressed-air operations that affect SUNDTJVs ability to comply with 
the conditions of the permanent variance; and (6) provide OTPCA and the 
OSHA Area Office in Dallas, Texas, 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 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 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 
no later than seven (7) days of having knowledge that it will cease to 
do business, has a new address or location for the main office, or 
transfers the operations covered by the permanent variance to a 
successor company. In addition, the condition specifies that the 
transfer of the 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 permanent 
variance and expedite the agency's administration and enforcement of 
the permanent variance. Stipulating that the 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 permanent variance,

[[Page 83159]]

thereby ensuring the safety of workers involved in performing the 
operations covered by the permanent variance.

VI. Order

    As of the effective date of this final order, OSHA is revoking the 
interim order granted to the employer on May 1, 2023, and replacing it 
with a permanent variance order. Note that there are not any 
substantive changes in the conditions between the interim order and 
this final order.
    OSHA issues this final order authorizing SUNDTJV 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 SUNDTJV stops the tunnel-
boring work, pressurizes the working chamber, and the CAWs either enter 
the working chamber to perform an intervention (i.e., inspect, 
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 Integrated 
Pipeline Tunnel Project, a 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 
part 1926 except for the requirements 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 Integrated Pipeline 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 includes the 
following:

1. CAW--Compressed-air worker
2. CFR--Code of Federal Regulations
3. DCI--Decompression Illness
4. DMT--Diver Medical Technician
5. TBM--Earth Pressure Balanced Tunnel Boring Machine
6. HOM--Hyperbaric Operations 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, 
SUNDTJV's project-specific HOM, and all work carried out under the 
conditions of this permanent variance.
    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 pounds per square inch absolute (p.s.i.a.), 1 atmosphere 
absolute, or 0 p.s.i.g.
    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 58 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--an illness (also called decompression 
sickness or ``the bends'') 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 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 is 
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 Tunnel Boring Machine--the machinery 
used to excavate a 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 SUNDTJV for working 
in compressed air during the Integrated Pipeline Tunnel Project.
    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 experienced 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.a. 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

[[Page 83160]]

atmospheric pressure. At sea-level, atmospheric pressure is 
approximately 14.7 p.s.i.a. Subtracting 14.7 from a pressure expressed 
in units of p.s.i.a. yields the gauge pressure, expressed as p.s.i.g. 
At sea level the gauge pressure is 0 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. SUNDTJV must implement the project-specific HOM submitted to 
OSHA as part of the application (see OSHA-2023-0004-0004). 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. SUNDTJV has demonstrated through documentation in the HOM that 
the TBM, including its hyberbaric chambers, is in compliance with the 
requirements of ASME PVHO-1.2019 (or more recent edition of Safety 
Standards for Pressure Vessels for Human Occupancy). SUNDTJV must 
notify OSHA before making any alterations to the TBM that would affect 
the PVHO certification. Any such alteration to the TBM would require 
recertification of compliance with ASME PVHO-1.2019 requirements and 
OSHA approval prior to use.
    3. SUNDTJV 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. SUNDTJV must ensure that there are no exposures to pressures 
greater than 58 p.s.i.g.
    5. SUNDTJV must ensure that air or oxygen is the only breathing gas 
in the working chamber.
    6. SUNDTJV must follow the 1992 French Decompression Tables for air 
or oxygen decompression as specified in the HOM; specifically, the 
extracted portions of the 1992 French Decompression tables titled, 
``French Regulation Air Standard Tables.''
    7. SUNDTJV must equip man-locks used by employees with an air or 
oxygen delivery system, as specified by the HOM for the project. 
SUNDTJV 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, SUNDTJV must maintain an adequate 
fire-suppression system approved for hyperbaric work areas.
    10. SUNDTJV must develop and implement one or more Job Hazard 
Analysis (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 its operation), the contents of the JHAs with 
affected employees. The JHAs must include all the job functions that 
the risk 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. SUNDTJV must develop a set of checklists to guide compressed-
air work and ensure that employees follow the procedures required by 
the permanent variance (including all procedures required by the HOM 
approved by OSHA for the project, 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. SUNDTJV 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.

E. Communication

    1. Prior to beginning a shift, SUNDTJV 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 rock 
slides, cave-ins, flooding, fires, or explosions.
    2. SUNDTJV must provide a power-assisted means of communication 
among affected workers and support personnel in hyperbaric conditions 
where unassisted voice communication is inadequate.
    (a) SUNDTJV must use an independent power supply for powered 
communication systems, and these systems have to 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) SUNDTJV must test communication systems at the start of each 
shift and as necessary thereafter to ensure proper operation.

F. Worker Qualifications and Training

    SUNDTJV 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 on hyperbaric conditions, before 
beginning hyperbaric operations, to each worker who performs work, or 
controls the exposure of others, and document this instruction. The 
instruction must include:
    (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;
    (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 (G) of this 
condition periodically and as necessary (e.g., after making changes to 
its hyperbaric operations).
    4. When conducting training for its hyperbaric workers, make this 
training available to OSHA personnel and notify the OTPCA at OSHA's 
national office and OSHA's Dallas Area Office before the training takes 
place.

G. Inspections, Tests, and Accident Prevention

    1. SUNDTJV 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

[[Page 83161]]

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 
and 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. SUNDTJV 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 tunneling project and for 90 days 
after the final project report is submitted to OSHA.

H. Compression and Decompression

    SUNDTJV must consult with its 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, 
SUNDTJV 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, 
SUNDTJV must:
    (a) Notify the OTPCA and the OSHA Area Office in Dallas, Texas at 
www.osha.gov/contactus/byoffice of any recordable injury, illness, or 
fatality (by submitting the completed OSHA Form 301 Injuries and 
Illness Incident Report) \19\ resulting from exposure of an employee to 
hyperbaric conditions, including those 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 notification must be made within 8 hours of the 
incident or 8 hours after becoming aware of a recordable injury, 
illness, or fatality; a copy of the incident investigation (OSHA Form 
301 Injuries and Illness Incident Report) must be submitted to OSHA 
within 24 hours of the incident or 24 hours after becoming aware of a 
recordable injury, illness, or fatality. In addition to the information 
required by OSHA Form 301 Injuries and Illness Incident Report, the 
incident-investigation report must include a root-cause determination, 
and the preventive and corrective actions identified and implemented.
---------------------------------------------------------------------------

    \19\ 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 to the OTPCA and the OSHA Area Office in 
Dallas, Texas within 15 working days of the incident that SUNDTJV 
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 OSHA Area Office Dallas, Texas within 
15 working days and in writing, of any change in the compressed-air 
operations that affects SUNDTJV's ability to comply with the conditions 
specified herein.
    (d) Upon completion of the Integrated Pipeline Tunnel Project, 
evaluate the effectiveness of the decompression tables used throughout 
the project, and provide a written report of this evaluation to the 
OTPCA and the OSHA Area Office in Dallas, Texas.

    Note:  The evaluation report must 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 Form 301 Injuries and Illness Incident Report and OSHA 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 OSHA Area Office in Dallas, Texas as 
soon as possible, but no later than seven (7) days, after it has 
knowledge that it will:
    (i) Cease doing 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 its application for a permanent 
variance.
    (g) This permanent variance cannot be transferred to a successor 
company without OSHA approval.
    OSHA hereby grants a permanent variance to SUNDTJV to the 
provisions of 29 CFR 1926.803 outlined in this notice.

VII. 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.
James S. Frederick,
Deputy Assistant Secretary of Labor for Occupational Safety and Health.
[FR Doc. 2023-26179 Filed 11-27-23; 8:45 am]
BILLING CODE 4510-26-P


