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[Federal Register Volume 77, Number 240 (Thursday, December =
13, 2012)]
[Notices]
[Pages 74193-74194]
From the Federal Register Online via the Government Printing Office [/www.gpo.gov/">http://www.gpo.gov/]
[FR Doc No: 2012-30080]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Centers for Disease Control and Prevention (CDC)

[CDC-2012-0012; NIOSH-254]


Request for Information on Edel-Kindwall Caisson Tables for=20
Preventing Decompression Illness in Construction Workers

AGENCY: National Institute for Occupational Safety and Health (NIOSH)=20
of the Centers for Disease Control and Prevention (CDC), Department of=20
Health and Human Services (HHS).

ACTION: Notice of public comment period.

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SUMMARY: The National Institute for Occupational Safety and Health=20
(NIOSH) of the Centers for Disease Control and Prevention (CDC) invites=20
comments and information on decompression tables used for protecting=20
tunneling (caisson) workers from developing decompression illnesses.
    Public Comment Period: Comments must be received by March 29, 2013.

ADDRESSES: Written comments, identified by CDC-2012-0012 and docket=20
number NIOSH-254, may be submitted by any of the following methods:
     Federal erulemaking portal: /www.regulations.gov/">http://www.regulations.gov/.=20
Follow the instructions for submitting comments.
     Mail: NIOSH Docket Office, Robert A. Taft Laboratories,=20
MS-C34, 4676 Columbia Parkway, Cincinnati, OH 45226.
     Email: nioshdocket@cdc.gov.
    All information received in response to this notice will be=20
available for public examination and copying at the NIOSH Docket=20
Office, 4676 Columbia Parkway, Cincinnati, Ohio 45226. The document and=20
instructions for submitting comments can be found at: /www.regulations.gov/">http://www.regulations.gov/. =
NIOSH includes all comments received without=20
change in the docket, including any personal information provided. All=20
electronic comments should be formatted as Microsoft Word. Please make=20
reference to CDC 2012-0012 and docket number NIOSH-254.

FOR FURTHER INFORMATION CONTACT: Frank J. Hearl, PE, Chief of Staff,=20
National Institute for Occupational Safety and Health, Centers for=20
Disease Control and Prevention, Patriots Plaza, Suite 9200, 395 E St.=20
SW., Washington, DC 20201. Telephone: (202) 245-0625 (this is not a=20
toll-free number).

SUPPLEMENTARY INFORMATION: High pressure tunneling operations are used=20
for some underground infrastructure projects. Compressed air is used to=20
prevent seepage of water or to stabilize unstable soil conditions.=20
Caisson work (a water-tight structure that allows underwater=20
construction to be performed) can also involve elevated pressure=20
worksites. This hyperbaric environment created by ambient pressure and=20
compressed air effects exposes caisson and tunnel workers to the risks=20
of decompression sickness (DCS) such as the ``bends.'' DCS is related=20
to intravascular or extravascular bubbles formed during reduction of=20
environmental pressure (decompression). The release of nitrogen bubbles=20
into blood or tissues can result in obstruction of blood flow or=20
pressure effects. Clinical manifestations of DCS include (but are not=20
limited to) joint pain (``bends''), lytic lesions of bones (dysbaric=20
osteonecrosis), cutaneous disorders (cutis marmorata), spinal cord and=20
brain disorders (stroke, paralysis, paresthesias, bladder dysfunction,=20
etc.), and cardiopulmonary disorders (shortness of breath ``chokes''),=20
arterial gas embolism.
    In order to prevent DCS, workers in higher hyperbaric environments=20
must be safely brought back to the non-work environmental ambient=20
pressure (decompressed) in decompression areas.
    Decompression tables generally utilize stepwise (staged)=20
progressions of gradually decreasing pressure at varying time intervals=20
based on work exposure pressures and length of work shift.
    In 1971, the Washington State Decompression Tables that were used=20
in multiple states became the federal code enforced by the Occupational=20
Health and Safety Administration (OSHA) and remain, unchanged, as the=20
decompression tables in force today. The maximum worksite pressures=20
allowed by OSHA (1926 Subpart S, Appendix A) and addressed by the OSHA=20
decompression tables is 50 pounds per square inch (psi) (~3.45 bar=20
gauge) [1]. They are considered inadequate for ``efficiently=20
eliminating nitrogen from the body'' at pressures in excess of 36.5 psi=20
[2].
    The Edel-Kindwall Caisson Tables were developed for NIOSH in 1981.=20
They are based on advances in hyperbaric research and are considered to=20
be more protective of worker health than the OSHA tables. As a result,=20
these tables have been used for variances to the OSH standard. NIOSH is=20
making these tables more easily accessible to construction users by=20
posting them to a new Web page at the NIOSH Web site at /www.cdc.gov/NIOSH/topics/Decompression/">http://www.cdc.go=
v/NIOSH/topics/Decompression/.
    However, the Edel-Kindwall tables are inadequate for dealing with=20
pressures greater than 50 psi. Many modern projects using Tunnel Boring=20
Machines involve pressures greater than 50 psi. There is a need for up-
to-date decompression tables.
    NIOSH is thus requesting information on the following: (1)=20
Information on types of projects where the Edel-Kindwall Tables have=20
been used, (2) Published and unpublished reports and findings relating=20
to the use of the Edel-Kindwall Tables, including information on=20
possible health effects or lack of observed health health effects in=20
tunnel/caisson workers who were

[[Page 74194]]

decompressed with data from the Edel-Kindwall Tables,(3) Information on=20
related control measures (e.g., engineering controls, work practices,=20
personal protective equipment) in use in workplaces where decompression=20
is required, and (4) Information on alternative tables and approaches=20
being used to protect tunneling workers from higher pressures greater=20
than 50 psi.

References

1. Hamilton RW, Bill Kay E. (2008) Boring deep tunnels. Third=20
conference on U.S.-Japan panel on aerospace-diving physiology &=20
technology and hyperbaric medicine.
2. Downs GJ, Kindwall EP. (1986) Aseptic necrosis in caisson=20
workers: A new set of decompression tables. Aviat Space & Environ=20
Med 57:569-574.


    Dated: December 4, 2012.
John Howard,
Director, National Institute for Occupational Safety and Health,=20
Centers for Disease Control and Prevention.
[FR Doc. 2012-30080 Filed 12-12-12; 8:45 am]
BILLING CODE 4163-19-P
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