22 July 2003
Source:
http://www.access.gpo.gov/su_docs/aces/fr-cont.html
This bears on the planned destruction of chemical weapons at several military storage depots:
Anniston Army Depot:
http://cryptome.org/anad-eyeball.htm
Newport Chemical Depot:
http://cryptome.org/newport-eyeball.htm
Tooele Chemical Depot:
http://cryptome.org/tooele-eyeball.htm
[Federal Register: July 22, 2003 (Volume 68, Number 140)]
[Notices]
[Page 43356-43358]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr22jy03-57]
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DEPARTMENT OF HEALTH AND HUMAN SERVICES
Centers for Disease Control and Prevention
Proposed Airborne Exposure Limits for Chemical Warfare Agents H,
HD, and HT (Sulfur Mustard)
AGENCY: Centers for Disease Control and Prevention (CDC), Department of
Health and Human Services (HHS).
ACTION: Notice of proposed worker and general population airborne
exposure limits (AELs) for chemical warfare agents H, HD, and HT
(sulfur mustard) to protect the health and safety of workers and the
public during treatment, transport, or disposal of these agents.
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Purpose: CDC presents results of its review of AELs for the
chemical warfare agents H, HD and HT (collectively referred to as
sulfur mustard, bis(2-chloroethyl)sulfide, CAS 505-60-2).\1\ All three
compounds are chemically and toxicologically related and therefore will
be treated here as a single compound represented by HD. Before
finalizing these proposals, CDC requests comments from the public, all
interested parties, environmental and health regulators, the Department
of Defense (DOD), and other organizations involved in handling or
demilitarizing chemical warfare agents. More specifically, CDC seeks
scientifically and professionally defensible data or information that
would be helpful in this evaluation of the AELs for sulfur mustard.
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\1\ HD is distilled sulfur mustard that has been purified by
washing and vacuum distillation, whereas Levinstein mustard (H)
contains about 30 percent sulfur impurities and has stronger
vesicant action. HT consists of 60 percent HD and 40 percent T
(related vesicant with lower freezing point and much lower
volatility), with reportedly similar characteristics to HD. T is not
expected to constitute an airborne vapor hazard.
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Preamble: This proposal updates the sulfur mustard AELs recommended
by CDC in 1988. In preparing this proposal, CDC found some evolution of
the methods used to derive AELs and some additional toxicity data
available for consideration. Even though no empirical evidence
indicated that the existing AELs for mustard are not protective of
health, CDC believed the new methods and information should be examined
for potential impacts on the exposure criteria. Considerations and
logic used to arrive at the proposed AELs may be requested from the
contact listed at the end of this announcement.
When reviewing the methods used to derive AELs, CDC found that the
Environmental Protection Agency's (EPA's) traditional ``reference
concentration'' (RfC) method (based on no observed adverse effect
level/lowest observed adverse effect level [NOEL/LOAEL] values) and the
newer categorical regression, or ``CatReg'' method, are both undergoing
internal review that could result in future variation in the way they
are applied and the numeric values ultimately derived. Accordingly, CDC
decided that both methods should be examined to help define a range of
potential values for the proposed AELs. This announcement summarizes
CDC's
[[Page 43357]]
findings and the resultant AELs being proposed. The proposed values
were developed in the context of applying professional judgment and did
not rely exclusively on any one method. Accordingly, the proposed AELs
reflect realistic risk management provisions associated with chemical
demilitarization and do not necessarily apply to other purposes.
CDC believes that incorporating risk management into the risk
assessment process is necessary and beneficial for the following
reasons: Extensive experience has shown that any exposure would be
expected to be episodic and acute; extensive air monitoring,
engineering, and procedural safeguards have effectively limited
exposures; and competing risks would be introduced if existing
requirements were significantly changed. Consequently, this proposal is
predicated on CDC's understanding of existing demilitarization
safeguards and procedures.
Rather than specify an 8-hour time-weighted average, CDC proposes
to designate a 5-minute ceiling level that reflects the extensive near-
real-time monitoring systems associated with chemical demilitarization
activities. Additionally, CDC proposes to recommend a 12-hour general
population limit (GPL-12), applicable to both the general population
and workers, to confirm that low-level exposure is not occurring. The
time duration of the GPL-12 is consistent with the sampling period for
existing air monitoring methods and the long work shifts in many
demilitarization operations.
CDC recommends a GPL value to allow facility perimeter monitoring
levels to be set at a concentration that ensures that carcinogenicity
protection goals are met. CDC proposes to change the definition of the
GPL to reflect the probable short duration of potential exposures to
the general public. Further discussion of this redefinition appears in
the available support documentation.
CDC believes this proposal meets the goals of protecting workers
and the public at potential airborne concentration levels below those
which would result in adverse health effects or irritation for acute
exposures, and further protects against risk of cancer from long-term
exposure. The criteria proposed in this announcement protect at a risk
level below one in one million excess cancers, which is considered to
be insignificant.
SUMMARY: CDC's proposals are based on comments by individual scientific
experts and interested participants at a public meeting convened by CDC
on September 11-12, 2001, in Atlanta, GA; the latest available
scientific data and technical reviews; exposure and risk assessment
approaches (e.g. CatReg and RfC methods); and CDC's understanding of
current risk management practices associated with the U.S. Army's
chemical agent demilitarization program. As a result of this re-
evaluation of the data and the continuing evolution of AEL derivation
methods, CDC proposes that the 1988 worker population limit (WPL) of
0.003 mg/m\3\, currently an 8-hour time-weighted average (TWA), becomes
a 5-minute Ceiling limit value (CEILING-5M); and the GPL of 0.0001 mg/
m\3\, currently a 72-hour time-weighted average (GPL-72), becomes a 12-
hour TWA (GPL-12) and it is adjusted to 0.00002 mg/m\3\ to meet
carcinogenicity protection levels below thresholds of significant risk
(Table 1). CDC also proposes that historical monitoring at the new GPL-
12 be implemented where workers are assigned, if reasonable potential
exists for mustard exposure. This is to ensure that undetected low-
level exposure is not occurring. The proposed Immediately Dangerous to
Life or Health (IDLH) value of 0.7 mg/m\3\ was derived by CDC/National
Institute for Occupational Safety and Health (CDC/NIOSH) in accordance
with standard NIOSH protocol.
Table 1.--CDC Proposed Mustard Airborne Exposure Limits
[All values expressed as mg/m\3\ in air]
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Proposed general
Existing worker Proposed worker daily Existing general population limit Proposed immediately
Mustard (H, HD, HT) criteria population limit (WPL- ceiling limit population limit (includes workers) (GPL- dangerous to life or
8) (CEILING-5M*) (GPL-72) 12*) health (IDLH)
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Exposure Level.................... 0.003................ **0.003.............. 0.0001.............. 0.00002................ 0.7[Dagger]
Averaging Time.................... 8 hours (TWA)........ <=5 minutes.......... 72 hours (TWA)...... <=12 hours[dagger] <=30 minutes
(TWA).
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* Administrative or appropriate personal protective equipment is required if mustard vapor exposure exceeds criteria.
** To be evaluated with a near real-time instrument with a cycle time of not more than 5 minutes.
[dagger] To be evaluated with historical air monitoring method with analysis within 72 hours of sampling (applicable to worker and general population to
detect low-level excursions of agent). The action level is recommended to be set at the GPL for this criterion.
[Dagger] The 30-minute period is not meant to imply that workers should stay in the work environment any longer than necessary; in fact, they should
make every effort should be made to exit immediately. IDLH condition requires highly reliable dermal and respiratory protection providing maximum
worker protection.
Although the proposed CEILING-5M is numerically identical to the
existing 1988 CDC criteria, the averaging time has been changed to
reflect actual operating conditions associated with ongoing
demilitarization activities. The averaging time for the GPL similarly
has been changed to reflect actual practice. As discussed in the
supporting documentation, these changes reduce the potential dose
associated with an exposure at each limit.
CDC believes that the proposed limits will protect workers and the
public from potential acute and long-term (e.g., carcinogenic) adverse
health effects from exposure to H, HD, and HT. Comments are hereby
sought to help CDC refine their evaluation prior to issuing final
recommended AELs.
DATES: Submit comments on or before October 1, 2003.
ADDRESSES: Comments may be submitted several ways:
1. By mail. Submit your comments to Dr. Paul Joe, Centers for
Disease Control and Prevention, 4770 Buford Highway, Mail Stop F-16,
Atlanta, Georgia 30341.
2. In person or by courier. Deliver your comments to the address
listed above.
3. Electronically. Submit your comments by e-mail to pbj4@cdc.gov,
or submit a computer disk to the address indicated above. Electronic
documents will be accepted in Corel WordPerfect[reg] or Microsoft
Word[reg] formats.
For a Copy of CDC's Detailed Proposal: Dr. Paul Joe, Centers for
Disease Control and Prevention, 4770 Buford Highway, Mail Stop F-16,
Atlanta, GA 30341, Telephone number:
[[Page 43358]]
770-488-7091, E-mail address: pbj4@cdc.gov.
Dated: July 16, 2003.
Joseph R. Carter,
Associate Director for Management and Operations, Centers for Disease
Control and Prevention.
[FR Doc. 03-18601 Filed 7-21-03; 8:45 am]
BILLING CODE 4163-18-P