industry’s most common application for nPB-based aerosols.  The
distribution of exposure levels in the seven samples ranging from 5.5 to
32 ppm corresponded to the range of ventilation rates reported--0, 300,
640, and 1900 cfm—with the highest ventilation rate resulting in the
lowest exposure levels and the lower ventilation levels resulting in the
values above 30 ppm.  The ventilation rate most consistent with use in a
confined space for in-place cleaning, 0 cfm, resulted in half the
exposures (one of two) exceeding 30 ppm.  The highest ventilation rate,
1900 cfm, occurred at a vented booth, which would not be feasible to
install for in-place cleaning applications—the majority of
applications for nPB-based aerosols.  The middle ventilation rates of
300 and 640 cfm occurred during use of a fan for an entire room
(regional ventilation), as might be expected for benchtop cleaning
(Confidential submission, 1998), but not for in-place cleaning in
confined spaces.  In modeling nPB exposure from aerosol solvent use at a
low ventilation rate of 450 cfm, a level that might be expected during
benchtop cleaning, 8-hour average concentrations of 16.5 to 33 ppm are
predicted, depending on the amount of nPB used (ICF, 2006a).  Exposure
levels for confined spaces with even lower ventilation rates, as we
would expect for in-place cleaning, would be even higher, likely
exceeding the high end of the range that EPA is considering.  Short-term
exposures of 370 and 1,100 ppm taken from workers’ collars in a room
with regional ventilation at 640 cfm, when averaged over an 8-hour
period, resulted in exposure levels of 12 and 34 ppm.  These exposures
occurred as a result of using nPB over a period up to 15 minutes, so it
is likely that users would have greater exposure than 30 ppm if they
used nPB for longer than 15 minutes per day, as with multiple uses.  The
available data sets have a small sample size, may not be representative
of in-place cleaning in confined spaces, and do not provide EPA with
convincing data that nPB is likely be used safely, at exposure levels at
or below the highest level in the range we are considering for
evaluation of acceptability.

 	EPA is concerned that many, and perhaps most, uses of nPB aerosol
solvents result in a high probability of exposures at or above even the
upper end of the range of exposures that the Agency is considering to be
potentially acceptable..  EPA is aware of no data on ventilation levels
demonstrating that most users of aerosol solvents, or of nPB in
particular, would use aerosols in locations with sufficiently high
ventilation levels to protect human health (e.g., 1900 cfm or greater).
We request data on worker exposure levels, typical ventilation rates,
and patterns for usage of nPB-based aerosols, considering both benchtop
and in-place use.

	EPA has found numerous other aerosol solvents acceptable.  These
aerosol solvents can be used safely in a manner consistent with their
respective acceptable exposure limits.  This is highlighted in a study
comparing concentrations of eight different chemicals that are
acceptable under the SNAP program in aerosol formulations:  HFE-7100,
HFE-7200, trans-1,2-dichloroethylene, HCFC-225ca and -225cb, acetone,
pentane, and HFC-134a.  In this study, with ventilation of only 48 cfm,
8-hr TWA exposure from the different chemicals varied from 35.5 ppm to
194.0 ppm, and all chemicals met their respective recommended exposure
levels (ICF, 2006a).  As discussed above in section V.A, when these
concentrations are adjusted for the chemicals’ respective molecular
weights, they would correspond to nPB concentrations of 29.5 to 394.4
ppm, which is at or above even the highest level the Agency would
consider acceptable.  The ventilation level in this study is closer to
what we would expect in a confined space where fans or vents cannot be
installed, as for in-place cleaning.  Based on these considerations, the
Agency believes that nPB used as an aerosol solvent would impose
significantly more risk to human health than other alternatives
available for this end use.

 	B.	Adhesives

	EPA proposes to find nPB unacceptable in the adhesive end use.  As for
aerosol solvents, we found that some alternative adhesive formulations
could reduce particular environmental risks more than nPB, such as
generation of ground level “smog” or ozone depletion potential.
However, we find the greatest concern in this end use is with nPB’s
human health effects.  We propose to find nPB unacceptable in adhesives
because it poses significantly greater risk to human health as compared
to other available alternatives in this end use.

	In the June 2003 NPRM, we initially proposed to find nPB acceptable in
adhesives based on the SNAP program principle that “EPA does not
intend to restrict a substitute if it poses only marginally greater risk
than another substitute….The Agency also does not want to intercede in
the market’s choice of available substitutes, unless a substitute has
been proposed or is being used that is clearly more harmful to human
health and the environment than other alternatives.”  (68 FR 33294,
citing the original March 18, 1994 SNAP rule at 59 FR 13046).  At the
time of the proposal, we considered data from NIOSH monitoring and
health hazard evaluations for three facilities using nPB-based
adhesives.  At two of the three facilities, NIOSH worked together with
the companies to install state-of-the-art ventilation equipment.
Looking at exposure data from all workers after ventilation
improvements, we believed it would be possible for facilities to meet
the proposed AEL of 25 ppm (68 FR 33294).

One public commenter suggested that EPA should reconsider whether
industrial exposures consistently occur and /or can be controlled to a
level at or below 25 ppm (Werner, 2003).  We reevaluated the exposure
data for the two plants that had improved their ventilation, focusing on
exposure to the workers that receive the highest exposures because they
directly spray the nPB-based adhesive.  We found that, even in the best
case, a substantial number of workers spraying nPB-based adhesives would
be exposed above the highest level in the range we are considering.

NIOSH investigators initially reported that mean exposures to nPB ranged
from 60 to 381 ppm (8-hour time weighted averages) at three different
foam-fabrication facilities using nPB-based adhesives (NIOSH, 2000a,
2000b, 2001, 2002a, 2002b, 2003a).  In one facility, average (mean) nPB
exposures were reduced from 169 ppm to 19 ppm, following installation of
ventilation equipment (NIOSH, 2000b).  Although use of spray booths at
this facility reduced the average exposure level to 19.4 ppm for all
workers, the majority of the sprayers directly using nPB-based adhesives
still would be exposed at unacceptably high levels.  Out of fourteen
sprayers at the Custom Products facility:

Six, or 43% of sprayers, would be exposed to more than 30 ppm.

Nine, or 64% of sprayers, would be exposed to more than 25 ppm.

Ten, or 71% of sprayers, would be exposed to more than 20 ppm.

Eleven, or 79% of sprayers, would be exposed to more than 15 ppm.

Thirteen, or 93% of sprayers, would be exposed to more than 10 ppm.

	At another facility using nPB-based adhesives, the average exposure was
reduced from 58 pm to 19 ppm after the company installed ventilation
recommended by NIOSH (NIOSH, 2001).  Data on exposure for sprayers found
fewer individuals receiving high exposures than at the facility
monitored in NIOSH (2000b), but 65% (22 of 34) of exposure samples for
sprayers were higher than 15 ppm, 33% (11 of 34) were higher than 20 ppm
and 15% (5 of 34) were higher than 25 ppm after improving ventilation.

	Overall, 42% of sprayers in these two facilities using nPB-based
adhesives were exposed to concentrations of nPB greater than 20 ppm (21
of 48 workers) and 23% (14 of 48 workers) were exposed to more than 25
ppm, even after installing state-of-the-art ventilation with assistance
from NIOSH.  Sprayers had significantly higher individual exposures than
workers who did not work directly with the nPB-based adhesive.

	In response to public comment and additional information available to
EPA since the June 2003 NPRM, we now propose that use of nPB-based
adhesives poses significantly higher risks to human health than other
available adhesives.  Since the June 2003 NPRM, there have been a number
of reports of workers working with nPB-based adhesives that have
suffered adverse, persistent neurological effects that resulted in
hospitalization (Beck and Caravati, 2003, and Majersik et al., 2004,
2005; Calhoun County, 2005; Miller, 2005; Raymond and Ford, 2005).
Based on data from actual facilities using adhesives, it is estimated
that a facility using nPB with average adhesive application rates and
average ventilation rates would have exposure levels of approximately 60
ppm on an 8-hr time-weighted average (ICF, 2006a).  Modeling of
exposures at high adhesive application rates and average or lower
ventilation rates resulted in exposures of approximately 250 to 2530 ppm
(ICF, 2006a).  We believe these modeling results show that most adhesive
users would exceed acceptable exposure levels by significant margins and
that it is unlikely that adhesive users would be able to use nPB safely.

	Considering the exposure data for nPB-based adhesives, we believe it is
unlikely that, even with improved ventilation, adhesive users could
reduce exposures to acceptable levels on a consistent basis.  In the
best case seen, a facility with low to average initial exposure levels
was able to reduce exposures to the middle of the range EPA is
considering after extensive assistance from NIOSH in installing
state-of-the-art ventilation.  We expect that many facilities will begin
with higher exposure levels and will not have the same level of
assistance to improve ventilation, thus making it unlikely that they
would achieve acceptable exposures.  Given the information above, we are
concerned that nPB-based adhesives cannot be reliably used in a manner
that protects human health.  We request comment and further data on
whether it is feasible to use nPB-based adhesives with worker exposure
levels consistently at or below any of the values in the range of
exposure levels that EPA is considering potentially acceptable (i.e., 17
to 30 ppm).

	The available information indicates that all acceptable carrier
solvents in adhesives other than nPB have projected or actual exposure
less than the appropriate workplace exposure limit EPA used in finding
those substitutes acceptable.  Examples of other carrier solvents
currently used in adhesives and acceptable under the SNAP Program
include hydrocarbon solvents, acetone, methylene chloride, and water.
EPA finds that there are other available alternatives that pose
significantly less risk to human health and the environment compared to
nPB in the adhesives end use.

	During the public comment period on the June 2003 NPRM, one commenter
representing the adhesives industry stated that there are some small but
critical applications that require nonflammability and high solvency
(Collatz, 2003).  The commenter did not specify what those applications
are, and whether there was information showing that other types of
adhesives, such as those using water, flammable solvents, or methylene
chloride, are technically infeasible in these applications.  We request
comment and data on whether there are any unique applications in the
adhesives end use for which there are no technically feasible
alternatives other than nPB and thus, for which nPB should be allowed.
If so, and if determined that nPB should be unacceptable except where no
other substitutes are feasible, we would consider finding nPB acceptable
subject to narrowed use limits, with requirements for each end user to
perform a demonstration that there are no other technically feasible
alternatives for their particular site, to install local exhaust
ventilation equipment designed to reduce exposures to acceptable levels
and to perform worker exposure monitoring.  Alternatively, if there was
sufficient information provided during the public comment period showing
that there are applications in which nPB can be safely used, we would
consider finding nPB acceptable in adhesives, subject to use conditions
requiring installation of local exhaust ventilation and worker exposure
monitoring.  This would allow for use of nPB in any applications where
it may be used safely if any such applications exist.

	C.	Coatings  tc "		4.	Coatings " \l 3

	We are proposing to find nPB acceptable, subject to use conditions, for
facilities that, as of [INSERT DATE OF PUBLICATION], have provided EPA
information demonstrating their ability to maintain workplace exposure
levels below even the minimum level of the range of exposures that EPA
is considering to be potentially acceptable (i.e., 17 to 30 ppm).  The
SNAP submission with information on coatings was made for a single
facility and EPA is unaware of anyone else interested in using nPB in
this end use.  Therefore, there are currently no analyses indicating
whether nPB would pose significantly greater risks in any coating
applications other than this facility.  Workplace exposure levels to nPB
from ammunition sealant at Lake City Army Ammunition Plant ranged from
less than 1 ppm up to 21 ppm on an eight-hour time-weighted average.
Thirty-four of 35 samples had concentrations below 10 ppm, and the mean
concentration for the plant was less than 4 ppm (Lake City Army
Ammunition Plant, 2004).  The vast majority of measurements show worker
exposure well below the lowest level in the range of exposures that EPA
is considering.  Thus, we believe that nPB can be used as safely as
other acceptable solvents used at their acceptable exposure limits under
the conditions at this facility.

	Other acceptable substitutes for ozone-depleting substances in
coatings, in general, include oxygenated solvents, hydrocarbon solvents,
terpenes, hydrofluoroethers 7100 and 7200, benzotrifluorides (include
parachlorobenzotrifluoride), monochlorotoluenes,
trans-1,2-dichloroethylene, chlorinated solvents, water-based
formulations, and high-solids formulations.  In the particular
application for ammunition coatings, the submitter evaluated a large
number of alternatives and found that n-propyl bromide was the only one
of 29 solvents tested that could meet performance specifications at this
facility (Harper, 2005).  Thus, it is not clear that there are other
substitutes available for this specific application, and exposure data
show that in this specific application, nPB can be used in a way that
does not pose significantly greater risks to human health compared to
other acceptable substitutes in the coatings end use.

VII.   What other regulatory options did EPA consider?

EPA considered several different options, but we prefer the approach
proposed in this rule.  We also take comment on the options discussed
below.

Alternate option for comment:  acceptable with use conditions requiring
exposure limit and monitoring

	We also take comment on a proposed alternate approach in which nPB
would be acceptable subject to use conditions in all the end uses
addressed in this action.  Under this alternate approach, users would
meet an exposure limit, monitor exposure of workers using nPB, and keep
records to demonstrate compliance with these requirements.  For purposes
of this alternative proposal, we selected 20 ppm to use as an exposure
limit above which use would be unacceptable, and 10 ppm as an action
level that allows reduced exposure monitoring, for the reasons discussed
below in section VII.A.1, “Use Conditions and Their Rationale.”
However, we are soliciting comment on whether a different exposure level
within the 17 to 30 ppm range should be selected.  The following
requirements would apply at each facility where nPB is used:

Exposure Limit

The owner or operator would be required to ensure that workers using nPB
are exposed to no more than 20 ppm on an 8-hour time-weighted average.
The exposure limit could be met through engineering controls (e.g.,
ventilation equipment), work practices, or reduced use of nPB.

Initial Worker Exposure Monitoring

For each facility where nPB is used, the owner or operator of the
facility would be required to ensure that personal breathing zone air
samples of each nPB user’s exposure would be collected on an
eight-hour, time-weighted average initially within 90 days after a final
rule becomes effective.  Monitoring measurements may be taken with an
organic chemical monitoring badge on the collar or a tube filled with
charcoal on the collar.

Periodic Exposure Monitoring

The owner or operator of the facility would be required to ensure that
personal breathing zone air samples of user exposure are collected
periodically on an eight-hour, time-weighted average depending on the
results of the most recent set of exposure data.  A monitoring program
could be instituted by the company or by the nPB supplier for that
facility.  Periodic sampling requirements would be based on the most
recent monitoring results, as follows:

Table 10.  Alternative Approach Exposure Levels and Periodic Exposure
Monitoring

If exposure measurements for nPB are at this level:	Then the owner or
operator:

all measurements at or below 10 ppm	is not required to perform periodic
exposure monitoring.

all measurements at or below 20 ppm, with some measurements above 10 ppm
must take personal breathing zone samples again at least once in the
next six months.

at least one measurement above 20 ppm	must stop using nPB in the
application exceeding the exposure limit until exposure data show that
20 ppm can be consistently met in the vast majority of cases.

unknown, in cases of new workplace conditions increasing exposure or new
applications of nPB	must take personal breathing zone samples as a test
before using nPB in new industrial applications or conditions, or within
7 days of an emergency caused by a leak, rupture or breakdown, and use
this value to determine the next time monitoring is required.

 For periodic monitoring, the owner or operator would be allowed either
to monitor each nPB user’s exposure, or to monitor exposure of a
representative nPB user in each job classification in a work area during
every work shift, where the monitored nPB user is expected to have the
highest exposure.

The owner or operator would be allowed to discontinue the periodic
8-hour TWA monitoring for nPB users at the facility where at least two
consecutive sets of measurements taken at least seven days apart are
below 10 ppm.

Monitoring for new conditions or applications

Whenever there is a change in workplace conditions that may increase
exposure or whenever a new application of nPB is introduced, the owner
or operator would be required to take personal breathing zone samples
accounting for all nPB users as a test before using nPB in manufacturing
or repair.  These could be either samples for each nPB user or samples
representing each job classification in a work area during a work shift,
so long as the samples are based on the user with the likely highest
exposure.  Examples of changes in workplace conditions that may increase
exposure include changes in production, process control equipment, or
work practices, or a leak, rupture, or other breakdown.  Examples of
introduction of a new application of nPB include aerosol contact
cleaning in a location with regional ventilation or natural ventilation,
where previous measurements were carried out on workers in a location
with local ventilation.  If the change occurs because of an
unpredictable emergency, then the owner or operator would need to ensure
exposure monitoring takes place within 7 days of the change.

Sampling methods and accuracy

Exposure samples would be required to be analyzed either by NIOSH method
1003 for halogenated hydrocarbons or method 1025 for 1-bromopropane and
2-bromopropane or by another method that is accurate to + 25% at the 95
percent confidence level.

Recordkeeping requirements

The owner or operator of the facility would be required to keep records
of the monitored exposure data at the facility for at least three years
from the date the measurements were taken for purposes of this rule.
These records would be required to be made available in the event of a
facility inspection or a request for the data by EPA.   Note that the
EPA’s recordkeeping requirement does not affect OSHA’s standard on
access to employee exposure and medical records, which requires
retaining any exposure records for at least 30 years (29 CFR
1910.1020(d)(ii)).

The regulatory listings by end-use under this alternate approach that
the Agency requests comment on would be as follows:

Table 11.  Alternate Approach:  AEROSOLS

SUBSTITUTES THAT ARE ACCEPTABLE SUBJECT TO USE CONDITIONS

End Use	Substitute	Decision	Use Conditions	Further Information

Aerosol solvents	n-propyl bromide (nPB) as a substitute for CFC-113,
HCFC-141b, and methyl chloroform	Acceptable subject to use conditions
The owner or operator of a facility must ensure that users of nPB
achieve an  exposure limit of 20 ppm on an 8-hour time-weighted average.

The owner or operator of a facility must ensure that workers using nPB
are monitored for their exposure to nPB using personal breathing zone
samples on an eight-hour, time-weighted average (8-hr TWA) no later than
90 days after the effective date of this rule.

If the most recent data from exposure monitoring shows all personal
breathing exposures to be at or below 10 ppm, no periodic exposure
monitoring is required.  If the most recent data from exposure
monitoring shows all exposures to be at or below 20 ppm, but some above
10 ppm, the owner or operator must take personal breathing zone samples
for nPB users at least once during the next six months.

The owner or operator may discontinue the periodic 8-hour TWA monitoring
for nPB users at the facility where at least two consecutive sets of
measurements taken at least seven days apart are below 10 ppm.

The owner or operator must determine the exposure of each nPB user by
either taking personal breathing zone air samples of each user's
exposure or samples that are representative of each user's exposure.
The samples are representative where the owner or operator has taken one
or more personal breathing zone air samples for at least one nPB user in
each job classification in a work area during every work shift, and the
nPB user sampled is expected to have the highest exposure to nPB.

The owner or operator also must perform exposure monitoring when a
change in workplace conditions indicates that employee exposure may have
increased or whenever new applications of nPB are introduced.  Perform
exposure monitoring before making planned changes, and perform
monitoring no later than 7 days after an emergency change in conditions.

All personal breathing zone samples must be analyzed either by NIOSH
method 1003 or 1025 or by another method that is accurate to + 25% at a
95 percent confidence level.

The owner or operator must keep records of nPB worker exposure data at
the facility for at least three years from the date the measurements
were taken.   	EPA recommends the use of personal protective equipment,
including chemical goggles, flexible laminate protective gloves and
chemical-resistant clothing.

Note that the Occupational Safety and Health Administration (OSHA) may
establish a final Permissible Exposure Limit (PEL) standard in the
workplace at 29 CFR part 1910 under 42 U.S.C. 7610(a).

OSHA’s standard on access to employee exposure and medical records
requires retaining exposure records for at least 30 years (29 CFR
1910.1020(d)(ii)).

Note: In accordance with the limitations provided in Section 310(a) of
the Clean Air Act (42 U.S.C. 7610(a)), nothing in this table shall
affect the Occupational Safety and Health Administrations’ authority
to promulgate and enforce standards and other requirements under the
Occupational Safety and Health Act of 1970 (29 U.S.C. 651 et seq.)

Table 12.  Alternate Approach:  ADHESIVES, COATINGS, AND INKS

SUBSTITUTES THAT ARE

ACCEPTABLE SUBJECT TO USE CONDITIONS

End Use	Substitute	Decision	Use Conditions	Further Information

Adhesives and coatings 	n-propyl bromide (nPB) as a substitute for
CFC-113, HCFC-141b, and methyl chloroform	Acceptable subject to use
conditions	The owner or operator of a facility must ensure that users of
nPB achieve an exposure limit of 20 ppm on an 8-hour time-weighted
average.

The owner or operator of a facility must ensure that workers using nPB
are monitored for their exposure to nPB using personal breathing zone
samples on an eight-hour, time-weighted average (8-hr TWA) no later than
90 days after the effective date of this rule.

If the most recent data from exposure monitoring shows all personal
breathing exposures to be at or below 10 ppm, no periodic exposure
monitoring is required.  If the most recent data from exposure
monitoring shows all exposures to be at or below 20 ppm, but some above
10 ppm, the owner or operator must take personal breathing zone samples
for nPB users at least once during the next six months.

The owner or operator may discontinue the periodic 8-hour TWA monitoring
for nPB users at the facility where at least two consecutive sets of
measurements taken at least seven days apart are below 10 ppm.

The owner or operator must determine the exposure of each nPB user by
either taking personal breathing zone air samples of each user's
exposure or samples that are representative of each user's exposure.
The samples are representative where the owner or operator has taken one
or more personal breathing zone air samples for at least one nPB user in
each job classification in a work area during every work shift, and the
nPB user sampled is expected to have the highest exposure to nPB.

The owner or operator also must perform exposure monitoring when a
change in workplace conditions indicates that employee exposure may have
increased or whenever new applications of nPB are introduced.   Perform
exposure monitoring before making planned changes, and perform
monitoring no later than 7 days after an emergency change in conditions.

All personal breathing zone samples must be analyzed either by NIOSH
method 1003 or 1025 or by another method that is accurate to + 25% at a
95 percent confidence level.

The owner or operator must keep records of nPB worker exposure data at
the facility for at least three years from the date the measurements
were taken.  	EPA recommends the use of personal protective equipment,
including chemical goggles, flexible laminate protective gloves and
chemical-resistant clothing.  nPB, also known as 1-bromopropane, is
Number 106-94-5 in the CAS Registry.

Note that the Occupational Safety and Health Administration (OSHA) may
establish a final Permissible Exposure Limit (PEL) standard in the
workplace at 29 CFR part 1910 under 42 U.S.C. 7610(a).

OSHA’s standard on access to employee exposure and medical records
requires retaining exposure records for at least 30 years (29 CFR
1910.1020(d)(ii)).

Note: In accordance with the limitations provided in Section 310(a) of
the Clean Air Act (42 U.S.C. 7610(a)), nothing in this table shall
affect the Occupational Safety and Health Administrations’ authority
to promulgate and enforce standards and other requirements under the
Occupational Safety and Health Act of 1970 (29 U.S.C. 651 et seq.)1.
Use Conditions and Their Rationale

	The major provisions of the use conditions and the related issues that
EPA considered in developing the alternate approach that we are taking
comment on are as follows:

Exposure limit.  A requirement to meet a workplace exposure limit would
be an interim measure to ensure that nPB will be used safely until OSHA
issues a final permissible exposure limit (PEL) under the Occupational
Safety and Health Act.  In the event that OSHA issues a final PEL, it
would supersede EPA’s exposure limit.  EPA is specifically deferring
to OSHA, and has no intention to assume responsibility to displace
OSHA’s authority under Public Law 91-596.  EPA’s exposure limit
would not pre-empt the authority of OSHA to take regulatory or
enforcement action with respect to exposure to this substance.  This is
made clear by the Clean Air Act under which EPA would promulgate this
regulation (Subchapter VI – Stratospheric Ozone Protection), which
provides at 42 U.S.C. 7610 in pertinent part: “…this chapter
[Chapter 85 – Air Pollution Prevention] shall not be construed as
superseding or limiting the authorities, under any other provision of
law, of the Administrator or any other Federal officer, department, or
agency.”  By issuing an exposure limit for nPB, EPA’s intention
would be to fill existing regulatory gaps during the interim period of
substitution away from ozone-depleting compounds and provide the needed
margin of protection for human health and the environment until OSHA
develops other regulatory controls or standards under appropriate
authorities.

	As discussed above in section IV.E.1, EPA is considering exposures
within the range of 17 to 30 ppm as potentially acceptable in order to
determine whether nPB may be used safely in each end use.  For purposes
of having a clear compliance target under this alternative approach for
public comment, we are using 20 ppm as the exposure limit above which
use would be unacceptable.  We chose this value because we expect it to
be protective against the reproductive and developmental effects
identified previously (live litter size, sperm motility, estrous
cycles).

Worker exposure monitoring.  The worker exposure monitoring requirements
under the use conditions in the alternate approach were modeled after
OSHA’s requirements for monitoring for methylene chloride.  29 CFR
1910.1052(d).  We expect that the regulated community would be familiar
with this approach and there might be fewer changes for regulated
businesses if OSHA later were to establish a workplace standard for nPB.
 Because the exposure limit would be an 8-hr TWA value that is derived
from studies that measured exposure via inhalation, the proposed use
conditions require the owner or operator to monitor 8-hr TWA values that
measure workers’ exposure in the breathing zone (e.g., samples from a
worker’s collar).  We are not proposing to monitor short-term
exposures because acute, short-term exposures of nPB are not of
significant health concern, so long as long-term exposures are below the
8-hour TWA limit or potentially acceptable exposure levels (ERG, 2004).

	Option for monitoring representative set of workers.  Personal breath
zone samples could be taken either from each worker using nPB or from a
representative set of exposed workers expected to have the highest
exposure.  Allowing exposure monitoring from representative workers
using nPB, rather than requiring separate monitoring for each individual
using nPB, would reduce overall compliance burden, while still detecting
any exposure levels in excess of the exposure limit and avoiding
underestimates of exposure.

	Initial monitoring.  Users already using nPB would need to undergo
exposure monitoring no later than 90 days after the date the final rule
becomes effective.  A user that has never used nPB before would need to
perform initial monitoring before beginning to use nPB in the
facility’s industrial applications.

	Periodic monitoring.	Monitoring would have to be performed periodically
on a schedule based on the results of the most recent set of exposure
monitoring data.  Monitoring from workers’ personal breathing zone
would be required during the next six months if an initial measurement
finds exposure levels between the action level and the 8-hour TWA
exposure limit.  No periodic monitoring would be required if initial
measurements are below the action level.  The action level would be the
value that is half the exposure limit, in this case 10 ppm.  OSHA
standards also set an action level of half the PEL.

	Under the alternate approach, monitoring would no longer be required
where the most recent exposure monitoring data found all worker
exposures at or below 10 ppm.  OSHA rules also reduce monitoring
requirements for exposures below the action level because if measured
values are that low, it is unlikely that any measurement will exceed the
PEL unless a major change to the process occurs.

	Monitoring for changes in workplace conditions or nPB use.  New
monitoring would be required if an event occurs that would make the most
recent set of monitoring data no longer representative.  EPA would
expect that the owner or operator would plan new applications of nPB or
changes to control equipment or work practices and would perform a test
for worker exposure levels before using nPB on a regular basis in that
application.  In the case of an emergency, such as a breakdown of
ventilation equipment or a leak, we would expect exposure monitoring to
be performed as soon as possible, and no later than 7 days after the
change in workplace conditions.   This period is intended to give an
owner or operator time to locate and purchase exposure monitoring
equipment in an emergency where the equipment may not already be
available at the facility.

Monitoring method and accuracy.  We take comment on the use of NIOSH
methods 1003 and 1025 (NIOSH, 2003b and c) for analyzing nPB exposure
under the proposed alternate approach.  Several of the studies that
supplied EPA with exposure data used this method and they are
standardized methods prepared by NIOSH, a recognized authority on
industrial hygiene.  In addition, we would allow other methods that are
accurate to + 25% at the 95 percent confidence level.  Based on the
accuracy of available methods, most OSHA standards require exposure
monitoring accurate to 25% at the 95 percent confidence level, as in the
methylene chloride standard (29 CFR 1910.1052(d)(1)(iii)(A)) and other
OSHA standards.

Recordkeeping requirements.  We would require that users keep records of
the worker exposure data for three years from the date the measurement
is taken. This would provide information allowing EPA to determine if
facilities are complying with the exposure limit and if workers exposed
to nPB are sufficiently protected.

Responsibility for meeting requirements.  Under the alternate approach,
the owner or operator of a facility using nPB would be responsible for
meeting the rule’s use conditions.

2.	Advantages and disadvantages of the alternate approach

Setting use conditions that require users to meet an exposure limit and
to monitor and keep records to demonstrate achieving the limit would
protect the health of nPB users while giving industry more flexibility
and more options for ODS substitutes, compared to finding nPB
unacceptable.  This could be especially useful for users of HCFC-141b as
an aerosol solvent that are seeking an effective ODS substitute.  If
there were any situations in which other available alternatives did not
provide as good performance, nPB would still be available as an option,
provided the use conditions could be met.  The monitoring requirements
would encourage good industrial hygiene and safe use of nPB.

Considering the list of use conditions above, we believe that setting
use conditions requiring an exposure limit, worker exposure monitoring,
and recordkeeping would be complex and potentially confusing.  Requiring
users to meet the exposure limit, although providing greater potential
flexibility, also would provide less certainty about how to comply.  A
user could spend considerable time and expense trying to meet the
exposure limit, only to find that it is not achievable.

Given the limited circumstances under which we expect aerosol and
adhesive users could meet an acceptable exposure limit and given the
availability of other, less toxic alternatives in both of these end
uses, EPA’s preferred option is to find nPB unacceptable in aerosols
and adhesives.  Further, considering that without regulatory
requirements, the users of nPB at the Lake City Army Ammunition Plant
have been operating with the vast majority of exposure levels below 17
ppm, the low end of the range of exposures that EPA is considering to be
potentially acceptable (Lake City Army Ammunition Plant, 2004), it
appears unnecessary to require an exposure limit in that application.

B.	Regulatory options where nPB would be acceptable with use conditions
requiring specific equipment

	We considered use conditions for the adhesive and aerosol solvent end
uses that would reduce the human health risks of using nPB by reducing
exposure levels with requirements for installation and use of
ventilation equipment.  We also offer for comment use conditions that
would require aerosol dispensing equipment that would reduce exposure
levels and that would allow use of aerosol blends with reduced amounts
of nPB to maintain acceptable exposure levels.

Aerosols

	For the aerosol solvent end use, EPA considered proposing a requirement
for installation of ventilation equipment.  Such a use condition would
need to specify and define which kinds of ventilation equipment would be
necessary.  For example, because one study on exposure levels found that
exposure levels reliably fell in or below the range that EPA is
considering (i.e., 17 to 30 ppm) only where both local exhaust
ventilation and regional ventilation equipment were used, a possible
requirement would be for installation of both local exhaust ventilation
and regional ventilation.  We would define local exhaust ventilation as
ventilation that removes vapors from a specific work location using
ducts and fans.  We would define regional ventilation as ventilation
that moves air around in a large working area, such as one or more fans
used for an entire room.  A problem with requiring the type of
ventilation equipment that all facilities must use is that it still
might not provide enough ventilation in some situations and in other
situations may be unnecessary to meet an exposure limit.

	Another approach for aerosols we considered was to require a specific
level of ventilation.  Possible criteria for the level of ventilation
would be the air flow rate, in cubic feet per minute (cfm) or cubic
meters per second, or the face velocity at the location where a user
would work, in feet per minute (fpm) or meters per second face velocity.
 Based on both modeling and exposure data from one study (ICF, 2006a;
Linnel, 2003), an appropriate air flow rate for nPB-based aerosols would
be greater than 1900 cfm and an appropriate face velocity would be 170
fpm.  Alternatively, we considered requiring that facilities meet the
guidelines for face velocity in spray booths from the ACGIH Ventilation
Manual, in the range of 100 to 150 fpm, depending on the specific type
of booth (ACGIH, 2002).

	These options would appear to provide greater flexibility for industry
compared to finding nPB unacceptable in aerosol solvents.  However, our
understanding is that in most aerosol applications, it might not be
feasible to install adequate ventilation, and thus, to reduce human
health risks.  In the case of benchtop cleaning or degreasing, such as
during rework of individual parts that are not yet sufficiently clean,
it is possible to transport the part to a hood or spray booth to provide
sufficient ventilation.  However, for applications that require in-place
cleaning such as cleaning energized electrical contacts and switches,
maintenance in underground mines, or cleaning hot elevator motors, it is
not feasible to install ventilation equipment in place or to remove the
parts for cleaning in ventilation equipment (CSMA, 1998; Linnell, 2003).
 Information available to EPA shows that benchtop cleaning is perhaps
25% or less of the market for the ODS being replaced in aerosols (US
EPA, 2004) and that electrical contact cleaning makes up the vast
majority of the market for nPB-based aerosols (Williams, 2005); thus, we
expect that necessary ventilation cannot be installed in most aerosol
applications for nPB.  It would be difficult to explain and potentially
confusing for users that an aerosol product may be used for cleaning in
one location in a facility, but not in another, particularly when the
ODS being substituted for could be used in all locations at safe
exposure levels.  Further, it would be difficult for EPA to enforce use
conditions on ventilation equipment, because aerosols are portable and
can easily be used outside of the ventilation equipment.  Other
acceptable substitutes, such as blends of HFEs or HFCs and
trans-dichloroethylene, are available in these end uses.

	Another option that the Agency considered is finding nPB acceptable as
an aerosol solvent, subject to the use condition that the aerosol
product must be dispensed from a device or a system that is capable of
maintaining acceptable exposure levels.  The Agency is aware of at least
two remote dispensing systems that could potentially mitigate exposures
when used with low-pressure aerosols (Micro Care’s Trigger Grip™ and
Miller Stephenson’s Cobra® Solvent Spray Cleaning Brush).  Vendor
data indicates that each aerosol can may last twice as long when using a
remote dispensing system, compared to standard aerosol usage, indicating
the ability to halve average exposure levels and reduce total solvent
use (Micro Care, 2006).  However, these types of systems would only be
practical for benchtop cleaning, and not electrical contact cleaning,
which comprises the majority of nPB aerosol use.  The Agency requests
comment on the viability and enforceability of a use condition requiring
aerosol dispensing systems or other mitigation devices that could
provide sufficient performance while ensuring acceptable workplace
exposure levels of nPB.

	Finally, the Agency considered another option by which the use of nPB
would be acceptable in aerosol solvent uses, subject to the condition
that users may only use blends of no more than fifty percent nPB and the
remainder being propellants and other solvents, with manufacturer’s
recommended exposure guidelines for compounds other than nPB being no
lower than 100 ppm.  Based on exposure modeling performed on simulations
of several commercial blends of nPB and another compound with a higher
exposure limit (HFC-365mfc), it appears that users should be able to
maintain exposures reliably below the range that EPA is considering for
acceptability (i.e., 17 to 30 ppm) when using a blend containing no more
than fifty percent nPB by weight at the ventilation levels modeled (ICF,
2006a).  We note that the modeling does not consider the possibility
that a user might need to use more of a blend with less nPB, since nPB
is more aggressive than many other solvents used in aerosols.  It also
does not address exposure levels in confined spaces as might occur
during in-place cleaning with aerosols.  We request comment and
relevant, empirical data on the 8-hour TWA exposures that can be
reliably attained when using blends containing 50% or less of nPB by
weight.  In order to make this option enforceable, EPA would require
users to keep records of nPB-containing aerosol blends they purchase,
including the MSDS or other documentation of the proportion of nPB in
the blend they use.  We request comment on whether this is a feasible,
enforceable option and whether it would provide useful flexibility to
industry while ensuring adequate health protection.

	2.	Adhesives

EPA also considered use conditions for ventilation equipment or for
specific ventilation levels for use of nPB-based adhesives.  However, to
date, we have found no study that demonstrates a ventilation option that
could consistently achieve even the highest level within the range that
EPA is considering for acceptability when using spray adhesives.  Even
with state-of-the-art ventilation equipment installed with the expert
assistance of NIOSH, adhesives users were not able to lower exposure
limits sufficient to protect the vast majority of their workers.
Modeling of different levels of adhesive usage and ventilation, based on
conditions at different facilities indicates that air flow rates would
need to be more than 100,000 cfm.  Even this high air flow rate might
not be sufficient, since an air flow rate of 28,500 cfm resulted in
exposure levels of 3.5 to 35 times an acceptable exposure level,
depending on the amount of adhesive used (ICF, 2006a, Att. D).  Less
toxic substitutes such as water-based adhesives and acetone-based
adhesives are available in this end use.

VIII. 	What are the anticipated costs of this regulation to the
regulated community? tc "What are the anticipated costs of this
regulation to the regulated community?"

	As part of our rulemaking process, EPA estimated potential economic
impacts of this proposed regulation.  In our analysis, we assumed that
capital costs are annualized over 15 years or less using a discount rate
for determining net present value of 7.0%.  Because the use condition
for coatings still permits nPB’s use in the only known coatings
application using nPB, we find no additional cost to the user community
from this regulatory provision.  We found that if this proposed rule
were to become final, the cost to the user community of the
unacceptability determinations, which are regulatory prohibitions on the
use of nPB in adhesives and aerosols, would be in the range of $2.3 to
$6.7 million per year for adhesive users and $36.3 to 39.7 million per
year for aerosol users.

	EPA also estimated the cost to the user community of the use conditions
in the proposed alternate approach for aerosols, adhesives, and
coatings.  The requirements for users to meet an acceptable exposure
limit and to perform exposure monitoring would be in the range of $ 42.3
to 67.5 million per year.  The upper end of the range of estimated
impacts assumes laboratory grade ventilation for aerosols, which we
expect to be significantly more expensive than standard industrial fume
hoods or spray booths (approximately $10,000 compared to $1,000 for each
hood).  For coatings, use of nPB is limited to a single facility that
already performs workplace exposure monitoring, and thus, no new costs
would be incurred.  For aerosols and adhesives, we assumed the
installation of fume hoods or spray booths, the use of personal
protective equipment, and monitoring for 1.9 to 2.0 times per year on
average.  Using these assumptions, we calculated the cost of the use
conditions in the proposed alternate approach at $18.0 to 24.0 million
for adhesive users, and $24.3 to 43.5 million for aerosol users.  The
estimated cost of the use conditions does not consider that some users
could choose to switch to other alternatives at a lower cost.

	Estimated costs of the proposed regulation and proposed alternate
approach are summarized in Table 13.  For more detailed information, see
section XIII.C. below and EPA’s analysis in the docket (US EPA, 2006).

Table 13.  Estimated Costs of Regulatory Options EPA is Providing for
Comment

Sector or End Use	Requirements under Proposed Rule	Annual Cost of
Proposed Rule	Requirements under Alternate Approach	Annual Cost of
Alternate Approach

Aerosol Solvents	Cease use of nPB and switch to a different ODS
substitute.	$ 36.3 to 39.7 million	Achieve 20 ppm; exposure monitoring
one or two times per year; Recordkeeping	$24.3 to 43.5 million

Coatings	Decision applies to use nPB in coatings at facilities that, as
of [INSERT DATE OF PUBLICATION], have provided EPA information
demonstrating their ability to maintain acceptable workplace exposures.
None	Achieve 20 ppm; exposure monitoring, one or two times per year;
recordkeeping. 	None

Adhesives	Cease use of nPB and switch to a different ODS substitute.	$
2.3 to 6.7 million	Achieve 20 ppm; exposure monitoring, one or two times
per year; recordkeeping	$ 18.0 to 24.0 million

Total

$38.6 to 46.4 million

$ 42.3 to 67.5 million

IX.	 How do the decisions for EPA’s June 2003 proposal compare to
those for this proposal?

	Table 14 compares the acceptability determination and evidence cited in
the June 2003 proposal and this proposal.

Table   SEQ Table \* ARABIC  1 4: n-Propyl Bromide Acceptability
Decision

Proposed Decision	2003 Proposed Rule	Current Proposed Rule—Preferred
Proposal

Industrial End Use #1:

Aerosol Solvents	Acceptable, Subject to a Use Condition (Limiting use to
nPB formulations containing no more than 0.05% by weight isopropyl
bromide; AEL of 25 ppm1 on 8-hr TWA recommended	Unacceptable

Industrial End Use #2:

Adhesives	Acceptable, Subject to a Use Condition  (Limiting use to nPB
formulations containing no more than 0.05% by weight isopropyl bromide;
AEL of 25 ppm1 on 8-hr TWA recommended	Unacceptable

Industrial End Use #3: Coatings	Not addressed	Acceptable, Subject to
Use Conditions (Decision limited to coatings at facilities that, as of
[INSERT DATE OF PUBLICATION], have provided EPA information
demonstrating their ability to maintain acceptable workplace exposures2

1 Proposed acceptable exposure limit of 25 ppm adjust upward from value
of 18 ppm based upon nPB’s effect on sperm motility from evaluation of
the WIL 2001 Study “An Inhalation Two-Generation Reproductive Toxicity
Study of 1-Bromopropane in Rats.”

ICF, 2001. ‘‘Brief Discussion of the BMD Approach: Overview of its
Purpose, Methods, Advantages, and Disadvantages.’’ Prepared for U.S.
EPA.

ICF, 2002a. ‘‘Risk Screen for Use of N Propyl Bromide.’’
Prepared for U.S. EPA, May, 2002.

ICF, 2002b. Comments on the NTP- Center for the Evaluation of Risks to
Human Reproduction, Final Report on 1- Bromopropane.  Cover Letter Dated
5/9/02.

Also, evaluation of documents by CERHR (2002a, b), Doull and Rozman
(2001), Rodricks (2002), Rozman and Doull (2002), SLR International
(2001), and others.

2 For purposes of this proposal, EPA is considering levels within the
range of 17-30 ppm based on the following information on nPB’s health
effects for purposes of determining acceptability: estrous cycle length
at 17 to 22 ppm, live litter size at 20 ppm, and sperm motility at 18 to
30 ppm from evaluation of the WIL 2001 Study “An Inhalation
Two-Generation Reproductive Toxicity Study of 1-Bromopropane in Rats”
and confirmed by comparison with other studies.  Also, considers
evaluation of documents by Stelljes and Wood (2004); TERA (2004); ICF,
2006a; ACGIH (2005); Rozman and Doull (2005); Stelljes (2005); and
others.

X. 	 How can I use nPB as safely as possible? tc "VIII. 	 How can I use
nPB as safely as possible?"

Below are actions that will help nPB users minimize exposure levels:

All end uses

All users of nPB should wear appropriate personal protective equipment,
including chemical goggles, flexible laminate protective gloves (e.g.,
Viton, Silvershield) and chemical-resistant clothing.  Special care
should be taken to avoid contact with the skin since nPB, like many
halogenated solvents, can be absorbed through the skin.  Refer to
OSHA’s standard for the selection and use of Personal Protective
Equipment, 29 CFR 1910.132.

Limit worker exposure to solvents to minimize any potential adverse
health effects.  Workers should avoid staying for long periods of time
in areas near where they have been using the solvent.  Where possible,
shorten the period during each day when a worker is exposed.  Where
respiratory protection is necessary to limit worker exposures,
respirators must be selected and used in accordance with OSHA’s
Respiratory Protection standard, 29 CFR 1910.134.

Use less solvent, or use a different solvent, either alone or in a
mixture with nPB.

Follow all recommended safety precautions specified in the
manufacturer’s MSDS.

Workers should receive safety training and education that includes
potential health effects of exposure to nPB, covering information
included on the appropriate MSDSs, as required by OSHA's Hazard
Communication Standard (29 CFR 1910.1200).

Request a confidential consultation from your State government on all
aspects of occupational safety and health.  You can contact the
appropriate state agency that participates in OSHA’s consultation
program.  These contacts are on OSHA’s web site at     HYPERLINK
"http://www.osha.gov/oshdir/consult.html."
http://www.osha.gov/oshdir/consult.html.   For further information on
OSHA’s confidential consultancy program, visit OSHA’s web page at
HYPERLINK "http://www.osha.gov/html/consultation.html"
http://www.osha.gov/html/consultation.html .

Use the employee exposure monitoring programs and product stewardship
programs where offered by manufacturers and formulators of nPB-based
products.

If the manufacturer or formulator of your nPB-based product does not
have an exposure monitoring program, we recommend that you start your
own exposure monitoring program, and/or request a confidential
consultation from your State government.

 	A medical monitoring program should be established for the early
detection and prevention of acute and chronic effects of exposure to
nPB.  The workers' physician(s) should be given information about the
adverse health effects of exposure to nPB and the workers' potential for
exposure.

Spray applications

For spray applications (e.g., aerosols), consider your available
options, and if using nPB, use sufficient ventilation to reduce exposure
to maintain acceptable exposure levels.

For ventilation, we recommend that you follow the design guidelines for
ventilation in ACGIH’s Industrial Ventilation: A Manual of Recommended
Practice (ACGIH, 2002).  In particular, the guidelines in Chapter 10.75
are appropriate for spray booths, and the guidelines in Chapter 10.35
are appropriate for laboratory hoods.

The ACGIH Ventilation Manual recommends a minimum flow rate of 150 cubic
feet per minute (cfm) for each sq-ft of opening for a small booth with
at least 4 sq-ft of open face area.  This equates to an average face
velocity of 150 ft/min.  For a large booth, the recommended face
velocity is 100 ft/min for walk-in booths and 100 to 150 ft/min for a
large spray booth where the operator works outside.  In general, the
opening should be kept as small as possible to accommodate the
work-pieces, generally 12 inches wider and taller than the largest piece
of work.  If all spraying is not directed towards the back of the booth
or the booth is too shallow for the size of the pieces being sprayed or
if disruptive air currents are present at the face of the booth, a
greater flow of air will be needed.

We note that these steps are useful for reducing exposure to any
industrial solvent, and not just nPB.

XI.	Statutory and Executive Order Reviews tc "Statutory and Executive
Order Reviews"

	A. 	Executive Order 12866:  Regulatory Planning and Review

	Under Executive Order (EO) 12866   SEQ CHAPTER \h \r 1 (58 FR 51735,
October 4, 1993), this action is a "significant regulatory action.”
It raises novel legal or policy issues arising out of legal mandates,
the President's priorities, or the principles set forth in the Executive
Order.   SEQ CHAPTER \h \r 1  Accordingly, EPA submitted this action to
the Office of Management and Budget (OMB) for review under EO 12866 and
any changes made in response to OMB recommendations have been documented
in the docket for this action.

	  SEQ CHAPTER \h \r 1 In addition, EPA prepared an analysis of the
potential costs and benefits associated with this action.  This analysis
is contained in the document “Analysis of Economic Impacts of Proposed
nPB Rule on Aerosols and Adhesives.”  A copy of the analysis is
available in the docket for this action (Ref. EPA-HQ-OAR-2002-0064) and
the analysis is briefly summarized here.  EPA estimates the total costs
of the proposed rule to between $38.6 and 46.4 million per year.

Paperwork Reduction Act

The information collection requirements in this proposed rule have been
submitted for approval to the Office of Management and Budget (OMB)
under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.  The
Information Collection Request (ICR) document prepared by EPA has been
assigned EPA ICR number 2224.01.

If the provisions of this proposed rule become final (i.e., if the
proposed regulatory language at the end of this document is finalized),
there would be no new information collection burden.  This proposed rule
contains no new requirements for reporting or recordkeeping.  OMB has
previously approved the information collection requirements contained in
the existing regulations in subpart G of 40 CFR part 82 under the
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and
has assigned OMB control number 2060-0226 (EPA ICR No. 1596.06).  This
ICR included five types of respondent reporting and record-keeping
activities pursuant to SNAP regulations:  submission of a SNAP petition,
filing a SNAP/Toxic Substance Control Act (TSCA) Addendum, notification
for test marketing activity, record-keeping for substitutes acceptable
subject to use restrictions, and record-keeping for small volume uses.

However, if EPA were to finalize the proposed alternate approach
described in section VII.A of this preamble, users of nPB would have an
information collection burden from exposure monitoring and
recordkeeping.  Under the proposed alternate approach, users of nPB
would be required to monitor worker exposure initially and periodically
(usually every 6 months) and keep records of these exposure data at the
facility for at least three years from the date the samples were taken.
This data is necessary to ensure that users of nPB are meeting the
regulatory use conditions.  If the data indicates that the use condition
is not being met, it could be used by EPA or citizens in an enforcement
action against the facility.  These data would be considered available
to the public and would not be considered confidential.

The estimated burden of recordkeeping for the entire regulated community
under the proposed alternate approach is as much as $ 7.0 million and
13,170 hours per year.  The estimated recordkeeping burden for a typical
user is $96 and 0.18 hours per worker per monitoring event.  We estimate
approximately 1.9 monitoring events per year per worker, assuming that
roughly 90% of exposed workers must be monitored every six months and
10% must be monitored once annually.  We estimate that up to 35,000
workers would be monitored for exposure to nPB.  Costs under the
proposed alternate approach include the annual cost of purchasing
passive organic exposure monitoring badges, the annual cost of services
for analyzing the resulting exposure, and the annual cost of reviewing
and filing the data up to 2 times per year.

	Burden means the total time, effort, or financial resources expended by
persons to generate, maintain, retain, or disclose or provide
information to or for a Federal agency.  This includes the time needed
to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to comply
with any previously applicable instructions and requirements; train
personnel to be able to respond to a collection of information; search
data sources; complete and review the collection of information; and
transmit or otherwise disclose the information.

	An Agency may not conduct or sponsor, and a person is not required to
respond to, a collection of information unless it displays a currently
valid OMB control number.  The OMB control numbers for EPA's regulations
are listed in 40 CFR Part 9 and 48 CFR Chapter 15.

To comment on the Agency's need for this information, the accuracy of
the provided burden estimates, and any suggested methods for minimizing
respondent burden, including through the use of automated collection
techniques, EPA has established a public docket for this rule, which
includes this ICR, under Docket ID number EPA-HQ-OAR-2002-0064.  Submit
any comments related to the ICR for this proposed rule to EPA and OMB.
See ‘Addresses’ section at the beginning of this notice for where to
submit comments to EPA.  Send comments to OMB at the Office of
Information and Regulatory Affairs, Office of Management and Budget, 725
17th St., N.W., Washington, DC 20503, marked "Attention: Desk Officer
for EPA."  Include the ICR number in any correspondence.  Since OMB is
required to make a decision concerning the ICR between 30 and 60 days
after [Insert date of publication in the FEDERAL REGISTER], a comment to
OMB is best assured of having its full effect if OMB receives it by
[Insert date 30 days after publication in the FEDERAL REGISTER].  The
final rule will respond to any OMB or public comments on the information
collection requirements contained in this proposal.

C.  	Regulatory Flexibility Act

	The Regulatory Flexibility Act (RFA) generally requires an agency to
prepare a regulatory flexibility analysis of any rule subject to notice
and comment rulemaking requirements under the Administrative Procedure
Act or any other statute unless the agency certifies that the rule will
not have a significant economic impact on a substantial number of small
entities.  Small entities include small businesses, small organizations,
and small governmental jurisdictions.  The RFA provides default
definitions for each type of small entity.  Small entities are defined
as: (1) a small business as defined by the Small Business
Administration’s (SBA) regulations at 13 CFR 121.201; (2) a small
governmental jurisdiction that is a government of a city, county, town,
school district or special district with a population of less than
50,000; and (3) a small organization that is any not-for-profit
enterprise which is independently owned and operated and is not dominant
in its field.  However, the RFA also authorizes an agency to use
alternate definitions for each category of small entity, “which are
appropriate to the activities of the agency” after proposing the
alternate definition(s) in the Federal Register and taking comment.  5
USC 601(3) - (5).  In addition, to establish an alternate small business
definition, agencies must consult with SBA’s Office of Advocacy.

	EPA proposed an alternate definition for regulatory flexibility
analyses under the RFA for rules related to the use of nPB as an
alternative to ozone-depleting substances (ODS) in metals, precision,
and electronics cleaning, adhesives, and aerosol solvents in the June
2003 NPRM (68 FR 33309, June 3, 2003).  EPA established this final
definition under section 601(3) of the RFA when we promulgated the final
rule on the acceptable use of nPB in metals, precision, and electronics
cleaning in the Rules and Regulations section of today’s Federal
Register.  For purposes of assessing the economic impacts of this
proposed rule on small entities, EPA defined “small business” as a
small business with less than 500 employees, rather than use the
individual SBA size standards for the numerous NAICS subsectors and
codes.  We believe that no small governments or small organizations are
affected by this rule.  EPA chose to use the alternate definition to
simplify the economic analysis.  This approach slightly reduced the
number of small businesses included in our analysis and slightly
increased the percentage of small businesses for whom the analysis
indicated the use of nPB in accordance with this proposed rule may have
an economically significant impact.  Furthermore, this size standard was
set by the Small Business Administration for all NAICS codes for
businesses using nPB-based adhesives, one of the end uses that would be
affected by this rule.

	After considering the economic impacts of this proposed rule on small
entities, I certify that this action will not have a significant
economic impact on a substantial number of small entities.  This rule
proposes to list nPB as an unacceptable substitute for ODS in aerosols
and adhesives.  EPA has analyzed the economic impacts of switching from
nPB to other alternative aerosol solvents or adhesives.  EPA estimates
that up to 3380 small industrial end users currently use nPB in the end
uses addressed by this proposed rule and thus could be subject to the
regulatory impacts of this rule.  This number includes approximately
3100 users of nPB-based aerosol solvents, and 280 users of nPB-based
adhesives.  Considering the regulatory impacts on adhesive and aerosol
users that must switch to other alternatives, we found that up to 258
(8%) small businesses would experience impacts of 1% or greater of
annual sales and no small businesses would experience impacts of 3% or
greater of annual sales.  Based on the relatively small number and low
percentage of small businesses that would experience significant
economic impacts, EPA concludes that this rule would not have a
significant economic impact on a substantial number of small entities.

	In the case of coatings uses, our understanding is that only a single
facility, the Lake City Army Ammunition Plant, is currently using
coatings with nPB as the carrier solvent, and this facility could
continue to use nPB following its current practices.  Therefore, we
consider there to be no economic impact of this rule on coatings users
and have not done further analysis for this end use.

	Types of businesses that would be subject to this proposed rule
include:

Manufacturers of computers and electronic equipment that clean with nPB
cleaning solvents (NAICS subsector 334).

Manufacturers of appliances, electrical equipment, and components that
require oil, grease, and solder flux to be cleaned off (NAICS subsection
335).

Manufacturers of transportation equipment, such as aerospace equipment
that requires cleaning either in a tank or with aerosols, or aircraft
seating, which is assembled using adhesives containing nPB as a carrier
solvent; and ship or boat builders applying  adhesives with nPB (NAICS
subsector 336).

Manufacturers of furniture, including various kinds of furniture with
cushions and countertops assembled using adhesives containing nPB as a
carrier solvent (NAICS subsector 337).

Foam fabricators, who assemble foam cushions or sponges using adhesives
containing nPB as a carrier solvent (NAICS code 326150).

	In order to consider the resources that affected small businesses have
available to operate and to respond to the proposed regulatory
requirements, EPA compared the cost of meeting the proposed regulatory
requirements to small businesses’ annual sales.  In our analysis for
this proposed rule, we used the average value of shipments for the
products manufactured by the end user as a proxy for sales or revenues,
since these data are readily available from the U.S. Department of
Commerce.  The following tables display the average value of shipments
for different sizes of business and different NAICS subsectors or codes
in the affected industrial sectors.  EPA then used data from these
sources to determine the potential economic impacts of this proposed
rule on small businesses.

Table 15.  Average Value of Shipments in NAICS Subsectors Using Aerosol
Solvents,

by Number of Employees at Business

Number of Employees at Business	Average Value of Shipments per Business
($) by NAICS Subsector Code

	334, Computer and Electronic Products	335, Electrical Equipment,
Appliance, and Component Mfg	336,

Transportation Equipment

1 to 4 employees	345,007	315,772	412,460

5 to 9 employees	1,317,238	1,243,065	1,414,384

10 to 19 employees	2,566,913	2,483,327	2,573,352

20 to 49 employees	5,672,245	5,389,945	5,738,739

50 to 99 employees	12,951,836	12,650,236	12,735,583

100 to 249 employees	31,258,875	31,290,638	34,256,544

250 to 499 employees	84,270,454	77,279,974	86,911,454

Avg Value Ship Small Businesses in Sub-sector	8,261,788	9,539,205
11,029,561

Avg Value Ship ALL Businesses in Subsector	20,810,094	13,417,905
45,029,773

Avg Value Shipments Subset Small Businesses using nPB	11,246,045
12,066,562	13,422,547

Table 16. Average Value of Shipments in NAICS Categories

Using nPB as a Carrier Solvent in Adhesives, by Number of Employees at
Business

Number of Employees at Business	Average Value of Shipments per Small
Business ($) by NAICS Sub Sector

	337121,

Upholstered household furniture

	337110,

Wood kitchen cabinet and counter tops	326150,

Urethane and other foam products (except polystyrene)	336360,

Motor vehicle seating and interior trim	337124,

Metal household furniture

1 to 4 employees	234,345	156,833	496,318	425,863	187,950

5 to 9 employees	963,021	622,744	1,305,183	1,728,132	903,393

10 to 19 employees	1,771,416	1,141,119	3,152,283	3,082,486	1,431,480

20 to 49 employees	3,653,623	2,619,197	6,615,331	5,508,370	3,538,684

50 to 99 employees	8,089,968	7,386,365	13,281,000	14,088,500	7,547,536

100 to 249 employees	17,502,175	17,151,091	31,524,872	44,310,286
19,821,719

250 to 499 employees	40,250,813	55,982,674	64,119,800	123,803,610	d(1)

Avg Small Businesses  in Sub sector	3,588,297	1,150,768	10,472,992
12,542,725	3,141,720

Avg ALL Businesses in Sub sector	5,490,101	1,475,602	11,110,822
44,808,573	5,239,747

Avg Subset Small Businesses using nPB	 11,519,540 	5,999,622 	18,950,068
	12,019,847 	20,401,301

 (1)“d” designates “Data withheld to avoid disclosing data of
individual companies; data are included in higher level totals.”  The
average value of shipments for businesses estimates those values marked
with “d,” and thus may be overestimated or underestimated.

	This proposed rule would list nPB as unacceptable for use in adhesives
and aerosols.  The available alternatives identified include adhesive
formulations based on water, methylene chloride, or flammable solvents
such as acetone and aerosol formulations of flammable solvents,
combustible solvents, blends of trans-dichloroethylene and HFEs or HFCs,
and HCFC-225ca/cb.  We considered various aspects of the cost of
switching to other alternatives, including the cost of meeting OSHA
requirements and the cost of the alternative adhesive.  We specifically
request public comment on the assumptions and costs used in EPA’s
analysis (US EPA, 2007).

	We estimate that up to 9 small businesses using nPB-based adhesives, or
roughly 3% of the 280 or so small businesses that use nPB-based
adhesives, would experience a cost increase (i.e., an impact) of greater
than 1.0% of annual sales, and no small businesses would experience an
impact of greater than 3% of annual sales if this proposed rule became
final.  For small businesses using nPB-based aerosols, we estimate that
approximately 249 would experience a cost increase of greater than 1.0%
of annual sales.  This equates to roughly 8% of the 3100 or so small
businesses currently using nPB-based aerosol solvents.  No small
businesses using aerosols would experience an impact of greater than 3%
of annual sales.  Approximately eight percent of all 3380 or so small
businesses choosing to use nPB in these end uses would experience an
impact of greater than 1.0% of annual sales and no small businesses
would experience an impact of greater than 3.0% of annual sales.
Because of the small total number and small percentage of affected
businesses that would experience an impact of greater than either 1.0%
or 3.0% of annual sales, EPA does not consider this proposed rule to
have a significant economic impact on a substantial number of small
businesses.

	We also analyzed the potential small business impacts of the proposed
alternate approach.  Under the proposed alternate approach, users would
have to: (1) meet an exposure level of 20 ppm on an eight-hour
time-weighted average, (2) monitor workers’ exposure to nPB using a
personal breathing zone sampler on an eight-hour time-weighted average
initially and periodically (every 6 months or longer, depending on the
concentration during initial monitoring), and (3) keep records of the
worker exposure data on site at the facility for at least three years
from the date of the measurement.  We assume that the cost of following
the proposed alternate approach is the cost of installing ventilation
for aerosols and adhesives or emission controls for solvent cleaning,
the cost of using personal protective equipment, and the cost of
monitoring worker exposure.  Approximately 67 to 387 aerosol solvent
users (2 to 13 percent), 25 to 54 adhesive users (9 to 19 percent), and
2.6 to 12.6 percent of all 3380 or so small businesses would experience
impacts of greater than 1% of annual sales if they chose to use nPB
subject to the proposed use conditions rather than switching to another
ODS substitute.  Four to nine users of nPB-based adhesives, or less than
1% of all small businesses affected by this proposal, would experience
impacts of 3% or greater of annual sales under the proposed alternate
approach.  Based on this analysis, the proposed alternate approach would
not create a significant adverse economic impact on a substantial number
of small entities.

	Although this proposed rule would not have a significant economic
impact on a substantial number of small entities if it became final, EPA
nonetheless has tried to reduce the impact of this rule on small
entities.  Before selecting preferred the regulatory option in this
proposed rule, we considered a number of regulatory options, such as:

•	Placing a narrowed use limit on the use of nPB in adhesives and
aerosols that would allow its use only in those cases where alternatives
are technically infeasible due to performance or safety issues.  This
would have required testing, recordkeeping, and some installation of
capital equipment.

Requiring that when nPB is used in adhesives or aerosols, it must be
used with local ventilation equipment and personal protective equipment.
  This would have required further installation of capital equipment,
without necessarily protecting workers as thoroughly as a required
acceptable exposure limit or requiring a switch to another alternative.

Prohibiting the use of nPB in all end uses.

Retaining the previously proposed requirement for a limit on iPB content
in nPB formulations.

The costs of a number of these options are included in EPA’s analysis
(US EPA, 2006; US EPA, 2007).

	In developing our regulatory options, we considered information we
learned from contacting small businesses using or selling nPB.  EPA
staff visited the site of a small business using nPB for cleaning
electronics.  We contacted several fabricators of foam cushions that
have used adhesives containing nPB.  We participated in meetings with a
number of adhesive manufacturers and users of adhesives in furniture
construction.  We developed a fact sheet and updated our program web
site to inform small businesses about the proposed rule and to request
their comments.

	We continue to be interested in the potential impacts of the proposed
rule on small entities and welcome comments on issues related to such
impacts.

	D.	Unfunded Mandates Reform Act

	Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public Law
104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and tribal
governments and the private sector.  Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with "Federal mandates" that may
result in expenditures to State, local, and tribal governments, in the
aggregate, or to the private sector, of $100 million or more in any one
year. Before promulgating an EPA rule for which a written statement is
needed, section 205 of the UMRA generally requires EPA to identify and
consider a reasonable number of regulatory alternatives and adopt the
least costly, most cost-effective or least burdensome alternative that
achieves the objectives of the rule.  The provisions of section 205 do
not apply when they are inconsistent with applicable law.  Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted.  Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan.  The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.  EPA has determined that this rule does not contain a
Federal mandate that may result in expenditures of $100 million or more
for State, local, and tribal governments, in the aggregate, or the
private sector in any one year.  This proposed rule does not affect
State, local, or tribal governments.  The enforceable requirements of
the rule for the private sector affect a number of end users in
manufacturing.  The estimated cost of the proposed requirements for the
private sector is approximately $38.6 to 46.4 million per year, and the
proposed alternate approach would cost the private sector approximately
$ 42.3 to 67.5 million per year.  Therefore, the impact of this rule on
the private sector is less than $100 million per year.  Thus, this rule
is not subject to the requirements of sections 202 and 205 of the UMRA.
EPA has determined that this rule contains no regulatory requirements
that might significantly or uniquely affect small governments.  This
regulation applies directly to facilities that use these substances and
not to governmental entities.

	E.	Executive Order 13132: Federalism

	Executive Order 13132, entitled “Federalism” (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
“meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.”
 “Policies that have federalism implications” is defined in the
Executive Order to include regulations that have “substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.”

	This proposed rule does not have federalism implications.  It will not
have substantial direct effects on the States, on the relationship
between the national government and the States, or on the distribution
of power and responsibilities among the various levels of government, as
specified in Executive Order 13132.  This regulation applies directly to
facilities that use these substances and not to governmental entities.
Thus, Executive Order 13132 does not apply to this rule.

	F.	Executive Order 13175:  Consultation and Coordination with Indian
Tribal

Governments

	Executive Order 13175, entitled “Consultation and Coordination with
Indian Tribal Governments” (65 FR 67249, November 6, 2000), requires
EPA to develop an accountable process to ensure “meaningful and timely
input by tribal officials in the development of regulatory policies that
have tribal implications.”  “Policies that have tribal
implications” is defined in the Executive Order to include regulations
that have “substantial direct effects on one or more Indian tribes, on
the relationship between the Federal government and the Indian tribes,
or on the distribution of power and responsibilities between the Federal
government and Indian tribes.”

	This proposed rule does not have tribal implications.  It will not have
substantial direct effects on tribal governments, on the relationship
between the Federal government and Indian tribes, or on the distribution
of power and responsibilities between the Federal government and Indian
tribes, as specified in Executive Order 13175.

	This proposed rule would not significantly or uniquely affect the
communities of Indian tribal governments, because this regulation
applies directly to facilities that use these substances and not to
governmental entities.  Thus, Executive Order 13175 does not apply to
this proposed rule.

Executive Order 13045:  Protection of Children from Environmental Health
and Safety Risks

	Executive Order 13045:  “Protection of Children from Environmental
Health Risks and Safety Risks” (62 FR 19885, April 23, 1997) applies
to any rule that: (1) is determined to be "economically significant" as
defined under Executive Order 12866, and (2) concerns an environmental
health or safety risk that EPA has reason to believe may have a
disproportionate effect on children.  If the regulatory action meets
both criteria, the Agency must evaluate the environmental health or
safety effects of the planned rule on children, and explain why the
planned regulation is preferable to other potentially effective and
reasonably feasible alternatives considered by the Agency.

	This proposed rule is not subject to the Executive Order because it is
not economically significant as defined in Executive Order 12866, and
because the Agency does not have reason to believe the environmental
health or safety risks addressed by this action present a
disproportionate risk to children.  The exposure limits and
acceptability listings in this proposed rule apply to the workplace.
These are areas where we expect adults are more likely to be present
than children, and thus, the agents do not put children at risk
disproportionately.

	The public is invited to submit or identify peer-reviewed studies and
data, of which the agency may not be aware, that assessed results of
early life exposure to nPB.

	H. 	Executive Order 13211:  Actions that Significantly Affect Energy
Supply, Distribution, or Use

	This rule is not a “significant energy action” as defined in
Executive Order 13211, “Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use” (66 FR 28355
(May 22, 2001)) because it is not likely to have a significant adverse
effect on the supply, distribution, or use of energy.  This action would
impact manufacturing of various metal, electronic, medical, and optical
products cleaned with solvents containing nPB and products made with
adhesives containing nPB.  Further, we have concluded that this rule is
not likely to have any adverse energy effects.

	I.	National Technology Transfer and Advancement Act

	As noted in the proposed rule, Section 12(d) of the National Technology
Transfer and Advancement Act of 1995 ("NTTAA"), Pub L. No. 104-113, §
12(d) (15 U.S.C. 272 note) directs EPA to use voluntary consensus
standards in its regulatory activities unless to do so would be
inconsistent with applicable law or otherwise impractical.  Voluntary
consensus standards are technical standards (e.g., materials
specifications, test methods, sampling procedures, and business
practices) that are developed or adopted by voluntary consensus
standards bodies. The NTTAA directs EPA to provide Congress, through
OMB, explanations when the Agency decides not to use available and
applicable voluntary consensus standards.

	This action does not involved technical standards. Therefore, EPA did
not consider the use of any voluntary consensus standards.  We note that
the American Conference of Governmental Industrial Hygienists (ACGIH),
although it sets voluntary standards, is not a voluntary consensus
standards body.  Therefore, use of an acceptable exposure limit from the
ACGIH is not subject to the NTTAA.

XII.	References tc "X.	References"

	The documents below are referenced in the preamble.  All documents are
located in the Air Docket at the address listed in section I.B.1 at the
beginning of this document.  Unless specified otherwise, all documents
are available electronically through the Federal Docket Management
System, Docket # EPA-HQ-OAR-2002-0064.  Some specific items are
available only in hard copy in dockets A-2001-07 or A-92-42 (legacy
docket numbers for SNAP nPB rule and for SNAP program and submissions).
Numbers listed after the reference indicate the docket and item numbers.

Availability

Harper, 2005.  Telephone call from M. Sheppard, EPA to Dr. S. Harper,
ATK. Re: Availability of other methyl chloroform substitutes for the
Lake City Army Ammunition Plant.  October 11, 2005.
(EPA-HQ-OAR-2002-0064-0150)

IRTA, 2000.    SEQ CHAPTER \h \r 1 Alternative Adhesive Technologies in
the Foam Furniture and Bedding Industries: A Cleaner Technologies
Substitution Assessment, Cost and Performance Evaluation.  Michael
Morris and Katy Wolf, Institute for Research and Technical Assistance.
Prepared for the U.S. EPA Office of Pollution Prevention Technology,
June 2000. (A-2001-07, II-D-70)

Seilheimer, 2001.    SEQ CHAPTER \h \r 1 Telephone Log of April 4, 2001
call between Margaret Sheppard, EPA, and Bob Seilheimer, Imperial
Adhesives.  (A-2001-07, II-B-5)

Williams, 2005.  Notes on conversation of Ed Williams, Technical
Manager, LPS Laboratories, and Margaret Sheppard, EPA.   November 3,
2005 (EPA-HQ-OAR-2002-0064-0198)

Impacts on the atmosphere, local air quality, and other environmental
impacts

Atmospheric and Environmental Research, Inc., 1995.  Estimates of the
Atmospheric Lifetime, Global Warming Potential and Ozone Depletion
Potential of n-Propyl Bromide.  Independent study prepared for Albemarle
Corporation.  (A-2001-07, II-D-17)

ATSDR, 1994. Toxicological Profile For Acetone.   Agency for Toxic
Substances and Disease Registry.  May, 1994.  Available at   HYPERLINK
"http://www.atsdr.cdc.gov/toxprofiles/tp21-c5.pdf"
http://www.atsdr.cdc.gov/toxprofiles/tp21-c5.pdf
(EPA-HQ-OAR-2002-0064-0118)

ATSDR, 1996. Toxicological Profile For 1,2-Dichloroethene.   Agency for
Toxic Substances and Disease Registry.  August, 1996.  Available at
HYPERLINK "http://www.atsdr.cdc.gov/toxprofiles/tp87-c5.pdf"
http://www.atsdr.cdc.gov/toxprofiles/tp87-c5.pdf
(EPA-HQ-OAR-2002-0064-0113)

ATSDR, 1997. Toxicological Profile For Trichloroethylene.   Agency for
Toxic Substances and Disease Registry.  September, 1997.  Available at
HYPERLINK "http://www.atsdr.cdc.gov/toxprofiles/tp19-c5.pdf"
http://www.atsdr.cdc.gov/toxprofiles/tp19-c5.pdf
(EPA-HQ-OAR-2002-0064-0123)

ATSDR, 2004.  Draft Toxicological Profile For 1,1,1-Trichloroethane.
Agency for Toxic Substances and Disease Registry.  September, 2004.
Updated draft for comment. Available at   HYPERLINK
"http://www.atsdr.cdc.gov/toxprofiles/tp70-c6.pdf"
http://www.atsdr.cdc.gov/toxprofiles/tp70-c6.pdf
(EPA-HQ-OAR-2002-0064-0132)

EDSTAC, 1998.  Final Report of the Endocrine Disruptor Screening and
Testing Advisory Committee.  August, 1998.  (EPA-HQ-OAR-2002-0064-0136)

Fisher Scientific, 2001.  Material Safety Data Sheet for acetone.
Updated March 19, 2001.  Available at   HYPERLINK
"http://www.mhatt.aps.anl.gov/dohn/msds/acetone.html"
http://www.mhatt.aps.anl.gov/dohn/msds/acetone.html
(EPA-HQ-OAR-2002-0064-0129)

Geiger et al., 1998.  Geiger, D.L., Call, D.J., and Brooke, L.T.  1988.
Acute Toxicities of Organic Chemicals to Fathead Minnows (Pimephales
promelas), Vol. 4.  In: Center for Lake Superior Environmental Stud.,
Univ.of Wisconsin-Superior, Superior, WI I:355.  (Summarized in ICF,
2004a)

HSDB, 2004.  Hazardous Substances Databank File for 1-Bromopropane.
Accessed 1/2004 from the World Wide Web at
http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~dLwM9e:1
(Summarized in ICF, 2004a)

ICF, 2003a.  ICF Consulting.  Revised Evaluation of the Global Warming
Potential for n-Propyl Bromide. (EPA-HQ-OAR-2002-0064-0164)

ICF, 2004a.  ICF Consulting.  Memo to E. Birgfeld, EPA, re: nPB Aquatic
Toxicity.  January 19, 2004.  (EPA-HQ-OAR-2002-0064-0177)

ICF, 2006a.  ICF Consulting.  Risk Screen on Substitutes for
Ozone-Depleting Substances for Adhesive, Aerosol Solvent, and Solvent
Cleaning Applications.  Proposed Substitute:  n-Propyl Bromide.  April
18, 2006.  Attachments:  A, Determination of an AEL; B, Derivation of an
RfC; C, Evaluation of the Global Warming Potential; D, Occupational
Exposure Analysis for Adhesive Applications; E, Occupational Exposure
Analysis for Aerosol Solvent Applications; F, General Population
Exposure Assessment for n-Propyl Bromide

LaGrega, M., Buckingham, P., Evans, J., and Environmental Resources
Management, 2001.  Hazardous Waste Management.  Second Edition.
McGraw-Hill, New York, NY.  2001.  (EPA-HQ-OAR-2002-0064-0112)

Linnell, 2003.  Comments from the Electronics Industry Alliance.
(EPA-HQ-OAR-2002-0064 items -0043, -0044, and -0045)

MOP 18, 2006.  Report of the Eighteenth Meeting of the Parties to the
Montreal Protocol on Substances that Deplete the Ozone Layer.  November
16, 2006.  (EPA-HQ-OAR-2002-0064-0163)

NPS, 1997.  Irwin, R.J., M. VanMouwerik, L. Stevens, M.S. Seese, and W.
Basham.  1997. Environmental Contaminants Encyclopedia.  National Park
Service,Water Resources Division, Fort Collins, Colorado.
(EPA-HQ-OAR-2002-0064-0086)

Steminiski, 2003.  July 27, 2003 Comment from J. Steminiski, Ph. D.
(EPA-HQ-OAR-2002-0064-0035 and -0043)

U.S. Economic Census, 2002a.  General Summary:  2002.  Subject Series.
Report No. EC02-31SG-1, October, 2005.  U.S. Census Bureau.
(EPA-HQ-OAR-2002-0064-0133)

U.S. Economic Census, 2002b.  U.S. Economic Census for Island Areas,
2002.  Report for Northern Marianas Islands, Rpt. No.  IA02-00A-NMI,
May, 2004.  U.S. Census Bureau. (EPA-HQ-OAR-2002-0064-0091)

U.S. Economic Census, 2002c.  U.S. Economic Census for Island Areas,
2002.  Report for Guam, Rpt. No. IA02-00A-GUAM, March, 2005.  U.S.
Census Bureau.  (EPA-HQ-OAR-2002-0064-0102)

U.S. Economic Census, 2002d.  U.S. Economic Census for Island Areas,
2002.  Report for Virgin Islands, Rpt. No. IA02-00A-VI , April, 2005.
U.S. Census Bureau.  (EPA-HQ-OAR-2002-0064-0131)

U.S. Economic Census, 2002e.  U.S. Economic Census for Island Areas,
2002.  Report for American Samoa, Rpt. No. IA02-00A-AS, April, 2005.
U.S. Census Bureau.  (EPA-HQ-OAR-2002-0064-0103)

U.S. Economic Census, 2002f.  U.S. Economic Census for Island Areas,
2002.  Report for Puerto Rico: Manufacturing, Rpt. No. IA02-00I-PRM,
October, 2005. U.S. Census Bureau.  (EPA-HQ-OAR-2002-0064-0107)

US EPA, 1980.  Ambient Water Quality Criteria for Dichloroethylenes. EPA
440/5-80-041  October, 1980.  Available at   HYPERLINK
"http://www.epa.gov/waterscience/pc/ambientwqc/dichloroethylenes80.pdf"
http://www.epa.gov/waterscience/pc/ambientwqc/dichloroethylenes80.pdf

US EPA, 1992.  Hazard Assessment Guidelines for Listing Chemicals on the
Toxic Release Inventory, Revised Draft.  Washington, DC:  Office of
Pollution, Prevention and Toxics. As referenced in ICF, 2004f.

US EPA, 1994a.  Chemical Summary for Methyl Chloroform, prepared by
Office of Pollution Prevention and Toxics, August, 1994.
(EPA-HQ-OAR-2002-0064-0121)

WMO, 2002:  Scientific Assessment of Ozone Depletion: 2002, Global Ozone
Research and Monitoring Project – Report No. 47, Geneva, 2003 Full
report available online at    HYPERLINK
"http://esrl.noaa.gov/csd/assessments/"
http://esrl.noaa.gov/csd/assessments/    (A-2001-07, II-A-20)

Wuebbles, Donald J.  2002.  “The Effect of Short Atmospheric Lifetimes
on Stratospheric Ozone.”  Written for Enviro Tech International, Inc.
Department of Atmospheric Sciences, University of Illinois-Urbana.
(EPA-HQ-OAR-2002-0064-0114)

Flammability and fire safety

	BSOC, 2000.  February 1, 2000 Tabulation of Flammability Studies on
n-Propyl Bromide from the Brominated Solvents Committee, and other
information on flammability of n-propyl bromide.  (A-2001-07, II-D-45)

Miller, 2003.  Albemarle Corporation comments- Flash Point Data for
n-Propyl Bromide.  (EPA-HQ-OAR-2002-0064-0040)

Morford, 2003a.  Enviro Tech International Comment re Section IV D
Flammability with Exhibits (7/25/03) (EPA-HQ-OAR-2002-0064-0030)

Morford, 2003b.  Enviro Tech International Supporting Exhibits on
Flammability (7/25/03) (EPA-HQ-OAR-2002-0064-0031)

Morford, 2003c.  Enviro Tech Int. Flammability of nPB & Comparison With
Methylene Chloride- Additional Comments on Flammability (7/29/03)
(EPA-HQ-OAR-2002-0064-0036)

Shubkin, 2003.  R. Shubkin, Poly Systems, EPA received 7/23/03 Re:
Comment on Flammability of n-Propyl Bromide as Discussed in Proposed
Rule Published in Federal Register (EPA-HQ-OAR-2002-0064-0025)

Weiss Cohen, 2003.  T. Weiss Cohen, Dead Sea Bromine Group,7/31/2003
Comment to Federal Register Proposed Rules of June 3, 2003, on
Protection of Stratospheric Ozone: Listing of Substitutes for
Ozone-Depleting Substances - n-Propyl Bromide
(EPA-HQ-OAR-2002-0064-0053)

Impact on human health; how did EPA assess impacts on human health?

ACGIH, 1991.  Skin Notation Documentation for Methyl Chloride. Available
online at www.acgih.org.

ACGIH, 2005.  Documentation for Threshold Limit Value for
1-Bromopropane.  2005.  Available online at   HYPERLINK
"http://www.acgih.org"  www.acgih.org .

Albemarle, 2003.  Product Description for Abzol® Cleaners.  2003.
(EPA-HQ-OAR-2002-0064-0148)

Beck and Caravati, 2003.   Neurotoxicity associated with 1-bromopropane
exposure.  Utah Poison Control Center, University of Utah, Salt Lake
City, UT. J Toxicology Clinical Toxicology  41(5):729. (Abstract from
conference). 2003.  (EPA-HQ-OAR-2002-0064-0111)

CERHR, 2002a.  NTP- Center for the Evaluation of Risks to Human
Reproduction Expert Panel Report on the Reproductive and Developmental
Toxicity of 1-Bromopropane [nPB].  March 2002.
(EPA-HQ-OAR-2002-0064-0096)

CERHR, 2002b.  NTP- Center for the Evaluation of Risks to Human
Reproduction Expert Panel Report on the Reproductive and Developmental
Toxicity of 2-Bromopropane [iPB].  March 2002.
(EPA-HQ-OAR-2002-0064-0083)

CERHR, 2003a.  NTP- CERHR Monograph on the Potential Human Reproductive
and Developmental Effects of 1-Bromopropane.  October 2003.
(EPA-HQ-OAR-2002-0064-0084)

CERHR, 2003b.  NTP- CERHR Monograph on the Potential Human Reproductive
and Developmental Effects of 2-Bromopropane.  October 2003.
(EPA-HQ-OAR-2002-0064-0079)

CERHR, 2004a. NTP-CERHR Expert Panel report on the reproductive and
developmental toxicity of 1-bromopropane.  Center for the Evaluation of
Risks to Human Reproduction. Repro Toxicol. Vol.18, pp.157-188.  2004.
(EPA-HQ-OAR-2002-0064-0096)

CERHR, 2004b.  NTP-CERHR Expert Panel report on the reproductive and
developmental toxicity of 2-bromopropane. Boekelheide, et al. Repro
Toxicol. Vol.18, pp.189-217.  2004.  (EPA-HQ-OAR-2002-0064-0098)

Chemtura, 2006.  Material Safety Data Sheet for n-propyl bromide.
April, 2006.  (EPA-HQ-OAR-2002-0064-0151)

ClinTrials, 1997a.  A 28-Day Inhalation Study of a VaporFormulation of
ALBTA1 in the Albino Rat.  Report No. 91189.  Prepared by ClinTrials
BioResearch Laboratories, Ltd., Senneville, Quebec, Canada.  May 15,
1997.  Sponsored by Albemarle Corporation, Baton Rouge, LA. (A-91-42,
X-A-4)

ClinTrials, 1997b.  ALBTA1: A 13-Week Inhalation Study of a Vapor
Formulation of ALBTA1 in the Albino Rat.  Report No. 91190.   Prepared
by ClinTrials BioResearch Laboratories, Ltd., Senneville, Quebec,
Canada.  February 28, 1997.  Sponsored by Albemarle Corporation, Baton
Rouge, LA. (A-91-42, X-A-5)

Confidential submission, 1998.  Airborne Exposure Assessment of
1-Bromopropane, 1998.  (A-2001-07, II-D-89).

Dunson et al, 2002.  Dunson, D., Colombo, and B., Baird, D. Changes with
age in the level and duration of fertility in the menstrual cycle.
Human Reproduction, Vol. 17, No. 5, pp. 1399-1403, 2002.
(EPA-HQ-OAR-2002-0064-0120)

Elf Atochem, 1995.  Micronucleus Test by Intraperitoneal Route in Mice.
n-Propyl Bromide.  Study No. 12122 MAS.  Study Director, Brigitte
Molinier.  Study performed by Centre International de Toxoicologie,
Misery, France, September 6, 1995.  (A-91-42, X-A-9)

Enviro Tech International, 2006.  Material Safety Data Sheet for Ensolv
(n-propyl bromide solvent)  (EPA-HQ-OAR-0064-0143)

Farr, 2003.  Comment on proposed rule on n-propyl bromide from Craig
Farr, Atofina.  July 31, 2003.  (EPA-HQ-OAR-2002-0064-0060)

Fueta et al., 2002.  Y. Fueta, K. Fukunaga, T. Ishidao, H. Hori.
Hyperexcitability and changes in activities of Ca2+/calmodulin-dependent
kinase II and mitogen-activated protein kinase in the hippocampus of
rats exposed to 1-bromopropane.  2002.  Life Sciences 72 (2002) 521-529.
 (EPA-HQ-OAR-2002-0064-0115)

Fueta et al., 2004. Y. Fueta, T. Fukuda, T. Ishidao, H. Hori.
Electrophysiology and immunohistochemistry in the hippocampal CA1 and
the Dentate Gyrus of Rats Chronically exposed to 1-Bromopropane, a
Substitute for Specific Chlorofluorocarbons.  Neuroscience 124 (2004)
593-603.  (EPA-HQ-OAR-2002-0064-0142)

Furuhashi, et al., 2006.  K. Furuhashi, J. Kitoh, J. Tsukamura, K.
Maeda, H. Wang, W. Li, S. Ichihara, T. Nakajima, and G. Ichihara.
Effects of exposure of rat dams to 1-bromopropane during pregnancy and
lactation on growth and sexual maturation of their offspring.
Toxicology 224 (2006) 219-228.  Available online at
www.sciencedirect.com.

Great Lakes Chemical Corporation, 2001.  Letter from E. Stouder, Great
Lakes Chemical Corporation, 2/20/01.  (A-2001-07, II-D-80)

HESIS, 2003.  California Department of Health Services - HESIS
1-Bromopropane (n-Propyl Bromide) Health Hazard Alert.
(EPA-HQ-OAR-2002-0064-0039)

Honma et al., 2003.  Honma, T, Suda M, Miyagawa M. “Inhalation of
1-bromopropane causes excitation in the central nervous system of male
F344 rats.” Neurotoxicology. 2003 Aug; 24 (4-5):563-75.
(EPA-HQ-OAR-2002-0064-0138)

Huntingdon Life Sciences, 2001. A Developmental Toxicity Study in Rat
Via Whole Body Inhalation Exposure. (A-2001-07, II-D-27)

ICF, 2002a.  Risk Screen for Use of N-Propyl Bromide.  ICF Consulting.
Prepared for U.S. EPA, May, 2002. (EPA-HQ-OAR-2002-0064-0006 through
-0012)

ICF, 2003.  ICF Consulting.  General Population Exposure Assessment for
N-Propyl Bromide.  June 03, 2003.  (EPA-HQ-OAR-2002-0064-0011)

ICF, 2004b.  ICF Consulting.  External Expert Review Panel on N-Propyl
Bromide.  December 13, 2004.

ICF, 2004c.  ICF Consulting.    SEQ CHAPTER \h \r 1 ICF Consulting
Review of the TERA Report.  December 13, 2004.

ICF, 2004d.  ICF Consulting.  Review of ACGIH’s Proposed Threshold
Limit Value for 1-Bromopropane.  April 26, 2004.

ICF, 2006a.  Full citation given above in section on “Impacts on the
atmosphere, local air quality, and other environmental impacts”

ICF, 2006b.  ICF Consulting.  Revised Memorandum regarding RTI
Metabolism Study on nPB.  April, 2006.  (EPA-HQ-OAR-2002-0064-0179)

ICF, 2006c.  ICF Consulting.  Evaluation of Memorandum from Dr. M.
Stelljes.  April, 2006.

Ichihara et al., 1998.  Ichihara M., Takeuchi Y., Shibata E., Kitoh J.,
et al. Neurotoxicity of 1-Bromopropane.  1998.  Translated by Albemarle
Corporation. (A-91-42, X-A-33)

Ichihara G., Jong X., Onizuka J., et al., 1999.  Histopathological
changes of nervous system and reproductive organ and blood biochemical
findings in rats exposed to 1-bromopropane.  (Abstract only)  Abstracts
of the 72nd Annual Meeting of Japan Society for Occupational Health.
May 1999. Tokyo.  (A-2001-07, II-A-15)

Ichihara G., Kitoh J., Yu, X., et al., 2000a. 1-Bromopropane, an
alternative to ozone layer depleting solvents, is dose-dependently
neurotoxic to rats in long-term inhalation   exposure.  Toxicol Sciences
55:116-123.  (A-2001-07, II-A-8)

Ichihara G., Yu X., Kitoh J., et al. 2000b. Reproductive toxicity of
1_bromopropane, a newly introduced alternative to ozone layer depleting
solvents, in male rats.  Toxicol Sciences 54:416_423. (A-2001-07,
II-A-7)

Ichihara G. et al., 2002.  Neurological Disorders in Three Workers
Exposed to 1-Bromopropane.  J Occu. Health 44:1-7.  (A-2001-07, II-D-64)

Ichihara et al., 2004a.  G. Ichihara, W. Li, X. Ding, S. Peng, X. Yu, E.
Shibata, T. Yamada, H. Wang, S. Itohara, S. Kanno, K. Sakai, H. Ito, K.
Kanefusa, and Y. Takeuchi.  A Survey on Exposure Level, Health Status,
and Biomarkers in Workers Exposed to 1-Bromopropane.   Am Jrnl of Ind
Med 45:63–75 (2004) (EPA-HQ-OAR-2002-0064-0093)

Ichihara et al., 2004b. Gaku Ichihara, Weihua Li, Eiji Shibata, Xuncheng
Ding, Hailan Wang, Yideng Liang, Simeng Peng, Seiichiro Itohara,
Michihiro Kamijima, Qiyuan Fan, Yunhui Zhang, Enhong Zhong, Xiaoyun Wu,
William M. Valentine, and Yasuhiro Takeuchi.  Neurological Abnormalities
in Workers of 1-Bromopropane Factory.  Env’l Health Perspectives, 30
June 2004.  (EPA-HQ-OAR-2002-0064-0139)

Ishidao et al., 2002.  Ishidao T, Kunugita N, Fueta Y, Arashidani K,
Hori H. Effects of inhaled 1-bromopropane vapor on rat metabolism.
Toxicol Lett. 2002 Aug 5;134(1-3):237-43  (EPA-HQ-OAR-2002-0064-0125)

Lake City Army Ammunition Plant, 2003.  SNAP application for n-Propyl
Bromide in coatings, T.J. Herman, ATK Alliant Lake City Small Caliber
Ammunition Company, dated 7/8/2003.  EPA Received 7/14/2003.
(EPA-HQ-OAR-2002-0064-0029)

Lake City Army Ammunition Plant, 2004.  March 9, 2004 Industrial Hygiene
Air Sampling Report for Normal Propyl Bromide Based Mouth Waterproofing
in Manufacture of 5.56 mm Ammunition.  S.A. Hawk.
(EPA-HQ-OAR-2002-0064-0211)

	Majersik et al., 2004.  Chronic Exposure to 1-Bromopropane Associated
with Spastic Paraparesis and Distal Neuropathy: A Report of Six Foam
Cushion Gluers.  Poster paper from 129th Annual Meeting of the American
Neurological Association, Toronto.  October, 2004
(EPA-HQ-OAR-2002-0064-0219)

Majersik et al, 2005.  “Spastic Paraparesis and Distal Neuropathy
Associated with Chronic Exposure to 1BP,” Presentation by Drs. J.
Majersik, M. Caravati, and J. Steffens at the North American Congress of
Clinical Toxicologists.  September 14, 2005.
(EPA-HQ-OAR-2002-0064-0116)

Miller, 2005.  “1-Bromopropane:  A Private Neurological Practice
Experience in 2000,” Presentation by Dr. J. M. Miller, at the North
American Congress of Clinical Toxicologists.  September 14, 2005
(EPA-HQ-OAR-2002-0064-0216)

Morford, 2003d.  White Paper:  “EPA Is Unlawfully Regulating
Occupational Exposures”  Attachment to public comments.
(EPA-HQ-OAR-2003-0064-0049)

Morford, 2003e.  Comment regarding proposed restriction on isopropyl
bromide  Richard Morford, Enviro Tech International.  August 3, 2003.
(EPA-HQ-OAR-2002-0064-0042)

Morford, 2003f.  Support for EPA Proposal to Approve n propyl bromide
and Comments Pursuant to Section D. Flammability of Protection of
Stratospheric Ozone: Listing of Substitutes for Ozone Depleting
Substances - n-Propyl Bromide: Proposed Rule Federal Register Vol. 68
No. 106, June 3, 2003.  Enviro Tech International, Inc. Comments
Regarding Proposed Rule & Exhibit A   Richard Morford, Enviro Tech
International.  August 3, 2003.  (EPA-HQ-OAR-2002-0064-0047)

Morford, 2003g.  Enviro Tech International, Inc. Combined Exhibits to
Comment 0047/Morford, 2003f on Proposed Rule  Richard Morford, Enviro
Tech International.  August 3, 2003.  (EPA-HQ-OAR-2002-0064-0048)

Morford, 2003h.  Initial Comments to Protection of Stratospheric Ozone:
Listing of Substitutes for Ozone Depleting Substances - n-Propyl
bromide: Proposed Rule Federal Register

	Vol. 68 No. 106, June 3, 2003.  Richard Morford, Enviro Tech
International.  June 26, 2003.  (EPA-HQ-OAR-2002-0064-0002)

NAS, 1983.  The National Academies of Science, Risk Assessment in the
Federal Government: Managing the Process, 1983.  Available online at
HYPERLINK "http://newton.nap.edu/catalog/366.html"
http://newton.nap.edu/catalog/366.html  (Executive summary in docket as
EPA-HQ-OAR-2002-0064-0108)

Nemhauser, 2005.  “Bromopropane:  A Health Hazard Evaluation
Revisited”  Presentation by Dr. J. Nemhauser, U.S Public Health
Service, Centers for Disease Control & Presentation at the North
American Congress of Clinical Toxicologists.  September 14, 2005.
(EPA-HQ-OAR-2002-0064-0105)

NIOSH, 2002a.  NIOSH Health Hazard Evaluation Report: HETA #
98-0153-2883; Custom Products, Inc.; Mooresville, NC.  National
Institute for Occupational Safety and Health.  November 2002.  Available
online at   HYPERLINK
"http://www.cdc.gov/niosh/hhe/reports/pdfs/1998-0153-2883.pdf"
http://www.cdc.gov/niosh/hhe/reports/pdfs/1998-0153-2883.pdf .
(EPA-HQ-OAR-2002-0064-0090)

NIOSH, 2002b.  NIOSH Health Hazard Evaluation Report: HETA
#2000-0410-2891; STN Cushion Company; Thomasville, NC.  National
Institute for Occupational Safety and Health.  August 2002.  Available
online at   HYPERLINK
"http://www.cdc.gov/niosh/hhe/reports/pdfs/2000-0410-2891.pdf"
http://www.cdc.gov/niosh/hhe/reports/pdfs/2000-0410-2891.pdf .
(A-2001-07, II-A-31)

NIOSH, 2003a.  NIOSH Health Hazard Evaluation Report #99-0260-2906  Marx
Industries, Inc. Sawmills, NC Available online at   HYPERLINK
"http://www.cdc.gov/niosh/hhe/reports/pdfs/1999-0260-2906.pdf"
http://www.cdc.gov/niosh/hhe/reports/pdfs/1999-0260-2906.pdf .
(EPA-HQ-OAR-2002-0064-0094)

NTP, 2003.  Results of 13-week Inhalation Testing by the National
Toxicology Program.  Available at   HYPERLINK
"http://ntp-apps.niehs.nih.gov/ntp_tox/"
http://ntp-apps.niehs.nih.gov/ntp_tox/

	index.cfm?fuseaction=ntpsearch.searchresults&searchterm=106-94-5

OEHHA, 2006.  State Of California Environmental Protection Agency,
Office Of Environmental Health Hazard Assessment.  Chemicals Known To
The State To Cause Cancer Or Reproductive Toxicity. June 9, 2006
(EPA-HQ-OAR-2002-0064-0124)

O’Malley, 2004.  Letter from Nancy O’Malley, Toxicology Advisor,
Albemarle Corporation to The Science Group of the American Conference of
Governmental Industrial Hygienists.  Comments on the draft Documentation
for proposed TLV for 1-bromopropane (1-BP).  July 30, 2004.
(EPA-HQ-OAR-2002-0064-0128)

Raymond and Ford, 2005.  “Clinical Case Presentations from a Foam
Furniture Fabrication Plant in North Carolina,” Presentation by Drs.
Larry Raymond and Marsha Ford at the North American Congress of Clinical
Toxicologists.  September 14, 2005 (EPA-HQ-OAR-2002-0064-0170)

Risotto, 2003.  Comments of the Halogenated Solvents Industry Alliance
on nPB proposed rule.  June, 2003.  (EPA-HQ-OAR-2002-0064-0050)

Rodricks, 2002.  October 21, 2002 remarks from Dr. J. Rodricks, Environ,
to R. Morford, Enviro Tech International concerning derivation of an OEL
for n-propyl bromide with cover letter to EPA from Enviro Tech
International (A-2001-07, II-D-65)

Rozman and Doull, 2002.  “Derivation of an Occupational Exposure Limit
for n-Propyl Bromide Using an Improved Methodology” App Occu. Env.
Hyg. 17: 711-716 (A-2001-07, II-D-63)

Rozman and Doull, 2005.  Presentation by Drs. Rozman and Doull at the
North American Congress of Clinical Toxicologists.  September 14, 2005.
(EPA-HQ-OAR-2002-0064-0126)

RTI, 2005.  Report on uptake and metabolism of 1-bromopropane in rats
and mice.  Research Triangle Institute report for the National
Toxicology Program.  June, 2005.  (EPA-HQ-OAR-2002-0064-0077, -0080,
-0081, -0082, -0101, -0104, -0137, -0137.1)

Ruckriegel, 2003.  Comment on n-Propyl Bromide Recommended Workplace
Exposure Level in Proposed Rule Published in Federal Register Vol. 68,
No. 106, June 3, 2003.  August 2, 2003 (EPA-HQ-OAR-2002-0064-0055)

Rusch and Bernhard, 2003.  Comments on proposed regulation of n-propyl
bromide from Steven Bernhardt and George Rusch, Honeywell.  August 1,
2003.  (EPA-HQ-OAR-2002-0064-0059)

Rusch, 2003.  Late comments on proposed regulation of n-propyl bromide
from George Rusch, Honeywell.  (EPA-HQ-OAR-2002-0064-0068)

Sekiguchi S, Suda M, Zhai YL, Honma T., “Effects of 1-bromopropane,
2-bromopropane, and 1,2-dichloropropane on the estrous cycle and
ovulation in F344 rats.” Toxicol Lett 2002 Jan 5;126(1):41-9
(A-2001-07, II-D-39)

SLR International, 2001. “Inhalation Occupational Exposure Limit for
n-Propyl Bromide.” Prepared for Enviro Tech International, Inc. 2001.
(A-2001-07, II-D-15)

Smith, 2003.  Comments on Protection of Stratospheric Ozone: Listing of
Substitutes for Ozone-Depleting Substances - n-Propyl Bromide, FR Vol.
68, No. 106, June 3, 2003.  R. L. Smith, Albemarle Corporation.  July
23, 2003. (EPA-HQ-OAR-2002-0064-0067)

Sohn et al., 2002.  Sohn YK, Suh JS, Kim JW, Seo HH, Kim JY, Kim HY, Lee
JY, Lee SB, Han JH, Lee YM, Lee JY. “A histopathologic study of the
nervous system after inhalation exposure of 1-bromopropane in rat.”
Toxicol Lett. 2002 May 28;131(3):195-201.  (EPA-HQ-OAR-2002-0064-0127)

Stelljes, 2003.  Comments from Dr. Marc Stelljes, SLR International, on
proposed rule on n-propyl bromide.  (HQ-EPA-OAR-2002-0064-0022)

Stelljes and Wood, 2004.  Stelljes, M., Wood, R.  Development of an
occupational exposure limit for n-propylbromide using benchmark dose
methods.  Regulatory Toxicology and Pharmacology 40 (2004) 136–150
(EPA-HQ-OAR-2002-0064-0087)

Stelljes, ME, 2005.  Mechanistic Hypothesis for n-Propylbromide and
Ramifications for Occupational Exposure Limit in the United States.
Technical Memorandum to EnviroTech International.  7 September, 2005.
(EPA-HQ-OAR-2002-0064-0144)

Stump, 2005.  “The Reproductive Toxicity of nPB in Rats,”
Presentation by Dr Donald Stump at the North American Congress of
Clinical Toxicologists.  September 14, 2005.
(EPA-HQ-OAR-2002-0064-0076)

Swanson, M.B., J.R. Geibig, and K.E. Kelly.  2002.  Alternative
Adhesives Technologies: Foam Furniture and Bedding Industries, Final
Draft.  Volume 2: Risk Screening and Comparison.  Chapter 4: Exposure
Assessment.  Produced by the University of Tennessee Center for Clean
Products and Clean Technologies under a grant from EPA’s Design for
the Environment Branch, Office of Pollution and Prevention and Toxics.
June 2002.  Available online at   HYPERLINK
"http://eerc.ra.utk.edu/ccpct/aap1.html"
http://eerc.ra.utk.edu/ccpct/aap1.html .

TERA, 2004.  Toxicological Excellence for Risk Assessment.  Scientific
Review of 1-Bromopropane Occupational Exposure Limit Derivations –
Preliminary Thoughts and Areas for Further Analysis.  2004.
(EPA-HQ-OAR-2002-0064-0189)

Toraason, M., Lynch, D.W., DeBorda, D.G., Singh, N., Krieg, E., Butler,
M.A.,Toennis, C.A., Nemhauser, J.B., 2006. DNA damage in leukocytes of
workers occupationally exposed to 1-bromopropane.  Mutation Research 603
(2006) 1–14  (EPA-HQ-OAR-2002-0064-0130)

US EPA, 1991. Guidelines for Developmental Toxicity Risk Assessment.
U.S. Environmental Protection  Agency.  (A-2001-07, II-A-51)

US EPA, 1994b.  U.S. Environmental Protection Agency (US EPA).  1994.
Methods for derivation of inhalation reference concentrations and
application of inhalation dosimetry.  EPA/600/8-90/066F.  Office of
Health and Environmental Assessment, Washington, DC.  1994. (A-2001-07,
II-A-16)

US EPA, 1995a.  The Use of the Benchmark Dose Approach in Health Risk
Assessment. EPA/630-R-94-007.  Risk Assessment Forum, Washington, DC.
(A-2001-07, II-A-17)

US EPA, 1995b.  SCREEN3 air dispersion model. (A-2001-07, II-A-53)

US EPA, 1996.  Guidelines for Reproductive Toxicity Risk Assessment.
U.S. Environmental Protection Agency, Risk Assessment Forum, Washington,
DC, 630/R-96/009, 1996. (EPA-HQ-OAR-2002-0064-0109)

Wang et al., 2003.   H. Wang, G. Ichihara, H. Ito, K. Kato, J. Kitoh, T.
Yamada, X. Yu, S. Tsuboi, Y. Moriyama, and Y. Takeuchi. 2003.
“Dose-Dependant Biochemical Changes in RateCentral Nervous System
after 12-Week Exposure to 1-Bromopropane”  NeuroToxicology 24: 199-206
 (EPA-HQ-OAR-2002-0064-0088)

Werner, 2003.  Comments from 3M on nPB proposed rule.
(EPA-HQ-OAR-2002-0064-0058).

WIL, 2001.  WIL Research Laboratories. “An inhalation two-generation
reproductive toxicity study of 1-bromopropane in rats.” Sponsored by
the Brominated Solvent Consortium.  May 24, 2001. (A-2001-07, II-D-10)

Yamada T. et al., 2003.  Exposure to 1-Bromopropane Causes Ovarian
Dysfunction in Rats. Toxicol Sci 71:96-103  (EPA-HQ-OAR-2002-0064-0097)

Listings for each end use

Beck and Caravati, 2003.    Full citation above for “Human Health”
section.

Calhoun County, 2005.  Summary of Court Case against Franklin
Technologies and Mid-South Adhesive Company in Calhoun County, MS.
(EPA-HQ-OAR-2002-0064-0217)

Collatz, 2003.  Comment entitled "Addition of n-Propyl-Bromide to the
Significant New Alternatives Policy (SNAP) List" submitted by Mark
Collatz, Director of Government Relations, The Adhesive and Sealant
Council, Inc.   04-Aug-2003. (EPA-HQ-OAR-2002-0064-0066)

Confidential submission, 1998.  Full citation above in “Human
Health” section.

CSMA, 1998.  Letter with attachments from J. DiFazio, Chemical
Specialties Manufacturers Association to C. Newberg, EPA  Re:
Maintaining the Current Exemption under Section 610 of the Clean Air Act
for Use of HCFC-141b in Electronic Cleaning and Aircraft Maintenance.
September 10, 1998.  (EPA-HQ-OAR-2002-0064-0153)

Harper, 2005.    Full citation above for “Availability” section.

ICF, 2006a.   Full citation above for section on “Impacts on the
atmosphere, local air quality, and other environmental impacts”.

Lake City Army Ammunition Plant, 2004.  Full citation above in “Human
Health”section.

Linnell, 2003.  Comments from the Electronics Industry Alliance.
(IV-D-25/EPA-HQ-OAR-2002-0064 items -0043, -0044, and -0045)

Majersik et al., 2004.  Full citation above for “Human Health”
section.

Majersik et al, 2005.   Full citation above for “Human Health”
section.

Miller, 2005.   Full citation above for “Human Health” section.

NIOSH, 2000a.  U.S. Dept. of Health and Human Services, Letter to Marx
Industries, Inc., February 1, 2000.  Re: results of nPB exposure
assessment survey conducted Nov. 16-17, 1999. (A-2001-07, II-D-7)

NIOSH, 2000b.  U.S. Dept. of Health and Human Services, Letter to Custom
Products Inc., December 21, 2000.  Re: results of nPB exposure
assessment survey conducted Nov. 16, 2000.  (HHE Report 98-0153)
(A-2001-07, II-D-8)

NIOSH, 2001.  U.S. Dept. of Health and Human Services, Letter to STN
Cushion Company, March 7, 2001.   Re: Results of nPB exposure assessment
survey conducted November 14, 2000. (A-2001-07, II-D-9)

NIOSH, 2002a.  Full citation above in “Human Health” section.

NIOSH, 2002b.  Full citation above in “Human Health” section.

NIOSH, 2003a.  NIOSH Health Hazard Evaluation Report #99-0260-2906  Marx
Industries, Inc. Sawmills, NC  Available online at   HYPERLINK
"http://www.cdc.gov/niosh/hhe/reports/pdfs/1999-0260-2906.pdf"
http://www.cdc.gov/niosh/hhe/reports/pdfs/1999-0260-2906.pdf .
(EPA-HQ-OAR-2002-0064-0094)

Raymond and Ford, 2005.   Full citation above for “Human Health”
section.

US EPA, 2004.  US EPA Solvent Market Report:  The U.S. Solvent Cleaning
Industry and the Transition to Non Ozone Depleting Substances.  Prepared
for U.S. Environmental Protection Agency, Significant New Alternatives
Policy (SNAP) Program by ICF Consulting.  September 2004.
(EPA-HQ-OAR-2002-0064-0106)

Werner, 2003.  Full citation above for “Human Health” section.

Williams, 2005.   Full citation above for “Availability” section.

What other options did EPA consider?

ACGIH, 2002.  Industrial Ventilation: A Manual of Recommended Practice
23rd Edition.  American Conference of Governmental Industrial
Hygienists, Cincinnati, Ohio  Available online at   HYPERLINK
"http://www.acgih.org"  www.acgih.org .

CSMA, 1999.   Full citation above for “Decisions for Each Sector and
End Use” section.

Ensolv, 2006.  Material Safety Data Sheet for Ensolv Solvents.  Enviro
Tech International.  February, 2006.  (EPA-HQ-OAR-2002-0064-0143)

ERG, 2004.  Analysis of Health and Environmental Impacts of ODS
Substitutes—Evaluating the need to set a short-term exposure or
ceiling limit for n-propyl bromide.  ERG.  June 8, 2004.

ICF, 2006a.   Full citation above for section on “Impacts on the
atmosphere, local air quality, and other environmental impacts”.

Lake City Army Ammunition Plant, 2004.   Full citation above for
“Decisions for Each Sector and End Use” section

Linnell, 2003.   Full citation above for “Ozone Depletion Potential
and Other Environmental Impacts” section.

Micro Care, 2006.  Web page for Micro Care Corporation on the Trigger
Grip™ Dispensing System.  URL at   HYPERLINK
"http://www.microcare.com/products/PDF/PS-05T_G.html"
www.microcare.com/products/PDF/PS-05T_G.html , last update January 19,
2006.  Also see
www.microcare.com/images/PDF-CSP-Allied%20Worker%20Exposures.pdf.

NIOSH, 2000a.  U.S. Dept. of Health and Human Services, Letter to Marx
Industries, Inc., February 1, 2000.  Re: results of nPB exposure
assessment survey conducted Nov. 16-17, 1999. (A-2001-07, II-D-7)

NIOSH, 2002a.  NIOSH Health Hazard Evaluation Report: HETA #
98-0153-2883; Custom Products, Inc.; Mooresville, NC.  National
Institute for Occupational Safety and Health.  November 2002.  Available
online at   HYPERLINK
"http://www.cdc.gov/niosh/hhe/reports/pdfs/1998-0153-2883.pdf"
http://www.cdc.gov/niosh/hhe/reports/pdfs/1998-0153-2883.pdf .
(EPA-HQ-OAR-2002-0064-0093)

NIOSH.  2002b.  NIOSH Health Hazard Evaluation Report: HETA
#2000-0410-2891; STN Cushion Company; Thomasville, NC.  National
Institute for Occupational Safety and Health.  August 2002.  Available
online at   HYPERLINK
"http://www.cdc.gov/niosh/hhe/reports/pdfs/2000-0410-2891.pdf"
http://www.cdc.gov/niosh/hhe/reports/pdfs/2000-0410-2891.pdf .
(A-2001-07, II-A-31)

NIOSH, 2003a.  NIOSH Health Hazard Evaluation Report #99-0260-2906  Marx
Industries, Inc. Sawmills, NC  Available online at   HYPERLINK
"http://www.cdc.gov/niosh/hhe/reports/pdfs/1999-0260-2906.pdf"
http://www.cdc.gov/niosh/hhe/reports/pdfs/1999-0260-2906.pdf .
(EPA-HQ-OAR-2002-0064-0094)

NIOSH, 2003b.  Method 1025 for 1- and 2-Bromopropane.  NIOSH Manual of
Analytical Methods, 4th Edition, March 15, 2003.
(EPA-HQ-OAR-2002-0064-0173)

NIOSH, 2003c.  Method 1003 for Halogenated Hydrocarbons.  NIOSH Manual
of Analytical Methods, 4th Edition, March 15, 2003.
(EPA-HQ-OAR-2002-0064-0134)

Williams, 2005.  Full citation above for “Availability” section.

What are the anticipated costs of this regulation to the regulated
community?

US EPA, 2006.  Analysis of Economic Impacts of nPB Rulemaking.  2006.

Comparison of EPA’s June 2003 proposal and this proposal

ACGIH, 2005.  Full citation above for “Human Health” section.

CERHR, 2002a.  Full citation above for “Human Health” section.

CERHR, 2002b.   Full citation above for “Human Health” section.

Doull and Rozman, 2001.  Derivation of an Occupational Exposure Limit
for n-Propyl Bromide, prepared by John Doull, Ph.D., M.D., and Karl K.
Rozman, Ph.D., D.A.B.T. submitted by Envirotech International, Inc.
(A-2001-07, II-D-14)

Full citation above for “Human Health” section.

ICF, 2002b. Comments on the NTP- Center for the Evaluation of Risks to
Human Reproduction, Final Report on 1-Bromopropane.  Cover Letter Dated
5/9/02.  (EPA-HQ-OAR-2002-0064-0013)

ICF, 2006a.   Full citation above for section on “Impacts on the
atmosphere, local air quality, and other environmental impacts”.

Rodricks, 2002.   Full citation above for “Human Health” section.

Rozman and Doull, 2002.   Full citation above for “Human Health”
section.

Rozman and Doull, 2005.  Full citation above for “Human Health”
section.

SLR International, 2001.  Full citation above for “Human Health”
section.

Stelljes and Wood, 2004.   Full citation above for “Human Health”
section.

Stelljes, ME.  2005.   Full citation above for “Human Health”
section.

TERA, 2004.  Full citation above for “Human Health” section.

WIL, 2001.  Full citation above for “Human Health” section.

How can I use nPB as safely as possible?

ACGIH, 2002.  Full citation above for “What other options did EPA
consider” section.

Statutory and Executive Order Reviews

US EPA, 2006.  Analysis of Economic Impacts of nPB Rulemaking.  2006.

US EPA, 2007.  Analysis of Economic Impacts of Proposed nPB Rule for
Aerosols and Adhesives.  2007.

List of Subjects in 40 CFR Part 82

Environmental protection, Administrative practice and procedure, Air
pollution control, Reporting and recordkeeping requirements.

Protection of Stratospheric Ozone:  Listing of Substitutes for
Ozone-Depleting

Substances–n-Propyl Bromide in
Adhesiveⱳ䌠慯楴杮ⱳ愠摮䄠牥獯汯൳潎楴散漠牐灯獯
摥删汵浥歡湩൧慐敧
漠–䅐䕇䕒⁆湅彤景摟捯浵湥⁴桜Ġㄔ〵―慰敧൳഍
慄整㩤†彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟
彟彟ൟ഍彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟彟
彟彟彟彟彟ൟ瑓灥敨⹌䨠桯獮湯摁業楮瑳慲潴൲഍
఍For the reasons set out in the preamble, 40 CFR part 82 is proposed
to be amended as follows:

PART 82 - PROTECTION OF STRATOSPHERIC OZONE

1.	The authority citation for Part 82 continues to read as follows:

Authority:  42 U.S.C. 7414, 7601, 7671 - 7671q.

2.	Subpart G is amended by adding Appendix Q to read as follows:

Subpart G - Significant New Alternatives Policy Program

*****

Appendix Q to Subpart G - Substitutes Subject to Use Restrictions and
Unacceptable Substitutes

Listed in the [publication date of final rule] final rule.

AEROSOLS

UNACCEPTABLE SUBSTITUTES

End Use	Substitute	Decision	Further Information

Aerosol solvents	n-propyl bromide (nPB) as a substitute for CFC-113,
HCFC-141b, and methyl chloroform	Unacceptable 	EPA finds unacceptable
risks to human health in this end use compared to other available
alternatives.  nPB, also known as 1-bromopropane, is Number 106-94-5 in
the CAS Registry.

ADHESIVES, COATINGS, AND INKS

SUBSTITUTES THAT ARE ACCEPTABLE SUBJECT TO USE CONDITIONS

End Use	Substitute	Decision	Use Conditions	Further Information

Coatings	n-propyl bromide (nPB) as a substitute for methyl chloroform,
CFC-113, and HCFC-141b	Acceptable subject to use conditions	Use is
limited to coatings at facilities that, as of [INSERT DATE OF
PUBLICATION], have provided EPA information demonstrating acceptable
workplace exposures.	EPA recommends the use of personal protective
equipment, including chemical goggles, flexible laminate protective
gloves and chemical-resistant clothing.

EPA expects that all users of nPB would comply with any final
Permissible Exposure Limit that the Occupational Safety and Health
Administration issues in the future under 42 U.S.C. 7610(a).

nPB, also known as 1-brompropane, is Number 106-94-5 in the CAS
Registry.

Note: As of [INSERT DATE OF PUBLICATION], the Lake City Army Ammunition
Plant is the only facility using nPB in coatings that has provided
information to EPA that meets this condition.

ADHESIVES, COATINGS, AND INKS

UNACCEPTABLE SUBSTITUTES

End Use	Substitute	Decision	Further Information

Adhesives	n-propyl bromide (nPB) as a substitute for CFC-113, HCFC-141b,
and methyl chloroform	Unacceptable	EPA finds unacceptable risks to human
health in this end use compared to other available alternatives.  nPB,
also known as 1-bromopropane, is Number 106-94-5 in the CAS Registry.

BILLING CODE 6560-50-P

  CFC-113 is also referred to as Freon-113, or
1,1,2-trifluoro-1,2,2-trichloroethane.  Its CAS Reg. No. is 76-13-1.

 Methyl chloroform is also referred to as 1,1,1-trichloroethane, TCA,
MCF, or 1,1,1.  Its CAS Reg. No. is 71-55-6.

 HCFC-141b is also referred to as 1,1-dichloro-1-fluoroethane.  Its CAS
Reg. No. is 1717-00-6.

 Also called trichlorethene or TCE, C2Cl3H, CAS Reg. No. 79-01-6.

 Also called PERC, tetrachloroethylene, or tetrachloroethene, C2Cl4, CAS
Reg. No. 127-18-4.

 nPB emissions in the tropics have an ODP of 0.071 to 0.100; the
portions of the U.S. outside the continental U.S., such as Alaska,
Hawaii, Guam, and the U.S. Virgin Islands, contain less than 1 percent
of the U.S.’s businesses in industries that could use nPB.  Thus,
their potential impact on the ozone layer must be significantly less
than that of the already low impact from nPB emissions in the
continental U.S.  (U.S. Economic Census, 2002a through f)

 iPB is also referred to as 2-bromopropane, 2-propyl bromide, or 2-BP.
Its CAS registry number is 75-26-3.

-

4

]

ž

.

਀ద

&

&

ᘀ嵦唀Ĉ㰀

&

@

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

N

&

&

&

&

&

&

&

&

&

̀Ĥ☊ଌF愀Ĥ

kdC

&

&

&

☊

\

&

&

kd¬

\

&

ô

ô

ༀꂄህā㜀$␸䠀$葞֠

&

@

&

Æ

&

&

Æ

&

Æ

&

Æ

&

@

&

Æ

&

Æ

&

@

&

Æ

&

Æ

&

@

愀ĤЀ.␃愁Ĥ

”ÿA

©

=

´

@

将

将

\

\

\

将

@

将

@

将

@

将

@

将

@

将

@

将

@

将

将

葠ːĀ"

kd

将

鈆

&

@

将

鈆

&

@

将

鈆

&

@

将

鈆

¢

£

@

&

@

@

@

&

@

&

@

\

&

&

\

&

╋਀&䘋

╋਀&䘋

╋਀&䘋

╋਀&䘋

╋਀&䘋

╋਀&䘋

ᵏ਀&䘋

ᵏ਀&䘋

@

@

&

옍#

옍#

h\

@

@

@

@

@

@

@

&

&

&

@

&

@

&

@

&

&

&

&

&

&

&

@

&

&

h

h

&

&

~

l

Û

Ý

øÿ?

F

&

øÿ?

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

øÿ?

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

&

¶

&

¶

&

¶

&

¶

¶

¶

&

¶

&

&

¶

&

¶

&

¶

&

¶

&

¶

&

&

@

&

@

@

&

&

&

&

&

☊

&

&

&

&

&

e and developmental effects, because, among other reasons, these
conditions would not necessarily screen out an individual from being
able to work, unlike for liver or nervous system effects.  Therefore,
for reproductive and developmental effects, we use a composite
uncertainty factor of 10.  See further discussion of uncertainty factors
in section V.C. below.

 Based on WIL, 2001, as analyzed in ICF, 2002.  The equivalent values
based upon Stelljes and Wood’s (2004) analysis of WIL, 2001 would be
slightly lower, from 16 to 28 ppm.

 Unlike samples measured directly in the breathing zone, area samples
measured in the study are not considered representative of actual
exposure and are not discussed here.  Short-term measurements taken over
15 minutes from personal samplers, although in some cases extremely
high, are not discussed in detail here because available toxicity
information does not indicate need for a short-term exposure limit for
nPB in addition to the 8-hr TWA limit (ACGIH, 2005; ERG, 2004).
Additional information on these other samples is in the occupational
exposure assessment for aerosols in the risk screen for nPB (ICF,
2006a).

 These measurements can be converted to estimates of nPB exposure by
multiplying the measured concentration of the alternate chemical by the
molecular weight of the same alternate chemical and dividing this by the
molecular weight of nPB, 123.  After performing this calculation, the
equivalent exposure levels for nPB vary from 29.5 ppm to 394.4 ppm.

 This corresponds roughly to a regional or room fan at low levels or
natural air currents in an open area.  Confined areas would have even
lower air exchange rates with higher exposure levels.

  We consider use of 1000 g/day to be the high end of typical use, based
on the setup of one of the exposure studies (Confidential Submission,
1998).  The typical aerosol solvent user in the electronics industry
uses a can per day (Williams, 2005).  This is comparable to or slightly
less than the spray rate assumed in the modeling.

 Pharmacodynamics refers to the biochemical and physiological effects of
chemicals in the body and the mechanism of their actions.

 Pharmacokinetics refers to the activity or fate of chemicals in the
body, including the processes of absorption, distribution, localization
in tissues, biotransformation, and excretion.

 The blood/air partition coefficient is the ratio of a chemical’s
concentration between blood and air when at equilibrium.

 Vendors of nPB-based products have recommended a wide range of exposure
limits, from 5 ppm to 100 ppm (Albemarle, 2003; Chemtura, 2006; Docket
A-2001-07, item II-D-19; Enviro Tech International, 2006; Farr, 2003;
Great Lakes Chemical Company, 2001).

 We performed the modeling for a facility using nPB-based adhesives
because the nPB emissions from this type of facility were expected to be