effective. While these cost-effectiveness numbers may seem high, EtO is
a highly potent carcinogen, and the cost-effectiveness numbers of these
options are within the range of the values that we have determined to
be cost-effective for highly toxic HAPs. We are proposing Option 1 for
the following reasons. While both options are considered generally
available under CAA section 112(d)(5), Option 1 would achieve greater
emission reductions than Option 2. Also, unlike Option 1 for existing
Group 2 room air emissions at area source facilities, companies
constructing new source(s) of Group 2 room air emissions in the future
can plan and design operations to avoid significant impact (or choose
not to build). Therefore, pursuant to CAA section 112(d)(5), we are
proposing to establish standards for new Group 2 room air emissions at
area source facilities. Specifically, we are proposing to require these
facilities to limit the Group 2 room air EtO emission rate to 2.8E-3
lb/hr. As explained in section III.B.8.a of this preamble, to ensure
complete capture of EtO emissions from this source and, in turn,
compliance with the proposed standard, we are proposing to require each
facility within this group to operate areas with Group 2 room air
emissions in accordance with the PTE requirements of EPA Method 204 of
appendix M to 40 CFR part 51. We are soliciting comment on this
proposed standard. In addition, we solicit comment on several aspects
of this requirement, including the true effectiveness of this
requirement on reducing EtO emissions, any capital and annual costs
that we did not account for, the time that is needed to comply with
this requirement, and any other potential barriers to or impacts of
imposing this requirement (Comment C-35).
9. Summary of Baseline Standards
    Pursuant to CAA sections 112(d)(2), 112(d)(3), and 112(d)(5), we
are proposing standards for a number of currently unregulated EtO
emission sources at commercial sterilizes.\35\ As mentioned earlier and
described in more detail in sections III.C and III.D of this preamble,
the EPA conducted a second section 112(f)(2) analysis for the source
category. For that analysis, the EPA conducted a baseline risk
assessment that took into account the current standards in subpart O as
well as implementation of the proposed 112(d) standards for the
currently unregulated emission sources discussed here in section III.B.
Table 18 summarizes these standards.
---------------------------------------------------------------------------

    \35\ In addition, we are proposing a correction to the current
standard under 112(d) for ARV at facilities where EtO use is at
least 10 tpy.

    Table 18--Summary of Standards After Proposed Actions Pursuant to CAA Sections 112(d)(2), 112(d)(3), and
                                                    112(d)(5)
----------------------------------------------------------------------------------------------------------------
        Emission source           Existing or new?       EtO use              Standards           CAA section
----------------------------------------------------------------------------------------------------------------
SCV............................  Existing.........  At least 10 tpy..  99 percent emission     Current standard.
                                                                        reduction.
                                                    At least 1 but     99 percent emission     Current standard.
                                                     less than 10 tpy.  reduction.
                                                    Less than 1 tpy..  99 percent emission     112(d)(5).
                                                                        reduction.
                                 New..............  At least 10 tpy..  99 percent emission     Current standard.
                                                                        reduction.
                                                    At least 1 but     99 percent emission     Current standard.
                                                     less than 10 tpy.  reduction.
                                                    Less than 1 tpy..  99 percent emission     112(d)(5).
                                                                        reduction.
ARV............................  Existing.........  At least 10 tpy..  99 percent emission     Current standard.
                                                                        reduction.
                                                    At least 1 but     99 percent emission     112(d)(5).
                                                     less than 10 tpy.  reduction.
                                                    Less than 1 tpy..  99 percent emission     112(d)(5).
                                                                        reduction.
                                 New..............  At least 10 tpy..  99 percent emission     Current standard.
                                                                        reduction.
                                                    At least 1 but     99 percent emission     112(d)(5).
                                                     less than 10 tpy.  reduction.
                                                    Less than 1 tpy..  99 percent emission
                                                                        reduction.
CEV............................  Existing.........  At least 10 tpy..  3.2E-4 lb/hr..........  112(d)(2) and (3)
                                                    At least 1 but     99 percent emission     112(d)(5).
                                                     less than 10 tpy.  reduction.
                                                    Less than 1 tpy..  99 percent emission     112(d)(5).
                                                                        reduction.
CEV............................  New..............  At least 10 tpy..  3.2E-4 lb/hr..........  112(d)(2) and
                                                                                (3).
                                                    At least 1 but     99 percent emission     112(d)(5).
                                                     less than 10 tpy.  reduction.
                                                    Less than 1 tpy..  99 percent emission     112(d)(5).
                                                                        reduction.
Group 1 room air emissions at    Existing and new.  N/A..............  1.3E-3 lb/hr \1\......  112(d)(2) and
 major sources.                                                                                (3).
Group 1 room air emissions at    Existing and new.  N/A..............  1.3E-3 lb/hr \1\......  112(d)(5).
 area sources.
Group 2 room air emissions at    Existing and new.  N/A..............  2.8E-3 lb/hr \1\......  112(d)(2) and
 major sources.                                                                                (3).
Group 2 room air emissions at    Existing.........  N/A..............  Follow either the       112(d)(5).
 area sources.                                                          Cycle Calculation
                                                                        Approach or the
                                                                        Bioburden/Biological
                                                                        Indicator Approach to
                                                                        achieve sterility
                                                                        assurance in
                                                                        accordance with ISO
                                                                        11135:2014 (July 15,
                                                                        2014) and ISO 11138-
                                                                        1:2017 (March
                                                                        2017)\2\.
                                 New..............  N/A..............  2.8E-3 lb/hr \1\......  112(d)(5).
----------------------------------------------------------------------------------------------------------------
\1\ We are also proposing to require each facility to operate areas with these emissions in accordance with the
  PTE requirements of EPA Method 204 of appendix M to 40 CFR part 51.
\2\ Owners and operators may also apply for an alternative means of emission limitation under CAA section
  112(h)(3).

C. What are the results of the risk assessment and analyses?

    We conducted a risk assessment for the Commercial Sterilization
Facilities source category using the risk assessment methods described
in section II.F of this preamble. We present results of the risk
assessment briefly below and in more detail in the Residual Risk
Assessment for the Commercial Sterilization Facilities Source Category
in Support of the 2022 Risk and Technology Review Proposed Rule, which
is available in Docket ID No. EPA-HQ-OAR-2019-0178. The risk assessment
was conducted on the 86 facilities in the commercial sterilization
source category that are currently in operation and 11 research and
development facilities, for a total of 97 facilities. To exercise
caution with respect to this source category, we included research
facilities in our assessment because there is a lack of certainty over
whether these are true research facilities, for which CAA section
112(c)(7) requires that a separate category be established. However,
EtO use at these facilities tends to be very low (less than 1 tpy), and
these facilities have low risk.
    All baseline risk results are developed using the best estimates of
actual emissions and release parameters summarized in section II.F.1.
Because allowable emissions and risks would be higher than actual
emissions in this case, and in light of our finding that risks are
unacceptable based on actual emissions, as discussed in section III.D.2
of this preamble, a separate assessment of allowable emissions appears
unnecessary.
    The results of the baseline chronic inhalation cancer risk
assessment using actual emissions are shown in Table 19. The MIR is
estimated to be 6,000-in-1 million, driven by EtO from Group 2 room air
emissions (70 percent) and sterilization chamber vents (28 percent).
The total estimated cancer incidence is 0.9 excess cancer case per
year, or one cancer case every 13 months. The estimated population
exposed to cancer risks between 1,000-in-1 million and the maximum risk
level of 6,000-in-1 million is 900 people. The total population exposed
to cancer risks greater than 100-in-1 million is 18,000 people. The
population exposed to cancer risks greater than or equal to 1-in-1
million living within 50 km of a facility is approximately 8.3 million
(see Table 19 of this preamble). Of the 97 facilities that were
assessed, 16 facilities have an estimated maximum cancer risk greater
than 100-in-1 million and six of those facilities have an estimated
maximum cancer risk greater than 1,000-in-1 million. The maximum
chronic noncancer TOSHI for the source category is estimated to be 0.04
(for neurological effects). The acute risk screening assessment of
reasonable worst-case inhalation impacts indicates

a maximum acute HQ of 0.002 for PpO based on the REL acute health
reference value. For EtO, the maximum HQ is 0.0005 based on the AEGL-2
acute health reference value.\36\
---------------------------------------------------------------------------

    \36\ Acute RELs, ERPG-1, and AEGL-1 acute health reference
values are not available for ethylene oxide.

                     Table 19--Sterilization Facilities Source Category Inhalation Risk Assessment Results Based on Actual Emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Estimated       Estimated       Estimated
                                           Maximum      population at   population at   annual cancer
                                         individual    increased risk  increased risk     incidence         Maximum chronic      Maximum screening acute
                                         cancer risk   of cancer >100- of cancer >=1-    (cases per       noncancer TOSHI \1\          noncancer HQ
                                       (in 1 million)   in-1  million   in-1 million        year)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Category......................           6,000          18,000       8,300,000             0.9  0.04 (Neurological).....  0.002 (REL).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The TOSHI is the sum of the chronic noncancer HQs for substances that affect the same target organ or organ system.

    An assessment of facility-wide (or ``whole facility'') risks was
performed to characterize the source category risk in the context of
whole facility risks. Non-source category emissions were estimated
using the EPA's 2017 NEI as described in section II.F.6. The facility-
wide assessment showed that risks from non-source category emission
sources were minimal. The MIR, populations above cancer risk
thresholds, incidence, and maximum chronic noncancer TOSHI in the
facility-wide risk assessment were the same as the source category risk
assessment (Table 19). We also examined areas surrounding sterilization
facilities for other significant emission sources of HAP. That analysis
determined that the vast majority of sterilization facilities are not
located nearby other significant sources of HAP as most are isolated or
located within office parks.\37\
---------------------------------------------------------------------------

    \37\ EPA Air Toxics Screening Assessment (AirToxScreen).
Available at: https://www.epa.gov/AirToxScreen.
---------------------------------------------------------------------------

    We then repeated our risk assessment for the Commercial
Sterilization Facilities source category assuming emission reductions
under CAA sections 112(d)(2), 112(d)(3), and 112(d)(5) as described
above and summarized in Table 18, with the exception of the proposed
Group 1 room air emission standards. Instead, the risk assessment was
based on requiring BMP (Option 2) under section 112(d)(5) for Group 1
room air emissions, which we had initially considered proposing instead
of an emission limit reflecting use of control devices (Option 1);
however, following our risk assessment, we continued to review our
regulatory options and determined that the emission limit reflecting
use of control devices (Option 1) is a more appropriate option than the
BMP for Group 1 room air emissions for the reason discussed in section
III.B.8. We are therefore proposing such emission limit instead of the
BMP under section 112(d)(5). While we have not reassessed risks based
on this one change in a proposed section 112(d)(5) standard, we do not
expect this change to affect the MIR for the source category in this
scenario, as it was driven by Group 2 room air emissions and
sterilization chamber vent emissions, although we anticipate that one
or more of the other results presented in Table 20 may be lower (e.g.,
populations at various risk thresholds and cancer incidence).
    In the scenario assuming emission reductions under the proposed CAA
sections 112(d)(2), 112(d)(3), and 112(d)(5),\38\ the MIR is estimated
to be 3,000-in-1 million driven by EtO from Group 2 room air emissions
(70 percent) and sterilization chamber vents (28 percent). The total
estimated cancer incidence is 0.3 excess cancer case per year, or one
cancer case every 3.3 years. The estimated population exposed to cancer
risks between 1,000-in-1 million and the maximum risk level of 3,000-
in-1 million is 200 people, down from 900 people in the baseline
scenario. The total population exposed to cancer risks greater than
100-in-1 million is 2,350 people, down from 18,000 people in the
baseline scenario. The population exposed to cancer risks greater than
or equal to 1-in-1 million living within 50 km of a facility is
approximately 3.2 million, down from 8.3 million. Of the 97 facilities
that were assessed, 13 facilities have an estimated maximum cancer risk
greater than 100-in-1 million (down from 16) and two of those
facilities have an estimated maximum cancer risk greater than 1000-in-1
million (down from six). The maximum chronic noncancer TOSHI for the
source category is estimated to be 0.003 for the neurological target
organ. The acute risk screening assessment of reasonable worst-case
inhalation impacts indicates a maximum acute HQ of 0.001 for propylene
oxide (PpO) based on the REL acute health reference value. For EtO, the
maximum HQ is 0.0003 based on the AEGL 2 acute health reference
value.\39\
---------------------------------------------------------------------------

    \38\ As explained immediately above, the risk assessment assumed
emission reductions from the BMP option (Option 2) for Group 1 room
air emissions, and that based on further analysis following the risk
assessment, we are proposing the emission limit reflecting use of
control devices (Option 1) instead of the BMP option assumed in the
risk assessment.
    \39\ RELs, ERPG-1, and AEGL-1 acute health reference values are
not available for ethylene oxide.

   Table 20--Sterilization Facilities Source Category Inhalation Risk Assessment Results Based on Actual Emissions After Emission Reductions Under CAA
                                                      Sections 112(d)(2), 112(d)(3), and 112(d)(5)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Estimated       Estimated       Estimated
                                           Maximum      population at   population at   annual cancer
                                         individual    increased risk  increased risk     incidence         Maximum chronic      Maximum screening acute
                                         cancer risk   of cancer >100- of cancer >=1-    (cases per       noncancer TOSHI \1\          noncancer HQ
                                       (in 1 million)   in-1  million   in-1 million        year)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source category......................           3,000       \2\ 2,350   \2\ 3,200,000         \2\ 0.3  0.003 (Neurological)....  0.001 (REL).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The TOSHI is the sum of the chronic noncancer HQs for substances that affect the same target organ or organ system.
\2\ These values may be lower due to the proposed Group 1 room air emission standards that were not included in the risk assessment.

D. What are our proposed decisions regarding risk acceptability, ample
margin of safety, and adverse environmental effect?

    As noted in section II.A of this preamble, the EPA sets standards
under CAA section 112(f)(2) using ``a two-step standard-setting
approach, with an analytical first step to determine an `acceptable
risk' that considers all health information, including risk estimation
uncertainty, and includes a presumptive limit on MIR of approximately
1-in-10 thousand'' (54 FR 38045, September 14, 1989). For this
proposal, the EPA estimated baseline risks based on actual emissions
from the Commercial Sterilization Facilities source category, as well
as emission reductions from the proposed standards for the currently
unregulated emissions sources under CAA sections 112(d)(2), 112(d)(3),
and 112(d)(5) as described above and summarized in Table 18. For the
purposes of risk acceptability, we considered the risks after the
emission reductions under CAA sections 112(d)(2), 112(d)(3), and
112(d)(5).
1. Determination of Risk Acceptability After Emission Reductions Under
CAA Sections 112(d)(2), 112(d)(3), and 112(d)(5)
    As noted in section II.D of this preamble, we weigh a wide range of
health risk measures and factors in our risk acceptability
determination, including the cancer MIR, the number of persons in
various cancer and noncancer risk ranges, cancer incidence, the maximum
noncancer TOSHI, the maximum acute noncancer HQ, the extent of
noncancer risks, the distribution of cancer and noncancer risks in the
exposed population, and risk estimation uncertainties (54 FR 38044,
September 14, 1989).
    For the Commercial Sterilization Facilities source category, the
risk results indicate that the cancer risks to the individual most
exposed are well above 100-in-1 million, which is the presumptive upper
end of the range of acceptability. The estimated inhalation cancer risk
to the individual most exposed to emissions from the source category is
3,000-in-1 million after emission reductions under CAA sections
112(d)(2), 112(d)(3), and 112(d)(5). The estimated incidence of cancer
due to inhalation exposures is 0.3 excess cancer case per year. The
population estimated to be exposed to cancer risks greater than 100-in-
1 million is approximately 2,350, and the population estimated to be
exposed to cancer risks greater than or equal to 1-in-1 million is
approximately 3.2 million. The estimated maximum chronic noncancer
TOSHI from inhalation exposure for this source category is 0.003 (for
neurological effects), indicating low likelihood of adverse noncancer
effects from long-term inhalation exposures. The acute risk screening
assessment of reasonable worst-case inhalation impacts indicates a
maximum acute HQ of 0.001. Therefore, we conclude that adverse effects
from acute exposure to emissions from this category are not
anticipated.
    Considering the health risk information and factors discussed
above, particularly the high MIR for the source category, we propose to
find that the risks from the Commercial Sterilization Facilities source
category, taking into account emission reductions under CAA sections
112(d)(2), 112(d)(3), and 112(d)(5) as described above and summarized
in Table 18, are unacceptable. As noted in section II.A of this
preamble, when risks are unacceptable, the EPA must determine the
emissions standards necessary to reduce risk to an acceptable level.
Therefore, pursuant to CAA section 112(f)(2), we are proposing certain
standards that are more protective than those shown in Table 18 based
on our proposed finding that risks from this source category remain
unacceptable even after the application of revised standards under
section 112(d).
a. Available Controls To Address Risks
    We evaluated several control options for reducing risks. Based on
the results of the risk assessment, we have identified SCVs and Group 2
room air emissions as the primary contributors to risks. Therefore, we
focused our analysis of control options on SCVs and Group 2 room air
emissions to reduce risk.
    As mentioned above, the MIR for the source category is estimated to
be 3,000-in-1 million, driven by EtO from one facility. Results from
our risk assessment indicate that, for that facility with the source
category MIR of 3,000-in-1 million, 28 percent of the risk is from
SCVs. The remaining risk is mostly from Group 2 room air emissions (70
percent).
    This facility is the only one within the source category where the
emissions from SCVs contribute to the facility's MIR exceeding 100-in-1
million, and this facility currently uses 44 tpy of EtO. The current
subpart O requires 99 percent emission reduction for SCVs at facilities
where EtO use is at least 1 tpy. An emission reduction of 99 percent is
also the proposed standard under CAA section 112(d)(5) for the
currently unregulated SCVs, which are those facilities where EtO use is
less than 1 tpy (see section III.B.1.a).
    Our data do not identify any add-on controls beyond those we have
already considered when promulgating the SCV standards in subpart O or
proposing the standards for the currently unregulated SCV standards in
section II.B.1. However, our evaluation of the performance data shows
that these controls can achieve greater than 99 percent reduction. We
therefore considered a more stringent SCV standard for facilities where
EtO use is at least 40 tpy, which would include the one and only
facility where the emissions from SCVs contribute to the facility's MIR
exceeding 100-in-1 million. The emission limit that we evaluated is
99.94 percent reduction, which would reduce this facility's SCV
emissions such that they no longer contribute to this facility's MIR
exceeding 100-in-a-million.\40\ We have

determined that this is feasible because our evaluation of performance
tests indicates that 27 out of 36 facilities with SCVs and using at
least 40 tpy of EtO are already exceeding this emission reduction from
their SCVs. Of those 27 facilities, 14 use wet scrubbers, six use
catalytic oxidizers, four use a wet scrubber and gas/solid reactor in
series, two use thermal oxidizers, and one uses a wet scrubber and
catalytic oxidizer in series.
---------------------------------------------------------------------------

    \40\ As mentioned above, the remaining risks from this facility
are from Group 2 room air emissions, which we will address
immediately below in the next subsection.
---------------------------------------------------------------------------

    As mentioned above, results from our risk assessment indicate that,
for the facility with the source category MIR of 3,000-in-1 million, 70
percent of the risk is from Group 2 room air emissions. In addition to
this facility, which is an area source, there are two other facilities,
also area sources, where Group 2 room air emissions contribute to the
facilities' MIRs exceeding 100-in-1 million.\41\ Because Group 2 room
air emissions are one of the two principal contributors to unacceptable
risks from existing area sources in this source category, we evaluated
available control options for reducing risks from Group 2 room air
emissions.
---------------------------------------------------------------------------

    \41\ As discussed earlier, the EPA has the authority to conduct
an (f)(2) review of GACT standards and is exercising that authority
in this action.
---------------------------------------------------------------------------

    As discussed in section III.B.8.g of this preamble, we are
proposing a GACT standard for currently unregulated Group 2 room air
emissions at existing area source facilities. Specifically, we are
proposing under CAA section 112(d)(5) that facilities follow either the
Cycle Calculation Approach or the Bioburden/Biological Indicator
Approach to achieve sterility in accordance with ISO 11135:2014 and ISO
11138-1:2017 is not exceeded.\42\
---------------------------------------------------------------------------

    \42\ As discussed in section III.B.8 of this preamble, we are
proposing an emission rate of 2.8E-3 lb/hr for all new area source
facilities, regardless of EtO use, under CAA section 112(d)(5).
---------------------------------------------------------------------------

    In proposing this standard, we also considered an emission rate of
2.8E-3 lb/hr that reflects the use of control devices (Option 1) but
did not propose that option based on our analysis of relevant factors
under section 112(d)(5). However, having proposed to determine under
CAA section 112(f)(2) that the risk for the source category is
unacceptable, we must determine the emissions standards necessary to
reduce risk to an acceptable level without considering costs.
Therefore, we are considering under section 112(f)(2) this emission
rate of 2.8E-3 lb/hr for reducing risks from existing area source
facilities where EtO use is at least 20 tpy, which would include all
three facilities where the Group 2 room air emissions contribute to
these facilities' MIRs exceeding 100-in-1 million.\43\
---------------------------------------------------------------------------

    \43\ The EtO usage at these three facilities range from 22 to 77
tpy.
---------------------------------------------------------------------------

    Another option for reducing Group 2 room air emissions is setting a
work practice standard to limit both the maximum volumetric flow rate
and maximum EtO concentration of the exhaust streams that contain these
emissions. Based on our estimate, this work practice standard would
reduce emissions below the 2.8E-3 lb/hr limit. We note that if both the
volumetric flow rate and EtO concentration are restricted, there are at
least two potential outcomes. One outcome is that a facility could keep
the volume of the enclosure constant but restrict the number of room
air changes (RACs) per hour. This could potentially result in an
increase in EtO concentration within the enclosure. In order to
maintain personnel safety, significant upgrades and changes may need to
be made, which could require significant costs. Another outcome is that
the facility could keep the number of RACs per hour constant but
restrict the volume of the enclosure. Both of these outcomes could
result in a reduced capacity to sterilize medical products, which is an
important consideration in light of the role that sterilization
facilities play in the medical supply chain.
b. Regulatory Options
    We considered more stringent SCV and Group 2 room air emission
standards to reduce risk from the source category to an acceptable
level. To that end, we identified the following two options. Control
Option 1 would require that (1) facilities where EtO use is at least 40
tpy reduce emissions from individual SCVs by 99.94 percent; and (2)
area source facilities where EtO use is at least 20 tpy limit the Group
2 room air EtO emission rate to 2.8E-3 lb/hr. Control Option 2 would
have the same two requirements as Option 1, except that the 2.8E-3 lb/
hr limit would not apply to facilities with MIR remaining greater than
100-in-1 million even after the imposition of the requirements under
Control Option 1, as determined by this risk assessment, and detailed
in Appendix 10 of the document titled Residual Risk Assessment for the
Commercial Sterilization Facilities Source Category in Support of the
2022 Risk and Technology Review Proposed Rule, which is available in
the docket for this rulemaking. For these two facilities,\44\ Option 2
would require work practice standards that would reduce Group 2 room
air emissions at these two facilities to a level that would lower their
MIR to 100-in-1-million, based on our estimates. Under this work
practice standard, Group 2 room air emissions would be limited to a
maximum volumetric flow rate of 2,900 dscfm and a maximum EtO
concentration of 30 ppbv.
---------------------------------------------------------------------------

    \44\ As explained below in section III.D.1.c, following our risk
modeling, which showed 3 facilities in this group, we conducted
additional analysis that resulted in stricter proposed standards
under section 112(d)(5) for Group 1 room air emissions, which in
turn changed the number of facilities (from three to two) that,
after taking into account emission reduction from Option 1, would
still have an MIR > 100-in-a-million due to group 2 room air
emissions.
---------------------------------------------------------------------------

    In considering the work practice standards described above, it is
important to understand the uncertainties related to the modeled EtO
emissions for the two area source facilities that would be subject to
these standards. For one facility, we did not receive any room area or
EtO monitoring data as part of the September 2021 ICR that could have
been used to quantify Group 2 room air emissions. Therefore, we modeled
emissions using our default assumption that 0.2 percent of EtO used is
emitted as part of Group 2 room air emissions. In addition, we did not
receive any information on how the air for areas where there are Group
2 room air emissions is leaving the facility (i.e., the height,
temperature, diameter, velocity, and flow rate of each release point
for these areas). Therefore, Group 2 room air emissions were modeled as
an area source. These factors increase the uncertainty of the MIR for
this facility. For the other facility, we understand that a new
approval order has recently been issued for this facility that includes
limits on Group 2 room air emissions.\45\ However, we do not know how
the dispersion characteristics for these emissions will change upon the
installation of additional controls. This increases the uncertainty of
the MIR for this facility.
---------------------------------------------------------------------------

    \45\ https://eqedocs.utah.gov/TempEDocsFiles/142039467_142039467_AgencyInterest_10301-10400_10377%20-%20BD%20Medical-%20Medical%20Device%20Manufacturing%20Plant_New%20Source%20Review_2022_DAQ-2022-008635.pdf.
---------------------------------------------------------------------------

c. Determination of Risk Acceptability After Emission Reductions Under
CAA Section 112(f)(2)
    As discussed above, we consider two options for reducing risks.
Control Option 1 would require (1) 99.94 percent emission reduction for
each SCV at facilities using at least 40 tpy EtO and (2) 2.8E-3 lb/hr
emission limit for Group 2 room air emissions at area source facilities
using at least 20 tpy. Control Option 2 would require (1)

99.94 percent emission reduction for each SCV at facilities using at
least 40 tpy EtO; (2) 2.8E-3 lb/hr emission limit for Group 2 room air
emissions at area source facilities using at least 20 tpy, except for 2
facilities with MIR > 100-in-1-million after imposition of the
requirements under Control Option 1; and (3) for these two facilities,
work practice standards that would bring their MIR to 100-in-1-million.
    In Table 21, we present the risks after the implementation of
Control Options 1 and 2 based on our risk assessment. The risk metrics
shown in the table include the cancer MIR, population exposed to cancer
risks greater than 100-in-1 million, population exposed to cancer risks
greater than or equal to 1-in-1 million, and the cancer incidence.

   Table 21--Post-Control Risk Assessment Results for the Commercial Sterilization Facilities Source Category
----------------------------------------------------------------------------------------------------------------
                                                                     Estimated       Estimated       Estimated
                                                      Maximum      population at   population at   annual cancer
             Control option scenario                individual    increased risk  increased risk     incidence
                                                    cancer risk   of cancer >100- of cancer >=1-    (cases per
                                                  (in-1-million)   in-1 million    in-1 million        year)
----------------------------------------------------------------------------------------------------------------
Option 1........................................             400             ~33   \1\ 1,290,000         \1\ 0.2
Option 2........................................             100               0   \1\ 1,260,000         \1\ 0.1
----------------------------------------------------------------------------------------------------------------
\1\ These values may be lower because the proposed Group 1 room air emission standards were not applied or
  accounted for in the risk assessment.

    Control Option 1 reduces the MIR from 3,000-in-1 million to 400-in-
1-million. The total number of facilities posing cancer risks greater
than 100-in-1 million would drop from 13 facilities at baseline after
emission reductions under CAA sections 112(d)(2), 112(d)(3), and
112(d)(5) to 3 facilities (two in Puerto Rico and one in Utah). We note
that 1 of those 3 facilities would be subject to the proposed Group 1
room air emission standards that were not included in the risk
assessment and its risks would be below 100-in-1 million (but it would
not impact the source category MIR). Additionally, the baseline
population exposed to risk levels greater than 100-in-1 million would
be reduced from 2,350 people to approximately 33 people. The total
population exposed to risk levels greater than or equal to 1-in-1
million living within 50 km of a facility would be reduced from 3.2
million people to 1.29 million people. The total estimated cancer
incidence of 0.9 drops to 0.2 excess cancer cases per year in Control
Option 1. We note that the populations at risk levels greater than or
equal to 1-in-1 million and the cancer incidence may be lower because
the proposed Group 1 room air emission standards were not applied or
accounted for in the risk assessment. Control Option 2 further reduces
the MIR to 100-in-1million, with no facilities or populations at risk
levels greater than 100-in-1 million. The total population exposed to
risk levels greater than or equal to 1-in-1 million living with 50 km
of a facility would be further reduced to 1.26 million people. Finally,
in Control Option 2, the total estimated cancer incidence would be
further reduced to 0.1 excess cancer cases per year. Again, the
populations at risk levels greater than or equal to 1-in-1 million and
the cancer incidence may be lower because the risk assessment did not
account for the proposed Group 1 room air emission standards.
    In summary, both Control Options 1 and 2 would provide significant
health benefits by reducing the cancer MIR from 3,000-in-1 million in
the baseline after emission reductions under CAA sections 112(d)(2),
112(d)(3), and 112(d)(5) to 400-in-1 million in Control Option 1 and to
100-in-1 million in Control Option 2. That said, as noted earlier in
this section, the EPA considers an MIR of ``approximately 1-in-10
thousand'' to be the presumptive limit of acceptability (54 FR 38045,
September 14, 1989). Therefore, because Control Option 2 provides an
MIR at the presumptive limit of 1-in-10 thousand (or 100-in-1 million),
we are proposing that Control Option 2 reduces risks to an acceptable
level. We expect that 40 facilities will be affected by the proposed
standards of Control Option 2, 36 of these 40 facilities will be
subject to the SCV provisions, and all of these 40 facilities are
expected to be subject to the provisions for Group 2 room air
emissions. We solicit comment on the proposed requirements for SCVs and
Group 2 room air emissions, including whether we should apply the
limits on volumetric flow rate and EtO concentration at facilities
where MIR is greater than 100-in-1 million after implementation of
Control Option 1 to all Group 2 room air emissions at facilities where
EtO use is at least 20 tpy (Comment C-36). In addition, for the same
reason discussed above in section III.B.1.a, we solicit comment on
whether to include an alternative lb/hr limit that is equivalent to
99.94 percent emission reduction for SCVs at facilities where EtO use
is at least 40 tpy and whether 3.1E-3 lb/hr, which we calculated using
the method described in section III.B.1.a, is an appropriate
alternative standard that is equivalent to the proposed 99.94 percent
emission reduction standard for SCVs at facilities where EtO use is at
least 40 tpy (Comment C-37). We also solicit comment on whether we
should determine that Control Option 1 would reduce risks to an
acceptable level, because, while the MIR is 400-in-1 million, the
population exposed to risk levels above 100-in-1 million is low (~33
people) and the population exposed to risks >=1-in-1 million is similar
to Control Option 2 (1,290,000 people in Control Option 1 and 1,260,000
people in Control Option 2) (Comment C-38).
2. Ample Margin of Safety
    The second step in the residual risk decision framework is
determination of whether the emission standards proposed to achieve an
acceptable risk level would protect public health with an ample margin
of safety, or whether more stringent emission standards would be
required. In making this determination, we considered the estimate of
health risk and other health information, along with additional factors
relating to the appropriate level of control, including costs and
economic impacts of controls, technological feasibility, uncertainties,
and other relevant factors, consistent with the approach of the 1989
Benzene NESHAP.
    As discussed in the previous section, SCVs and Group 2 room air
emissions

are the primary contributors to risks. At step 1 of our review of
residual risks under section 112(f), we determined that more stringent
standards for SCVs at facilities with EtO usage of at least 40 tpy and
Group 2 room air emissions at area source facilities with EtO usage of
at least 20 tpy are necessary to reduce risks to an acceptable level.
For step 2 of our review of residual risks, which requires EPA to
evaluate whether more stringent standards are necessary to provide an
ample margin of safety to protect public health, we considered
additional options to further reduce emissions from SCVs and Group 2
room air emissions.
    Table 22 of this preamble presents the summary of costs and EtO
emission reductions we estimated for the control options we considered,
which are described immediately following the table. For details on the
assumptions and methodologies used in the costs and impacts analyses,
see the technical memorandum titled Technical Support Document for
Proposed Rule--Industry Profile, Review of Unregulated Emissions, CAA
Section 112(d)(6) Technology Review, and CAA Section 112(f) Risk
Assessment for the Ethylene Oxide Emissions Standards for Sterilization
Facilities NESHAP, which is available in the docket for this
rulemaking.

     Table 22--Nationwide Emission Reductions and Cost Impacts of Control Options Considered for Commercial
                         Sterilization Facilities in the Ample Margin of Safety Analysis
----------------------------------------------------------------------------------------------------------------
                                                                      Total       EtO emission         Cost
                 Control option                   Total capital    annualized      reductions     effectiveness
                                                 investment ($)   costs ($/yr)        (tpy)        ($/ton EtO)
----------------------------------------------------------------------------------------------------------------
A--99.94 percent emission reduction requirement        $737,689        $266,687            0.17       $1,531,726
 for SCVs at facilities where EtO use is at
 least 10 tpy but less than 40 tpy.............
B--99.6 percent emission reduction requirement                0               0               0              N/A
 for SCVs at facilities where EtO use is at
 least 10 tpy but less than 40 tpy (prevent
 backsliding)..................................
C--99.8 percent emission reduction requirement           92,211          34,939          1.8E-2        1,947,753
 for SCVs at facilities where EtO use is at
 least 1 tpy but less than 10 tpy..............
D--99.2 percent emission reduction requirement                0               0               0              N/A
 for SCVs at facilities where EtO use is at
 least 1 tpy but less than 10 tpy (prevent
 backsliding)..................................
E--99.3 percent emission reduction requirement          368,845          92,295          3.4E-2        2,724,634
 for SCVs at facilities where EtO use is less
 than 1 tpy....................................
F--Limit Group 2 room air emissions to a             28,542,825       2,861,119            1.52        1,883,935
 maximum volumetric flow rate of 2,900 dscfm
 and a maximum EtO concentration of 30 ppbv \1\
G--Existing Group 2 room air emission limit of       98,400,887      10,648,525          5.5E-2      194,111,365
 2.8E-3 lb/hr at area source facilities where
 EtO use is less than 20 tpy...................
----------------------------------------------------------------------------------------------------------------
\1\ As discussed later in this section, these costs only include PTE and do not include the costs of upgrades
  and changes needed to maintain personnel safety or potential revenue losses from a reduced capacity to
  sterilize product.

    As mentioned earlier, available performance data show controls for
reducing SCV emissions have much improved. We therefore consider
potential options to further reduce SCV emissions. We considered two
options for SCVs at facilities where EtO use is at least 10 tpy but
less than 40 tpy (Control Options A and B). Under Control Option A, we
considered 99.94 percent emission reduction for SCVs at facilities
where EtO use is at least than 10 tpy but less than 40 tpy. This is the
same limit as that we are proposing for all facilities where EtO use is
at least 40 tpy in order to bring the source category risk to an
acceptable level. Under Control Option B, we considered the maximum SCV
emission reduction that all facilities where EtO use is at least 10 tpy
but less than 40 tpy are currently meeting. This emission reduction is
99.6 percent. We also considered two options for SCVs at facilities
where EtO use is at least 1 tpy but less than 10 tpy (Control Options C
and D). Under Control Option C, we considered the maximum SCV emission
reduction with which compliance can be demonstrated \46\ at all
facilities where EtO use is at least 1 tpy but less than 10 tpy
considering current emission profiles. This emission reduction is 99.8
percent. Under Control Option D, we considered the maximum SCV emission
reduction that all facilities where EtO use is at least 1 tpy but less
than 10 tpy are currently meeting. This emission reduction is 99.2
percent. We identified one option for SCVs at facilities where EtO use
is less than 1 tpy. Specifically, under Control Option E, we considered
the maximum SCV emission reduction for which compliance can be
demonstrated at all facilities where EtO use is less than 1 tpy
considering current emission profiles. This emission reduction is 99.3
percent. The ample margin of safety analysis for these options is
discussed below.
---------------------------------------------------------------------------

    \46\ i.e., Based on facility characteristics, there is no
compliance demonstration issue because the required EtO
concentration to meet this limit would be at or above 30 ppbv (3 x
RDL).
---------------------------------------------------------------------------

    As mentioned above, Control Options A and B address SCVs at
facilities where EtO use is at least 10 tpy but less than 40 tpy. For
Control Option A, which would require 99.94 percent emission reduction
for SCVs at all facilities where EtO use is at least 10 tpy but less
than 40 tpy, we found a total capital cost of $737,689 and a total
annualized cost of $266,687. The estimated EtO emissions reductions are
0.17 tpy with a cost effectiveness of $1,531,726 per ton of EtO. While
we do not know what the full extent of risk reductions would be, we
expect that some risk reduction would occur as a result of reduced EtO
emissions.
    Control Option B would require 99.6 percent emission reduction
(reflecting the maximum reduction that all facilities within this EtO
usage amount are meeting). While there would be no costs, there would
also be no further reductions in emissions and in turn no further
reductions in risks; at best Option B would simply prevent backsliding
in the performance of current SCV emission controls at these
facilities. In light of the above, we believe that Option A would be a
better choice than Option B for further reducing emissions from SCVs at
facilities where EtO use is at least 10 tpy but less than 40 tpy.

    Control Options C and D address SCVs at facilities where EtO use is
at least 1 tpy but less than 10 tpy. For Control Option C, which would
require 99.8 percent emission reduction (reflecting the maximum
reduction with which compliance can be demonstrated at all facilities
where EtO use is at least 1 tpy but less than 10 tpy), we determined a
total capital cost of $92,211 and a total annualized cost of $34,939.
The estimated EtO emissions reductions are 1.8E-2 tpy with a cost
effectiveness of $1,947,753 per ton of EtO. While we do not know what
the full extent of risk reductions would be, we expect that some risk
reduction would occur as a result of reduced EtO emissions.
    Control Option D would require 99.2 percent emission reduction
(reflecting the maximum reduction that all facilities within this EtO
usage amount are meeting). While there would be no costs, there would
also be no reductions in emissions and in turn no reductions in risks;
at best Option D would simply prevent backsliding in the performance of
current SCV emission controls at these facilities. In light of the
above, we believe that Option C would be a better choice than Option D
for further reducing emissions from SCVs at facilities where EtO use is
at least 1 tpy but less than 10 tpy.
    Control Option E addresses SCVs at facilities where EtO use is less
than 1 tpy. Specifically, Control Option E would require that these
facilities reduce emissions from each SCV by 99.3 percent (the maximum
emission reduction with which compliance can be demonstrated at all
facilities using less than 1 tpy). We expect that some risk reduction
would occur as a result of reduced EtO emissions but do not know what
the full extent of risk reductions would be. The costs were found to be
a $368,845 total capital investment and a $92,295total annualized cost.
The estimated EtO emissions reductions are 3.4E-2 tpy with a cost
effectiveness of $2,724,634 per ton of EtO. Our established methodology
for assessing economic impacts of regulations indicates that the
potential for adverse economic impacts begins when the cost to sales
ratio exceeds five percent. Considering Control Option E, along with
the standards that we have proposed up to this point, the cost to sales
ratio for one company operating a facility where EtO use is less than 1
tpy would be 11 percent, far exceeding our estimated five percent at
which point the potential for adverse economic impacts begins. Based on
the available economic information, assuming market conditions remain
approximately the same, we are concerned that this company would not be
able to sustain the costs associated with any additional control
requirements.
    We consider two potential options to further reduce Group 2 room
air emissions (Control Options F and G). Under Control Option F, Group
2 room air emissions would be limited to a maximum volumetric flow rate
of 2,900 dscfm and a maximum EtO concentration of 30 ppbv at all
facilities. These are the same limits as that we are proposing for
facilities where MIR is greater than 100-in-1 million after
implementation of Control Option 1 in order to bring the source
category risk to an acceptable level.\47\ Under Control Option G,
existing Group 2 room air emissions would be limited to 2.8E-3 lb/hr at
area source facilities where EtO use is less than 20 tpy. This is the
same limit as that we are proposing for all facilities where EtO use is
at least 20 tpy (except for facilities where MIR is greater than 100-
in-1 million after implementation of Control Option 1) to bring the
source category risk to an acceptable level. The ample margin of safety
analysis for these options is discussed below.
---------------------------------------------------------------------------

    \47\ As explained in section III.C.1, reducing the source
category risk to an acceptable level would require a separate and
more stringent standard for these two facilities.
---------------------------------------------------------------------------

    Under Control Option F, which would require that Group 2 room air
emissions be limited to a maximum volumetric flow rate of 2,900 dscfm
and a maximum EtO concentration of 30 ppbv at all facilities, we were
unable to fully estimate costs because it is unknown how this would
affect operations. As discussed in section III.C.1.a, if both the
volumetric flow rate and EtO concentration are restricted, there are at
least two potential outcomes. One outcome is that a facility could keep
the volume of the enclosure constant but restrict the number of RACs
per hour. This could potentially result in an increase in EtO
concentration within the enclosure. In order to maintain personnel
safety, significant upgrades and changes may need to be made, which
could require significant costs. Another outcome is that the facility
could keep the number of RACs per hour constant but restrict the volume
of the enclosure. While both outcomes could result in potential costs
savings from reduced air handling, this may be offset by a loss a
revenue from a reduced capacity to sterilize product. This could also
impact the supply of medical devices. We did not consider this a viable
option in light of the potentially adverse safety, production capacity,
and cost implications of this option as described above.
    Under Control Option G, which would limit Group 2 room air emission
to 2.8E-3 lb/hr at area source facilities where EtO use is less than 20
tpy \48\ costs were found to be a $98,400,887 total capital investment
and a $10,648,525 total annualized cost. The estimated EtO emissions
reductions are 5.5E-2 tpy with a cost effectiveness of $194,111,365 per
ton of EtO. While we do not know what the full extent of risk
reductions would be, we expect that some risk reduction would occur as
a result of reduced EtO emissions. However, the cost to sales ratio for
three companies operating three facilities where EtO use is less than
20 tpy would range from 17 to 56 percent, far exceeding our estimated
five percent at which point the potential for adverse economic impacts
begins. Based on the available economic information, assuming market
conditions remain approximately the same, we are concerned that these
companies would not be able to sustain the costs associated with any
additional control requirements.
---------------------------------------------------------------------------

    \48\ This is the proposed MACT standard for Group 2 room air
emissions at major sources; it is also our proposed standard for
Group 2 room air emissions at area source facilities where EtO usage
is at least 20 tpy.
---------------------------------------------------------------------------

    Based on our ample margin of safety analysis, including all health
information and the associated cost and feasibility as discussed above,
we propose that requiring the standards that based on our analysis
would bring risks to an acceptable level, along with Control Options A
and C here in the present analysis, would provide an ample margin of
safety to protect public health. These standards, which we are
proposing under the AMOS analysis, consist of 99.94 percent reduction
for SCVs at facilities where EtO use is at least 10 tpy but less than
40 tpy, as well as 99.8 percent emission reduction for SCVs at
facilities where EtO use is at least 1 tpy but less than 10 tpy. We are
soliciting comment on our proposed determination, including whether
Control Options B, D, E, F, or G would provide an ample margin of
safety to protect public health. (Comment C-39). In addition, for the
same reason discussed above in section III.B.1.a, we solicit comment on
whether to include an alternative lb/hr limit that is equivalent to
99.94 percent emission reduction for SCVs at facilities where EtO use
is at least 10 tpy but less than 40 tpy, and whether 1.2E-3 lb/hr for
existing sources and 1.0E-3 lb/hr for new sources, which we calculated
using

the method described in section III.B.1.a, are appropriate alternative
standards that are equivalent to the proposed 99.94 percent emission
reduction standard for SCVs at facilities where EtO use is at least 10
tpy but less than 40 tpy. Similarly, we solicit comment on whether to
include alternative lb/hr limits that are equivalent to 99.8 percent
emission reduction for SCVs at facilities where EtO use is at least 1
tpy but less than 10 tpy, and whether 7.2E-4 lb/hr for existing sources
and 5.5E-4 lb/hr for new sources, which we calculated using the method
described in section III.B.1.a, are appropriate alternative standards
that are equivalent to the proposed 99.8 percent emission reduction
standard for SCVs at facilities where EtO use is at least 1 tpy but
less than 10 tpy (Comment C-40).
3. Environmental Effects
    The emissions data indicate that no environmental HAP are emitted
by sources within this source category. In addition, we are unaware of
any adverse environmental effects caused by HAP emitted by this source
category. Therefore, we do not expect there to be an adverse
environmental effect as a result of HAP emissions from this source
category and we are proposing that it is not necessary to set a more
stringent standard to prevent, taking into consideration costs, energy,
safety, and other relevant factors, an adverse environmental effect.
4. Summary of Proposed Standards
    Pursuant to CAA sections 112(d)(2), 112(d)(3), and 112(d)(5), we
are proposing standards for a number of currently unregulated EtO
emission sources at commercial sterilizers.\49\ The EPA also conducted
a section 112(f)(2) analysis. For that analysis, the EPA conducted a
baseline risk assessment that took into account the implementation of
the current standards in subpart O as well as the proposed 112(d)
standards for the currently unregulated emission sources discussed here
in section III.B. Having proposed to determine that the risk is
unacceptable for the source category, the EPA is proposing under
section 112(f)(2) standards, including tightening certain proposed
section 112(d) standards, to bring the risk from this source category
to an acceptable level and provide ample margin of safety to protect
public health. Table 23 summarizes the proposed section 112(d) and
112(f)(2) standards.
---------------------------------------------------------------------------

    \49\ In addition, we are proposing a correction to the current
standard under 112(d) for ARV at facilities with EtO usage >=10 tpy.

  Table 23--Summary of Standards After Taking Actions Pursuant to CAA Sections 112(d)(2), 112(d)(3), 112(d)(5),
                                                  and 112(f)(2)
----------------------------------------------------------------------------------------------------------------
         Emission source           Existing or new?         EtO use            Standards          CAA section
----------------------------------------------------------------------------------------------------------------
SCV.............................  Existing..........  At least 40 tpy...  99.94 percent       112(f)(2).
                                                                           emission
                                                                           reduction.
                                                      At least 10 tpy     99.94 percent       112(f)(2).
                                                       but less than 40    emission
                                                       tpy.                reduction.
                                                      At least 1 but      99.8 percent        112(f)(2).
                                                       less than 10 tpy.   emission
                                                                           reduction.
                                                      Less than 1 tpy...  99 percent          112(d)(5).
                                                                           emission
                                                                           reduction.
                                  New...............  At least 40 tpy...  99.94 percent       112(f)(2).
                                                                           emission
                                                                           reduction.
                                                      At least 10 tpy     99.94 percent       112(f)(2).
                                                       but less than 40    emission
                                                       tpy.                reduction.
                                                      At least 1 but      99.8 percent        112(f)(2).
                                                       less than 10 tpy.   emission
                                                                           reduction.
                                                      Less than 1 tpy...  99 percent          112(d)(5).
                                                                           emission
                                                                           reduction.
ARV.............................  Existing..........  At least 10 tpy...  99 percent          112(f)(2).
                                                                           emission
                                                                           reduction.
                                                      At least 1 but      99 percent          112(d)(5).
                                                       less than 10 tpy.   emission
                                                                           reduction.
                                                      Less than 1 tpy...  99 percent          112(d)(5).
                                                                           emission
                                                                           reduction.
                                  New...............  At least 10 tpy...  99 percent          112(f)(2).
                                                                           emission
                                                                           reduction.
                                                      At least 1 but      99 percent          112(d)(5).
                                                       less than 10 tpy.   emission
                                                                           reduction.
                                                      Less than 1 tpy...  99 percent
                                                                           emission
                                                                           reduction.
CEV.............................  Existing..........  At least 10 tpy...  3.2E-4 lb/hr......  112(d)(2) and (3).
                                                      At least 1 but      99 percent          112(d)(5).
                                                       less than 10 tpy.   emission
                                                                           reduction.
                                                      Less than 1 tpy...  99 percent          112(d)(5).
                                                                           emission
                                                                           reduction.
                                  New...............  At least 10 tpy...  3.2E-4 lb/hr......  112(d)(2) and (3).
                                                      At least 1 but      99 percent          112(d)(5).
                                                       less than 10 tpy.   emission
                                                                           reduction.
                                                      Less than 1 tpy...  99 percent          112(d)(5).
                                                                           emission
                                                                           reduction.
Group 1 room air emissions at     Existing and new..  N/A...............  1.3E-3 lb/hr \1\..  112(d)(2) and (3).
 major sources.
Group 1 room air emissions at     Existing and new..  N/A...............  1.3E-3 lb/hr \1\..  112(d)(5).
 area sources.
Group 2 room air emissions at     Existing and new..  N/A...............  2.8E-3 lb/hr \1\..  112(d)(2) and (3).
 major sources.
Group 2 room air emissions at     Existing..........  At least 20 tpy...  2.8E-3 lb/hr \1\    112(f)(2).
 area sources.                                                             \2\.
                                                      Less than 20 tpy..  Follow either the   112(d)(5).
                                                                           Cycle Calculation
                                                                           Approach or the
                                                                           Bioburden/
                                                                           Biological
                                                                           Indicator
                                                                           Approach to
                                                                           achieve sterility
                                                                           assurance in
                                                                           accordance with
                                                                           ISO 11135:2014
                                                                           (July 15, 2014)
                                                                           and ISO 11138-
                                                                           1:2017 (March
                                                                           2017) \3\.
                                  New...............  N/A...............  2.8E-3 lb/hr \1\..  112(d)(5).
----------------------------------------------------------------------------------------------------------------
\1\ We are also proposing to require each facility to operate areas with these emissions in accordance with the
  PTE requirements of EPA Method 204 of appendix M to 40 CFR part 51.

\2\ Facilities where MIR is greater than 100-in-1 million after implementation of Control Option 1 must instead
  limit the total volumetric flow rate of exhaust streams that contain Group 2 room air emissions to a maximum
  of 2,900 dscfm at each facility, and the EtO concentration of these streams must not exceed 30 ppbv.
\3\ Owners and operators may also apply for an alternative means of emission limitation under CAA section
  112(h)(3).

E. What environmental justice analysis did we conduct?

    Consistent with the EPA's commitment to integrating EJ in the
Agency's actions, and following the directives set forth in multiple
Executive orders, the Agency has carefully considered the impacts of
this action on communities with EJ concerns. Overall, the results of
the proximity demographic analysis (see first three columns of Table
24) indicate that the percent of the population living within 10 km of
the 97 facilities that is Hispanic or Latino is substantially higher
than the national average (34 percent versus 19 percent), driven
largely by the seven facilities in Puerto Rico. The baseline proximity
analysis indicates that the proportion of other demographic groups
living within 10 km of commercial sterilizers is closer to the national
average. The baseline risk-based demographic analysis (see ``baseline''
column in Tables 24 to 26), which focuses on those specific locations
that are expected to have higher cancer risks (greater than or equal to
1-in-1 million, greater than or equal to 50-in-1 million, and greater
than 100-in-1 million), suggests that African Americans are
disproportionally represented at the higher risk levels. The post-
control risk-based demographic analysis focuses on how the options
considered in this proposed regulatory action would affect the
distribution of risks within the population identified in the baseline.
The CAA section 112(d)(2), (3), and (5) post-control scenario is shown
in Tables 24 to 26 and the residual risk post-control options are shown
in Tables 27 to 29. The post-control options show a substantial
reduction in the number of individuals at each risk level, as well as a
significant reduction in the proportion of African Americans that
experience higher risk levels from facilities in this source category.
EPA projects that a majority of the individuals that would remain at
risk after implementation of the proposed standards is Hispanic or
Latino, driven largely by the facilities in Puerto Rico. These three
distinct but complementary analyses indicate the potential for EJ
concerns associated with this source category in the baseline, as well
as the substantial benefits these proposed standards would have in
reducing EtO emissions and associated health risks in communities with
EJ concerns. For more details see the remainder of this section.
    Executive Order 12898 directs EPA to identify the populations of
concern who are most likely to experience unequal burdens from
environmental harms, which are specifically minority populations
(people of color), low-income populations, and indigenous peoples (59
FR 7629, February 16, 1994). Additionally, Executive Order 13985 is
intended to advance racial equity and support underserved communities
through Federal Government actions (86 FR 7009, January 20, 2021). The
EPA defines EJ as ``the fair treatment and meaningful involvement of
all people regardless of race, color, national origin, or income, with
respect to the development, implementation, and enforcement of
environmental laws, regulations, and policies.'' \50\ The EPA further
defines fair treatment to mean that ``no group of people should bear a
disproportionate burden of environmental harms and risks, including
those resulting from the negative environmental consequences of
industrial, governmental, and commercial operations or programs and
policies.'' In recognizing that people of color and low-income
populations often bear an unequal burden of environmental harms and
risks, the EPA continues to consider ways of protecting them from
adverse public health and environmental effects of air pollution. For
purposes of analyzing regulatory impacts, the EPA relies upon its June
2016 ``Technical Guidance for Assessing Environmental Justice in
Regulatory Analysis,'' \51\ which provides recommendations that
encourage analysts to conduct the highest quality analysis feasible,
recognizing that data limitations, time, resource constraints, and
analytical challenges will vary by media and circumstance. The
Technical Guidance states that a regulatory action may involve
potential EJ concerns if it could: (1) Create new disproportionate
impacts on minority populations, low-income populations, and/or
Indigenous peoples; (2) exacerbate existing disproportionate impacts on
minority populations, low-income populations, and/or Indigenous
peoples; or (3) present opportunities to address existing
disproportionate impacts on minority populations, low-income
populations, and/or Indigenous peoples through this action under
development.
---------------------------------------------------------------------------

    \50\ https://www.epa.gov/environmentaljustice.
    \51\ See https://www.epa.gov/environmentaljustice/technical-guidance-assessing-environmental-justice-regulatory-analysis.
---------------------------------------------------------------------------

    For this proposal, the EPA examined the potential for the 97
facilities that were assessed to pose concerns to EJ communities both
in the baseline and under the control options considered in this
proposal. Specifically, the EPA analyzed how demographics and risk are
distributed both pre- and post-control, enabling us to address the core
questions that are posed in the EPA's 2016 Technical Guidance for
Assessing Environmental Justice in Regulatory Analysis. In conducting
this analysis, we considered key variables highlighted in the guidance
including ``minority populations (people of color and Hispanic or
Latino), low-income populations, and/or indigenous peoples''. The
methodology and detailed results of the demographic analysis are
presented in a technical report, Analysis of Demographic Factors for
Populations Living Near Ethylene Oxide Commercial Sterilization and
Fumigation Operations, available in the docket for this action.
    To examine the potential for EJ concerns in the pre-control
baseline, the EPA conducted two baseline demographic analyses, a
proximity analysis and a risk-based analysis. The baseline proximity
demographic analysis is an assessment of individual demographic groups
in the total population living within 10 kilometers (km) and 50 km of
the facilities. In this preamble, we focus on the 10 km radius for the
demographic analysis because it encompasses all the facility MIR
locations and captures 100 percent of the population with risks greater
than 100-in-1 million. The results of the proximity analysis for
populations living within 50 km are included in the technical report
included in the docket for this proposed rule.
    The baseline risk-based demographic analysis is an assessment of
risks to individual demographic groups in the population living within
the 10 km and 50 km radii around the facilities prior to the
implementation of any controls proposed by this action (``baseline'').
Again, in this preamble, we focus on the results for populations living
within 10 km of facilities. Results for populations living within 50 km
are included in the technical report included in the docket for this
proposed rule.

1. Demographics
    The first three columns of Tables 24, 25, and 26 of this document
show the total population, population percentages, and population count
for each demographic group for the nationwide population and the total
population living within 10 km of EtO sterilization facilities. A total
of 19.4 million people live within 10 km of the 97 facilities that were
assessed. The results of the proximity demographic analysis indicate
that the percent of the population that is Hispanic or Latino is
substantially higher than the national average (34 percent versus 19
percent), driven by the seven facilities in Puerto Rico, where an
average of 99 percent of the 658,000 people living within 10 km of the
facilities are Hispanic or Latino. The percent of the population that
is ``Other and multiracial'' (13 percent) is higher than the national
average (8 percent). The percentages of the population that are African
American (13 percent) or Native American (0.3 percent) are similar to
or less than the national averages (12 percent and 0.7 percent,
respectively). The percent of people living below the poverty level (14
percent) and those over the age of 25 without a high school diploma (15
percent) are higher than the national averages (13 percent and 12
percent, respectively). The percent of people living in linguistic
isolation is double the national average (10 percent versus 5
percent).\52\ However, we note that this estimate of linguistic
isolation is largely driven by the facilities in Puerto Rico, where an
average of 67 percent of the population is in linguistic isolation in
comparison to the national average.
---------------------------------------------------------------------------

    \52\ Linguistic Isolation is defined in the U.S. Census Bureau's
American Community Survey as ``a household in which all members age
14 years and over speak a non-English language and also speak
English less than ``very well'' (have difficulty with English).''
---------------------------------------------------------------------------

    In summary, the baseline proximity analysis indicates that the
percent of Hispanic or Latino populations living near commercial
sterilizers (within 10 km) is higher than what would be expected based
on the national average distribution. This is largely driven by the
seven facilities located in Puerto Rico where, on average, the
population of 658,000 people living within 10 km of these seven
facilities is 99 percent Hispanic or Latino. In addition, the
population around the facilities in Puerto Rico has 67 percent living
in linguistic isolation, 45 percent living below the poverty level, and
24 percent over 25 without a high school diploma.
2. Baseline Risk-Based Demographics
    The baseline risk-based demographic analysis results are shown in
the ``baseline'' column of Tables 24, 25, and 26. This analysis focused
on the populations living within 10 km of the facilities with estimated
cancer risks greater than or equal to 1-in-1 million (Table 24),
greater than or equal to 50-in-1 million (Table 25), and greater than
100-in-1 million (Table 26). The risk analysis indicated that emissions
from the source category, prior to the reductions we are proposing,
expose a total of 5.3 million people to a cancer risk greater than or
equal to 1-in-1 million around 78 facilities, 119,000 people to a
cancer risk greater than or equal to 50-in-1 million around 42
facilities, and 18,000 people to a cancer risk greater than 100-in-1
million around 16 facilities. The demographics of the baseline
population with estimated cancer risks greater than or equal to 1-in-1
million are very similar to the total population within 10 km.
Specifically, the percent of the population that is Hispanic or Latino
is significantly above the national average (38 percent versus 19
percent), the percent below the poverty level is above national average
(16 percent versus 13 percent), the percent over 25 without a high
school diploma is above the national average (18 percent versus 12
percent), and the percent linguistic isolation is two times the
national average (11 percent versus 5 percent). In contrast, the
smaller populations with baseline cancer risk greater than or equal to
50-in-1 million (119,000 people) and >100-in-1 million (18,000 people)
are predominantly made up of African Americans (45 and 34 percent
versus 12 percent nationally), have a higher percentage of the
population below the poverty level (22 and 23 percent versus 13 percent
nationally), the percent over 25 without a high school diploma is above
the national average (17 and 16 percent versus 12 percent) and
linguistic isolation is above the national average (7 and 10 percent
versus 5 percent). This shows that risks tend to be higher where more
African American residents reside and where poverty is higher than in
the rest of the area within 10 km. It should be noted that, the higher
percentage African American population with baseline cancer risk
greater than or equal to 50-in-1 million is driven largely by seven
facilities that have African American populations that are between two
and eight times the national average. The higher percentage African
American population with baseline cancer risk greater than 100-in-1
million is driven largely by three facilities that are located in
communities where the proportion of African American residents is
between 2.5 and 8 times the national average. The population with
higher baseline cancer risks living within 10 km of the facilities
consists of a substantially smaller percentage of Hispanic or Latino
(18 and 19 percent) than the total population living within 10 km (34
percent Hispanic or Latino) and is near the national average (19
percent).
    In summary, the baseline risk-based demographic analysis, which
focuses on those specific locations that are expected to have higher
cancer risks, suggests that African Americans are the one demographic
group disproportionally represented where risk is highest. The
population with risks greater than 100-in-1 million living within 10 km
of a commercial sterilizer has a significantly higher proportion of
African Americans (34 percent) than the national average (12 percent).
3. Risk-Based Demographics Considering Standards Under CAA Sections
112(d)(2), (3), and (5)
    This analysis focused on the populations living within 10 km of the
facilities with estimated cancer risks greater than or equal to 1-in-1
million (Table 24), greater than or equal to 50-in-1 million (Table
25), and greater than 100-in-1 million (Table 26) after implementation
of standards that we are proposing under CAA sections 112(d)(2), (3),
and (5). The results of our analysis of risk-based demographics
considering standards under CAA sections 112(d)(2), (3), and (5) are
shown in the last column of Tables 24, 25, and 26 titled ``Baseline and
CAA Section 112(d)(2), (3), and (5).'' In this analysis we evaluated
how the proposed CAA sections 112(d)(2), (3), and (5) emission
reductions in this proposed regulatory action affect the distribution
of risks identified in the baseline. This enables us to characterize
the post-control risks and to evaluate whether the proposed action
creates or mitigates potential EJ concerns as compared to the baseline.
Note that as described in section III.C, the risk results in this
scenario were based on requiring BMP (Option 2) under section 112(d)(5)
for Group 1 room air emissions, instead of the proposed emission limit
reflecting use of control devices (Option 1). Therefore, the
populations at the various risk levels may be lower than reported here
(and the demographics slightly different).
    The risk analysis indicated that the emissions from the source
category, after implementation of the emissions reductions we are
proposing under CAA

section 112(d), reduces the number of people living within 10 km of a
facility and with a cancer risk greater than or equal to 1-in-1 million
from 5.3 million people around 78 facilities to 2.6 million people
around 73 facilities, reduces the number of people living within 10 km
of a facility and with a cancer risk greater than or equal to 50-in-1
million from 119,000 people around 42 facilities to 19,000 people
around 20 facilities, and reduces the number of people living within 10
km of a facility and with a cancer risk greater than 100-in-1 million
from 18,000 people around 16 facilities to 2,350 people around 13
facilities.
    The demographics of the population with estimated cancer risks
greater than or equal to 1-in-1 million considering the standards we
are proposing under CAA section 112(d) are very similar to both the
total population within 10 km and to the baseline population with risks
greater than or equal to 1-in-1 million. Specifically, the percent of
the population that is Hispanic or Latino is significantly above the
national average (32 percent versus 19 percent), the percent below the
poverty level is above national average (16 percent versus 13 percent),
the percent over 25 without a high school diploma is above the national
average (16 percent versus 12 percent), and the percent linguistic
isolation is two times the national average (10 percent versus 5
percent).
    After implementation of the standards we are proposing under CAA
section 112(d), the percentage and number of African Americans at
cancer risks greater than or equal to 50-in-1 million and greater than
100-in-1 million is significantly reduced. For example, African
Americans exposed to risks greater than 100-in-1 million went from 34
percent or 6,000 people in the baseline to 11 percent or 300 people
after implementation of the proposed technology review emissions
reductions. It should be noted that, the percentage of the population
that is Hispanic or Latino exposed to risks greater than 100-in-1
million went up from 18 percent in the baseline to 51 percent after the
proposed technology review emissions reductions. However, the number of
Hispanic or Latino people with risks greater than 100-in-1 million was
reduced from 3,000 to 1,200 people. Similarly, the percentage of the
population that are below the poverty level or are linguistically
isolated with a cancer risk greater than 100-in-1 million went up from
the baseline, but the number of people in these demographics decreased
significantly. For example, the proportion of the population with risks
greater than 100-in-1 million that were below the poverty level was
much higher than the baseline (34 percent versus 23 percent), but the
number of people was reduced from 4,000 people to 800 people.
    In summary, the proposed CAA section 112(d) standards significantly
reduced the number of people in all demographic groups that are exposed
to risks greater than or equal to 1-in-1 million, greater than and
equal to 50-in-1 million, and greater than 100-in-1 million.
Specifically, the percent of the population that is African American
who are at a cancer risk greater than or equal to 50-in-1 million and
greater than 100-in-1 million was reduced from about 40 percent in the
baseline to about 15 percent after the technology review controls. The
percentage of Hispanic or Latino people increased as the higher risk
facilities in Puerto Rico make-up an increasing portion of the
remaining populations with higher cancer risks.

      Table 24--Comparison of Baseline and CAA Section 112(d)(2), (3), and (5) Post-Control Demographics of
Populations With Cancer Risk Greater Than or Equal to 1-in-1 Million Living Within 10 km of Facilities That Were
                                                    Assessed
----------------------------------------------------------------------------------------------------------------
                                                                       Total       Cancer risk >=1-in-1 million
                                                                    population   -------------------------------
                Demographic group                   Nationwide     living within
                                                                   10 km of EtO      Baseline      Post-control
                                                                    facilities
----------------------------------------------------------------------------------------------------------------
Total Population................................            328M           19.4M            5.3M        \1\ 2.6M
Number of Facilities............................  ..............              97              78          \1\ 73
----------------------------------------------------------------------------------------------------------------
                                Race and Ethnicity by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
White...........................................       60 [197M]       40 [7.7M]       40 [2.1M]     \1\ 43 [1M]
African American................................        12 [40M]       13 [2.5M]       15 [780K]   \1\ 19 [480K]
Native American.................................        0.7 [2M]       0.3 [56K]       0.3 [16K]    \1\ 0.3 [7K]
Hispanic or Latino (includes white and nonwhite)        19 [62M]       34 [6.5M]         38 [2M]   \1\ 32 [840K]
Other and Multiracial...........................         8 [27M]       13 [2.6M]        7 [360K]    \1\ 6 [150K]
----------------------------------------------------------------------------------------------------------------
                                      Income by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............................        13 [44M]       14 [2.8M]       16 [800K]   \1\ 16 [400K]
Above Poverty Level.............................       87 [284M]      86 [16.6M]       84 [4.5M]   \1\ 84 [2.2M]
----------------------------------------------------------------------------------------------------------------
                                     Education by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Over 25 and without a High School Diploma.......        12 [40M]         15 [3M]       18 [900K]   \1\ 16 [400K]
Over 25 and with a High School Diploma..........       88 [288M]      85 [16.4M]       82 [4.4M]   \1\ 84 [2.2M]
----------------------------------------------------------------------------------------------------------------
                              Linguistically Isolated by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated.........................         5 [18M]         10 [2M]       11 [600K]   \1\ 10 [300K]
----------------------------------------------------------------------------------------------------------------
\1\ These values may be lower because the proposed Group 1 room air emission standards were not applied or
  accounted for in the risk assessment.
Notes:
 Nationwide population and demographic percentages are based on the Census Bureau's (Census) 2015-2019
  American Community Survey (ACS) 5-year block group averages. Total population count within 10 km is based on
  2010 Decennial Census block population.

 To avoid double counting, the ``Hispanic or Latino'' category is treated as a distinct demographic
  category. A person who identifies as Hispanic or Latino is counted as Hispanic or Latino, regardless of race.
 The number of facilities represents facilities with a cancer MIR above level indicated. When the MIR
  was located at a user assigned receptor at an individual residence and not at a census block centroid, we were
  unable to estimate population and demographics for that facility.
 The sum of individual populations with a demographic category may not add up to total due to rounding.

      Table 25--Comparison of Baseline and CAA Section 112(d)(2), (3), and (5) Post-Control Demographics of
  Populations With Cancer Risk Greater Than or Equal to 50-in-1 Million Living Within 10 km of Facilities That
                                                  Were Assessed
----------------------------------------------------------------------------------------------------------------
                                                                       Total       Cancer risk >=50-in-1 million
                                                                    population   -------------------------------
                Demographic group                   Nationwide     living within
                                                                   10 km of EtO      Baseline      Post-control
                                                                    facilities
----------------------------------------------------------------------------------------------------------------
Total Population................................            328M           19.4M         119,000      \1\ 19,000
Number of Facilities............................  ..............              97              42          \1\ 20
----------------------------------------------------------------------------------------------------------------
                                Race and Ethnicity by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
White...........................................       60 [197M]       40 [7.7M]        33 [39K]    \1\ 54 [10K]
African American................................        12 [40M]       13 [2.5M]        45 [54K]     \1\ 19 [4K]
Native American.................................        0.7 [2M]       0.3 [56K]       0.1 [200]  \1\ 0.1 [<100]
Hispanic or Latino (includes white and nonwhite)        19 [62M]       34 [6.5M]        19 [23K]     \1\ 25 [5K]
Other and Multiracial...........................         8 [27M]       13 [2.6M]          3 [4K]     \1\ 2 [400]
----------------------------------------------------------------------------------------------------------------
                                      Income by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............................        13 [44M]       14 [2.8M]        22 [26K]     \1\ 23 [4K]
Above Poverty Level.............................       87 [284M]      86 [16.6M]        78 [93K]    \1\ 77 [15K]
----------------------------------------------------------------------------------------------------------------
                                     Education by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Over 25 and without a High School Diploma.......        12 [40M]         15 [3M]         17 [8K]     \1\ 15 [2K]
Over 25 and with a High School Diploma..........       88 [288M]      85 [16.4M]       83 [111K]    \1\ 85 [17K]
----------------------------------------------------------------------------------------------------------------
                              Linguistically Isolated by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated.........................         5 [18M]         10 [2M]         7 [54K]     \1\ 13 [4K]
----------------------------------------------------------------------------------------------------------------
\1\These values may be lower because the proposed Group 1 room air emission standards were not applied or
  accounted for in the risk assessment.
Notes:
 Nationwide population and demographic percentages are based on Census' 2015-2019 ACS 5-year block group
  averages. Total population count within 10 km is based on 2010 Decennial Census block population.
 To avoid double counting, the ``Hispanic or Latino'' category is treated as a distinct demographic
  category. A person who identifies as Hispanic or Latino is counted as Hispanic or Latino, regardless of race.
 The number of facilities represents facilities with a cancer MIR above level indicated. When the MIR
  was located at a user assigned receptor at an individual residence and not at a census block centroid, we were
  unable to estimate population and demographics for that facility.
 The sum of individual populations with a demographic category may not add up to total due to rounding.
 To account for the uncertainty of demographics estimates in smaller populations, any population values
  of 100 persons or less have been shown simply as ``<100.''

      Table 26--Comparison of Baseline and CAA Section 112(d)(2), (3), and (5) Post-Control Demographics of
 Populations With Cancer Risk Greater Than 100-in-1 Million Living Within 10 km of Facilities That Were Assessed
----------------------------------------------------------------------------------------------------------------
                                                                       Total      Cancer risk >=100-in-1 million
                                                                    population   -------------------------------
                Demographic group                   Nationwide     living within
                                                                   10 km of EtO      Baseline      Post-control
                                                                    facilities
----------------------------------------------------------------------------------------------------------------
Total Population................................            328M           19.4M          18,000       \1\ 2,350
Number of Facilities............................  ..............              97              16          \1\ 13
----------------------------------------------------------------------------------------------------------------
                                Race and Ethnicity by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
White...........................................       60 [197M]       40 [7.7M]         45 [8K]    \1\ 37 [900]
African American................................        12 [40M]       13 [2.5M]         34 [6K]    \1\ 11 [300]
Native American.................................        0.7 [2M]       0.3 [56K]      0.1 [<100]           0 [0]
Hispanic or Latino (includes white and nonwhite)        19 [62M]       34 [6.5M]         18 [3K]   \1\ 51 [1.2K]
Other and Multiracial...........................         8 [27M]       13 [2.6M]         3 [500]    \1\ 1 [<100]
----------------------------------------------------------------------------------------------------------------

                                      Income by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............................        13 [44M]       14 [2.8M]         23 [4K]    \1\ 34 [800]
Above Poverty Level.............................       87 [284M]      86 [16.6M]        77 [14K]  \1\ 66 [1.55K]
----------------------------------------------------------------------------------------------------------------
                                     Education by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Over 25 and without a High School Diploma.......        12 [40M]         15 [3M]         16 [2K]    \1\ 17 [700]
Over 25 and with a High School Diploma..........       88 [288M]      85 [16.4M]        84 [15K]  \1\ 83 [1.65K]
----------------------------------------------------------------------------------------------------------------
                              Linguistically Isolated by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated.........................         5 [18M]         10 [2M]         10 [6K]    \1\ 31 [300]
----------------------------------------------------------------------------------------------------------------
\1\ These values may be lower because the proposed Group 1 room air emission standards were not applied or
  accounted for in the risk assessment.
Notes:
 Nationwide population and demographic percentages are based on Census' 2015-2019 ACS 5-year block group
  averages. Total population count within 10 km is based on 2010 Decennial Census block population.
 To avoid double counting, the ``Hispanic or Latino'' category is treated as a distinct demographic
  category. A person who identifies as Hispanic or Latino is counted as Hispanic or Latino, regardless of race.
 The number of facilities represents facilities with a cancer MIR above level indicated. When the MIR
  was located at a user assigned receptor at an individual residence and not at a census block centroid, we were
  unable to estimate population and demographics for that facility.
 The sum of individual populations with a demographic category may not add up to total due to rounding.
 To account for the uncertainty of demographics estimates in smaller populations, any population values
  of 100 persons or less have been shown simply as ``<100.''

4. Residual Risk Post-Control Risk-Based Demographics
    This analysis focused on the populations living within 10 km of the
facilities with estimated cancer risks greater than or equal to 1-in-1
million (Table 27), greater than or equal to 50-in-1 million (Table
28), and greater than 100-in-1 million (Table 29) after implementation
of the control options investigated under the residual risks analysis
as described in section III.D of this preamble. The demographic results
for the control options are in the columns titled ``Control Option 1''
and ``Control Option 2.'' One of these control options would be
implemented in addition to the CAA section 112(d)(2), (3), and (5)
post-control emissions reductions. Therefore, in this analysis, we
evaluated how all of the proposed controls and emission reductions
described in this action affect the distribution of risks. This enables
us to characterize the post-control risks and to evaluate whether the
proposed action creates or mitigates potential EJ concerns as compared
to the baseline. Again, as described in section III.C, the risk results
in this scenario were based on requiring BMP (Option 2) under section
112(d)(5) for Group 1 room air emissions, instead of the proposed
emission limit reflecting use of control devices (Option 1). Therefore,
the populations at the various risk levels may be lower than reported
here (and the demographics slightly different).
    The risk analysis indicated that the number of people exposed to
risks greater than or equal to 1-in-1 million within 10 km of a
facility (Table 27) is reduced from 2.6 million people after
implementation of the CAA section 112(d)(2), (3), and (5) controls to
approximately 1.15 million people after implementation of one of the
residual risk control options. This represents a significant reduction
(about 60 percent reduction) in the size of the populations at risk for
each of the three residual risk control options investigated when
compared to the populations after implementation of the technology
review controls. The populations with a cancer risk greater than or
equal to 1-in-1 million are located around 73 facilities for both post-
control options.
    The demographics of the post-control population living within 10 km
of a facility and with an estimated cancer risks greater than or equal
to 1-in-1 million for control options 1 and 2 (Table 27) are very
similar to the CAA section 112(d)(2), (3), and (5) post-control
population with risks greater than or equal to 1-in-1 million.
Specifically, the percent of the population that is Hispanic or Latino
is significantly above the national average (37 percent versus 19
percent), the percent below poverty is above national average (16
percent versus 13 percent), the percent over 25 without a high school
diploma is above the national average (16 percent versus 12 percent),
and the percent linguistic isolation is almost two times the national
average (9 percent versus 5 percent).
    The risk analysis indicated that the number of people living within
10 km of a facility and exposed to risks greater than or equal to 50-
in-1 million (Table 28) is reduced from 19,000 people after
implementation of the CAA section 112(d)(2), (3), and (5) controls to
1,400 to 2,000 people after implementation of one of the residual risk
control options. This represents a 90 percent reduction in the size of
the populations at risk for each of the three residual risk control
options investigated when compared to the populations after
implementation of the CAA section 112(d)(2), (3), and (5) controls. The
populations living within 10 km of a facility and with a cancer risk
greater than or equal to 50-in-1 million are located around 11
facilities for both post-control options.
    The demographics of the post-control population living within 10 km
of a facility and with estimated cancer risks greater than or equal to
50-in-1 million for control options 1 and 2 (Table 28)

are significantly different from the population after implementation of
the CAA section 112(d)(2), (3), and (5) controls. Specifically, the
percent of the population that is Hispanic or Latino is significantly
higher at 79 percent and 72 percent for control options 1 and 2,
respectively. This higher percentage is driven by three facilities in
Puerto Rico and one in Texas, for which the population is over 95
percent Hispanic or Latino. However, the number of Hispanic or Latino
people with risks greater than or equal to 50-in-1 million was reduced
by about 80 percent from 5,000 people to 1,600 and 1,000 people for
Option 1 and 2, respectively. Similarly, the percentage of the
population that is below the poverty level or linguistically isolated
went up from the CAA section 112(d)(2), (3), and (5) post-control
population, but the number of people in these demographics decreased
significantly.
    The risk analysis indicated that the number of people living with
10 km of a facility and exposed to risks greater than 100-in-1 million
(Table 29) is reduced from 2,350 people after implementation of the CAA
section 112(d)(2), (3), and (5) controls to 33 people for Option 1 and
to zero people for Option 2. For control Option 1, there are three
facilities with risks greater than 100-in-1 million. Two of these
facilities are located in Puerto Rico and one is in Utah.\53\ The
demographics in Table 29 are for one of the facilities in Puerto Rico.
For the other two facilities, the MIR was located at individual
residences closest to the facilities and not at a census block
centroid. Therefore, we were unable to estimate the risk-based
population and risk-based demographics for those facilities. However,
the proximity analysis indicated that the demographics for all people
living within 10 km of the other Puerto Rico facility are almost
identical to the one shown in Table 29. The proximity analysis shows
that the population of all people living within 10 km of the Utah
facility is 80 percent white with the percent Hispanic or Latino,
African American, below the poverty level, over 25 without a high
school education, and linguistic isolation all below the national
average.
---------------------------------------------------------------------------

    \53\ As described in section III.D.1.c, we expect the risks at
one of the facilities in Puerto Rico to be below 100-in-1 million
after accounting for the proposed Group 1 room air emission
reductions.
---------------------------------------------------------------------------

    For control Option 2, there are no facilities or people with risks
greater than 100-in-1 million. Therefore, there are no greater than
100-in-1 million demographics to discuss.
    In summary, as shown in the residual risk post-control risk-based
demographic analysis, the options under consideration in this proposal
would reduce the number of people and facilities expected to have
cancer risks greater than or equal to 1-in-1 million, greater than or
equal to 50-in-1 million, and greater than 100-in-1 million
significantly. Under Option 1, the percentage of population that is
Hispanic or Latino, below the poverty level, over 25 without a high
school diploma, and in linguistic isolation increases as the cancer
risk increases. This trend is driven largely by the higher risk
facilities in Puerto Rico. Under Option 1, the number of Hispanic or
Latino people that are exposed to risks greater than or equal to 1-in-1
million is reduced by 50 percent, the number of Hispanic or Latino
people that are exposed to risks greater than or equal to 50-in-1
million is reduced by 70 percent, and the number of Hispanic or Latino
people that are exposed to risks greater than 100-in-1 million is
reduced by 97 percent. The three facilities remaining above 100-in-1
million for Option 1 are located in Puerto Rico (two facilities) and
Utah. The two facilities in Puerto Rico have Hispanic or Latino
populations of greater than 99 percent and the population around the
facility in Utah is 80 percent white.
    Under Option 2, the number of Hispanic or Latino people that are
exposed to risks greater than or equal to 1-in-1 million is reduced by
50 percent, the number of Hispanic or Latino people that are exposed to
risks greater than or equal to 50-in-1 million is reduced by 80
percent, and the number of Hispanic or Latino people that are exposed
to risks greater than 100-in-1 million is reduced by 100 percent. We
note that, primarily driven by the higher risk facilities in Puerto
Rico, the percentage of population that is Hispanic or Latino, below
the poverty level, over 25 without a high school diploma, and in
linguistic isolation increases as the cancer risk increases from
greater than or equal to 1-in-1 million to greater than 50-in-1
million. Under Option 2, there are no facilities or people with risks
greater than 100-in-1 million.

Table 27--Comparison of Post-Control Demographics for Populations With Cancer Risk Greater Than or Equal to 1-in-
               1 Million Living Within 10 km of Sterilizer Facilities for Various Control Options
----------------------------------------------------------------------------------------------------------------
                                                                     Cancer risk >=1-in-1 million
                                                     -----------------------------------------------------------
        Demographic group             Nationwide       Post-control CAA
                                                      section 112(d)(2),   Control option 1    Control option 2
                                                         (3), and (5)
----------------------------------------------------------------------------------------------------------------
Total Population................  328M..............  2.6M \1\..........  1.2M \1\..........  1.1M \1\
Number of Facilities with Pop.                        73 \1\............  73 \1\............  73 \1\
 Above Cancer Level.
----------------------------------------------------------------------------------------------------------------
                                Race and Ethnicity by Percent [number of people]
----------------------------------------------------------------------------------------------------------------
White...........................  60 percent [197M].  43 percent [1M]     38 percent [447K]   38 percent [429K]
                                                       \1\.                \1\.                \1\
African American................  12 percent [40M]..  19 percent [480K]   18 percent [209K]   18 percent [208K]
                                                       \1\.                \1\.                \1\
Native American.................  0.7 percent [2M]..  0.3 percent [7K]    0.4 percent [5K]    0.4 percent [4.5K]
                                                       \1\.                \1\.                \1\
Hispanic or Latino (includes      19 percent [62M]..  32 percent [840K]   37 percent [431K]   37 percent [419K]
 white and nonwhite).                                  \1\.                \1\.                \1\
Other and Multiracial...........  8 percent [27M]...  6 percent [150K]    7 percent [76K]     7 percent [74K]
                                                       \1\.                \1\.                \1\
----------------------------------------------------------------------------------------------------------------
                                      Income by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............  13 percent [44M]..  16 percent [400K]   16 percent [182K]   16 percent [177K]
                                                       \1\.                \1\.                \1\
Above Poverty Level.............  87 percent [284M].  84 percent [2.2M]   84 percent [1M]     84 percent [900K]
                                                       \1\.                \1\.                \1\

                                     Education by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
> 25 w/o a HS Diploma...........  12 percent [40M]..  16 percent [400K]   16 percent [186K]   16 percent [181K]
                                                       \1\.                \1\.                \1\
> 25 w/HS Diploma...............  88 percent [288M].  84 percent [2.2M]   84 percent [1M]     84 percent [900K]
                                                       \1\.                \1\.                \1\
----------------------------------------------------------------------------------------------------------------
                              Linguistically Isolated by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated.........  5 percent [18M]...  10 percent [300K]   9 percent [105K]    9 percent [100K]
                                                       \1\.                \1\.                \1\
----------------------------------------------------------------------------------------------------------------
\1\ These values may be lower because the proposed Group 1 room air emission standards were not applied or
  accounted for in the risk assessment
Notes:
 Nationwide population and demographic percentages are based on Census' 2015-2019 ACS 5-year block group
  averages. Total population count within 10 km is based on 2010 Decennial Census block population.
 To avoid double counting, the ``Hispanic or Latino'' category is treated as a distinct demographic
  category. A person who identifies as Hispanic or Latino is counted as Hispanic or Latino, regardless of race.
 The number of facilities represents facilities with a cancer MIR above level indicated. When the MIR
  was located at a user assigned receptor at an individual residence and not at a census block centroid, we were
  unable to estimate population and demographics for that facility.
 The sum of individual populations with a demographic category may not add up to total due to rounding.

 Table 28--Comparison of Post-Control Demographics for Populations With Cancer Risk Greater Than or Equal to 50-
              in-1 Million Living Within 10 km of Sterilizer Facilities for Various Control Options
----------------------------------------------------------------------------------------------------------------
                                                                    Cancer risk >= 50-in-1 million
                                                     -----------------------------------------------------------
                                                          CAA section
        Demographic group             Nationwide        112(d)(2), (3),
                                                         and (5) post-     Control option 1    Control option 2
                                                            control
----------------------------------------------------------------------------------------------------------------
Total Population................  328M..............  19,000 \1\........  1,985 \1\.........  1,368 \1\
Number of Facilities with Pop.                        20 \1\............  11 \1\............  11 \1\
 Above Cancer Level.
----------------------------------------------------------------------------------------------------------------
                                Race and Ethnicity by Percent [number of people]
----------------------------------------------------------------------------------------------------------------
White...........................  60 percent [197M].  54 percent [10K]    12 percent [200]    15 percent [200]
                                                       \1\.                \1\.                \1\
African American................  12 percent [40M]..  19 percent [4K]     7 percent [100]     10 percent [100]
                                                       \1\.                \1\.                \1\
Native American.................  0.7 percent [2M]..  0.1 percent [<100]  0.2 percent [<100]  0.3 percent [<100]
                                                       \1\.                \1\.                \1\
Hispanic or Latino (includes      19 percent [62M]..  25 percent [5K]     79 percent [1,600]  72 percent [1000]
 white and nonwhite).                                  \1\.                \1\.                \1\
Other and Multiracial...........  8 percent [27M]...  2 percent [400]     2 percent [<100]    3 percent [<100]
                                                       \1\.                \1\.                \1\
----------------------------------------------------------------------------------------------------------------
                                      Income by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............  13 percent [44M]..  23 percent [4K]     35 percent [700]    26 percent [400]
                                                       \1\.                \1\.                \1\
Above Poverty Level.............  87 percent [284M].  77 percent [15K]    65 percent [1,300]  74 percent [1K]
                                                       \1\.                \1\.                \1\
----------------------------------------------------------------------------------------------------------------
                                     Education by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
> 25 w/o a HS Diploma...........  12 percent [40M]..  15 percent [2K]     20 percent [400]    20 percent [300]
                                                       \1\.                \1\.                \1\
> 25 w/HS Diploma...............  88 percent [288M].  85 percent [17K]    80 percent [1,600]  80 percent [1K]
                                                       \1\.                \1\.                \1\
----------------------------------------------------------------------------------------------------------------
                              Linguistically Isolated by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated.........  5 percent [18M]...  13 percent [4K]     34 percent [700]    21 percent [300]
                                                       \1\.                \1\.                \1\
----------------------------------------------------------------------------------------------------------------
\1\ These values may be lower because the proposed Group 1 room air emission standards were not applied or
  accounted for in the risk assessment
Notes:
 Nationwide population and demographic percentages are based on Census' 2015-2019 ACS 5-year block group
  averages. Total population count within 10 km is based on 2010 Decennial Census block population.
 To avoid double counting, the ``Hispanic or Latino'' category is treated as a distinct demographic
  category. A person who identifies as Hispanic or Latino is counted as Hispanic or Latino, regardless of race.
 The number of facilities represents facilities with a cancer MIR above level indicated. When the MIR
  was located at a user assigned receptor at an individual residence and not at a census block centroid, we were
  unable to estimate population and demographics for that facility.
 The sum of individual populations with a demographic category may not add up to total due to rounding.
 To account for the uncertainty of demographics estimates in smaller populations, any population values
  of 100 persons or less have been shown simply as ``<100''.

Table 29--Comparison of Post-Control Demographics for Populations With Cancer Risk Greater Than 100-in-1 Million
                    Living Within 10 km of Sterilizer Facilities for Various Control Options
----------------------------------------------------------------------------------------------------------------
                                                                           Cancer risk >100-in-1 million
                                                                 -----------------------------------------------
                                                                    CAA section
                Demographic group                   Nationwide      112(d)(2),    Control option  Control option
                                                                   (3), and (5)          1               2
                                                                   post-control
----------------------------------------------------------------------------------------------------------------
Total Population................................            328M       2,350 \1\              33               0
Number of Facilities with Pop. Above Cancer                               13 \1\           3 \1\               0
 Level..........................................
----------------------------------------------------------------------------------------------------------------
                                Race and Ethnicity by Percent [number of people]
----------------------------------------------------------------------------------------------------------------
White...........................................      60 percent      37 percent     0.9 percent
                                                          [197M]       [900] \1\             [0]
African American................................      12 percent      11 percent     0.1 percent
                                                           [40M]       [300] \1\             [0]
Native American.................................     0.7 percent   0 percent [0]   0 percent [0]
                                                            [2M]
Hispanic or Latino (includes white and nonwhite)      19 percent      51 percent      99 percent
                                                           [62M]      [1.2K] \1\          [<100]
Other and Multiracial...........................       8 percent       1 percent     0.1 percent
                                                           [27M]      [<100] \1\             [0]
----------------------------------------------------------------------------------------------------------------
                                      Income by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............................      13 percent      34 percent      61 percent
                                                           [44M]       [800] \1\          [<100]
Above Poverty Level.............................      87 percent      66 percent      39 percent
                                                          [284M]     [1.55K] \1\          [<100]
----------------------------------------------------------------------------------------------------------------
                                     Education by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
> 25 w/o a HS Diploma...........................      12 percent      17 percent      27 percent
                                                           [40M]       [700] \1\          [<100]
> 25 w/HS Diploma...............................      88 percent      83 percent      73 percent
                                                          [288M]     [1.65K] \1\          [<100]
----------------------------------------------------------------------------------------------------------------
                              Linguistically Isolated by Percent [Number of People]
----------------------------------------------------------------------------------------------------------------
Linguistically Isolated.........................       5 percent      31 percent      84 percent
                                                           [18M]       [300] \1\          [<100]
----------------------------------------------------------------------------------------------------------------
\1\ These values may be lower because the proposed Group 1 room air emission standards were not applied or
  accounted for in the risk assessment
Notes:
 Nationwide population and demographic percentages are based on Census' 2015-2019 ACS 5-year block group
  averages. Total population count within 10 km is based on 2010 Decennial Census block population.
 To avoid double counting, the ``Hispanic or Latino'' category is treated as a distinct demographic
  category. A person who identifies as Hispanic or Latino is counted as Hispanic or Latino, regardless of race.
 The number of facilities represents facilities with a cancer MIR above level indicated. When the MIR
  was located at a user assigned receptor at an individual residence and not at a census block centroid, we were
  unable to estimate population and demographics for that facility.
 The sum of individual populations with a demographic category may not add up to total due to rounding.
 To account for the uncertainty of demographics estimates in smaller populations, any population values
  of 100 persons or less have been shown simply as ``<100''.

F. What are the results and proposed decisions based on our technology
review, and what is the rationale for those decisions?

1. SCV At Facilities Where EtO Use Is at Least 10 Tpy
    The current subpart O contains emission standards for SCVs at
facilities where EtO use is at least 10 tpy. There are 47 facilities
where EtO use is at least 10 tpy, all of which have SCVs. Of these
facilities, 26 currently use wet scrubbers to control their SCV
emissions, 11 use catalytic oxidizers, and six use a wet scrubber and
gas/solid reactor in series, four use thermal oxidizers, and one uses a
wet scrubber and catalytic oxidizer in series. Performance tests are
available for SCVs at all facilities where EtO use is at least 10 tpy.
We reviewed these performance tests, and the reported emission
reductions ranged from 99.6 percent to 99.999996 percent.
    We considered two potential options as part of the technology