National Emission Standards for Hazardous Air Pollutants: Ethylene Oxide Commercial Sterilization and Fumigation Operations

 
CONTENT
Federal Register, Volume 84 Issue 239 (Thursday, December 12, 2019)
[Federal Register Volume 84, Number 239 (Thursday, December 12, 2019)]
[Proposed Rules]
[Pages 67889-67899]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-26804]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 63
[EPA-HQ-OAR-2019-0178; FRL-10003-08-OAR]
RIN 2060-AU37
National Emission Standards for Hazardous Air Pollutants:
Ethylene Oxide Commercial Sterilization and Fumigation Operations
AGENCY: Environmental Protection Agency (EPA).
ACTION: Advance notice of proposed rulemaking.
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SUMMARY: In this advance notice of proposed rulemaking (ANPRM), the
U.S. Environmental Protection Agency (EPA) is soliciting information
that will aid in potential future revisions to the Ethylene Oxide
Emission Standards for Sterilization Facilities. The EPA is soliciting
information and requesting comment on potential control measures for
reducing ethylene oxide (EtO) emissions from commercial sterilization
facilities. These control measures include controls for fugitive
emissions of EtO, safety measures for the chamber exhaust vents (CEVs),
process equipment improvements, and advances in add-on control
technologies for point sources. In addition, the EPA is considering,
and requesting comment on, how best to assess potential impacts on
small businesses. The EPA is also
[[Page 67890]]
taking comment on the available EtO usage data for individual
facilities and on additional data contained in the modeling file that
will be used to evaluate the impact of emissions from commercial EtO
sterilizers.
DATES: Comments. Comments must be received on or before February 10,
2020.
ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2019-0178, by any of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov/
(our preferred method). Follow the online instructions for submitting
comments.
     Email: [email protected]. Include Docket ID No. EPA-
HQ-OAR-2019-0178 in the subject line of the message.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2019-0178.
     Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Docket ID No. EPA-HQ-OAR-2019-0178, Mail Code 28221T, 1200
Pennsylvania Avenue NW, Washington, DC 20460.
     Hand/Courier Delivery: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
The Docket Center's hours of operation are 8:30 a.m.-4:30 p.m., Monday-
Friday (except federal holidays).
    Instructions: All submissions received must include the Docket ID
No. for this action. Comments received may be posted without change to
https://www.regulations.gov/, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the SUPPLEMENTARY
INFORMATION section of this document.
FOR FURTHER INFORMATION CONTACT: For questions about this action,
contact Mr. Jonathan Witt, Sector Policies and Programs Division (E143-
05), Office of Air Quality Planning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711; telephone number:
(919) 541-5645; email address: [email protected].
SUPPLEMENTARY INFORMATION:
    Docket. The EPA has established a docket for this action under
Docket ID No. EPA-HQ-OAR-2019-0178. All documents in the docket are
listed in Regulations.gov. Although listed, some information is not
publicly available, e.g., Confidential Business Information (CBI) or
other information whose disclosure is restricted by statute. Certain
other material, such as copyrighted material, is not placed on the
internet and will be publicly available only in hard copy. Publicly
available docket materials are available either electronically in
Regulations.gov or in hard copy at the EPA Docket Center, Room 3334,
WJC West Building, 1301 Constitution Avenue NW, Washington, DC. The
Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding legal holidays. The telephone number for the Public
Reading Room is (202) 566-1744, and the telephone number for the EPA
Docket Center is (202) 566-1742.
    Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2019-0178. The EPA's policy is that all comments received will be
included in the public docket without change and may be made available
online at https://www.regulations.gov/, including any personal
information provided, unless the comment includes information claimed
to be CBI or other information whose disclosure is restricted by
statute. Do not submit information that you consider to be CBI or
otherwise protected through https://www.regulations.gov/ or email. This
type of information should be submitted by mail as discussed below.
    The EPA may publish any comment received to its public docket.
Multimedia submissions (audio, video, etc.) must be accompanied by a
written comment. The written comment is considered the official comment
and should include discussion of all points you wish to make. The EPA
will generally not consider comments or comment contents located
outside of the primary submission (i.e., on the Web, cloud, or other
file sharing system). For additional submission methods, the full EPA
public comment policy, information about CBI or multimedia submissions,
and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
    The https://www.regulations.gov/ website allows you to submit your
comment anonymously, which means the EPA will not know your identity or
contact information unless you provide it in the body of your comment.
If you send an email comment directly to the EPA without going through
https://www.regulations.gov/, your email address will be automatically
captured and included as part of the comment that is placed in the
public docket and made available on the internet. If you submit an
electronic comment, the EPA recommends that you include your name and
other contact information in the body of your comment and with any
digital storage media you submit. If the EPA cannot read your comment
due to technical difficulties and cannot contact you for clarification,
the EPA may not be able to consider your comment. Electronic files
should not include special characters or any form of encryption and be
free of any defects or viruses. For additional information about the
EPA's public docket, visit the EPA Docket Center homepage at https://www.epa.gov/dockets.
    The EPA is soliciting comment on numerous aspects of the action.
The EPA has indexed each comment solicitation with an alpha-numeric
identifier (e.g., ``C-1,'' ``C-2,'' ``C-3'') to provide a consistent
framework for effective and efficient provision of comments.
Accordingly, the EPA asks that commenters include the corresponding
identifier when providing comments relevant to that comment
solicitation. The EPA asks that commenters include the identifier in
either a heading, or within the text of each comment (e.g., ``In
response to solicitation of comment C-1, . . .'') to make clear which
comment solicitation is being addressed. The EPA emphasizes that the
Agency is not limiting comment to these identified areas and encourages
provision of any other comments relevant to this action.
    Submitting CBI. Do not submit information containing CBI to the EPA
through https://www.regulations.gov/ or email. Clearly mark the part or
all of the information that you claim to be CBI. For CBI information on
any digital storage media that you mail to the EPA, mark the outside of
the digital storage media as CBI and then identify electronically
within the digital storage media the specific information that is
claimed as CBI. In addition to one complete version of the comments
that includes information claimed as CBI, you must submit a copy of the
comments that does not contain the information claimed as CBI directly
to the public docket through the procedures outlined in Instructions
above. If you submit any digital storage media that does not contain
CBI, clearly indicate on the outside of the digital storage media that
it does not contain CBI. Information not marked as CBI will be included
in the public docket and the EPA's electronic public docket without
prior notice. Information marked as CBI will not be disclosed except in
accordance with procedures set forth in 40 CFR part 2. Send or deliver
information identified as CBI only to the following address: OAQPS
Document Control Officer (C404-02), OAQPS, U.S. Environmental
Protection Agency, Research Triangle Park, North Carolina
[[Page 67891]]
27711, Attention Docket ID No. EPA-HQ-OAR-2019-0178.
    Preamble acronyms and abbreviations. We use multiple acronyms and
terms in this preamble. While this list may not be exhaustive, to ease
the reading of this preamble and for reference purposes, the EPA
defines the following terms and acronyms here:
ANPRM advance notice of proposed rulemaking
APCD air pollution control device
ARV aeration room vent
CAA Clean Air Act
CBI Confidential Business Information
CEV chamber exhaust vent
CFR Code of Federal Regulations
EOSA Ethylene Oxide Sterilization Association
EPA Environmental Protection Agency
EtO ethylene oxide
GACT generally available control technology
HAP hazardous air pollutant(s)
IR infrared
IRIS Integrated Risk Information System
LEL lower explosive limit
MACT maximum achievable control technology
NAICS North American Industry Classification System
NATA National Air Toxics Assessment
NESHAP national emission standards for hazardous air pollutants
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
OSHA Occupational Safety and Health Administration
ppmv parts per million by volume
PRA Paperwork Reduction Act
PTE permanent total enclosure
SBA Small Business Administration
SBAR Small Business Advocacy Review
SCV sterilization chamber vent
tpy tons per year
    Organization of this document. The information in this preamble is
organized as follows:
I. General Information
    A. What is the purpose of this ANPRM?
    B. Does this action apply to me?
    C. Where can I get a copy of this document and other related
information?
II. Background
    A. Statutory Background
    B. Regulatory Background
    C. Risks Associated With EtO Emissions
III. Small Business Considerations
IV. Request for Comment
    A. Modeling File and Annual EtO Usage Data
    B. Control of Fugitive Emissions
    C. Chamber Exhaust Vent Control and Safety Considerations
    D. Other Point Source Control Options
    E. Types of Sterilization Facilities
V. Statutory and Executive Order Reviews
I. General Information
A. What is the purpose of this ANPRM?
    This ANPRM is intended to solicit information from the public in
order to inform the EPA as the Agency considers proposing a future
rulemaking to further address emissions of EtO from commercial
sterilizers. This ANPRM focuses on considerations pertinent to
potential future amendments to 40 CFR part 63, subpart O, in order to
further address emissions of EtO from commercial sterilizers. Subpart O
contains the emissions control standards for hazardous air pollutants
(HAP) that apply to commercial EtO sterilization facilities. In this
ANRPM, the EPA identifies additional control technologies and measures
that may be used to reduce emissions of EtO and provides an opportunity
for stakeholders to provide additional information about these
technologies and measures. In addition, the EPA is seeking information
about the costs associated with controlling EtO emissions from all
sources and, specifically, those that qualify as small businesses. The
EPA is also taking comment on facility and emissions data as part of
the modeling file that will be used to evaluate the impact of emissions
from commercial EtO sterilizers.
B. Does this action apply to me?
    The current standards in 40 CFR part 63, subpart O, regulate
emissions of EtO from existing and new commercial sterilization
operations using 907 kilograms per year (1 ton per year (tpy)) of EtO
or more. The EtO Commercial Sterilization and Fumigation Operations
source category covers the use of EtO as a sterilant and fumigant
following the production of various products (e.g., medical equipment
and supplies) and in miscellaneous sterilization and fumigation
operations at both major and area sources. These commercial
sterilization facilities use EtO as a sterilant for heat- or moisture-
sensitive materials and as a fumigant to control microorganisms or
insects. Materials may be sterilized at the facility that produces or
uses the product, or by contract sterilizers (i.e., firms under
contract to sterilize products manufactured by other companies). Table
1 of this preamble lists the entities that are regulated by the current
subpart O rule.
Table 1--NESHAP and Industrial Source Categories Affected by This Action
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                                                                  NAICS
                        Source category                            code
                                                                   \1\
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Surgical and Medical Instrument Manufacturing..................   339112
Surgical Appliance and Supplies Manufacturing..................   339113
Pharmaceutical Preparation Manufacturing.......................   325412
Spice and Extract Manufacturing................................   311942
Dried and Dehydrated Food Manufacturing........................   311423
Packaging and Labeling Services................................   561910
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\1\ North American Industry Classification System.
    The table is not meant to be exhaustive, but rather provides a
guide for readers regarding the entities that are likely to be affected
by future regulation for this source category. The EtO Commercial
Sterilization and Fumigation Operations source category includes
medical equipment suppliers; pharmaceutical suppliers; other health-
related industries; spice manufacturers; and contract sterilizers (see
57 FR 31576, July 16, 1992). 40 CFR part 63, subpart O, also applies to
large libraries and large museums and archives, but does not apply to
hospitals, doctor offices, clinics, or other facilities whose primary
purpose is to provide medical services to humans or animals; beehive
fumigators; and research and laboratory facilities. In addition, review
and comments are welcome from manufacturers of devices capable of
measuring, monitoring, reducing, abating, or destroying EtO,
particularly if such devices are or will soon be available in the
commercial marketplace.
C. Where can I get a copy of this document and other related
information?
    In addition to being available in the docket, an electronic copy of
this ANPRM is available on the internet. Following signature by the EPA
Administrator, the EPA will post a copy of this ANPRM at the following
address: https://www.epa.gov/stationary-sources-air-pollution/ethylene-oxide-emissions-standards-sterilization-facilities. Following
publication in the Federal Register, the EPA will post the Federal
Register version of the ANPRM and key technical documents at this same
website.
II. Background
A. Statutory Background
    Section 112 of the Clean Air Act (CAA) establishes the regulatory
process used to develop standards for emissions of HAP from stationary
sources. In the first stage of this process, the EPA
[[Page 67892]]
promulgates technology-based standards under CAA section 112(d) for
categories of sources identified as emitting one or more of the HAP
listed in CAA section 112(b). Sources of HAP emissions are either major
sources or area sources, and CAA section 112 establishes different
requirements for major source standards and area source standards.
``Major sources'' are those that emit or have the potential to emit 10
tpy or more of a single HAP or 25 tpy or more of any combination of
HAP. All other sources are ``area sources.'' For major sources, CAA
section 112(d)(2) provides that the technology-based national emission
standards for hazardous air pollutants (NESHAP) must reflect the
maximum degree of emission reductions of HAP achievable (after
considering cost, energy requirements, and non-air quality health and
environmental impacts). These standards that reflect the maximum degree
of emission reductions of HAP are commonly referred to as maximum
achievable control technology (MACT) standards. CAA section 112(d)(3)
also establishes a minimum control level for MACT standards, known as
the MACT ``floor.''
    The EPA must also consider control options that are more stringent
than the floor. Standards more stringent than the floor are commonly
referred to as beyond-the-floor standards. The EPA may establish
standards more stringent than the floor based on considerations of the
cost of achieving the emission reductions, any non-air quality health
and environmental impacts, and energy requirements. In certain
instances, as provided in CAA section 112(h), the EPA may set work
practice standards where it is not feasible to prescribe or enforce a
numerical emission standard. For area sources, CAA section 112(d)(5)
gives the EPA discretion to set standards based on generally available
control technologies or management practices (GACT standards) in lieu
of MACT standards.
    In the second stage, the EPA evaluates MACT standards to determine
whether additional standards are needed to address any remaining risk
associated with HAP emissions. This second stage is commonly referred
to as the ``residual risk review.'' In addition to the residual risk
review required by CAA section 112(f)(2), CAA section 112(d)(6)
requires the EPA to review standards set under CAA section 112 every 8
years. This review is commonly referred to as the ``technology review''
and the EPA often conducts the residual risk review simultaneously with
the first required technology review in what is commonly referred to as
a ``risk and technology review.'' The methodology used by the agency to
conduct risk and technology reviews is explained in the document titled
CAA Section 112 Risk and Technology Reviews: Statutory Authority and
Methodology, in the docket for this ANPRM.
    In the CAA section (d)(6) technology reviews, the EPA is to review
standards set under CAA section 112 and revise them ``as necessary
(taking into account developments in practices, processes, and control
technologies)'' no less frequently than every 8 years. CAA section
112(d)(6). In conducting these reviews, the EPA is not required to
recalculate the MACT floor. Natural Resources Defense Council (NRDC) v.
EPA, 529 F.3d 1077, 1084 (D.C. Cir. 2008); Association of Battery
Recyclers, Inc. v. EPA, 716 F.3d 667, 673 (D.C. Cir. 2013).
B. Regulatory Background
    On July 16, 1992 (57 FR 31576), the EPA published a list of major
and area sources for which NESHAP were to be promulgated (i.e., the
source category list). Ethylene oxide commercial sterilization and
fumigation operations were listed as a category of major sources and
area sources.
    On December 6, 1994 (59 FR 62585), the EPA promulgated MACT and
GACT standards for the EtO Emission Standards for Sterilization
Facilities source category. In that final rule, the EPA set MACT for
major sources under CAA section 112(d)(2). For area sources, the EPA
established GACT standards pursuant to CAA section 112(d)(5). This
rulemaking addressed EtO emissions originating from three major types
of emission points: The sterilization chamber vent (SCV), the aeration
room vent (ARV), and the CEV. The SCV evacuates EtO from the
sterilization chamber following sterilization, fumigation, and any
subsequent gas washes. The ARV evacuates EtO-laden air from the
aeration room, which is used to facilitate off-gassing. The CEV
evacuates EtO-laden air from the sterilization chamber after the
chamber door is opened for product unloading following the completion
of sterilization and associated gas washes. Another source of emissions
within this source category are fugitive emissions, but the EPA has not
set standards for those emissions.
    Following promulgation of the rule, the EPA suspended certain
compliance deadlines and ultimately removed the MACT and GACT standards
for CEVs due to safety concerns. In the late 1990s, there were multiple
explosions at commercial EtO sterilization facilities. In response, the
EPA suspended all rule compliance dates pending the investigation of
the explosions (62 FR 64736, December 9, 1997). In 1998, the suspension
of the compliance dates was extended for the ARVs and the CEVs (63 FR
66990, December 4, 1998), although the requirements for the SCVs went
into effect in 1998. It was also later determined that EtO emissions
from aeration rooms could be safely controlled, and the suspensions for
the ARVs were not further extended past December 2000 (64 FR 67789,
December 3, 1999). For CEVs, it was determined that the primary
contributing issue leading to the explosions was that EtO
concentrations were above the safe limit (i.e., above the lower
explosive limit (LEL)), within the CEV gas streams, and the EPA
extended the suspension of the rule requirements for CEVs. The EPA
could not conclude at the time that the CEVs could be safely
controlled, so MACT and GACT requirements for CEVs were removed in 2001
(66 FR 55577, November 2, 2001) and have not been re-instated. The EPA
is soliciting comment on the impacts associated with potentially
reinstating requirements for CEVs in a future rulemaking.
    In addition, the EPA conducted a residual risk analysis and a
technology review under CAA section 112(f)(2) and CAA section
112(d)(6), respectively, and issued a final decision on the risk and
technology review (71 FR 17712, April 7, 2006). No changes were made to
the requirements as part of that action.
    The HAP standards that currently apply to sterilization facilities
covered by 40 CFR part 63, subpart O are shown in the following table:
                            Table 2--Current EtO Standards for Commercial Sterilizers
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 Existing and new sources subcategory   Sterilization chamber      Aeration room vent      Chamber exhaust vent
                 \1\                          vent (SCV)                 (ARV)                  (CEV) \2\
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Sources using 10 ton or more of EtO    99 percent (see 40 CFR   1 ppm maximum outlet     No control.
 in any consecutive 12-month period.    63.362(c)).              concentration or 99-
                                                                 percent emission
                                                                 reduction (see 40 CFR
                                                                 63.362(d)).
[[Page 67893]]

Sources using 1 ton or more of EtO     99 percent (see 40 CFR   No control.............  No control.
 but less than 10 ton of EtO in any     63.362(c)).
 consecutive 12-month period.
Sources using less than 1 ton of EtO   Recordkeeping (minimal   Recordkeeping (minimal   Recordkeeping (minimal
 in any consecutive 12-month period.    recordkeeping            recordkeeping            recordkeeping
                                        requirements apply       requirements apply       requirements apply
                                        (see 40 CFR              (see 40 CFR              (see 40 CFR
                                        63.367(c)).).            63.367(c)).).            63.367(c)).).
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\1\ Determined as a rolling 12-month emission rate.
\2\ The CEV emission source was included in the original standard but was later eliminated from 40 CFR part 63,
  subpart O, in 2001.
    The NESHAP applies to both major and area sources that use at least
1 ton of EtO in sterilization or fumigation operations in each 12-month
period.
C. Risks Associated With EtO Emissions
    The National Air Toxics Assessment (NATA) released in August 2018
identified EtO emissions as a potential concern in several areas across
the country. (NATA is the Agency's nationwide air toxics screening
tool, designed to help the EPA and state, local, and tribal air
agencies identify areas, pollutants, or types of sources for further
examination.) The latest NATA estimates that EtO significantly
contributes to potential elevated cancer risks in some census tracts
across the U.S. (less than 1 percent of the total number of tracts).
These elevated risks are largely driven by an EPA risk value that was
updated in December 2016.\1\ The EPA conducted a previous assessment of
the health effects of EtO exposure in 1985. Subsequently, EtO was
designated a HAP under the 1990 CAA amid increasing concerns regarding
the adverse effects of EtO exposure due to newly published human and
animal studies of this chemical. Consequently, the EPA's Office of Air
and Radiation expressed an interest in having the Integrated Risk
Information System (IRIS) Program update the EPA's 1985 EtO assessment.
In response, the IRIS Program began work on the current EtO assessment
in the early 2000s and, following two external peer reviews, completed
this work in December 2016.
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    \1\ Evaluation of the Inhalation Carcinogenicity of Ethylene
Oxide, December 2016, EPA/635/R-16/350Fc.
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    Further investigation on NATA inputs and results led to the EPA
identifying commercial sterilization using EtO as a source category
contributing to some of these risks, which has led the EPA to evaluate,
in greater depth, the potential health risks associated with emissions
of EtO. Over the past year, the EPA has been gathering additional
information to help evaluate opportunities to reduce EtO emissions
through potential rule revisions and more immediate emission reduction
steps. Considering these results, the EPA is seeking comment in this
ANPRM on a number of potential control strategies for facilities in the
EtO Emission Standards for Sterilization Facilities source category
that would seek to reduce the fugitive emissions of EtO and to improve
point source emission controls for commercial sterilizers.
III. Small Business Considerations
    When the EPA undertakes a proposed rulemaking, it should identify
any small entities within the source category and determine whether
there is the potential for significant economic impacts to small
businesses or other entities from any regulatory actions being
considered. An entity is determined to be small based on the ultimate
parent company's NAICS code and as defined by the U.S. Small Business
Administration (SBA) (https://www.sba.gov/document/support--table-size-standards).\2\ A parent company's size is defined in terms of annual
revenue or number of employees; Table 3 of this preamble lists the size
standards for parent companies of entities regulated by the current 40
CFR part 63, subpart O rule.
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    \2\ SBA determines whether an entity qualifies as a small
business concern by counting its receipts, employees, or other
measures including those of all its domestic and foreign affiliates,
regardless of whether the affiliates are organized for profit (13
CFR 121.103(a)(6)).
                                    Table 3--SBA Size Standards by NAICS Code
----------------------------------------------------------------------------------------------------------------
                                                                            Size standards      Size standards
             NAICS code                        Source category             (annual revenue--      (number of
                                                                               millions)          employees)
----------------------------------------------------------------------------------------------------------------
339112.............................  Surgical and Medical Instrument      ..................               1,000
                                      Manufacturing.
339113.............................  Surgical Appliance and Supplies      ..................                 750
                                      Manufacturing.
325412.............................  Pharmaceutical Preparation           ..................               1,250
                                      Manufacturing.
311942.............................  Spice and Extract Manufacturing....  ..................                 500
311423.............................  Dried and Dehydrated Food            ..................                 750
                                      Manufacturing.
561910.............................  Packaging and Labeling Services....                 $12  ..................
----------------------------------------------------------------------------------------------------------------
    To date, of the 108 facilities that the EPA has identified within
the EtO Emission Standards for Sterilization Facilities source
category, we have identified approximately 35 facilities owned by small
businesses. At the parent company level, there are 59 total parent
companies, 27 of which are small parent companies.
    Identifying potential impacts on specific entities is challenging
because of the lack of detailed facility data for this source category.
Among other things, the EPA is seeking information about the costs
associated with controlling EtO emissions from sources that qualify as
small businesses. The EPA will use information received in response to
this ANPRM to further assess the potential impacts of emission
reduction strategies that may be considered. Given the potential
impacts of certain emission reduction strategies
[[Page 67894]]
on these small businesses, the EPA intends to convene a Small Business
Advocacy Review (SBAR) Panel before taking any significant regulatory
action. The EPA is in the process of requesting nominations for small
entity representatives to serve as part of a possible SBAR Panel.
IV. Request for Comment
    The EPA is requesting comment (1) on available control technologies
for reducing emissions of EtO and (2) on developments in practices,
measurement, monitoring, processes, and control technologies for the
control of EtO from commercial sterilization facilities. The EPA has
been investigating these issues through discussions with stakeholders,
reviews of operating permits, and research. As part of the information
gathering to date, the EPA has consulted with the EtO sterilization
industry, including companies, trade associations, and control
technology vendors, to better understand the current state of controls
for EtO emission sources. The EPA held teleconferences and meetings
with 12 different EtO trade associations, air pollution control device
(APCD) manufacturers, industry representatives, and other government
agencies to better understand sterilization processes, emissions
(including measurement and monitoring), current control techniques, and
how widely such techniques are used, as well as how control
efficiencies are determined and guaranteed by manufacturers. The
discussions have focused on common operational practices, including
practices used by EtO commercial sterilization facilities to determine
EtO concentration at various emissions points in the process. Despite
this outreach and information gathering, there are still several
important information gaps that would be useful to fill prior to any
future rulemaking activity.
    Through information gathering and discussions with stakeholders,
the EPA identified the process controls and operational practices
discussed below for consideration as possible methods for reducing the
amount of EtO released into the ambient air. Under section 114(a) of
the CAA, the EPA may require sources to report data in a manner
prescribed by the Agency. For the EtO Commercial Sterilization and
Fumigation Operations source category, the EPA intends to undertake a
CAA section 114 information collection to provide information to
support any future rulemaking actions, such as the upcoming technology
review.
A. Modeling File and Annual EtO Usage Data
    In order to ensure the accuracy of the data that could be used for
any future rulemaking for this source category, the EPA is soliciting
comment on available EtO usage data for individual facilities and on
additional data contained in the modeling file that the EPA intends to
use to evaluate the impacts of EtO emissions (Comment C-1). For the
modeling file, the EPA requests that companies review the data for
their facilities to ensure that the information presented is accurate
and complete, including current facility and process information,
emissions data,\3\ and release parameters. The EPA further requests
that after reviewing the modeling file for this purpose, companies
submit to the EPA any corrected and supplemental information as part of
their comments. The modeling file is available at the following
website: https://www.epa.gov/stationary-sources-air-pollution/ethylene-oxide-emissions-standards-sterilization-facilities. The current known
EtO usage data is available in the docket.
---------------------------------------------------------------------------
    \3\ Primarily derived from the EPA's 2014 National Emissions
Inventory, version 2.
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B. Control of Fugitive Emissions
    Fugitive EtO emissions at commercial sterilization facilities
generally occur from (1) off-gassing associated with the handling of
EtO prior to charging the sterilizer chamber; (2) off-gassing of
sterilized product following product transfer from the sterilizer
chamber to the aeration room; (3) off-gassing from uncontrolled and
under-controlled aeration rooms; and (4) any off-gassing that may occur
after product is removed from the aeration room. For the purpose of
this rule, fugitive emissions are those emissions which are not routed
to an existing pollution control device. The magnitude of the fugitive
emissions from the industry is not well characterized, and the extent
of the fugitive emissions may be dependent on building design, the
building air handling system, and the capacity of the existing air
pollution control system. A recent analysis of ambient air monitoring
data performed in close proximity to a commercial sterilizer in
Illinois \4\ indicated that the previous EtO emission estimates for
this facility may have been underestimated. Specifically, this analysis
indicated that the fugitive component of the emissions accounted for
approximately 0.5 percent of the total EtO usage at that facility,
which was significantly higher than previously assumed.
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    \4\ https://www.epa.gov/il/outdoor-air-monitoring-willowbrook-community.
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    The EPA is requesting comment on the use of an emission factor of
0.5 percent of EtO usage for the calculation of fugitive emissions from
this source category (Comment C-2a). In addition, the EPA is requesting
comment on any data that can be used to help quantify facility-wide and
area/room-specific fugitive emissions from commercial EtO sterilizers
(e.g., internal and ambient air monitoring data), along with relevant
monitoring characteristics such as monitoring collection equipment and
techniques, averaging time, equipment detection limits, equipment
quality assurance, and quality control procedures employed (Comment C-
2b). If commenters believe that alternative fugitive EtO calculation
procedures or emission factors should be considered, the EPA requests
that commenters provide documentation that supports the basis or bases
for why an alternative methods or factors should be considered (Comment
C-2c).
1. Permanent Total Enclosure
    Permanent total enclosures (PTEs) are permanently installed
structures that completely surround source(s) of emissions such that
all volatile organic compound emissions (i.e., EtO emissions) are
captured and contained for discharge to a control device(s).
Specifically, PTEs could capture emissions from sterilizer chamber
rooms, aeration rooms, EtO drum storage areas, shipping areas, or any
facility areas through which sterilized product is moved or EtO
equipment is in service. The EPA's current understanding is that the
existing building, or portions of the building, in which EtO could be
released could serve as the enclosure, for example, by enclosing and
adapting the building or portions of the building to meet the design
criteria of a PTE. EPA Method 204 (40 CFR part 51, appendix M) provides
the design criteria as well as procedures for verifying the capture
efficiency of the enclosure.\5\ Additionally, EPA Method 204 includes
requirements to route the captured and contained EtO-laden gas for
delivery to an APCD. Based on recent regulations enacted in
Illinois,\6\ as well as increasing public awareness, multiple EtO
commercial sterilization facilities have either implemented or are
[[Page 67895]]
planning to implement PTEs to capture and control fugitive emissions
from the sterilization processes.
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    \5\ 40 CFR part 51, appendix M, EPA Method 204--Criteria and
Verification of a Permanent or Temporary Total Enclosure. U.S. EPA.
    \6\ http://www.ilga.gov/legislation/publicacts/fulltext.asp?Name=101-0022 and
    http://www.ilga.gov/legislation/publicacts/fulltext.asp?Name=101-0023.
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    The EPA is requesting facility-specific data items that can be used
more accurately to assess the cost and emission capture/reduction of
PTEs (Comment C-3). In addition, the EPA welcomes detailed facility-
specific data and information regarding building and chamber design,
including details on the square feet and height of the rooms where EtO
is used, their temperature set point (during summer, winter, and
intermediate seasons), relative humidity, air flow, number of air
changes per hour, area of natural draft openings as defined in EPA
Method 204, the typical EtO concentration in parts per million by
volume (ppmv) within these rooms, and quantification of emissions
reductions obtained via PTE, along with a description of the
measurement device(s), measurement device detection limits and
interferences, and measurement device quality assurance and quality
control procedures and costs, the time required to implement PTE, the
number of facilities currently implementing PTE or planning to do so,
and the extent to which aspects of PTE might differ for small business
facilities (also Comment C-3).
2. Pollution Prevention and Other Operational Practices
    Some facilities follow other operational practices to reduce
fugitive emissions. These operational practices include leak detection
and repair programs that encompass monitoring for fugitive leaks from
drums, valves, and connection lines containing EtO; controlling air
flow in the building to capture fugitive emissions (e.g., sweep vents)
in areas where EtO is processed and sending these emissions to existing
controls; putting process controls in place to minimize storage of
fumigated material in uncontrolled areas; reducing emissions from EtO-
laden waste water; and reducing levels of EtO injected into the
sterilization chamber.
    Fugitive emissions may occur from EtO drum storage and handling.
The EPA understands that personnel at commercial sterilizer facilities
inspect the valves on EtO drums for leaks when delivered to their
facilities and that the connectors are also checked for leaks after
they are attached to a sterilizer chamber.\7\ EtO drums contain
approximately 400 pounds of compressed EtO liquid along with a blanket
of nitrogen. The pressurized drums are commonly equipped with two
valves: One for the nitrogen blanket, and the other for unloading the
EtO liquid. Leak checks similar to what is required by EPA Method 21
(40 CFR part 60, appendix A) are conducted on these valves and
connectors. Additionally, the drum storage room area may be enclosed
and vented to either an APCD or to the atmosphere. The EPA requests
comment on these and additional operational practices for monitoring
leaks from EtO drums, including appropriate procedures and/or methods
to use and the optimal frequency of monitoring; the emission reductions
likely to be achieved by specific practices; the costs associated with
specific practices; the time required to implement a leak check program
for EtO drums; the number of facilities currently implementing these
leak checks or plan to do so; and the extent to which aspects of these
leak checks might differ for small business facilities (Comment C-4).
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    \7\ National Fire Prevention Association 55 Chapter 14.
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    EtO supply lines are used to connect the EtO drum to the sterilizer
chamber. Prior to its use for charging EtO, the EtO line connection is
often pressurized with nitrogen from the storage drum to the sterilizer
chamber, to confirm that there are no leaks. The line connection is
held at that pressure for a set time period, and if the line connection
is able to maintain the pressure level, it is considered leak free. The
EPA is seeking comment on the available operational practices for
conducting regular pressure testing on the connection line between the
EtO drum and sterilizer chamber. The EPA solicits comment on the
feasibility of conducting the tests, the methods to be used or
considered for use, the optimal frequency of such tests or methods,
emission reductions likely to be achieved by specific practices, and
the costs associated with specific practices, the time required to
implement a leak check program for EtO supply lines, the number of
facilities currently implementing these leak checks or plan to do so,
and the extent to which aspects of these leak checks might differ for
small business facilities (Comment C-5).
    Sweep vents or floor vents are used to move and capture room air
from the main room areas as operators move sterilized product from area
to area at the facility. Sweep vents often maintain the sterilizer
chamber room area and the aeration room area under negative pressure.
Some facilities route the room air captured in sweep vents to an APCD,
and other facilities vent the captured room air to the atmosphere. The
floor sweeps serve to reduce the EtO in work areas to minimize
occupational exposure to EtO. Facilities often measure the EtO
concentration in the sterilizer chamber room area and aeration room
area using a gas chromatography or infrared instrument. The EPA
solicits comment on circumstances in which it would not be feasible to
connect sweep vents to an APCD (including specific facility designs
that may affect such feasibility); the level of capture likely be
achieved for EtO fugitive emissions by specific practices; the costs
associated with specific practices; the time required to implement
sweep vents or floor vents; the number of facilities currently
implementing sweep vents or floor vents; and the extent to which
aspects of sweep vents or floor vents might differ for small business
facilities (Comment C-6).
    The EPA is aware that emissions may occur from water that comes
into contact with EtO during the sterilization process. Potential
emissions may come from, but are not limited to, disposal of water used
in once-through liquid-ring vacuum pumps, as well as water used in
recovering EtO for re-use in sterilization. The EPA solicits comment on
the circumstances in which EtO may come into contact with water within
commercial sterilization facilities; the frequency with which such
water is or should be disposed; methods of disposal; any operational
practices that are or may be used to mitigate emissions from waste
water; the feasibility of implementing such operational practices; and
costs associated with disposal and with specific operational practices,
the time required to implement wastewater EtO emissions reductions; the
number of facilities currently implementing wastewater EtO emissions
reductions; and the extent to which aspects of wastewater EtO emissions
reductions might differ for small business facilities (Comment C-7).
    The EPA is also interested in obtaining information on other
operational practices, not discussed in the preceding paragraphs, that
may be available to reduce EtO emissions from commercial sterilization
facilities. The EPA solicits comment on the availability,
applicability, and technical feasibility of such operational practices;
the emission reductions likely to be achieved by such measures; the
cost of such measures; the time required to implement such measures;
the number of facilities currently implementing such measures; and the
extent to which aspects of such measures might differ for small
business facilities (Comment C-8).
[[Page 67896]]
C. Chamber Exhaust Vent Control and Safety Considerations
1. Reinstating the Chamber Exhaust Vent Control Requirement
    The CEV evacuates EtO-laden air from the sterilization chamber
prior to unloading and while the chamber is being unloaded (and
reloaded). The chamber exhaust enables facilities to meet U.S.
Occupational Safety and Health Administration (OSHA) workplace exposure
standards.\8\ Following the removal of the CEV regulatory requirement
in 2001 (66 FR 55577, November 2, 2001), many EtO sterilization
facilities ceased, or never implemented, controls for EtO emissions
from the CEV. In more recent years, however, facilities have begun to
control EtO from the CEV, and multiple facilities currently control the
CEV. The safety issues that prevented earlier control techniques from
being applied were linked to EtO concentrations in the sterilizer
chamber that exceeded the LEL for EtO. Since the late 1990s and early
2000s, facilities have revised their operating procedures related to
the CEV.
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    \8\ 29 CFR 1910.1047.
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    Currently, some facilities that control EtO emissions from the CEV
have made process changes to avoid exceedance of the LEL; such process
changes include (1) reducing the EtO concentration in the sterilizer
chamber before opening the sterilizer chamber door and venting
emissions to an APCD, and (2) using an automated lock on the sterilizer
chamber door that does not allow the door to open until EtO
concentration is significantly less than the LEL. As part of the
process change, facilities have enacted additional final air washes in
the sterilization cycle to further reduce the EtO concentration in the
sterilizer chamber prior to opening the sterilizer door and venting to
the APCD. In addition, the automated lock on the sterilizer chamber
door does not allow the door to open until a non-explosive EtO
concentration level is achieved in the chamber. The MACT floor for CEVs
at existing and new sources, for sources using 10 tpy or more of EtO,
is routing emissions from the CEV such that they are combined with a
stream that is already being routed to a control device that achieves
99-percent emission reduction.\9\ Typical APCDs used to control EtO
emissions from CEVs include the following: Catalytic oxidizers, dry bed
scrubbers, wet acid scrubbers, combination wet acid scrubbers and dry
bed scrubbers, and balancer/abator systems. The EPA solicits comment on
implications of potentially reinstating the requirement to control the
CEV and is soliciting information regarding the feasibility, emission
reductions achieved, cost, the time required to reinstate the
requirements; the number of facilities currently reducing their CEV
emissions; the extent to which aspects of CEV emissions reductions
might differ for small business facilities, and associated safety
considerations (Comment C-9).
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    \9\ D. Hearne and K. Schmidtke, MRI, to D. Markwordt, U.S. EPA.
October 24, 1994. Revised Calculation of MACT Floors for Major
Source Chamber Exhaust Vents at Ethylene Oxide Commercial
Sterilization and Fumigation Operations; National Emissions
Standards for Hazardous Air Pollutants (NESHAP) (Legacy Docket ID
No. A-88-03, Docket Entry IV-B-02).
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2. Implementing an In-Chamber Concentration Limit
    To further reduce EtO emissions from the SCV, some facilities set
an upper in-chamber concentration limit on the EtO in the sterilization
chamber prior to opening the chamber door and engaging the CEV.
Increased air washes to remove EtO from the sterilizer chamber have
been implemented over time to accommodate control of the CEV. To safely
control the CEV, the concentration must be significantly below the LEL
of EtO. The reduction of the in-chamber concentration at the end of the
sterilization cycle is directly linked to venting of the CEV to an APCD
and has enabled control of the CEV. A 2007 report from the National
Institute for Occupational Safety and Health determined that additional
air washes were essential for mitigating any safety issues.\10\ A
report by the Chemical Safety and Hazard Investigation Board on an
explosion that occurred at a commercial EtO sterilization facility in
2004 arrived at the same conclusion.\11\
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    \10\ National Institute for Occupational Safety and Health,
Preventing Worker Injuries and Deaths from Explosions in Industrial
Ethylene Oxide Sterilization Facilities (Revised Edition). August
2007. https://www.cdc.gov/niosh/docs/2007-164/.
    \11\ Chemical Safety and Hazard Investigation Board,
Investigation Report: Sterigenics (4 Employees Injured). March 2006.
https://www.csb.gov/sterigenics-ethylene-oxide-explosion/.
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    While an in-chamber, EtO concentration monitoring technique was not
available when the original NESHAP was promulgated in 1994, in-chamber
monitors are available today. Monitors based on the photoacoustic
principle are available and currently in use at sterilization
facilities. These monitors are used to measure the in-chamber
concentration of EtO to confirm that the chamber concentration is well
below the LEL of EtO. The LEL of EtO is 3.0 percent by volume, or
30,000 ppmv.\12\ To ensure safe conditions when opening the sterilizer
chamber at the end of the sterilization cycle and to ensure limited
fugitive emissions released from the open sterilizer chamber door,
facilities reduce the EtO concentration to significantly less than the
LEL, often to ranges of 10 to 25 percent of the LEL (i.e., 3,000 to
7,500 ppmv). (LESNI 2019) \13\
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    \12\ https://pubchem.ncbi.nlm.nih.gov/compound/Ethylene-oxide#section=Lower-Explosive-Limit-(LEL).
    \13\ See memorandum, Meeting Minutes for Discussion with
Representative of LESNI, located at Docket ID No. EPA-HQ-OAR-2019-
0178. March 7, 2019.
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    The reduction of the in-chamber concentration is achieved through
additional air washes in the sterilizer chamber. The number of
additional air washes required to reach a concentration below the LEL
is dependent on the parameters in the individual validated
sterilization cycle. Some cycles that operate under shallow vacuum
conditions, or need higher EtO concentration levels to reach sterility,
may require additional air washes to lower the in-chamber concentration
to this level.
    The addition of air washes may increase the costs to operate the
sterilizer chamber vacuum pump, as well as the costs to operate the
APCD used to control emissions from the SCV. In addition, the overall
facility sterilization capacity may be reduced due to the increased
length of time required to complete the sterilization cycle. The EPA
solicits comment on (1) the feasibility of using additional air washes
in the sterilization chamber to further decrease in-chamber EtO
concentration; (2) the emission reductions likely to be achieved by
additional air washes; (3) associated costs; (4) the EtO concentration
that should be typically reached before allowing activation of the CEV;
(5) the time required to implement an EtO concentration reduction
program; (6) the number of facilities currently reducing EtO
concentration before activating the CEV; and (7) the extent to which
EtO concentration reduction efforts might differ for small business
facilities (Comment C-10).
3. Interlock System Tied to In-Chamber Concentration Limit
    To further reduce fugitive emissions of EtO from leaving the
sterilizer chamber and risking the immediate health and safety of
facility operators, most facilities have installed door interlock
systems on their sterilizer chambers. These door interlock systems are
tied to the monitoring and control
[[Page 67897]]
equipment already operating within the sterilizer chamber. The
interlock system ensures that the sterilizer chamber doors are unable
to be opened by facility personnel prior to achieving the prescribed
in-chamber concentration of EtO, i.e., below the LEL. By preventing
premature opening of the sterilizer chamber door prior to reaching a
non-explosive EtO concentration, the door interlock system accomplishes
two things: (1) It ensures that gas from the sterilizer chamber is
prevented from being directed to the CEV until the EtO concentration
within the chamber is well below the LEL, and (2) it greatly reduces
the amount of fugitive EtO that operators will be exposed to over the
course of the work day. Industry trade associations have indicated that
environmental health and safety issues surrounding worker exposure have
been a major focus of EtO sterilization-centered working groups over
recent years (AdvaMed 2019).\14\
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    \14\ See memorandum, Meeting Minutes for Discussion with
Representatives of AdvaMed, located at Docket ID No. EPA-HQ-OAR-
2019-0178. July 2, 2019.
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    The combination of an in-chamber EtO concentration limit and an
interlock system tied to that limit enables facilities to continue to
meet OSHA workplace exposure standards with respect to emissions from
the sterilizer chamber.
    The EPA is soliciting comment on cost, the time required to
implement an interlock system, the number of facilities currently
utilizing interlock systems, and the extent to which aspects interlock
systems might differ for small business facilities, and safety
considerations for an interlock system on the sterilizer chamber door
that is linked to the in-chamber concentration (Comment C-11).
D. Other Point Source Control Options
1. Balancer/Abator System
    Add-on control devices such as wet acid scrubbers, catalytic
oxidizers, and dry bed scrubbers are commonly used to control the
emissions of EtO from the commercial sterilization source category.
Generally, the add-on APCD is designed based on the maximum flow rates
and EtO concentrations from the emission sources vented to the device.
An APCD used for reducing the EtO emissions from the Commercial
Sterilization and Fumigation Operations source category that was
developed since the initial NESHAP is a combination water balancer and
catalytic oxidizer, also referred to as the balancer/abator system.
This system vents EtO to the water balancer, where a significant
portion of the EtO is stored within the water, so that a flow of air at
a constant EtO concentration can be fed to the catalytic oxidizer. The
SCVs are first vented to the water balancer, and the stream from the
balancer is then to the catalytic oxidizer. The ARVs and CEVs are
sources of more dilute EtO-laden streams and, therefore, are not vented
to the water balancer--they are vented directly to the catalytic
oxidizer. Emissions from the ARVs and CEVs are first mixed with the
stripped EtO stream from the SCV and then emissions from all three
vents are routed to the catalytic oxidizer. The water balancer does not
convert the EtO into ethylene glycol, as the scrubbing water is not
acidic enough to drive the conversion (i.e., addition of sulfuric acid
would drive the conversion to ethylene glycol).
    One advantage of this APCD is related to the intermittent venting
of high EtO concentration streams from the sterilizer chamber. The
concentration of EtO within an SCV stream can vary depending on how
much EtO is used for sterilizing a product, as well as what
sterilization phase the chamber is in at the time of exhaust (e.g.,
dwell period, gas washing, etc.). The number of chambers venting to one
balancer also has an impact on overall concentration. The water
balancer essentially ``stores'' the EtO peaks from the SCV in the
water, and the catalytic oxidizer is designed based on a relatively
constant flowrate and EtO concentration from the combination of the
stream from the balancer and the ARV and CEV emission streams, rather
than based on the peak flowrates and EtO concentrations from the SCV.
    The balancer/abator system design was introduced in the U.S. in
2006, and there are at least four facilities currently using this APCD
in four states and territories. The balancer/abator system achieves
99.9-percent reduction of EtO emissions and EtO concentrations of 0.5
milligrams per normal cubic meter (roughly equivalent to 0.27 ppmv)
(LESNI 2019).\15\ The ARV and CEV concentrations are characterized as
dilute concentrations in a high-volume air flowrate. The balancer/
abator system helps normalize both the flowrate and the EtO
concentration fluctuations. The EPA is soliciting comment on use of the
balancer/abator system, the emission reductions likely to be achieved
from such use, the associated costs, the time required to implement a
balancer/abator system, the number of facilities currently using
balancer/abator systems, and the extent to which aspects of a balancer/
abator system might differ for small business facilities (Comment C-
12).
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    \15\ See memorandum, Meeting Minutes for Discussion with
Representative of LESNI, located at Docket ID No. EPA-HQ-OAR-2019-
0178. March 7, 2019.
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2. Improvements to Existing Point Source Controls
    While the current standard for control device efficiency requires
99-percent removal (along with a 1-ppmv alternative for ARVs), the EPA
is aware of many situations in which testing has revealed emission
control performance that is significantly superior to the current
standard. The EPA is soliciting comment on potential improvements to
control device efficiencies and observed removal efficiencies or outlet
concentrations, along with any costs potential implementation issues
associated with achieving those higher control efficiencies, the time
required to improve existing point source controls, the number of
facilities that have made improvements to their existing point source
controls, and the extent to which improvements to existing point source
controls might differ for small business facilities (Comment C-13).
3. Improved Monitoring Instruments for Ethylene Oxide
    Since the regulations at 40 CFR part 63, subpart O, were finalized
in 2001, there have been significant improvements in monitoring
equipment, including new continuous monitoring instruments that are
considerably more sensitive than previous monitoring technology. In the
past, there have been concerns over detecting low concentrations of
EtO, but instrumentation is now available with a detection capability
in the single parts per billion by volume within the exhaust stack for
the APCD. Instrument manufacturers have developed innovative techniques
which use optical spectroscopy that allow for greater sensitivity and
better time-resolution than the current monitoring techniques specified
in the rule. The EPA is requesting comment on the feasibility of using
continuous monitoring systems and is soliciting comment on the cost
considerations for installing and operating the monitoring units,
particularly for control devices. The EPA is also soliciting comment on
the number of facilities currently using improved monitoring
instruments (Comment C-14).
4. Accelerated Aerator Design and Aeration Cells
    One process equipment improvement available is the use of
accelerated aeration cells. The use of focused
[[Page 67898]]
aeration was discussed in the 1992 EtO Sterilization Background
Information Document,\16\ including use of both smaller, heated
aeration chambers (43 degrees Celsius ([deg]C)) and vacuum cycles on
the small aeration cells. The use of aeration cells rather than
aeration rooms significantly reduces the volume of air vented to the
APCD. The EPA does not have information on the total number of
facilities that are using aeration cells.
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    \16\ U.S. EPA, Office of Air Quality Planning and Standards,
Emission Standards Division. Ethylene Oxide Emissions for Commercial
Sterilization Fumigation Operations Background Information for
Proposed Standards. October 1992 (Legacy Docket A-88-03, Docket
Entry II-A-022).
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    A large aeration room requires large volumetric flowrates to move
the EtO out of the room. Such rooms have low EtO concentrations and
large volumes of gas and entail many air changeovers (e.g., 20 air
changes per hour). It may take 5 to 10 days to complete the aeration
cycle for such a room. Replacing the large aeration room with an
aeration cell reduces the volumetric flowrate from the emission source.
Use of smaller aeration cells may reduce the amount of aeration time
needed, remove the EtO more efficiently, and reduce the residual EtO in
the final product.
    Combining heated aeration cells with high-turbulence air flow or
with vacuum cycles is a newer approach to aeration for commercial
sterilization, sometimes referred to as acceleration aeration. Heated
chambers are typically in the range of 40 [deg]C to 60 [deg]C. Inlet
air is introduced at multiple inlet ports along the side of the
aeration cell and removed at multiple outlet points along the top of
the cell to provide even distribution of air throughout the cell.
Combining aeration cells with high-turbulence air movement throughout
the cell can accelerate the aeration process by reducing the number of
air changeovers needed to remove the EtO from the product. One
manufacturer noted that shallow vacuum intervals vary between 50 and
700 millibars, and that the use of shallow vacuum is expected to reduce
the aeration time by 65 percent or more compared with traditional
aeration procedures. Based on discussions with one trade organization,
at least one company is currently modifying a facility so that it will
incorporate the new accelerated aerator design (EOSA 2019).\17\
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    \17\ See memorandum, Meeting Minutes for Discussion with
Representatives of the Ethylene Oxide Sterilization Association
(EOSA), located at Docket ID No. EPA-HQ-OAR-2019-0178. March 18,
2019.
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    The EPA is soliciting comment on the use of accelerated aeration
design and aeration cells; the emission reductions likely to be
achieved by such changes; the feasibility of implementation of such
changes; associated costs; the time required to implement accelerated
aeration design or aeration cells; the number of facilities currently
using accelerated aeration design or aeration cells; and the extent to
which aspects accelerated aeration or aeration cells might differ for
small business facilities (Comment C-15).
5. Cascading Air Method
    Some facilities use cascading air to reduce the overall volume of
air use for sterilization processes. A facility using a cascading
technique does not use fresh air as feed air but rather reuses air from
a low-concentration fugitive area as the feed air to another area. For
example, reuse of the fugitive air from the warehouse can be used as
intake air to the aeration room or aeration cell. Use of cascading air
reduces the amount of air that needs to be processed by the APCD. In
this example, rather than using a larger APCD to handle and control the
volume of air from the ARV plus the warehouse room area, the facility
routes the warehouse air to the aeration room, and the ARV emissions
are then routed to a smaller APCD.
    The EPA solicits comment of the feasibility of the cascading air
technique; the emissions reductions that are likely to be achieved; the
feasibility of implementation; associated costs; the time required to
implement the cascading air method; the number of facilities currently
using the cascading air method; and the extent to which aspects of the
cascading air method might differ for small business facilities
(Comment C-16).
E. Types of Sterilization Facilities
1. Single-Item Sterilizer Facilities
    The EPA has identified 27 commercial EtO sterilization facilities
that use a single-item sterilizer model. While a traditional
sterilization chamber tends to be a larger vessel that accommodates
pallets containing diverse products, a single-item sterilizer is
generally smaller and may use much less EtO to sterilize products
(e.g., approximately 10 percent of the EtO that a traditional
sterilization chamber would use). In the single-item sterilization
process, workers place the product into a plastic pouch, a slight
vacuum is applied, EtO gas is injected into the pouch and sealed, and
the sealed pouch is placed in a room, chamber, or cabinet under
specific temperature and humidity where EtO both sterilizes and then
off-gasses or aerates. The EtO slowly dissipates from the pouch or bag
by diffusion. Once the product is removed from the room, chamber, or
cabinet, the product is held in the warehouse for 2 days before
shipping. Just as is the case with traditional sterilizer chambers, EtO
is stored in a pressurized drum when the single-item sterilization
approach is used, although the cylinder tends to be smaller than EtO
storage drums used at traditional sterilization facilities. EtO usage
in a single-item sterilizer facility is often much less than in
traditional sterilizer chambers.
    Facilities using the single-item sterilizer process were previously
thought to typically use much less than 1 ton of EtO per year,\18\ and
under 40 CFR part 63, subpart O, processes that use less than 1 ton of
EtO are only subject to the recordkeeping requirements. Processes that
use over 1 ton of EtO per year are subject to additional requirements.
A recent review of single-item sterilizers found the EtO usage for at
least four of these facilities to be in excess of 1 ton.\19\ The EPA is
requesting comment on (1) specific emissions controls that are used or
could be used at single-item sterilizers in EtO commercial
sterilization, and (2) whether there are any technical or process
differences between single-item sterilization and traditional
sterilizer chambers that should be considered when adopting measures to
reduce emissions. The EPA is seeking additional information on costs
associated with single-item sterilization use (including costs related
to machine purchase and maintenance, design considerations, and
implementation) and on costs associated with compliance with the
NESHAP's emissions limits under the current subpart O regulations. The
EPA also solicits comment on the number of facilities that are single-
item sterilization facilities (Comment C-17).
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    \18\ Ethylene Oxide Commercial Sterilization and Fumigation
Operations NESHAP Implementation Document, EPA-456/R-97-004, March
2004.
    \19\ See annual EtO usage data provided in Docket ID No. EPA-HQ-
OAR-2019-0178.
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2. Combination Sterilizer Facilities
    The EPA is aware of another technology, a combination sterilizer,
that is used in the EtO commercial sterilization industry. In
combination sterilizers, the sterilization step and aeration step occur
in sequence in the same chamber. The chamber is evacuated and EtO gas
is injected into the chamber. After the sterilization process is
completed, air washes are used to remove most of the EtO from the
product. The exhausted EtO may be vented to the atmosphere or to a
carbon canister, with charcoal adsorbent, to
[[Page 67899]]
control the EtO. One advantage of this sterilization approach is a
reduction of EtO fugitive emissions due to the elimination of the step
in which product is moved from the sterilization chamber to the
aeration equipment.
    The EPA is seeking information and comment on the viability of
replacing traditional EtO sterilization operations with combination
sterilizers. The EPA is also seeking information on the emissions
associated with combination sterilizers relative to traditional
sterilizers; the control devices typically used for these types of
chambers; costs associated with operating emissions controls for
combination EtO sterilizers; and the number of facilities currently
using combination sterilizers (Comment C-18).
3. Sterilization Facilities Owned by Small Businesses
    As discussed in section III of this ANPRM, small businesses make up
a significant portion of the EtO Commercial Sterilization and
Fumigation Operations source category. Given their prevalence within
this industry, it is important that the EPA understand any technical or
process differences between facilities owned by small businesses and
facilities in the rest of the source category. Specifically, the EPA
requests comment on the extent to which facilities owned by small
businesses may differ operationally from facilities operated by larger
businesses, including whether the emissions profiles differ
consistently. The EPA also solicits comment on whether small businesses
tend to own small facilities, and whether small businesses tend to use
processes that have higher or lower emissions (Comment C-19).
4. Other Distinctions Among Sterilization Facilities
    While the EPA has noted differences between the types of
sterilization facilities mentioned above, the EPA is also soliciting
comment on whether there are other types of sterilization facilities
that are markedly different in terms of processes, operations, costs,
or environmental impact when compared with traditional sterilization
facilities (Comment C-20).
V. Statutory and Executive Order Reviews
    Additional information about statutes and relevant Executive Orders
can be found at https://www.epa.gov/laws-regulations/laws-and-executive-orders.
    Under Executive Order 12866, Regulatory Planning and Review (58 FR
51735, October 4, 1993), this action is a significant regulatory action
that was submitted to the Office of Management and Budget (OMB) for
review. Any changes made in response to OMB recommendations have been
documented in the docket. This action does not propose or impose any
requirements, and instead seeks comments and suggestions for the Agency
to consider in possibly developing a subsequent proposed rule. Should
the EPA subsequently determine to pursue a rulemaking, the EPA will
address relevant statutes and Executive Orders as applicable to that
rulemaking.
    Dated: December 5, 2019.
Andrew R. Wheeler,
Administrator.
[FR Doc. 2019-26804 Filed 12-11-19; 8:45 am]
 BILLING CODE 6560-50-P