[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
------------------------------------------------------------------------
\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
----------------------------------------------------------------------------------------------------------------
 Existing and new sources subcategory   Sterilization chamber      Aeration room vent      Chamber exhaust vent
                 \1\                          vent (SCV)                 (ARV)                  (CEV) \2\
----------------------------------------------------------------------------------------------------------------
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)).).
----------------------------------------------------------------------------------------------------------------
\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.
---------------------------------------------------------------------------

    \1\ Evaluation of the Inhalation Carcinogenicity of Ethylene 
Oxide, December 2016, EPA/635/R-16/350Fc.
---------------------------------------------------------------------------

    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.
---------------------------------------------------------------------------

    \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.
---------------------------------------------------------------------------

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.
---------------------------------------------------------------------------

    \4\ https://www.epa.gov/il/outdoor-air-monitoring-willowbrook-community.
---------------------------------------------------------------------------

    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.
---------------------------------------------------------------------------

    \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.
---------------------------------------------------------------------------

    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).
---------------------------------------------------------------------------

    \7\ National Fire Prevention Association 55 Chapter 14.
---------------------------------------------------------------------------

    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).
---------------------------------------------------------------------------

    \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\
---------------------------------------------------------------------------

    \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/.
---------------------------------------------------------------------------

    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.
---------------------------------------------------------------------------

    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\
---------------------------------------------------------------------------

    \14\ See memorandum, Meeting Minutes for Discussion with 
Representatives of AdvaMed, located at Docket ID No. EPA-HQ-OAR-
2019-0178. July 2, 2019.
---------------------------------------------------------------------------

    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).
---------------------------------------------------------------------------

    \15\ See memorandum, Meeting Minutes for Discussion with 
Representative of LESNI, located at Docket ID No. EPA-HQ-OAR-2019-
0178. March 7, 2019.
---------------------------------------------------------------------------

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.
---------------------------------------------------------------------------

    \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).
---------------------------------------------------------------------------

    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\
---------------------------------------------------------------------------

    \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.
---------------------------------------------------------------------------

    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