United States Office of Air Quality EPA-453/R-94-084b
Environmental Protection Planning and Standards November 1994
Agency Research Triangle Park NC 27711
Air
& HA Ethylene Oxide
Emissions from
Commercial
Sterilization/Fumigation
Operations
Background
Information for
Final Standards:
Summary of Public Comments
and Responses
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NATIONAL EMISSIONS STANDARDS FOR
COMMERCIAL STERILIZATION AND FUMIGATION
FACILITIES --
BACKGROUND INFORMATION FOR FINAL
STANDARDS
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NATIONAL EMISSIONS STANDARDS
FOR HAZARDOUS AIR POLLUTANTS FOR
COMMERCIAL STERILIZATION AND FUMIGATION FACILITIES-
BACKGROUND INFORMATION FOR FINAL STANDARDS
Summary of Public Comments and Responses
Emissions Standards Division
U. S. Environmental Protection Agency
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
November 1994
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This report has been reviewed by the Emission Standards
Division of the Office of Air Quality Planning and Standards, EPA
and approved for publication. Mention of trade names or
commercial products is not intended to constitute endorsement or
recommendation for use. Copies of this report are available
through the Library Services Office (MD-35), U.S. Environmental
Protection Agency, Research Triangle Park, North Carolina 27711;
from the Office of Air Quality Planning and Standards Technology
Transfer Network, U.S. Environmental Protection Agency, Research
Triangle Park, North Carolina 27711; or, for a fee, from the
National Technical Information Services, 5285 Port Royal Road,
Springfield, Virginia 22161.
Publication No. EPA-453/R-94-084b
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ENVIRONMENTAL PROTECTION AGENCY
Background Information for Final Standards
Commercial Sterilization/Fumigation Operations
Prepared by:
Bruce Jordan (Date)
Director, Emission Standards Division
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
1. The final national emissions standard limits emissions of
ethylene oxide from existing and new commercial
sterilization/fumigation operations. The final standards
implement Section 112 of the Clean air Act as amended in
1990 and are based on the Administrator's determination of
July 16, 1992 (57 FR 31576) that commercial sterilization
sources generate a large amount of ethylene oxide, a
hazardous air pollutant listed in Section 112(b) of the Act.
2. Copies of this document have been sent to the following
Federal Departments: Labor, Health and Human Services,
Defense, Transportation, Agriculture, Commerce, Interior,
and Energy; the National Science Foundation; the Council on
Environmental Quality; members of the State and Territorial
Air Pollution Program Administrators; the Association of
Local Air Pollution Control Officials; EPA Regional
Administrators; Office of Management and Budget; and other
interested parties.
3. For additional information contact:
Mr. David Markwordt (MD-13)
Emission Standards Division
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Telephone: (919) 541 0837
4. Copies of this document may be obtained from:
U.S. EPA Library (MD-35)
Research Triangle Park, North Carolina 27711
Technology Transfer Network
Telephone No. for data transfer: (919) 541-5742
Telephone No. for information: (919) 541-5384
National Technical Information Service
5285 Port Royal Road
Springfield, Virginia 22161
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TABLE OF CONTENTS
1 .0 SUMMARY 1-1
1.1 SUMMARY OF IMPACTS OF PROMULGATED ACTION . . 1-1
1.2 SUMMARY OF CHANGES TO THE MACT FLOOR FOR
MAJOR SOURCE CHAMBER EXHAUST VENTS 1-2
1.3 SUMMARY OF CHANGES SINCE PROPOSAL 1-4
1.4 REFERENCES 1-10
2.0 SUMMARY OF PUBLIC COMMENTS 2-1
2.1 SELECTION OF SOURCE CATEGORIES TO BE
REGULATED 2-1
2.1.1 Source Type 2-1
2.1.2 Source Size 2-14
2.2 REGULATORY APPROACH 2-17
2.2.1 MACT Floor Interpretation 2-17
2.2.2 Technology Neutral MACT 2-19
2.2.3 MACT Considerations for Sterilization
Chamber Vents 2-20
2.2.4 Role of Risk 2-22
2.2.5 Consideration of State and Local
Regulations 2-24
2.2.6 MACT and GACT Considerations for
Aeration Room Vents 2-27
2.2.7 MACT for Chamber Exhaust Vents .... 2-35
2.3 COMPLIANCE DATES 2-38
2.4 MONITORING REQUIREMENTS 2-39
2.4.1 Initial Performance Testing 2-39
2.4.2 Monitoring for Acid-Water Scrubbers . 2-43
2.4.3 Monitoring for Catalytic Oxidizers . . 2-48
2.4.4 Monitoring for Other Control Equipment 2-54
2.4.5 Monitoring Requirements for
Sterilization Chamber Vents 2-54
2.4.6 Monitoring Requirements for Chamber
Exhaust Vents 2-55
2.4.7 Monitoring Requirements for Aeration
Room Vents 2-56
2.4.8 Monitoring Requirements in General . . 2-57
2.5 TEST METHODS 2-61
2.6 REPORTING AND RECORDKEEPING REQUIREMENTS . . 2-63
2.6.1 General 2-63
2.6.2 Relationship to the General
Provisions 2-63
2.6.3 Reporting Frequency 2-64
2.7 WORDING OF THE REGULATION 2-64
2.8 MISCELLANEOUS 2-66
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LIST OF TABLES
TABLE 2 -1.
COMMENTS RECEIVED ON THE PROPOSED EO
STERILIZATION NESHAP .
Page
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1 . 0 SUMMARY
On March 7, 1994, the Environmental Protection Agency (EPA)
proposed national emissions standards for hazardous air
pollutants (NESHAP) for commercial sterilization and fumigation
operations (59 FR 10591) under authority of § 112 of the amended
Clean Air Act (Act). Public comments were requested on the
proposal in the Federal Register. There were 19 commenters
composed of States, environmental groups, control equipment
vendors, trade groups, and commercial sterilizer
owners/operators.
The comments that were submitted along with responses to
these comments are summarized in this document. The summary of
comments and responses serves as the basis for the revisions made
to the standards between proposal and promulgation.
1.1 SUMMARY OF IMPACTS OF PROMULGATED ACTION
These standards will reduce nationwide emissions of
hazardous air pollutants (HAP) from commercial ethylene oxide
sterilization and fumigation operations by 1,030 megagrams (Mg)
(1,140 tons), or by 96 percent, in 1997 compared to the emissions
that would result in the absence of the standards.1 The
standards for sterilization chamber vent and aeration room vent
emissions are unchanged from those in the proposed preamble
[950 Mg (1,050 tons) and 48 Mg (53 tons), respectively] [as
published in the Federal Register on March 7, 1994,
(59 FR 10595)]. The standards for chamber exhaust vent emissions
account for a nationwide reduction of 34 Mg (37 tons) in 1997.^
No significant adverse secondary air impacts, water, solid waste,
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or energy impacts are anticipated from the promulgation of these
standards (59 FR 10595-10596).
Implementation of this regulation is expected to result in
nationwide annualized costs for existing ethylene oxide
commercial sterilization facilities of about $6.6 million beyond
baseline.2 Capital cost incurred by a typical uncontrolled
existing source such as a large commercial sterilization and
fumigation operation using 68,000 kilograms per year (kg/yr)
[(75 tons per year (tons/yr)] of ethylene oxide would be about
$310,000 for controlling the sterilization chamber vent emissions
(unchanged since proposal, see 59 FR 10596) and about $290,000
for controlling the aeration room vent and chamber exhaust vent
emissions.2 The annualized cost incurred by this typical source
to operate the control devices would be about $100,000 for the
sterilization chamber vent (unchanged since proposal, see
59 FR 10596) and about $80,000 for the aeration room vent and
chamber exhaust vent.2 The costing analysis is summarized and
can be found in detail in Chapter 7 of the background information
for proposed standards3 and changes to capital and annualized
costs since proposal are provided in reference 2.
The economic impact analysis done prior to proposal showed
that the economic impacts from the proposed standards would not
be significant (59 FR 10596). No changes have been made to the
promulgated rule since proposal that would increase the economic
impacts to a significant level. The economic impact analysis is
summarized in the proposal preamble (59 FR 10596) and a detailed
discussion can be found in Chapter 8 of the background
information for proposed standards.3
1.2 SUMMARY OF CHANGES TO THE MACT FLOOR FOR MAJOR SOURCE
CHAMBER EXHAUST VENTS4
The only major change to the regulation from its proposal is
the reevaluation of the MACT floor for major source chamber
exhaust vents. A general discussion of the MACT floor
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determination is given in the preamble to the proposed rule
(59 FR 10592-10593). Information submitted by commenters on the
proposed regulation indicated that a controlled MACT floor exists
for existing major source chamber exhaust vents. The control of
these vents involved the ducting of the emissions from the
chamber exhaust to a control device installed to control aeration
room vent emissions. For a source that controls aeration room
vent emissions already, the emissions from the chamber exhaust
vent are manifolded to this control device. To facilitate
combined control of the two emissions points, the air flow rate
from the aeration room to the control device is reduced when
control of emissions from the chamber exhaust vent is necessary.
This combined flow option for use with an existing control device
may also be used for manifolding the chamber exhaust vent
emissions to the sterilization chamber vent control device.
Because there are approximately 50 major sources contained
in the Agency's commercial sterilization data base, the best
controlled six facilities (12 percent) comprise the MACT floor.
The Agency therefore contacted six facilities that commenters
listed as controlling chamber exhaust vent emissions to ascertain
their major source status. Each of these six facilities
indicated that they were a major source (annual ethylene oxide
use of 20,000 pounds or more). While commenters reported
emissions reduction information for these sources, the
efficiencies reported reflect the efficiency achieved by the
control device to which multiple vent emissions are vented; the
emissions reductions achieved for the chamber exhaust vent
emissions were not verified with actual test data. Therefore,
the MACT floor for the chamber exhaust vent at existing major
source commercial ethylene oxide sterilization and fumigation
operations is control of the chamber exhaust vent. The best
controlled similar source controls emissions from the chamber
exhaust vent, and the MACT floor for new major sources is
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therefore control of the chamber exhaust vent emissions. The
emissions from the chamber exhaust vent at both new and existing
major sources either must be vented (manifolded) to a control
device achieving 99 percent emissions reduction that controls the
emissions from either the aeration room or sterilization chamber
vent control device or must be vented to a dedicated control
device that achieves at least 99 percent emissions reduction.
1.3 SUMMARY OF CHANGES SINCE PROPOSAL
Several changes have been made since the proposal of these
standards in response to public comments. The majority of the
changes have been made to clarify portions of the rule that were
unclear to the commenters. Other changes include reassessment of
the MACT floor for the chamber exhaust vent, addition of another
referenced control technology, allowing alternative monitoring
scenarios, and extending the compliance period for all sources.
All changes that have been made to the regulation are fully
explained in the responses to the comments. A summary of the
requirements for each emissions source is outlined below and
contains the following information: (1) changes to the
requirements since proposal have been identified in the outline
along with the section of this background information document
(BID) containing the discussion and rationale for the change, and
(2) in instances where no changes have been made to the
regulation since proposal, a reference has been identified for
locating the rationale used in determining the requirements.
OUTLINE-MAJOR CHANGES TO REGULATION SINCE PROPOSAL
I. STERILIZATION CHAMBER VENT
A. Standards for Sterilization Chamber Vents
No change in the level of the standards for major and area
sources from proposal on March 7, 1994. [See 59 FR 10591 (EPA
Air Docket A-88-03, Docket Entry III-A-01), pp. 10597-10600 for
rationale.]
B. Format of the Standards for Sterilization Chamber Vents
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No change in the format of the standards from proposal in
March 1994. [See 59 FR 10591 (EPA Air Docket A-88-03, Docket
Entry III-A-01 and III-A-02), pp. 10600-10601 for rationale.]
C. Compliance and Performance Testing for Sterilization
Chamber Vent
The monitoring parameters for the control devices at both
major and area sources have changed from proposal in March 1994
as follows:
1. For acid-water scrubbers, the monitoring requirement has
changed from continuously monitoring the ethylene glycol in the
proposed rule to weekly monitoring of either the ethylene glycol
concentration or the level of scrubber liquor in the scrubber
liquor tank in the final rule. (See Section 2.4.2.)
2. For oxidation units, the monitoring requirement has
changed from continuously monitoring the temperature within a
specific range (+10°F) in the proposed rule to continuously
monitoring a minimum baseline temperature in the final rule.
(See Section 2.4.3.)
II. AERATION ROOM VENT
A. Standard for Aeration Room Vent
1. Existing and New Major Sources. No change in the level
of the standards from proposal in March 1994. [See 59 FR 10591
(EPA Air Docket A-88-03, Docket Entry III-A-01 and III-A-02),
pp. 10597-10598 for rationale.]
2. New Area Sources. No change in the level of the
standard from proposal in March 1994. [See 59 FR 10591 (EPA Air
Docket A-88-03, Docket Entry III-A-01 and III-A-02), pp. 10598-
10599 for rationale.]
3. Existing Area Sources. Information submitted by
commenters indicated that existing area sources are controlling
emissions from the aeration room vent; there are at least eight
(12 percent of 68) facilities known to control aeration room vent
emissions. The MACT floor for existing area sources for aeration
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room vents is control.5 Just as MACT was rejected and GACT was
selected based on cost effectiveness of over $100,000/ton for new
area sources, the Administrator explained in the preamble to the
proposed rule that if information was submitted indicating a
controlled floor for existing area sources, MACT would be
rejected and GACT selected for existing area sources. Due to the
high cost effectiveness associated with control of existing area
source aeration room vents, MACT has been rejected and GACT
selected for this source category; GACT for this source category
is no control. [See Section 2.2.6 and see 59 FR 10591 (EPA Air
Docket A-88-03, Docket Entry III-A-01 and III-A-02), pp. 10599-
10600 for rationale.]
B. Format of the Standard for Aeration Room Vent
1. Major Sources. The final rule provides additional
flexibility to facilities by allowing sources to comply with
either the 1 part per million volume (ppmv) concentration
limitation as proposed [see 59 FR 10591 (EPA Air Docket A-88-03,
Docket Entry III-A-01 and III-A-02), pp. 10600-10601 for
rationale] or a 99 percent emissions reduction (based on
commenters' suggestions, see Section 2.2.6).
2. Area Sources. No control; no change from proposal in
March 1994.
C. Compliance and Performance Testing for Aeration Room
Vents
1. Major Sources. Facilities may demonstrate compliance by
continuously monitoring either the ethylene oxide concentration
from the aeration room vent after the control device as proposed
or by parametrically monitoring the control device achieving
99 percent emissions reduction. The monitoring parameters for
demonstrating compliance are as follows [same as listed above in
Sterilization Chamber Vent]: for oxidation units, the monitoring
requirement has changed from continuously monitoring the
temperature within a specific range (±10°F) in the proposed rule
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to continuously monitoring a minimum baseline temperature in the
final rule. (See Section 2.4.3.)
2. Area Sources. No control and therefore no compliance
requirements are necessary; no change from proposal in
March 1994.
III. CHAMBER EXHAUST VENTS
A. Standard for Chamber Exhaust Vent
1. Major Sources. Based on information submitted by
commenters and subsequent followup, there are at least six
(12 percent of 50) existing major sources known to control
chamber exhaust vent emissions by manifolding emissions to a
sterilization chamber vent or aeration room vent control device
(see Section 2.2.7). The MACT floor for existing major sources
for chamber exhaust vents is control of chamber exhaust vent
emissions by a control device. The best controlled source
controls emissions from the chamber exhaust vent by venting to a
control device; the MACT floor for new sources is therefore
control of chamber exhaust vent emissions.4 (See § 112(d) of the
Act) The standard for chamber exhaust vents specifies that a
facility may either manifold the emissions to controls for the
sterilization chamber vent or the aeration room vent or may
reduce emissions by 99 percent. (See Section 2.2.7.)
2. Area Sources. No control but facilities must
demonstrate that the source is under the 5,300 ppmv concentration
limit; no change from proposal in March 1994. [See 59 FR 10591
(EPA Air Docket A-88-03, Docket Entry III-A-01 and III-A-02),
pp. 10598-10600 for rationale.] Additional flexibility has been
added to the standard in that sources may choose to demonstrate
control by reducing emissions by 99 percent. (See
Section 2.2.7.)
B. Format of the Standard for Chamber Exhaust Vent
1. Major Sources. Sources will comply by venting to a
device achieving a 99 percent emissions reduction. The percent
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emissions reduction is consistent with the data submitted by
commenters for control devices the emissions are vented to and as
is consistent with the format for both the SCV and the ARV
standards (for manifolding purposes). (See Section 2.2.7.)
2. Area Sources. The final rule provides flexibility to
facilities by allowing sources to comply with the concentration
limit as proposed [see 59 FR 10591 (EPA Air Docket A-88-03,
Docket Entry III-A-01 and III-A-02), pp. 10600-10601 for
rationale] or with a 99 percent emissions reduction limitation
(see Section 2.2.7) .
C. Compliance and Performance Testing for Chamber Exhaust
Vent
1. Major Sources. Sources that manifold emissions would
determine the monitoring parameters based on the initial
compliance test and the parameters determined for the
sterilization chamber vent or the aeration room vent control
device. Sources with dedicated control devices would determine
the monitoring parameters based on the control technology used.
The monitoring parameters for dedicated control devices are
as follows [same as listed above in SCV]:
- for acid-water scrubbers, the requirement is weekly
monitoring of either the ethylene glycol concentration or the
level of scrubber liquor in the scrubber liquor tank. (See
Section 2.4.2.)
- for oxidation units, the requirement is continuously
monitoring a minimum baseline temperature. (See Section 2.4.3.)
2. Area Sources. Facilities must demonstrate that there
are no increases in emissions from the chamber exhaust vent by
either monitoring the ethylene oxide concentration in the
sterilization chamber prior to activation of the chamber exhaust
or by controlling the emissions from this vent. A facility may
choose to comply with the 5,300 ppmv limitation by manifolding
the emissions to a control device for the sterilization chamber
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vent or controlling the emissions with a dedicated control
device. Sources that manifold emissions would determine the
monitoring parameters based on the initial compliance test and
the parameters determined for the sterilization chamber vent.
Sources with dedicated control devices would determine the
monitoring parameters based on the control technology used.
The monitoring parameters for the dedicated control devices
are as follows [same as listed above sterilization chamber
vents]:
- for acid-water scrubbers, the requirement is weekly
monitoring of either the ethylene glycol concentration or the
level of scrubber liquor in the scrubber liquor tank. (See
Section 2.4.2.)
- for oxidation units, the requirement is continuously
monitoring a minimum baseline temperature. (See Section 2.4.3.)
IV. IMPACTS FOR THE PROMULGATED REGULATION
A. Air. Additional ethylene oxide emissions reduction is
achieved by controlling emissions from major source chamber
exhaust vents (see Section 2.2.7); the nationwide emissions
reduction increases from 93 percent (1,100 tons) reduction
anticipated in the proposed rule [see 59 FR 10591 (EPA Air
Docket A-88-03, Docket Entry III-A-01 and III-A-02), p. 10595 for
rationale] to 96 percent (1,140 tons) reduction anticipated in
the final rule.1
B. Water, Solid Waste, Noise. Minimal change from the
impacts discussed in the preamble to the proposed rule. [See
59 FR 10591 (EPA Air Docket A-88-03, Docket Entry III-A-01 and
III-A-02), p. 10596 for rationale.]
C. Energy. Minimal change from the impacts discussed in
the preamble to the proposed rule. [See 59 FR 10591 (EPA Air
Docket A-88-03, Docket Entry III-A-01 and III-A-02), p. 10596 for
rationale.]
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D. Cost. The combination of aeration room vent and chamber
exhaust vent control costs is approximately $290,000 at a typical
source, an increase of $20,000 from the $270,000 average facility
cost for controlling only the aeration room vent (increase over
proposal costs for the aeration room vent due to duct work for
the chamber exhaust vent); total nationwide costs increased from
$6.4 million to $6.6 million.2
E. Economic. Not a significant regulation per Executive
Order 12866 (58 FR 51735); minimal change from proposal. [See
59 FR 10591 (EPA Air Docket A-88-03, Docket Entry III-A-01 and
III-A-02), pp. 10604-10605 for rationale.]
V. MISCELLANEOUS
A. The compliance time for all sources has been extended
from 2 to 3 years. This extension has been provided to allow
sources additional time in complying with these standards. New
sources with startup after the 3 year compliance date will be
required to comply upon startup of the source.
B. Several commenters requested clarification of General
Provisions requirements as they relate to this rule. A table
identifying the relationship of the final General Provisions
requirements has been added to the final rule. Language similar
to that contained in the General Provisions has been added to
this regulation in cases where a direct reference to the General
Provisions was not appropriate.
C. Reporting of excess emissions is required semiannually,
whether the source has experienced excess emissions or not; the
Administrator may determine on a case basis that more frequent
reporting is necessary.
1.4 REFERENCES
1. U. S. Environmental Protection Agency. Ethylene Oxide
Commercial Sterilization Data Base. Research Triangle Park,
North Carolina. U. S. Environmental Protection Agency Air
Docket A-88-03, Docket Entry IV-A-01.
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Memorandum from Schmidtke, K.L., Midwest Research Institute
to Markwordt, D.W., EPA/CPB/CMS. October 24, 1994. Costing
of Controls for the Chamber Exhaust Vent. U. S.
Environmental Protection Agency Air Docket A-88-03, Docket
Entry IV-B-03.
U. S. Environmental Protection Agency. Ethylene Oxide
Emissions from Commercial Sterilization/Fumigation
Operations, Background Information for Proposed Standards.
Draft EIS. October 1992. U. S. Environmental Protection
Agency Publication No. EPA-453/D-93-016. U. S.
Environmental Protection Agency Air Docket A-88-03, Docket
Entry II-A-22.
Memorandum from Hearne, D.G., and Schmidtke, K.L., Midwest
Research Institute to Markwordt, D.W., EPA/CPB/CMS.
October 24, 1994. Revised Calculation of MACT Floors for
Major Source Chamber Exhaust Vents at Ethylene Oxide
Commercial Sterilization and Fumigation Operations. U. S.
Environmental Protection Agency Air Docket A-88-03, Docket
Entry IV-B-02.
Memorandum from Schmidtke, K.L., Midwest Research Institute
to Markwordt, D.W., EPA/CPB/CMS. October 27, 1994. Revised
Calculation of the MACT Floor for Area Source Aeration Room
Vents. U. S. Environmental Protection Agency Air
Docket A-88-03, Docket Entry IV-B-05.
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2.0 SUMMARY OF PUBLIC COMMENTS
A total of 18 letters commenting on the proposed rule and
the BID for the proposed standards were received during the
public comment period. Two comments were received after the
close of the comment period and were considered in finalizing the
regulation. A list of commenters, their affiliations, and the
EPA tracking number assigned to their correspondence is given in
Table 2-1.
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TABLE 2-1 AT END OF DOCUMENT
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TABLE 2-1 AT END OF DOCUMENT
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TABLE 2-1 AT END OF DOCUMENT
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For the purpose of presentation, the comments have been
categorized under the following topics:
1. Selection of Source Categories to be Regulated;
2. Regulatory Approach;
3. Compliance Dates;
4. Monitoring Requirements;
5. Test Methods;
6. Reporting and Recordkeeping Requirements;
7. Wording of the Regulation; and
8. Miscellaneous
2.1 SELECTION OF SOURCE CATEGORIES TO BE REGULATED
2.1.1 Source Type
Comment: One commenter (10) expressed concern that EPA has
not addressed ethylene oxide storage areas and the point where
the ethylene oxide storage tank is connected to the sterilization
unit as possible emissions points. At a minimum, EPA should
prevent uncontrolled venting of the unused ethylene oxide from
the tank. One commenter (19) stated that the final rule should
address equipment leaks and sterilizer door hood exhaust
emissions. The commenter indicated that these emissions points
are addressed by regulations in California.
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One commenter (17) stated that fugitive leak emissions
should be addressed in these standards. One commenter (18)
stated that a separate standard based on leak monitoring should
be established to address equipment leaks. This commenter and
one other (03) recommended that the regulation should address
leak detection and repair (LDAR) and prohibit operation of a
sterilizer (03, 18) or aerator (03) unless the maximum
concentration of ethylene oxide as measured 1 centimeter away
from any portion of the equipment, with an FID calibrated with
methane or other approved gas (18), is less than 10 ppmv.
Response: The main fugitive emissions point for
sterilization and fumigation operations is the sterilization
chamber door. The chamber door is opened slightly prior to
unloading products from the sterilization chamber, and this
opened door is an emissions point that must be properly
ventilated in order to meet OSHA standards to reduce worker
exposure to ethylene oxide. The OSHA requirement specifies that
the level of exposure to workers not exceed 1 ppmv or 1.8 mg/m3
ethylene oxide over a normal 8-hour (hr) workday and 40-hr
workweek. Emissions from the opened chamber door are typically
vented automatically by the chamber exhaust vent. Emissions from
the other fugitive emissions points listed by the commenters are
addressed by the OSHA standards for ethylene oxide sources and
are negligible. The Agency believes that the OSHA requirements
limiting worker exposure to a maximum of 1 ppmv ethylene oxide
should be sufficient to limit these fugitive emissions points and
protect employees. Based on additional data submitted by a
commenter, the chamber exhaust vent will be controlled at both
existing and new major sources (see Section 2.2.7) .
In the Agency's experience, venting of ethylene oxide from
the storage tanks is not practiced, and the Agency has received
no evidence to show that uncontrolled venting occurs. The Agency
believes that common practice for handling empty or nearly empty
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ethylene oxide tanks includes closing the valve at the outlet of
the tank, removing the tank from the line to the sterilization
chamber, and returning the tank to the chemical company or
supplier for reuse.
Comment: One commenter (10) stated that the standards for
the sterilization chamber vent should be written to specifically
delineate that the ethylene oxide drain emissions are to be
eliminated by use of a closed-loop, recirculating vacuum pump
drain and that these emissions are to be included with the
sterilization chamber vent emissions and are subject to the
99 percent control requirement. Another commenter (03) also
requested that a clear statement that it is unlawful to cause or
allow discharge of ethylene oxide to the wastewater stream from
the sterilizer exhaust pump working fluid be included in the
rule. Another (19) also stated that the final rule should
address vacuum pump drain emissions.
One commenter (06b) supported EPA's proposed requirements
for the sterilizer vacuum pump.
Response: The background information document for the
proposed standards identifies emissions from wastewater
associated with the use of once-through vacuum pumps as a
component of the sterilization chamber vent emissions stream.
Under the proposed rule, the emissions from this entire stream
are to be reduced by 99 percent. The proposed regulation
therefore provides sources with the flexibility to convert to a
closed-loop vacuum pump (a recirculating fluid pump that has no
wastewater emissions) or retain the once-through pump and choose
to control the wastewater emissions of ethylene oxide by some
other method. However, because the definition of sterilization
chamber vent includes emissions from any vacuum pump used, the
control efficiency of these vacuum pump drain emissions must be
included in the overall calculation for 99 percent emissions
reduction required for this vent. The Agency does not believe
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that an equipment-based standard such as the commenter suggests
is necessary for the vacuum pump emissions to achieve a
99 percent reduction in emissions.
Comment: Two commenters (04, 07) supported the exemptions
for research and laboratory facilities. One of these commenters
(04) stated that the regulation should not apply to research and
development vessels located at commercial sterilization
facilities, provided they meet the other requirements of
§ 63.360. The commenter stated that companies should not be
penalized for locating small research and development units at a
site where commercial sterilization occurs. The commenter added
that these units would be exempt from the proposed rule if they
were located at different sites. The commenter noted that this
is particularly onerous if the research and development units are
located in a different part of the site from the commercial scale
units and cannot utilize the same control device. Another
commenter (18) also requested that EPA clarify the application of
§ 63.360(e) to include in the exemption research and development
installations on the site of manufacturing facilities and for
profit facilities that perform contract research (e.g., product
testing) as their primary "product."
Two commenters (05, 10) indicated that the regulation should
apply to research and laboratory facilities. One commenter (05)
stated that the rule should be expanded to include research and
development vessels, provided the vessels meet the other
requirements of § 63.360. Another commenter (11) stated the rule
should include any research or laboratory facility that uses more
than the limit established in § 63.360(c). This commenter also
stated that these vessels are generally used to validate process
parameters for the production and sterilization of medical
components and, as such, are part of the manufacturing process,
not a true R&D function. This commenter also indicated that the
cost to control such equipment, because of its small size and low
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usage, is minimal. Costs for equipment would range from $15,000
to $65,000 and should not create an economic hardship for a
manufacturer even if the sterilizer is located remotely from the
main manufacturing unit.
Response: Section 112(c)(7) of the Act requires the
Administrator to establish a separate category for research and
laboratory facilities. Sources that engage in purely research
and development activities are exempt from this regulation,
however, all sterilization chambers located at commercial
sterilization facilities that are otherwise an affected source
are not exempt from the final rule. Sterilization chambers used
to develop pressure, temperature, and humidity settings are
considered part of the process procedure and are not considered
to be research or laboratory operations as defined in the Act.
Comment: One commenter (07) supported the exemptions for
medical services facilities.
Seven commenters (03, 10, 11, 15, 16, 17, 19) suggested that
the rule should apply to medical care facilities. One of these
commenters (10) indicated that their state is attempting to
locate, control, and permit all sources of ethylene oxide. This
state controls hospital sources, which typically have low release
heights and are located in urban areas, because exposure and the
associated effect on health would be great. This commenter also
stated that exempting hospital sterilizers would prevent the
regulation of a large amount of ethylene oxide which would have a
significant effect on health. Another commenter (17) noted that
in several states, many significant sources would be exempt from
the standards as written. The commenter pointed out that these
sources are not only the largest ethylene oxide emitters but are
often located in residential areas and are themselves the site of
some of the most sensitive receptors in the population. Another
of these commenters (15) indicated that hospital sterilizers are
controlled in Rhode Island and that modelling of hospitals in
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their state has shown health impacts considerably higher than
acceptable levels. The commenter added that members of the
public and sensitive individuals (e.g., persons with compromised
health, pregnant women, young children) are often within close
proximity to hospital ethylene oxide emissions. Another
commenter (03) suggested that exempting hospitals and other
sources, which emit significant quantities of ethylene oxide to
potentially sensitive populations, is unacceptable.
One commenter (16) stated that ethylene oxide emissions from
medical facilities such as hospitals represent approximately
64 percent of the sources and 17 percent of the total ethylene
oxide emissions in California. Another commenter (10) indicated
that hospital sterilizers in New York use over one-third of the
total ethylene oxide used statewide. One commenter (11)
indicated that the source-type exemptions and the ethylene oxide
usage cutoffs in § 63.360 exempt approximately 9,000 hospitals
and leave close to 600 tons/yr ethylene oxide uncontrolled, not
the 15 tons/yr of ethylene oxide left uncontrolled that was
presented in the preamble [the 15 tons/yr was calculated as the
residual ethylene oxide emissions from commercial sterilizers
after the standards].
Two commenters (10, 11) provided information regarding the
economic burden of controlling ethylene oxide emissions from
hospital sources. One of these commenters (11) indicated that
the financial burden to a hospital is minimal as the control
equipment for this segment costs between $15,000 and $35,000,
depending on sterilizer size. The other commenter (10) indicated
that the economic burden associated with controlling the medical
services facilities has not resulted in a significant removal of
sterilizers from hospitals in their state.
One commenter (17) suggested that because some distinction
between hospitals and commercial interests is warranted, EPA
could consider reduced administrative requirements for medical
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facilities. One commenter (18) stated that in the event EPA
chooses to regulate hospital sterilizers using less than 1 ton/yr
ethylene oxide, an exemption should be provided for sources
subject to stringent State/local standards, Title V permits
should not be required, and administrative requirements should be
limited.
One commenter (19) stated that EPA's actions under § 112(d)
should not be treated as a distinct activity wholly separate from
work under § 112(k). This commenter stated that EPA should
address smaller ethylene oxide sources under these standards
rather than under the urban air toxics program. The commenter
noted that this would be more protective of human health and the
environment and reduce the level of effort required from the
Agency. This commenter also stated that the proposed rule
ignores EPA's broader responsibility under the Clean Air Act to
establish abatement strategies for sources of air toxics
emissions in urban areas, a program that provides additional
impetus and legal authority to establish lower applicability
cutoffs and to regulate sterilizers located at medical
institutions such as hospitals. The commenter also stated that
the exempt and excluded facilities under the proposed rule typify
area sources of hazardous air pollution that contribute to health
risks in urban areas; control of emissions from such sources will
be needed to achieve the legislative mandate to reduce cumulative
exposures to hazardous air pollutants from many relatively small
emissions sources. In addition, the commenter indicated that
ethylene oxide is prototypical of the type of pollutant and uses
that Congress directed EPA to address under the urban air toxics
program and that EPA should address such pollutants and source
categories under the § 112(d) standards rather than deferring
control to the § 112(k) program, which is running behind
schedule.
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Two commenters (15, 17) stated that if hospitals are not
included in this regulation, then they should be listed as a
separate source category for MACT standards; one of these
commenters (17) also stated these operations should be subject to
later review under § 112(f). Another commenter (19) indicated
that if EPA does not address hospital sterilizers under these
NESHAP, hospital sterilizers should be added to the list of
source categories as soon as possible and EPA should concurrently
propose application of the commercial sterilizer standards to
hospital sterilizers. This commenter noted that hospital
sterilization was initially included on the proposed source
category list but was dropped from the final source category list
and that the commenter was therefore unaware that this category
had been dropped until reading the definition of "commercial
sterilizer" in this proposed rule and realizing that it was being
defined so as to exclude hospitals. The commenter stated that
EPA should broaden the definition of commercial sterilization to
include hospital sterilizers. The commenter asserted that there
is no fundamental difference between ethylene oxide sterilization
carried out in a commercial sterilizer as defined in the proposed
rule and ethylene oxide sterilization in a hospital.
Response: The reference to hospital sterilizers was
included in the regulation for clarification purposes in defining
commercial sterilizers. It is important to note that
sterilization at hospital facilities was not exempted in a true
sense but was omitted based on the definition of commercial
sterilization. The EPA originally listed "commercial
sterilization facilities" and "hospital sterilization facilities"
as two separate categories on the proposed source category list.
These source categories by definition did not overlap. When it
was decided not to include hospital sterilizers on the final
source category list, only commercial sterilization facilities
remained on the list. Source categories have to be on the source
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category list to be regulated by EPA under § 112(d) of Title III.
The source category list was published on July 16, 1992
(57 FR 31576); the public was given an opportunity to review and
comment on the list. Section 112(c) requires EPA to establish a
list of source categories of major and area sources that emit
these HAP and to promulgate regulations for each of these source
categories under § 112(d); this section also specifies that the
source category list will be periodically revised in response to
public comment or new information. If hospitals are added to the
source category list at a future date, hospital sterilizers will
be placed in the 10-year promulgation bin. In addition, the
majority of hospital sources emit less than 1 ton/yr. If this
rule for commercial sterilization had been developed in
conjunction with hospital sterilization, the majority of hospital
sterilization sources would not be included due to the area
source emissions exemption of 1 ton/yr (see Section 2.1.2).
The Agency believes that it is appropriate to address the
urban air toxics program of § 112(k) separately from this
rulemaking. The urban toxics study will include a large variety
of sources; hospital sterilization sources and sources with
emissions less than 1 ton/yr will likely be assessed as part of
this under § 112(k).
Because sterilization operations performed at medical
facilities are not subject to these NESHAP, consideration of
alternative administrative requirements and Title V issues for
medical facilities is not necessary. (See Section 2.2.4 for
discussion of risk and see Section 2.2.6 for discussion of
§ 112 (f) .)
Comment: One commenter (18) stated that the Agency has
expanded the source category description to include fumigation
operations while limiting the source category to operations that
use ethylene oxide as the sterilant/fumigant. The commenter
recommended that EPA provide rationale for their decision to
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restrict the applicability of the rule to ethylene oxide and not
cover operations that use other sterilant/fumigant gases (e.g.,
methyl bromide) and to amend the source category description in
the source category list. Another commenter (17) also suggested
that other sterilants and fumigants besides ethylene oxide (e.g.,
methyl bromide) should be regulated under this source category,
and if they are not included, then these operations using the
other sterilants and fumigants should be listed as a separate
source category. Another commenter (06b) questioned whether EPA
will regulate manufacturers of ethylene oxide as well.
Response: The Agency would like to point out that
fumigation processes have always been a part of this regulation
and were not added to the source category; the Agency considers
sterilization and fumigation processes to be the same, with the
processes being used for eliminating microorganisms and vermin
(insects), respectively. As is evident, the only HAP compound
regulated in this rule for the commercial sterilization and
fumigation source category is ethylene oxide. The category
listed on the final source category list (57 FR 31576) for which
this rule was developed relates specifically to ethylene oxide
commercial sterilization processes. Other categories of
sterilization facilities using other HAP as the sterilizing
compound were not identified on the source category list and
therefore will not be regulated by EPA at this time. Other types
of sterilization processes may be added to the source category
list in the future.
While ethylene oxide production is not listed specifically
on the source category list, ethylene oxide is one of
approximately 400 chemicals listed in the Synthetic Organic
Compound Manufacturing Industry NESHAP (SOCMI; also referred to
as the Hazardous Organic NESHAP, or the HON). Manufacturers who
produce ethylene oxide and emit HAP compounds as a result of this
production or who use ethylene oxide as a raw material in the
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production of another listed SOCMI chemical are subject to the
SOCMI NESHAP.
Comment: One commenter (10) noted that some States, by
State law, are not able to regulate pollutant emissions more
stringently than a Federal regulation. The commenter added that
this would prevent these States from regulating facilities
exempted in §§ 63.360(b) through (f), such as hospital
sterilizers. Another commenter (17) stated that EPA should
mandate strong standards on a national scale and not rely on
State and local agencies to compensate with stronger measures,
since some States will be precluded from going beyond Federal
requirements.
One commenter (18) requested that if the sources are
regulated under a stringent State or local standard, EPA should
continue to exempt hospital sterilizers and small sterilizers
(using less than 1 ton/yr ethylene oxide) from any otherwise
applicable requirements, including Title V permitting and
administrative requirements. This commenter also recommended
that EPA require control of the aeration room vents unless they
are required to control aeration room vent emissions under a
stringent State or local requirement.
Response: There are several State and local regulations
that require control of ethylene oxide emissions from commercial
sterilization operations. The EPA agrees that there may be
instances where the Federal emissions standards could be less
stringent than a State or local standard. The NESHAP are
intended to be representative of maximum achievable control on a
national basis, and the Agency recognizes that in some areas the
standards may not address individual air pollution control needs.
While States are prohibited from adopting standards that are less
stringent, they may go beyond the Federal requirement and adopt
standards that are more stringent. Certain States use Federal
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rules as a baseline for their own regulations and it is at the
State's discretion to go beyond the Federal requirement.
The fact that a State currently regulates a particular
source that is also the subject of NESHAP does not predispose
those facilities to exemption from the Federal regulation and its
requirements. The NESHAP apply to all major and in some
instances area sources within the subject source category.
However, if a source is currently controlling emissions from
commercial sterilization to comply with a State or local rule,
they may have sufficient control in place to meet this standard
as well. In addition, reporting required for a State rule may
also be submitted to fulfill the reporting requirements for the
Federal rule given that all of the appropriate information is
contained in the State report (i.e., ethylene oxide usage, test
data, excess emissions, etc.). States will likely be delegated
the authority for implementing rules for Part 63.
2.1.2 Source Size
Comment: Eight commenters (03, 10, 11, 15, 16, 17, 18, 19)
requested that EPA reevaluate the emissions cutoff for area
sources. These commenters pointed out that several States are
requiring lower cutoffs, as low as 2.5 pounds per year (Ib/yr),
than the 1 ton/yr cutoff found in the proposed rule and indicated
that these State regulations should be considered. One of these
commenters (16) indicated that facilities with ethylene oxide
emissions less than 1 ton/yr represent a large segment of the
ethylene oxide emitted in its district. Another commenter (11)
suggested that the emissions cutoff should be 100 Ib/yr
[0.05 ton/yr] for area sources. Another (19) suggested that the
emissions cutoff be lowered to include sources using 4 Ib/yr or
more of ethylene oxide. One commenter (17) indicated that the
applicability threshold should be established to include area
sources as well as sources that are considered "major."
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One commenter (18) stated that EPA's justification for the
1 ton/yr cutoff (cost-effectiveness data and low emissions
contribution) was not sufficient and was counter to the
commenter's experience; the commenter requested a better
justification for this cutoff. One commenter (19) stated that
cost-effectiveness analysis is inappropriate and irrelevant to
EPA's selection of an applicability cutoff. The commenter stated
that the 1 ton/yr cutoff is arbitrary and inequitable, both for
commercial sterilizers and for people living near ethylene oxide
facilities. The commenter added that EPA's reliance on
cost-effectiveness analysis to establish a regulatory cutoff of
one ton is inappropriate because it does not speak to feasibility
or to the actual cost to a facility or affordability of controls.
The commenter referred to CARB estimates of the costs of
compliance with its commercial and hospital ethylene oxide
sterilization regulations indicating an annualized cost of
$24,000 - costs that most small businesses would be able to
absorb without significant adverse impact on their profitability.
The commenter stated that the fact that controls are in place for
all sterilizers down to the 4 Ib/yr use level in California
indicates that it is not only achievable, but also affordable, to
control ethylene oxide emissions from sources under 1 ton/yr.
The commenter stated that local impacts on individuals living
near ethylene oxide sources should be the critical issue in
determining an applicability cutoff. The commenter asserted that
because there is a greater potential for human exposure from
thousands of small sources located in commercial and residential
areas that vent ethylene oxide directly into the atmosphere than
from the few facilities that manufacture the substance, these
smaller sources should be controlled under the standards.
Two commenters (10, 16) indicated that the majority of
ethylene oxide sterilization and fumigation sources located in
their State and district will not be subject to the proposed rule
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due to the combination of the ethylene oxide usage cutoff and the
source exemptions; another commenter (18) stated that the
exemptions of the proposed rule apply to all ethylene oxide
sterilizers in their district. One of these commenters (10)
stated that, considering the large number of ethylene oxide
sources and the high toxicity of this contaminant, the
applicability of the final rule should be expanded so that a
larger number of facilities would be controlled by this Federal
MACT standard.
Two commenters (10, 11) indicated that the emissions cutoff
limit for the sterilization chamber vent should be either
eliminated or reduced. One of these commenters (11) pointed out
that several States require controls for emissions from
sterilization chamber vents for sources as low as 25 Ib/yr
[0.013 ton/yr]. This commenter suggested reducing the emissions
cutoff to 100 Ib/yr [0.05 ton/yr] for sterilization chamber
vents. The other commenter (10) suggested that the emissions
cutoff should be eliminated or substantially reduced.
One commenter (11) requested that the emissions cutoff for
regulation of exhaust chamber vents be lowered to 5,000 Ib/yr
[2 .5 tons/yr] .
Response: The Agency believes the 1 ton/yr emissions cutoff
for affected area sources is appropriate for this regulation.
The Agency believes low emissions contribution and high cost
effectiveness are sufficient reasons for placing the cutoff at
1 ton/yr. The EPA has considered the potential cost (including
costs for monitoring, recording, and recordkeeping) to small
sources by establishing a cutoff at 1 ton/yr. Emissions cutoffs
for area sources are at the discretion of the Agency. The
commenters presented no compelling reason to lower the cutoff for
commercial sterilization area sources; in addition, the Agency
received no information from commenters to support their
statements regarding the impacts to the public. Sources emitting
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less than 1 ton/yr of ethylene oxide will continue to be exempt
from requirements for the sterilization chamber, chamber exhaust,
and aeration room vents. (See Section 2.2.4 for discussion of
risk.)
Comment: One commenter (03) indicated that an applicability
statement based on facility-wide usage [of ethylene oxide] would
be appropriate and that control requirements should be based on
the amount of ethylene oxide emissions; this commenter also
stated that the control technology requirements should be based
on technical feasibility for a facility emitting a specified
amount of the pollutant, regardless of the type of facility. One
commenter (17) agreed that the applicability for the rule should
be based on actual usage of ethylene oxide rather than on a
theoretical maximum potential-to-emit.
Another commenter (05) suggested that the potential-to-emit
issue (opened to public comment and separate rulemaking in the
final General Provisions) should be fast-tracked or the NESHAP
for ethylene oxide should be delayed to avoid confusion and
inappropriate characterization of a given source.
Response: Ethylene oxide usage data are used for
"applicability" purposes in determining sources subject to the
regulation. The applicability of the standards is based on
actual annual ethylene oxide usage and is Federally enforceable.
The provisions addressing the General Provisions in the final
regulation indicate that applicability for these source
categories is based on actual emissions rather than potential-to-
emit. Control levels are not based on the emissions levels of
the source; the control requirements for NESHAP regulation of
major and area sources are based on MACT or MACT/GACT
determinations. All sources subject to these NESHAP with similar
ethylene oxide usage, regardless of the type of facility, are
required to control at the same stringency.
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2.2 REGULATORY APPROACH
2.2.1 MACT Floor Interpretation
Comment: One commenter in two comment submittals (01 and
19) stated that the Agency should average the emissions
limitations achieved by the sources in the top 12 percent of a
source category in order to determine the average emissions
limitation of the best performing 12 percent of the existing
sources. The commenter stated that EPA should not use the
88th percentile to calculate the MACT floor and supplied several
instances from the legislative history of the Clean Air Act to
support this statement. The commenter agrees with EPA that this
matter is of great precedential importance and asserted that an
incorrect interpretation of the MACT floor would increase the
likelihood of more emissions remaining wholly uncontrolled in
spite of MACT standard setting efforts and an increased
likelihood of court intervention in determining the legislative
intent of the MACT floor language.
The commenter also stated that the fact that the average
yields an emissions limitation corresponding to no particular
technology should not preclude its use; the MACT floor is a
floor. The commenter added that in cases where the actual
average does not match the most stringent emissions limitation
achievable by any particular technology, EPA may properly set the
MACT standard above the median; EPA has the authority to go above
the floor but lacks the authority to go below the floor or to
manipulate the floor to make it contrary to Congressional intent.
The commenter stated that the final rule should use a straight
average, not a median; if the final rule uses a median, the
Agency must explain why use of a median is appropriate as a
matter of statutory interpretation and provide a reasoned
explanation for the decision to use the median in this case.
Response: The Agency appreciates the commenter's opinion on
the determination of the MACT floor. In a March 9, 1994,
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Federal Register notice reopening the public comment period for
determination of the MACT floor for NESHAP source categories
(59 FR 11018), the Agency considered more than one interpretation
of the statutory language concerning the MACT floor for existing
sources and solicited comment on them. After consideration of
the comments received in response to this request, the Agency
published a final rule in the Federal Register on June 6, 1994,
(59 FR 29196). In this final rule, the Agency determined that
the MACT floor would be determined by averaging the best
performing 12 percent of sources. This was the method followed
in determining the MACT floor in the proposed rule and is the
method being used in determining the MACT floor in the final
rule. In this notice, the Agency left open the use of the
94th percentile in cases where the average does not match a
control technology.
Regarding the commenter's concern about use of the
94th percentile (median value) for determining the MACT floor, a
discussion in Section 2.2.6 of additional data supplied by a
commenter for area source aeration room vents indicates the MACT
floor for existing area source aeration room vents is controlled.
In the final rule, the MACT floor is determined based on a mean
rather than a median value.
2.2.2 Technology Neutral MACT
Comment: Several commenters (08, 17 and 18) supported EPA's
approach in determining MACT as technology neutral. One of these
commenters (18) supported this flexibility because it would
provide implementing agencies the authority (through delegation
under Subpart E) to approve or deny the selected technology.
Another of these commenters (17) stated that it was acceptable to
allow sources to select their control methods provided they meet
a specified percent reduction, which gives industry flexibility
as well as an incentive to develop new control technologies.
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This commenter added that this flexibility must be accompanied by
a mandate to sources to meet a strong performance standard.
One commenter (18) recommended that the language of
§ 63.362(a) should be revised to require control of ethylene
oxide emissions from the sterilization chamber vent with an
approved abatement device and then specify the performance of the
device.
Response: The Agency appreciates the support for the
development of these emissions reduction and emissions limitation
standards. The Agency does not believe that it is necessary to
require equipment-based standards such as one of the commenters
recommends for sterilization chamber vents. The Agency has
selected emissions reduction standards that provide the owner or
operator the flexibility to choose how to achieve the required
emissions reductions.
2.2.3 MACT Considerations for Sterilization Chamber Vents
Comment: Six commenters (10, 11, 13, 15, 18, 19) suggested
that more stringent control requirements for the MACT standards
are appropriate. One commenter (19) stated that they disagree
with EPA's belief that there is little or no practical difference
between a 99 percent control requirement and a 99.9 percent
control requirement, because either standard would compel use of
the same general type of control device and that the device, in
actual practice, would achieve whatever reductions it is capable
of, regardless of the numeric standard. The commenter asserted
that a more stringent standard would lead to better operation and
maintenance practices that would enhance the degree of emissions
reductions achieved. The commenter stated that EPA has not set
the standards based on information available from control device
vendors regarding the efficiency of their control devices. The
commenter referred to information from vendors indicating greater
than 99.9 percent control from catalytic oxidation units. The
commenter stated that based on this information and information
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in the BID, the final standard require 99.9 percent emissions
reduction using catalytic oxidation for new sources.
One commenter (11) supplied information for sterilization
facilities that indicated an emissions reduction of 99.9 percent
from the sterilization chamber vent. The commenter was aware of
29 industrial units operating at this level of efficiency. One
commenter (10) identified two major sources and three area
sources above 1 ton/yr controlling sterilization chamber
emissions by at least 99.8 to 99.9 percent. The commenter
suggested that EPA contact these and other manufacturers to
validate their claims and consider a higher control efficiency
requirement for the sterilizer vent. The commenter stated that
all sources in New York with an emissions rate potential greater
than or equal to 1.0 Ib/hr are required to install 99 percent
control or greater or best available control technology (BACT).
One commenter (15) stated that the proposed 99 percent control
efficiency for sterilization chamber vent emissions is not
stringent enough nor is it consistent with the requirements of
new source MACT. One commenter (18) recommended that EPA adopt a
99.9 percent level of control for existing sources subject to the
NESHAP as is the case in California. The commenter stated that
new source MACT for sterilization chamber vents should be set at
99.99 percent emissions reduction as this level of reduction has
been shown in the BAAQMD.
One commenter (13) added that air permits issued recently in
New Jersey have required a destruction efficiency of at least
99 percent, however, the annual emissions from some facilities
meeting the minimum destruction efficiency requirement may be
subject to additional control measures, such as improved
dispersion and higher efficiency control, because of the
carcinogenic risk of ethylene oxide.
Response: These NESHAP were based on the technological
state of achieved emissions control (i.e., MACT for major
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sources, MACT and GACT for area sources). The Agency appreciates
the submittal of data. Regarding the commenters' view on the
establishment of the MACT floor at 99 percent emissions reduction
for sterilization chamber vents, the Agency notes that the
information submitted by commenters was not sufficient to
demonstrate that an emissions reduction of 99.9 percent could be
achieved on a continuous basis. The Agency therefore does not
believe that a reassessment of MACT for the sterilization chamber
vent is technically defensible. The Agency believes that the
control technologies in use at the facilities the commenter is
referring to (i.e., facilities achieving 99.9 percent control)
are the same technologies that will be used at facilities
required to meet the 99 percent standard.
Comment: One commenter (04) suggested that the use of
thermal oxidizers should also be considered MACT for sterilizer
chamber vents. The commenter noted that it was aware of several
facilities that are using this technology to control chamber
vents and that field test data from these units have demonstrated
99 percent removal efficiency as long as a stable flame is
present, regardless of stack temperature.
Response: The MACT for sterilization chamber vents is
99 percent reduction of ethylene oxide emissions and is
technology neutral; an owner or operator may comply with MACT by
use of any technology capable of meeting the 99 percent emisson
reduction efficiency. The Agency agrees that thermal oxidizers
meet the reduction efficiency and has included compliance
provisions for thermal oxidizers in § 63.363. The requirements
of this technology are similar to those for the catalytic
oxidizers; monitoring requirements are included in Section 2.4.4.
2.2.4 Role of Risk
Comment: Five commenters (10, 13, 15, 17, 19) indicated
that the resulting risk from the proposed rule is unacceptable.
One of these commenters (19) asserted that more stringent
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standards would be justified because of the extreme toxicity of
ethylene oxide. This commenter also suggested the establishment
of a lesser quantity cutoff [i.e., a lower emissions cutoff,
because the term lesser quantity cutoff is specific to lowering
of the 10 tons major source cutoff] for area sources due to the
health evidence for ethylene oxide [below 1 ton/yr]. Another
commenter (10) stated that the State of New York regulates all
ethylene oxide emissions points under 6NYCRR Part 212 as a high
toxicity contaminant. The commenter added that because of the
hazardous health effects associated with exposure to small
concentrations of a high toxicity contaminant, emissions points
that release from 0.1 to 1.0 Ib/hr are also required to install
controls, and controls may be required for emissions rates less
than this. This commenter provided modelling data indicating
risk factors and cancer incidences for New York facilities that
would result from the proposed rule:
1. For sterilization chamber vent sources with less than
1 ton/yr ethylene oxide emissions, the short-term effect results
in an impact over 32,400 //g/m3 and the cancer risk for an
uncontrolled 1 ton source of ethylene oxide was estimated to be
over 200 in 1 million;
2. The risk factor and cancer incidence resulting from the
5,300 ppmv limit on the chamber exhaust vent are over
144,000 //g/m3 and 1 in 500, respectively;
3. The risk factors and cancer incidences resulting at a
10 tons source from the overall proposed rule include a
short-term modelled impact for the three combined emissions
points of over 900 //g/m3 and a cancer risk estimated to be 1 in
3,500; and
4. The short-term impacts for a source not covered by the
NESHAP range from 650 to 900 //g/m3 and the cancer risk was
estimated at 40 in 1 million.
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Another commenter (13) stated that the New Jersey Department
of Environmental Protection and Energy regulates ethylene oxide
emissions as VOC's and further requires that the incremental risk
of cancer posed by new and modified equipment is no more than
1 in 10,000 and preferably less than 1 in 1,000,000. This
commenter estimated risk factors for EPA's proposed chamber
exhaust standards and stated that this would amount to 40 Ib/yr
(from a facility using the least amount of ethylene oxide
addressed by these standards), which for many facilities would
pose more than 1 in 1 million increased cancer risk. This
commenter suggested that emissions from the chamber exhaust
should be controlled at major sources because of the risks posed
by the amount of ethylene oxide uncontrolled from this vent. The
commenter suggested that a lower concentration of about
1,000 ppmv be considered for the chamber exhaust vent standards.
One commenter (15) stated that the impacts are unacceptable
without controls on aeration emissions. This commenter stated
that ethylene oxide emissions in excess of 100 Ib/yr result in
unacceptable impacts and another (17) stated that emissions of
ethylene oxide less than 1 ton/yr can pose a substantial health
risk.
Response: The Agency has considered the data submitted by
commenters regarding the risk of ethylene oxide related to the
regulation. While risk may be considered in some determinations
related to this rule, such as including area sources on the
source category list, it is important to note that these NESHAP
are technology-based standards and are determined by the maximum
emissions reduction achieved in practice, not by risk assessment.
Therefore, statements requesting that MACT be more stringent due
to the risk impacts from ethylene oxide are not appropriate. In
addition, the Agency is required to consider MACT for area
sources but may elect to require GACT if MACT is unreasonable.
Where appropriate, the Agency has considered the health effects
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of ethylene oxide in conjunction with cost effectiveness. Risk
for sources below I ton/yr and for aeration room vents at
affected area sources greater than 1 ton/yr were calculated by
the Agency and were not determined to be significant when
considered in conjunction with cost effectiveness. While the
Agency appreciates the information submitted by commenters
indicating high risk impacts associated with the standards, the
EPA is not certain of the methodologies used to calculate the
submitted risk information and did not receive sufficient
information that supports the commenters' statements regarding
risk for each of the emissions points.
The Agency also notes that it is required to focus on the
remaining risk from emissions not subject to the NESHAP. After
implementation of these NESHAP for the source category, the
Agency will examine the residual risk for major sources and area
sources subject to MACT for this source category under § 112(f)
of the amended Act. The Agency will then promulgate standards if
necessary to reduce excessive risks.
2.2.5 Consideration of State and Local Regulations
Comment: Five commenters (10, 16, 17, 18, 19) suggested EPA
consider State and local regulations in MACT determinations. One
commenter (19) stated that EPA's proposed standards for major and
area sources are inadequate because they exempt certain emissions
points from control and because the standards for the emissions
points that are regulated do not reflect "maximum achievable
control technology" as required by the Clean Air Act. The
commenter stated that EPA should consider State and local
regulations when identifying MACT and the MACT floor. The
commenter added that a consideration of State and local standards
would compel EPA to lower applicability levels, increase the
stringency of the emissions limits for major and area sources for
aeration rooms, sterilizer vents, and to control chamber exhaust
vents and other emissions points. This commenter disagrees with
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EPA's position that standards may not be established without
emissions reduction data regardless of State and local
regulations.
Several commenters (16, 17 and 19) stated that the best
controlled similar sources for ethylene oxide sterilization and
fumigation are those facilities in the State of California that
are currently meeting the requirements of CARB's ATCM and AQMD's
Rule 1405. The commenters suggested that the MACT floor for new
and existing sources be revised to reflect a higher destruction
efficiency (the commenter submitted a copy of AQMD Rule 1405 and
the respective control technologies and emissions cutoffs). One
commenter (16) suggested that EPA adopt more stringent levels
such as those currently being implemented and enforced in
California. The commenter added that this is feasible and cost
effective as evidenced by the commenter's experience (the
commenter stated that data are available to support this
suggestion). One commenter (19) indicated California State and
local regulations that require more stringent controls than those
required under the proposed regulation. The commenter stated
that a review of State and local aeration room vent standards
would compel EPA to regulate aeration room emissions from area
sources (the commenter noted California State and local
regulations). The commenter also referred EPA to SCAQMD for
emissions reduction data on chamber exhaust control devices. The
commenter recommended that controls be required for chamber
exhaust vents at major and area sources because California
requires controls of this vent at facilities using more than
600 Ib/yr of ethylene oxide. Another commenter (18) stated that
because BAAQMD regulations require control of chamber exhaust
vents at sources using more than 600 Ib/yr of ethylene oxide, the
NESHAP should be revised to include these controls at least for
new sources.
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One commenter (10) stated that EPA has failed to consider
New York's program when determining the MACT standard for
ethylene oxide commercial sterilization. The commenter stated
that the State of New York maintains a Source Management System
(SMS) data base of 79 facilities with ethylene oxide sterilizers;
EPA did not evaluate the MACT standard and the 12 percent MACT
floor using New York's current data base. The commenter stated
that failure to use current data neglects sources located and
controls required for ethylene oxide sources in New York in
recent years.
Response: The standards for this source category were based
on the data available to the Administrator at the time of
proposal and on data submitted by commenters after proposal.
Section 112(d)(3) of the Act states that MACT emissions
limitations are based on the "best performing . . . existing
sources . . . for which the Administrator has emissions
information." The Agency developed a nationwide commercial
sterilization data base that it believes accurately represents
commercial ethylene oxide sterilization and fumigation operations
on a national basis (commenters submitted additional data
regarding control of area source aeration room vents and major
source chamber exhaust vents and this information was
incorporated into the data base, see Sections 2.2.6 and 2.2.7,
respectively). This data base was used in determining MACT
floors for the emissions points addressed in the NESHAP and
includes information on 13 New York and 19 California commercial
ethylene oxide sterilization and fumigation operations. The
Agency appreciates notification that a State data base is
available.
The EPA did consider State programs in determining these
standards. In regard to the emissions reduction required for
sources in New York and California, the Agency appreciates the
information and believes that it supports the Agency's findings
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of the level of control at the MACT floor. The statement that
there are 79 facilities with ethylene oxide sterilizers in New
York does not necessarily correspond with the Agency's data base
because the Agency is uncertain whether this figure represents
sterilization units at facilities that are not addressed under
these standards (e.g., hospital sterilization facilities).
Because the standards in the final rule require the same minimum
level of control as the New York State requirements (99 percent
emissions control for the sterilization chamber vent, a maximum
emissions concentration of 1 ppmv ethylene oxide for the aeration
room, and a control requirement or an emissions limit for the
chamber exhaust vent), the Agency does not see where its
determination of MACT has not considered these facilities. The
California control requirements include a 99 or 99.9 percent
control efficiency for the sterilization chamber vent depending
on the size of the source and a 95 or 99 percent control
requirement for the aeration room vent depending on the source
size. The Agency has not received sufficient information to
demonstrate an emissions reduction of 99.9 percent on a
continuous basis. The California regulation also requires
combined control of the aeration room vent and the chamber
exhaust vent for sources greater than 2.5 tons/yr ethylene oxide
usage but does not require source testing to confirm the
emissions reduction achieved continuously. The New York and
California requirements do apply to commercial ethylene oxide
sterilization and fumigation operations using smaller amounts of
ethylene oxide, i.e., nonmajor sources, but it is the prerogative
of any State to be more stringent than Federal emissions
standards.
2.2.6 MACT and GACT Considerations for Aeration Room Vents
Comment: One commenter (18) recommended that sources using
at least 20,000 Ib/yr [10 tons/yr] of ethylene oxide be required
to reduce aeration room vent emissions by 99 percent or to
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1 ppmv, whichever is more stringent, and that emissions below the
detection limit of the test be considered in compliance. One
commenter (17) stated that because the 1 ppmv emissions limit can
be circumvented by increasing the air flow through the vent,
sources required to meet the standard should be required to meet
a <1 ppmv concentration and 99-percent control requirement, so
that the more stringent limit prevails.
One commenter (14) stated that the standard as written would
not allow use of one piece of equipment to control both the
sterilizer vent and aeration room vent emissions, i.e., if there
are simultaneous emissions from both vents, it may not be
possible to show that aeration room vent emissions are controlled
to less than 1 ppmv. Use of a catalytic oxidizer will give
99 percent control of aeration room vent emissions, which
typically are less than 50 ppmv, so that controlled emissions
will be under the 1 ppmv limit. However, given that sterilizer
vent emissions, which may be several thousand parts per million,
are also controlled, total emissions from a combined control
system may be greater than 1 ppmv even with overall 99 percent
control.
Response: The Agency proposed a 1 ppmv emissions limit for
major source aeration room vents because the inlet concentrations
from the aeration room vents are typically relatively low and
because the outlet concentrations of some of the controlled
aeration room vents approach the levels of detection for ethylene
oxide and would preclude a demonstration of compliance with an
"equivalent" percent reduction standard (i.e., the control device
is achieving 99 percent reduction and the outlet concentration is
below the detection limit). The commenters' suggestion to
require the more stringent limit or reduction for this emissions
point is not technically feasible for sources with low ethylene
oxide concentration because the outlet may not be detectable.
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While the inlet concentration for most aeration room vents
alone is typically less than 100 ppmv, the inlet concentration to
the control device for some aeration room vents, especially those
manifolded with other vents such as the chamber exhaust vent, may
be greater than 100 ppmv. If a control device used to control
these emissions is operating at 99 percent efficiency, then such
a source would not meet the 1 ppmv standard for this emissions
point. The final rule therefore provides additional flexibility
for facilities by allowing owners or operators of major sources
to control emissions from aeration room vents either to a maximum
outlet concentration of 1 ppmv or a 99 percent reduction of the
inlet concentration, whichever is less stringent. There has been
no change in the level of the standard for major source aeration
room vents since proposal; the percent reduction and the
concentration limit are equivalent requirements.
Comment: Eleven commenters (03, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19) indicated that control requirements for area sources
are not appropriate. One commenter (10) believed that risk
should be considered when determining whether to apply MACT or
GACT to area sources. Two commenters (16 and 19) suggested that
MACT standards be used for new area sources as well as for
existing area sources. One of these commenters (16) stated that
they have annual source test results to support this
recommendation and stated that the availability, feasibility, and
cost effectiveness of controls have been demonstrated in the
South Coast Air Basin. One commenter (13) stated that the
proposed control requirements for area sources (i.e., MACT for
existing area sources and GACT for new area sources) [aeration
room vents] appear to be applied contrary to the method expected.
The commenter added that this leads to the standards for new
sources being less stringent than the standards for existing
sources, which is the reverse of common practice. The commenter
recommended that the same emissions standards be applied to both
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new and existing area sources. The commenter suggested that MACT
be applied to area sources, with less stringent requirements for
recordkeeping and reporting than for major sources. One
commenter (11) suggested that EPA recalculate the best performing
12 percent MACT floor for area sources.
Four commenters (03, 11, 17, 18) indicated that the
regulation for aeration room vents should apply to sources having
emissions less than 10 tons/yr. One of these commenters (03)
indicated that all facilities should be required to control
emissions from the aeration room vent and indicated that some
States do require control of this vent. One commenter (15)
suggested that all regulated sources be required to control both
aeration and sterilizer exhaust emissions. The commenter stated
that such controls have been required in Rhode Island for
commercial sterilizers. One commenter (13) suggested that
aeration room vent emissions be directed through the sterilizer
control device. The commenter stated that the acid-water
scrubber should be effective at this low concentration but
questioned if catalytic oxidizers would be effective. One
commenter (12) constructed an acid-water scrubber for combined
control of sterilization chamber and aeration room vents. One
commenter (10) indicated that one catalytic oxidizer at a
New York facility controls both the sterilizer vents and aerator
exhaust.
Another commenter (17) recommended a 1 ton/yr emissions
cutoff for regulation of aeration rooms and also indicated that
several State and local agencies have adopted this cutoff,
proving that such measures are feasible and cost effective. The
commenter added that this cut-off would be more protective of
public health. This commenter also stated that aeration room
vents should be controlled by 95 to 99 percent at new sources
using 600 Ib/yr [0.3 ton/yr] or more. One commenter (18)
recommended that sources using between 600 Ib/yr and 5,000 Ib/yr
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[0.3 to 2.5 tons/yr] of ethylene oxide should be required to
reduce emissions from the aeration room vent by 95 percent;
facilities using more than 5,000 Ib/yr [2.5 tons/yr] of ethylene
oxide should be required to control aeration room vent emissions
by 99 percent.
Two commenters (11, 14) indicated manifolded control for the
aeration room vent would be cost-effective. One commenter (11)
suggested an emissions cutoff of 5,000 Ib/yr [2.5 tons/yr] and
indicated that this level has been adopted in several States.
This commenter indicated that control of the aeration room vent
would be appropriate because one catalytic oxidation unit can
control the aeration vent as well as the sterilization chamber
vent, and the capital burden to the facility would therefore be
minimal. The commenter added that increases in cost would come
in the form of higher operating costs due to the continuous
operation of the emissions control equipment. This commenter
further stated that if the facility is utilizing heated aeration
cells, cost can be further mitigated by reclaiming waste heat for
the aeration rooms from the catalytic process. This commenter
submitted information on 36 facilities utilizing catalytic
oxidation for the control of aeration room emissions to a minimum
level of 99 percent reduction. The commenter stated that many of
these facilities are below the 20,000 Ib/yr [10 tons/yr] ethylene
oxide use limit and suggested that EPA correlate emissions levels
using their existing data base and reevaluate the aeration room
vent MACT floor.
One commenter (14) stated that the total national cost of
controlling ethylene oxide emissions would be reduced by the use
of manifolded controls for sterilizer and aeration room vents.
The commenter stated that the cost of a manifolded control system
would be much less than the $600,000 cost estimate made by EPA
for separate controls at such a facility. This commenter stated
that the proposed standard does not take account of the
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possibility of using one piece of equipment to control both
sterilizer vent and aeration room vent emissions. The commenter
added that even though one piece of equipment can control
emissions from both points at a lower cost than two separate
devices, the standard as written would preclude this alternative
which is being offered commercially today. The commenter
suggested that the final rule expressly allow the use of
manifolded controls in order to provide the opportunity for lower
compliance cost and improved cost effectiveness. The commenter
stated that such a manifolded device would greatly reduce the
costs of control as estimated by EPA in the preamble and
background information document.
Response: All sources emitting less than 1 ton/yr of
ethylene oxide will continue to be exempt from the emissions
limits of this regulation (see Sections 2.1.2 and 2.2.4). For
affected area sources, the Administrator stated in the preamble
to the proposed rule that if commenters supplied data to indicate
that existing area sources are controlling aeration room vent
emissions and that there is a controlled MACT floor, MACT would
be rejected and GACT selected based on cost effectiveness, as
provided for in § 112(d)(5) of the amended Act. Given that the
cost effectiveness is high, rejection of a MACT standard that
would require aeration room vent control in favor of a GACT
standard with no control would alleviate this cost burden for
area sources. The Agency believes that the costs associated with
requiring controls on aeration room vents at area sources are
prohibitive after consideration of the emissions reduction
achieved by such controls.
While the Agency agrees with the commenters regarding the
attractiveness of manifolded control devices for some vents, in
some cases it may not be possible to manifold an additional
emissions vent type. Control devices are typically designed to
control a specific vent, such as packed-bed scrubbers for the
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sterilization chamber vent. The Agency does not believe that
combined control for the aeration room vent is feasible at all
sources and has not received information demonstrating that the
high flow rate and low concentrations typical of aeration room
vent emissions may be easily combined with an existing control
device. While several of the commenters suggested that combined
control for the area source aeration room vents provides lower
costs, the EPA does not believe it is appropriate to base its
cost estimates on a manifolded system for this vent since this
approach may not be an option for all existing sources. In
addition, the cost for aeration room vent control includes not
only the necessary ducting to a control device if manifolding is
feasible but also the cost to construct a new aeration room if
the source is not currently controlling these emissions. It has
also been suggested by commenters that the aeration room vent
emissions be combined with emissions from the chamber exhaust
vent, but the MACT floor for chamber exhaust vents at area
sources remains at no control (see Section 2.2.7). While the
Agency has required control of major source chamber exhaust vents
and has received information that emissions from this vent are
commonly combined with emissions from other vents, in general,
the only costs for controlling the chamber exhaust vent at major
sources are attributable to ducting.
The commenters submitted sufficient data to enable the
Agency to reassess the MACT floor for aeration room vents at
existing area sources. The MACT floor for existing sources in
the final regulation is controlled. However, data received from
commenters were not sufficient to allow the Agency to alter its
cost-effectiveness calculations associated with controlling
emissions from the aeration room vents of existing area sources.
Due to this high cost effectiveness, MACT has been rejected and
GACT selected for existing aeration room vents in the final rule.
The final rule therefore applies GACT to both existing and new
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area sources and does not require reduction of emissions from
aeration room vents. Control of only the sterilization chamber
vents (99 percent emissions limitation) is required for area
sources.
Comment: One commenter (13) stated that applying GACT
rather than MACT may exempt new area sources from operating
permit requirements. The commenter stated that if GACT is chosen
for new area sources, it should be applied to existing area
sources also, to avoid the confusion of some sources in a
category being exempt from operating permits on the basis of
their construction date. If MACT is chosen then both existing
and new area sources could be covered by a model "General
Permit," which would streamline the paperwork to obtain an
operating permit, along with a 5-year extension of operating
permit requirements.
One commenter (18) recommended that EPA exempt area source
sterilizers from Title V permits because limited benefits would
be expected from the periodic review of these permits for this
source category. The commenter added that in the event EPA
chooses to regulate sterilizers using less than 1 ton/yr, Title V
permits should not be required.
Response: Regarding the application of the Title V
operating permit program to area sources, the final rule for the
operating permit program promulgated on July 21, 1992
(57 FR 32250) states that "... any other source, including an
area source, subject to a hazardous air pollutant standards under
section 112..." is an affected source required to comply with the
Part 70 operating permit requirements. The final rule later
specifies that the Part 70 permitting program will be used to
implement standards for area sources developed using GACT. The
Agency therefore believes that no confusion will result from
regulation of area sources with either MACT or GACT. In regard
to the commenter's request for an extension of the permit
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requirements, the Agency believes that the 5 year extension for
nonmajor sources contained in Title V would be appropriate.
Comment: Four commenters (10, 13, 18, 19) expressed concern
regarding the role of § 112(f) in determining the applicability
of MACT or GACT to area sources. One commenter (18) stated that
area sources should be regulated under MACT because such sources
should be subject to later review under § 112(f) . Another
commenter (13) stated that avoiding the application of § 112(f)
(residual risk analysis) should not be a factor in deciding to
exempt area sources from MACT because smaller sources can often
pose a high risk, especially with a pollutant like ethylene
oxide. One commenter (10) stated that § 112(f) should be
considered when deciding whether to select MACT or GACT for an
area source category. Another commenter (19) also suggested that
the residual risk analysis requirements of § 112(f) should be
considered when determining whether MACT or GACT should apply to
area sources when they asserted that the setting of GACT
standards for area sources would weaken protection from ethylene
oxide exposure and would remove these sources from consideration
under the residual risk analysis required by § 112(f).
Response: The Agency is required to examine the residual
risk under § 112(f) of the Act for major sources and for area
sources regulated by MACT. The Agency has not attempted to avoid
the requirements of § 112(f) in its determinations to apply GACT
to area source aeration room vents in this source category, as
one commenter suggests. While the Agency is required to examine
area sources regulated by MACT, the Agency notes that it may also
choose to examine the residual risk for area sources subject to
GACT as well. Therefore, area sources subject to GACT may be
included in the residual risk study and § 112(f) standards may be
promulgated for these area sources as well as for those subject
to MACT.
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2.2.7 MACT for Chamber Exhaust Vents
Comment: Nine commenters (03, 06b, 10, 11, 13, 14, 17, 18,
19) suggested controlling emissions from the chamber exhaust
vent. One commenter (17) stated that they were aware of
facilities that are required to vent the emissions from the
chamber exhaust vents to the control device. One commenter (13)
suggested that emissions from the chamber exhaust should be
controlled at major sources because of the risks posed by the
amount of ethylene oxide uncontrolled from this vent. The
commenter suggested that a lower concentration of about
1,000 ppmv be considered for the chamber exhaust vent standards.
A commenter (19) referred EPA to SCAQMD for emissions reduction
data on chamber exhaust control devices. The commenter
recommended that controls be required for chamber exhaust vents
at major and area sources because California requires controls of
this vent at facilities using more than 600 Ib/yr of ethylene
oxide. Another commenter (18) stated that because BAAQMD
regulations require control of chamber exhaust vents at sources
using more than 600 Ib/yr of ethylene oxide, the NESHAP should be
revised to include these controls at least for new sources. A
commenter (03) indicated that the Puget Sound has facilities that
control emissions when the sterilization chamber door is opened
and including small sources where chamber exhaust vents are
routed to the control device. One commenter (06b) stated that
they already have two catalytic oxidizers in place that utilize
the combined feed of aeration and sterilizer vacuum pump [chamber
exhaust vent] flows and that combining sterilizer exhaust and
aeration exhaust reduces the use of clean-burning natural gas, a
nonrenewable energy source. One commenter (10) stated that the
chamber exhaust and the aerator exhaust, which are similar in
nature, could be vented to a single control device. This
commenter stated that chamber exhaust vent emissions could be
combined with aeration exhaust and routed to a single control
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device even though they are unaware of a facility so-controlled.
One commenter (15) suggested that all regulated sources be
required to control both aeration and sterilizer exhaust
emissions. The commenter stated that such controls have been
required in Rhode Island for commercial sterilizers.
One commenter (14) noted that relatively inexpensive control
of chamber exhaust vent ethylene oxide emissions should be
possible through the use of a single piece of equipment to
control the emissions from multiple points. The commenter
suggested that the chamber exhaust vent could be manifolded to
the control device used to control either sterilization chamber
or aeration room vent emissions; use of such systems should
provide additional emissions reductions for small marginal
increase in total costs and thus with reasonable cost
effectiveness. The commenter suggested that EPA reconsider its
rejection of regulatory alternative A, which required 99 percent
reductions in chamber exhaust vent emissions at major sources.
One commenter (11) supplied information on 32 systems where
emissions from the chamber exhaust or door hood were controlled
to a minimum level of 99 percent. The commenter suggested that
the MACT floor requirements be changed for both major and area
sources to control sterilizer chamber exhaust vents to a level of
99 percent by either directing the emissions to the control
device or by introducing further cycle/process changes to reduce
the in-chamber concentration to below 5,300 ppmv by conducting
further sterilizer evacuations which would be controlled by the
sterilizer vent emissions control device. This commenter
requested that the emissions cutoff for regulation of exhaust
chamber vents be lowered to 5,000 Ib/yr [2.5 tons/yr]. Another
commenter (10) stated that the MACT standard for chamber exhaust
vents should include the number of air washes, including the
vacuum, residence time, and temperature associated with these air
washes, required prior to opening the sterilizer chamber door.
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Response: The Agency agrees with the commenters regarding
the attractiveness of manifolded control devices for controlling
ethylene oxide emissions for some emissions points. The Agency
appreciates the commenter's submittal of data indicating that
manifolding is practiced for the chamber exhaust vent. The data
were sufficient in detail to allow a reassessment of the MACT
floor for the chamber exhaust vent at major sources. At least
six chamber exhaust vents at major sources are controlled by
manifolding the vent to the aeration room vent or sterilization
chamber vent control device when a catalytic oxidizer is used.
The Agency contacted the commenter for additional information and
has incorporated the data into the commercial sterilization data
base. The MACT floor for major source chamber exhaust vents in
the final regulation is control by ducting this vent to a control
device for the sterilization chamber or aeration room vent or
venting to a dedicated control device achieving 99 percent
emissions reduction. A specific manifolding or venting scenario
for control of this vent has not been specified because the
Agency believes that the owners or operators of a particular
source are best able to determine the most efficient way to
comply with the standards.
The MACT floor for area source chamber exhaust vents remains
unchanged since proposal at no control. While the level of the
standard at area sources has not changed, an addition has been
made to the requirements to provide flexibility to facilities.
Area sources may comply with the ethylene oxide concentration
limit as was proposed or may comply with a 99 percent emissions
reduction for chamber exhaust vent emissions that are vented to a
control device (either manifolded to a control device for
sterilization chamber vent emissions or vented to a dedicated
control device).
The Agency is providing additional flexibility to sources in
demonstrating compliance with the standards in the final rule and
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has included language that provides alternative monitoring
requirements and compliance provisions for controlled chamber
exhaust vents and aeration room vents. The Agency has provided a
mechanism for sources choosing to manifold vents or vent types to
demonstrate compliance with the standards but believes that one
approach should not be endorsed or preferenced over another. The
final rule allows a source to demonstrate compliance for either
the chamber exhaust vent or aeration room vent through parametric
monitoring of the performance of a control device. Whether the
control device is manifolded to other vents or vent types is
immaterial to the compliance demonstration, provided that the
conditions for demonstrating compliance are met.
2.3 COMPLIANCE DATES
Comment: Three commenters (04, 05, 12) suggested the
compliance date should be 3 years after the effective date; one
commenter (04) indicated that a compliance date of 3 years was
originally stated in the draft proposed rule available on the EPA
Technology Transfer Network. Two of these commenters (04, 05)
stated that 2 years would not be enough time for many companies
to complete material and process evaluations and to obtain
regulatory approval associated with investigating and converting
to alternative sterilization methodologies. Another of these
commenters (12) indicated that 2 years would not be enough time
to: (1) design a system for the aeration cells that will comply
fully with the new standard, (2) obtain bids, (3) build the
necessary control equipment and associated auxiliary systems,
(4) install the system in such a way that it minimizes down time,
and (5) start up and debug the system. This commenter provided
the following schedule: (1) research available technology and
systems--6 to 8 months; (2) prepare and submit permitting
requirements--3 months; (3) receive approval for construction
permit from the State--8 months; and (4) order systems, complete
facility modifications, installation, and debugging the system--
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12 to 15 months. This schedule indicated a total of 29 to
34 months for completion.
One commenter (19) stated that the compliance date should be
shortened to 1 year after the effective date. The commenter
stated that industry has been provided a great deal of notice
that emissions would be regulated, and that industry
representatives indicated during hearings for the California
regulation development that controls would be operable within
1 year.
Response: The Agency agrees with several of the commenters
that the compliance time frame for ethylene oxide commercial
sterilization and fumigation facilities should be extended. The
EPA recognizes that some of the facilities within the source
category will have to investigate and install control devices at
their facility to meet the standards. Also, some sources may
wish to investigate alternative sterilization methods. Based on
reasons presented by some of the commenters, EPA has extended the
compliance date to 3 years after the promulgation date for all
sources subject to this rule. The extension of the compliance
date is appropriate and should not result in adverse effects on
the environment because several large emitters, i.e., major
sources, are already well-controlled. At the same time, the
extension provides smaller, less well-controlled sources
additional time to achieve compliance. The EPA believes that the
3 year timeframe will address these commenters' concerns and
still ensure implementation of controls in a timely fashion. New
sources with startup after the 3 year compliance date will be
required to comply with the emissions standards upon startup of
the source.
2.4 MONITORING REQUIREMENTS
2.4.1 Initial Performance Testing
Comment: One commenter (18) stated that the conditions
during the initial compliance test for the sterilization chamber
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vent do not reflect standard operating conditions; this presents
problems for both of the referenced control technologies.
Two commenters (17 and 18) stated that EPA should reconsider
the determination of a temperature baseline for catalytic
oxidizers because there will be significant differences in the
temperature responses exhibited during the compliance tests (run
on an empty chamber) and actual operation with material present
in the sterilization chamber. The commenters recommended that
EPA review actual source test data for a variety of different
sterilizers, running with no load and with a full load, to
determine the impact these variables are likely to have.
Response: The Agency believes that the conditions specified
during the initial compliance test primarily affect the
concentration of ethylene oxide being delivered to the control
device. Although the concentration of ethylene oxide may be
different from standard operating conditions, the differing
amount is not expected to preclude the control device from
meeting the standard. The conditions for the initial test
(i.e., empty chamber) were specified to eliminate interference
from product retention of ethylene oxide.
For sterilization chamber vent emissions controlled with
oxidation units, two initial compliance tests will be performed
on the sterilization chamber vent: one during the first
evacuation of the sterilizer chamber to demonstrate that the
control device is designed properly and one during the last
evacuation to establish the appropriate baseline temperature.
During the compliance test for the first evacuation, the owner or
operator should deliver the same mass of ethylene oxide to the
chamber as would be used for typical operation. Demonstration of
the baseline temperature during the last evacuation addresses
concerns that a baseline temperature established during the first
evacuation would not be sustainable for subsequent evacuations
where the ethylene oxide concentration is lower. For an
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oxidation unit, the temperature will not elevate as significantly
with the lower concentration in the last evacuation, and an
appropriate baseline temperature will be determined. Because an
additional compliance test has been added at the final evacuation
where inlet concentration is lower, the final regulation permits
sources to demonstrate compliance with the standard during the
performance test for the last evacuation if the outlet
concentration is below the detection level of ethylene oxide when
the inlet concentration is approximately 50 ppmv or lower; the
source must be able to demonstrate the inlet concentration.
The initial compliance test for the chamber exhaust vent
will be performed with procedures similar to those used for the
performance during the last evacuation of the sterilization
chamber. Use of a low ethylene oxide concentration that allows
demonstration of the emissions reduction achieved during the
performance test will provide a baseline temperature applicable
to all chamber exhaust vent cycles. As explained above for the
last evacuation for the sterilization chamber, the final
regulation permits the source to demonstrate compliance with the
standard if the outlet concentration is below the detection limit
for ethylene oxide and the inlet concentration is approximately
50 ppmv or lower.
The Agency believes that the revised monitoring requirements
in the final rule are not adversely affected by the conditions
during the initial compliance test and that these conditions
enable correct measurement of the emissions reduction achieved by
the control devices and the setting of monitoring parameters to
assure future compliance with the standards.
Comment: One commenter (18) stated that requiring the
ethylene glycol solution to be maintained at the average
concentration recorded during the initial source test is
unreasonable and may present practical difficulties for the
source. The commenter stated that because sources could perform
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at a level substantially above the required 99 percent control
during the initial test, the actual performance could fall off by
as much as two orders of magnitude before the source would be
controlled to less than 99 percent, but if parametric monitoring
showed departure from the established baseline, the source could
be found in violation. The commenter recommended that the
baseline for the parameters be set when the source is operating
at the compliance level or an appropriate range should be
established.
Two commenters (03, 17) stated that the proposed compliance
determination and monitoring requirements for acid-water
scrubbers would require a facility to determine the maximum
concentration of ethylene glycol in the scrubber liquor under a
"worst-case" situation. One commenter (17) stated that the
sterilization chamber vent monitoring requirements for acid-water
scrubbers may not be appropriate because the baseline established
during the initial performance test may be derived when the
source is achieving greater control efficiency than is required
under the standards. The commenter added that as the equipment
ages, a degradation of the control may be experienced such that
the monitored parameter may show noncompliance with the standard
when in fact, the source is still in compliance. The commenter
requested that if parametric monitoring was to be implemented for
these controls, the baseline must correspond to the required
level of control, not a higher level.
Two commenters (11 and 16) suggested that annual performance
testing be required (in addition to the initial performance test)
as part of the monitoring requirements for the standards. One
commenter (19) stated that the final rule should include more
frequent performance testing of control equipment to prevent
deterioration of the control equipment.
Response: The Agency has incorporated monitoring
requirements into the proposed and final regulations that provide
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a continuous determination of compliance with the standards. The
underlying principles for these monitoring requirements are that
the parameters monitored (where parametric monitoring is used)
are to be a direct indicator of compliance. Under the final
rule, limits for monitored parameters will first be established
during an initial performance test and will be monitored
thereafter. In the interest of reducing the costs to affected
facilities, additional (e.g., annual) compliance tests are not
required under the final rule. The Agency believes that an
initial performance test of the control device is sufficient to
establish the monitoring parameters needed for determining
continuous compliance. However, the Agency offers the
flexibility to a source to perform additional performance tests
and reestablish new limits for monitored parameters at any time.
The Agency believes that this flexibility will address the
commenter's concerns about a source showing noncompliance with a
higher emissions limit than is contained in the standard when the
source is in compliance with the actual standard.
The final rule does not require that the ethylene glycol
concentration be maintained at an average concentration
established during the initial performance test. The ethylene
glycol concentration established during the initial compliance
test is a concentration not to be exceeded by the source. In
determining the monitoring parameters for the acid-water
scrubber, it would be advantageous for the owner or operator to
do the initial performance test at the end of the liquor cycle
when the ethylene glycol concentration is at the highest point
that still provides a 99 percent reduction for the acid-water
scrubber. Because the baseline parameter has been changed from
an average value (e.g., maintain ethylene glycol concentration at
the average baseline concentration) to a maximum or minimum value
(e.g., maintain temperature below the minimum oxidation
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temperature), it is not necessary to specify appropriate ranges
for these parameters as one commenter suggested.
2.4.2 Monitoring for Acid-Water Scrubbers
Comment: Eight commenters (03, 04, 05, 06a, 06b, 13, 17,
18) provided comments on the monitoring requirements for
acid-water scrubbers. Several commenters (04, 05, 06b, 17, 18)
stated that continuously measuring ethylene glycol concentration
is not feasible, practicable, or necessary. Two commenters (03,
17) stated that the proposed compliance determination and
monitoring requirements for acid-water scrubbers would require a
facility to determine the maximum concentration of ethylene
glycol in the scrubber liquor under a "worst-case" situation.
One commenter (17) stated that ethylene glycol monitoring is not
the best parameter to monitor to assure compliance with the
sterilizer vent standards and that EPA should select a parameter
other than ethylene glycol concentration or offer other
parameters as alternatives. The commenter suggested that acid
concentration is much easier to measure than ethylene glycol
concentration and would be a better surrogate for scrubber
performance.
One commenter (04) stated that acid-water control units
operate on a batch basis with glycol concentration starting near
zero at the beginning of an operating cycle and increasing up to
a predetermined maximum, at which time the glycol is removed and
neutralized. The commenter added that makeup water is added, pH
adjusted, and a new cycle begins. The commenter stated that
enough acid is added at the beginning of each cycle to maintain
the proper pH through the complete cycle. One commenter (13)
stated that the proposed monitoring requirements for acid-water
scrubbers (i.e., continuous monitoring of the scrubber liquor
ethylene glycol concentration) for sterilization chamber vents
seems excessive since the time between changes of the liquor is
often several months. The commenter suggested the initial use of
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frequent monitoring to determine the rate at which the
concentration increases in the liquor, followed by less frequent
monitoring, especially if the maximum content of ethylene glycol
is set safely below the level required to attain the desired
level of efficiency. One commenter (05) stated that their
facilities typically operate 3.5 months before approaching the
manufacturers recommended ethylene glycol concentration limit.
One commenter (06b) stated that a new batch of scrubber liquor
requires a physical check of the system parameters and that only
the ethylene glycol concentration would change gradually and
predictably over the time that the batch fills the storage tanks;
continuous or even hourly monitoring of glycol concentration
would therefore not be needed. The commenter stated that
facilities having typical scrubber units would not see changes in
the ethylene glycol concentration of even 0.5 percent by weight
per day of sterilization. The commenter added that to detect
such relatively small changes in glycol concentration would
require specific onsite gas chromatographic analysis that would
cost over $15,000 and require special instrument training of
hourly employees.
Two commenters (04, 05) stated that they knew of no means to
continuously monitor acidified ethylene glycol concentration.
One commenter (06a) questioned the ability of available
technology to continuously monitor the ethylene glycol
concentration in the scrubber liquor due to the sample matrix,
which is very acidic and contains other dihydric glycols which
can interfere with accurate determinations of ethylene glycol.
This commenter indicated that periodic determinations are
achievable, providing adequate sample preparations are carried
out in a laboratory.
Several commenters (03, 04, 05, 06b, 13, 17, 18) suggested
alternate or modified monitoring requirements for acid-water
scrubbers. The following alternatives were suggested:
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1. Establish a maximum limit on the amount of ethylene
oxide used or scrubbed (03, 17, 18), after which the scrubbing
liquor must be changed (17);
2. Measure pH (17, 18) periodically or prior to scrubbing a
batch of ethylene oxide (18);
3. Measure ethylene glycol concentration (05, 06b, 13) at
the end of each week of operation (05) or less than continuously
(06b, 13);
4. Monitor the level of the scrubbing liquid in the tank
(17, 18) and establish a maximum tank level that correlates to an
ethylene glycol concentration after which the liquor must be
changed (17) ; and
5. Monitor all of the following: monitor gas flow rate or
tower pressure differential, the liquid flow rate (or liquid
height for reaction/detoxification units), and the liquid
temperature; measure pH at the start and end of each operating
cycle; and measure the ethylene glycol concentration at the end
of each operating cycle (04) .
One commenter (18) recommended that if ethylene glycol
concentration is to be used as a surrogate parameter for scrubber
efficiency, an acceptable range be established, based on a
correlation between ethylene glycol concentration and scrubber
performance. One commenter (03) indicated that monitoring the
ethylene oxide usage would be a much easier method for sources
and the regulatory community to implement. One commenter (04)
stated that their recommendations for monitoring parameters
provide more effective process control and assurance of
compliance. The commenter also suggested that maximum or minimum
values for each parameter would be established based on
manufacturers' recommended limits and verified during initial
compliance testing.
Response: The Agency agrees with the commenters that the
continuous monitoring requirements proposed for acid-water
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scrubbers are not necessarily appropriate. The Agency has
carefully considered each of the suggested alternative monitoring
scenarios submitted by the commenters.
One alternative monitoring parameter suggested by the
commenters is tracking of ethylene oxide usage. The owner or
operator would correlate the maximum ethylene oxide usage to the
maximum ethylene glycol concentration that still provides a
99 percent emissions reduction for the scrubber. Implementing
use of this parameter would require: (1) accurate recordkeeping
of all ethylene oxide purchases and use, (2) determination of the
ethylene oxide emissions split for each emissions point vented to
the control device, and (3) determination of ethylene oxide
retention properties for each product sterilized. The Agency
does not believe this monitoring approach is appropriate due to
uncertainty and variability associated with both the emissions
split for each vent and the ethylene oxide retention rates of
ethylene oxide for products sterilized. Tracking of ethylene
oxide usage has not been included in the final regulation as a
referenced monitoring parameter.
Several commenters suggested pH as an appropriate monitoring
parameter for acid-water scrubbers. Monitoring the pH of the
scrubber liquor is not technically feasible because the pH change
over the life of the liquor cycle is typically not measurable.
Because the Agency has not received sufficient data indicating
that pH monitoring is an acceptable parameter for demonstrating
continuous compliance, the Agency has not included pH monitoring
as a referenced monitoring parameter in the final rule.
Continuous monitoring of ethylene glycol concentration to
determine compliance has been refuted by commenters based on the
small incremental changes in ethylene glycol concentration
expected over the liquor cycle and the cost of analysis equipment
and employee training and time for performing the analysis on a
continuous basis. The Agency has determined through contact with
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vendors and industry that ethylene glycol concentration is
commonly used for compliance determination but agrees that
continuous monitoring of ethylene glycol concentration is not
necessary. Monitoring of the ethylene glycol concentration
demonstrates that ethylene oxide from the vent outlets is being
removed and converted to ethylene glycol in the scrubber liquor.
Based on the slow change in concentration, the final rule
requires monitoring of the ethylene glycol concentration once per
week. With less frequent monitoring, it is possible for an
affected source to sample the liquor and send to a laboratory
offsite for analysis to avoid the cost for analysis equipment.
Monitoring of the scrubber liquor level in the tank was also
suggested by commenters as an alternative parameter to monitor.
The owner or operator would correlate the maximum level of liquor
allowed in the tank to a maximum ethylene glycol concentration
that still provides a control efficiency of 99 percent for the
scrubber. The increase in mass (until total solution is 40 to
60 percent ethylene glycol by weight) and therefore volume in the
scrubber liquor storage tank demonstrates that ethylene oxide
from the vents is being scrubbed and converted to ethylene glycol
in the scrubber liquor. The owner or operator must place liquid
level indicators on the liquor storage tank; minimal employee
time and training is necessary for monitoring the liquor level in
the tank. [This parameter may be used for monitoring systems
that continuously collect the liquor (i.e., a batch operation)
and purge the system only at the end of the cycle. While the EPA
does not believe that common practice for scrubber systems in
this source category includes periodic purging of the liquor
cycle, systems that do not follow a batch process will not be
permitted to use this monitoring parameter.]
Monitoring of the operating parameters (i.e., liquid to gas
flow rate ratio and temperature) of the scrubber in addition to
beginning and end of cycle pH monitoring and end of cycle
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ethylene glycol concentration monitoring was suggested by
commenters. As discussed above, the Agency does not believe pH
monitoring for the system is technically feasible for this source
category, and ethylene glycol monitoring demonstrates that the
scrubber system is absorbing ethylene oxide from the inlet gas
stream. While the EPA agrees that monitoring operating
parameters may add some benefit, the EPA is reluctant to require
these parameters as referenced monitoring parameters in the final
regulation because the Agency has not received data indicating
that the monitoring of these additional parameters contributes to
the continuous compliance indication as determined by ethylene
glycol monitoring. The EPA believes that ethylene glycol
monitoring provides a sufficient demonstration of compliance.
The Agency has subsequently revised the referenced
monitoring parameters in the final rule to require either:
(1) weekly monitoring of the ethylene glycol concentration in the
scrubber liquor, or (2) weekly monitoring of the level of liquor
in the scrubber liquor tank. Operating the scrubber with a
monitored ethylene glycol concentration above the maximum
concentration determined during an initial performance test is a
violation of the applicable standard. Operation of the scrubber
with a liquor level in the tank above the maximum as determined
during an initial performance test is a violation of the
applicable standard. The Agency believes that these monitoring
alternatives provide an adequate measure of compliance while
providing reduced burden to owners and operators of the affected
sources. A source may choose an alternative to the monitoring
parameters referenced in the final regulation if the alternative
monitoring parameter is approved by the regulating Agency, as
provided for in § 63.8 of the General Provisions. (See
Section 2.4.1 for determining monitoring parameters at "worst-
case" operation.)
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2.4.3 Monitoring for Catalytic Oxidizers
Comment: Six commenters (04, 06b, 11, 13, 17, 18) suggested
modifications to the monitoring requirements for catalytic
oxidizers. Several commenters (13, 17, 18) stated that the
control of the catalyst bed temperature to +10°F may not be
practicable. One commenter (13) stated that maintenance of such
a temperature range is feasible under steady state conditions but
would be difficult under the continuously varying concentrations
encountered in the evacuation process for the sterilization vent.
This commenter suggested the use of a continuous temperature
control monitor and recorder on both the inlet and outlet of the
oxidizer. The commenter stated that compliance would be shown by
having the inlet temperature above a minimum and the outlet
temperature below a maximum; both temperatures would be
determined during a compliance test when 99 percent efficiency
was achieved.
One commenter (04) suggested that the current requirement of
+10°F be deleted and replaced with manufacturers' recommended
maximum/minimum temperatures. The commenter stated that
catalytic oxidation units used to control chamber vents would
operate at widely varying temperatures, depending on the amount
of ethylene oxide in the feed stream(s), and that various field
tests on one manufacturer's units have demonstrated 99 percent
removal efficiencies as long as the catalyst bed temperature is
280°F or higher. Another commenter (11) stated that it is well
proven that catalytic units will work as designed if a minimum
operation temperature is maintained for the particular catalyst.
This commenter stated that compliance with the standards would be
shown by having the catalyst bed temperature fall above a minimum
operating temperature +10°F established during a performance test
and below a maximum temperature limit established by the
manufacturer of the control device. The commenter added that the
upper baseline temperature could change with different feed
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rates, environmental conditions, and air flows and suggested that
this upper limit be set on a baseline standard cycle. The
commenter suggested that a temperature variation in excess of
50°F from this monitored temperature would constitute a violation
of the standards. Both commenters (04 and 11) suggested that
monitoring the catalyst bed temperature coupled with periodic
efficiency tests (minimum annually) should be utilized for
monitoring compliance.
Another commenter (06b) stated that the control efficiency
of catalytic oxidation units is dependent on catalyst
temperature. This commenter stated that any catalyst used in
catalytic oxidizers has been tested in the lab and in the field
to show a reliable profile of temperature versus control
efficiency. The commenter added that all methods of oxidizing
ethylene oxide in air are more effective when the oxidation
temperature is higher and that the limitation of +10°F from the
baseline temperature is unrealistic and penalizes those that
operate their equipment with a high knowledge of their control
efficiency. The commenter stated that this temperature
requirement would disallow the use of ethylene oxide control from
the sterilizer vacuum pumps [chamber exhaust vent] to be combined
with aeration feed to a catalytic oxidizer. The commenter stated
that only catalytic oxidizers controlling emissions from
sterilizer vacuum pump exhausts would show marked temperature
changes and that these changes would always be greater than the
proposed 10°F limitation. The commenter added that they already
have two catalytic oxidizers in place that utilize the combined
feed of aeration and sterilizer vacuum pump [chamber exhaust
vent] flows and that combining sterilizer exhaust and aeration
exhaust reduces the use of clean-burning natural gas, a
nonrenewable energy source. This commenter noted that in the
"aeration only" feed streams of ethylene oxide, there is seldom
any temperature rise of even 10°F for any new hot
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aeration/degassing cycles started because the total feed
concentrations to the oxidizer are typically 40 parts per million
or less. The commenter stated that all aeration cycles show a
higher concentration of ethylene oxide degassing early in the
cycle (although not necessarily at the beginning of the aeration
cycle), usually declining asymptotically with the heated
aeration. Two commenters (04, 11) stated that aeration room
compliance for catalytic oxidation systems should be determined
by continuously monitoring the lower operational temperature
limit for the catalyst bed coupled with periodic efficiency tests
(minimum annually).
One commenter (13) stated that calibration of the
temperature controller to +10°F is acceptable but seems difficult
under § 63.363(b)(2)(ii), where a source is required to control
the temperature of an oxidizer chamber under operating conditions
to +10°F using a temperature monitor accurate to +10°F. Two
commenters (17 and 18) stated that the temperature probe required
in §§ 63.363(b)(1)(ii) and (2)(ii) should at least be accurate to
within 1°F because, as written, any measurement that is at or
below the limit of accuracy would be considered a violation.
One commenter (06b) stated that except for major
concentrations of ethylene oxide (above 2,000 parts per million)
or of cases where the allowable high temperature limits were
exceeded, the catalyst will deactivate slowly over a period of
years. The commenter stated that this deactivation is fairly
reliable and predictable over the long-term, which is shown by
performing the annual source test on all catalytic units. One
commenter (11) submitted life data from two systems from major
sources showing that the performance of the catalyst after one
and 2 years has not changed from the original compliance test.
The commenter also referred to life test data previously
submitted to EPA performed on a catalytic system. The commenter
noted that the catalyst in this system operated for 8 years
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before the catalyst performance fell below 99 percent destruction
and the catalyst was then replaced. The commenter noted that
this proved that the catalyst will not fail catastrophically and
that catalyst life doesn't dramatically change over long periods
of time.
Response: The Agency agrees with the commenters that the
monitoring requirements for catalytic oxidizers may not be
appropriate; the baseline temperature limit of +10°F is not
practicable in all situations. The Agency has considered the
alternatives suggested. The commenters suggested that a more
accurate measure of compliance would be a requirement that the
temperature remain above a minimum oxidation temperature. The
Agency has included compliance provisions in the final rule
requiring that the oxidation temperature be above a minimum
baseline temperature determined during an initial performance
test for the sterilization chamber vent, the aeration room vent,
and the chamber exhaust vent. The Agency has not included a
maximum temperature as part of the monitoring requirements as
some commenters suggested because temperatures above the minimum
temperature do not adversely affect performance of the oxidizer
unit.
For the sterilization chamber vent, the final rule requires
owners or operators of affected sources to: (1) monitor the
oxidation temperature continuously, (2) calculate an average
oxidation temperature over each cycle (the length of the cycle is
based on the cycle length during the performance test), and
(3) calculate a three-cycle average every third cycle; an average
monitored oxidation temperature more than 5.6°C (10°F) below the
baseline temperature established during the initial performance
test at a time when the control device achieves a 99 percent
emissions reduction is a violation. Similar requirements have
been added to the monitoring requirements for sources that vent
chamber exhaust vent emissions to a control device.
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For aeration room vents controlled with catalytic oxidizers,
the Agency agrees that additional flexibility regarding the
monitoring requirements is warranted. The final rule requires
owners or operators at major sources to monitor either: (1) the
concentration of ethylene oxide emissions from the aeration room
vent outlet, or (2) the oxidation temperature. For major
aeration room vent sources monitoring the ethylene oxide
concentration, the owner or operator will: (1) measure the
concentration once per hour, and (2) calculate a 3-hour average
every third hour. A 3-hour average ethylene oxide concentration
greater than 1 ppmv is a violation of the standard. For major
aeration room vent sources monitoring the oxidation temperature,
the owner or operator will: (1) monitor the oxidation
temperature continuously, (2) calculate an average oxidation
temperature over each hour, and (3) calculate a 3-hour average
every third hour. An average monitored oxidation temperature
more than 10°F below the baseline temperature established during
an initial performance test at a time when the control device
achieves either a 99 percent emissions reduction or a maximum
outlet ethylene oxide concentration of 1 ppmv or less is a
violation of the standard. The purpose of the monitoring
requirements is to show "continuous" compliance with the
standards, and since these monitoring requirements have been
developed with this purpose, there would be no reason to require
annual compliance testing. An affected source may perform
compliance tests other than the initial compliance tests required
by the final rule (see Section 2.4.1).
The Agency agrees with the commenters' concerns regarding
the accuracy of the temperature probe used to measure the
oxidation temperature. The final rule requires that the
temperature probe have the same accuracy (+10°F) but requires the
oxidation temperature to be above a minimum temperature
established during a performance test (i.e., if the monitored
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temperature falls below this level, a violation of the applicable
standard has occurred).
Comment: One commenter (18) stated that the language of
63.363(b)(2)(ii) (determination of violation for catalytic
oxidation) should be clarified to specify that compliance is
based on the average temperature.
Response: Section 63.365(f) in the final rule details the
method for determining the baseline temperature for oxidizer
units. The baseline temperature is determined by averaging
temperature readings from three test runs. Monitoring will
consist of continuous temperature measurement to be averaged over
a period of time (i.e., cycles or hours). Depending on the vent
type, the source will then calculate an average over the last
three cycles or hours. A monitored temperature average more than
10°F below the baseline temperature is a violation of the
standard.
Comment: One commenter (14) suggested semiannual
calibration of temperature monitor accuracy for sources using
catalytic oxidizers given the relative stability of the
thermocouples used. The commenter added that failure of
thermocouple monitors tends to be catastrophic, with results that
are immediately obvious to facility owners or operators.
Response: The Agency is aware of the reliability of
thermocouples; thus, revised guidance on the calibration and
maintenance of thermocouples have been added. The final rule
requires semiannual calibration of temperature monitors.
2.4.4 Monitoring for Other Control Equipment
Comment: One commenter (04) recommended that monitoring of
thermal oxidizers consist of continuous monitoring of fuel gas
pressure, pilot flame presence, combustion air flow, and system
temperature.
Response: The Agency has included thermal oxidizers as a
referenced control technology in the final rule and has therefore
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incorporated compliance provisions, monitoring requirements, and
recordkeeping and reporting requirements for thermal oxidizers.
While the Agency agrees that monitoring of each of the mentioned
parameters indicates flame stability, the Enhanced Monitoring
Reference Document, September 1993, suggests that the outlet
oxidation temperature be monitored. Other NESHAP have also
incorporated this monitoring requirement for thermal oxidation
units, such as the HON. The Agency believes that monitoring of
this temperature parameter is sufficient to indicate continuous
compliance for this control device. The compliance provisions
for thermal oxidizers are as follows: during three performance
test runs when the control device meets the applicable standard,
the owner or operator shall establish as an operating parameter a
baseline temperature averaged over the three runs; thereafter,
operation of the sterilizer with the average oxidation
temperature more than 10°F below this baseline temperature shall
constitute noncompliance with the standard.
2.4.5 Monitoring Requirements for Sterilization Chamber Vents
Comment: One commenter (19) stated that actual measurement
of inlet and outlet concentrations of ethylene oxide for the
sterilization chamber vents should be required to demonstrate
compliance with the percent reduction requirements.
Response: Direct monitoring of the inlet and outlet
concentrations would require installation of an online gas
chromatograph system and the appropriate personnel and training
for operation of the analysis equipment; the Agency believes that
this monitoring option is costly for this source category. The
Agency believes that the parametric monitoring requirements
contained in the final rule are sufficient to demonstrate
compliance with the standards. The monitoring requirements were
revised in response to comments received from control device
vendors, industry, and State and local environmental regulatory
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agencies and incorporate monitoring provisions as required by the
amended Act.
2.4.6 Monitoring Requirements for Chamber Exhaust Vents
Comment: One commenter (04) suggested that facilities that
send chamber exhaust vent discharge to a control device be exempt
from the monitoring requirements proposed for chamber exhaust
vents. The commenter added that monitoring of the control device
under these conditions should assure compliance with the
standards.
Several commenters (04, 05, 11, 17, 18) suggested that
facilities discharging chamber exhaust vents to the atmosphere
should have the option of demonstrating end-of-cycle chamber
concentrations of less than 5,300 ppmv by using specific
validated cycle parameters and controlling additional cycles with
the sterilization chamber vent control device. One commenter
(04) suggested that this validation of cycle parameters include
key process parameters affecting ethylene oxide removal from the
vessel (initial concentration, number and depth of air washes),
coupled with actual measurement of chamber concentration for
representative cycles. This commenter suggested that compliance
could be assured through the initial validation and review of
sterilization cycle charts which are part of the permanent batch
record. Another commenter (05) stated that bringing of the
sterilization chamber to one atmosphere and holding it there
while sampling the chamber ethylene oxide concentration before
activating the fan would allow ethylene oxide to diffuse from the
chamber and increase employee exposures. This commenter added
that multiple chambers cycling in close succession would compound
this problem. The commenter suggested validating the operating
parameters during the initial performance test and following
these parameters as part of the monitoring for the chamber
exhaust standard.
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Response: The Agency agrees with the commenters' that
additional flexibility should be provided to owners or operators
of area and major source commercial ethylene oxide sterilization
and fumigation operations regarding the demonstration of
compliance with the chamber exhaust standards. The final rule
contains provisions for the owner or operator of major and area
affected sources to demonstrate compliance with the applicable
chamber exhaust standards. Major source facilities, which are
required to control emissions from the chamber exhaust, must
demonstrate compliance by monitoring parameters established
during a performance test for the control device that is used to
control emissions. Area source facilities must monitor the
ethylene oxide concentration in the sterilization chamber prior
to operation of the chamber exhaust or may choose to control
emissions from the chamber exhaust vent and demonstrate
compliance by monitoring parameters established during a
performance test for the control device that is used to control
these emissions. In general, the monitoring requirements and
compliance provisions for devices controlling emissions from the
chamber exhaust vents are similar to the monitoring requirements
and compliance provisions for devices controlling emissions from
sterilization chamber vents.
2.4.7 Monitoring Requirements for Aeration Room Vents
Comment: Seven commenters (04, 05, 06a, 09, 11, 17, 18)
provided comments on the monitoring requirements for aeration
room vents. Several commenters (04, 05, 06a, and 11) stated that
the proposed monitoring requirements for aeration room vents at
major sources are unobtainable given that the industry-accepted
detection limit for ethylene oxide is 0.5 ppmv based on
laboratory quality equipment not used continuously. The
commenters also expressed concern that ethylene oxide monitoring
would be inaccurate due to the heated sample stream, moisture
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present in sample lines, and the presence of other hydrocarbons
and trace organics in the sample stream.
One commenter (09) requested clarification on the
measurement of the ethylene oxide concentration for the aeration
room vent. Specifically, the commenter requested clarification
on whether this was a maximum from a single point sample or a
maximum average of continuous monitoring of several samples.
One commenter (17) stated that because the 1 ppmv emissions
limit can be circumvented by increasing the airflow through the
vent, sources required to meet the standard should be required to
meet a <1 ppmv concentration and 99-percent control requirement,
so that the more stringent limit prevails. The commenter also
stated that a concentration measurement that is below the
detection limit of 0.2 ppmv should also indicate compliance. One
commenter (18) recommended that emissions below the detection
limit of the test be considered in compliance.
Response: The Agency recognizes the potential difficulties
associated with accurately monitoring the ethylene oxide
concentration on a continuous basis. In the final rule, the
Agency has provided sources the flexibility to monitor the
ethylene oxide concentration or to monitor control device
parameters that provide continuous monitoring of compliance. If
the source chooses to measure ethylene oxide concentration in its
monitoring program, then the ethylene oxide concentration for the
aeration room vent shall be measured hourly and averaged over
three 1-hour measurements. The aeration room vent standards
specify that this concentration shall be 1 ppmv or less for
affected sources. Measurements of ethylene oxide below the
detection limit are considered to be in compliance.
2.4.8 Monitoring Requirements in General
Comment: Six commenters (05, 06a, 09, 11, 16, 19) provided
general remarks regarding monitoring requirements. One commenter
(05) stated that each operator of a commercial sterilization
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facility should be able to demonstrate compliance by establishing
during the initial performance test the operating parameters of
their systems (including control technologies) that will achieve
compliance, validate those parameters, and then operate to those
parameters and use the procedures outlined in § 63.366 to report
deviations. The commenter added that if compliance could not be
demonstrated in this manner then additional controls (scrubbers,
catalytic oxidizers, etc.) would be in order. One commenter (17)
recommended that the final rule consider the entire control
device as a whole and that appropriate compliance demonstrations
and other considerations be determined on a case-by-case basis
where new technologies or hybrid systems are employed. One
commenter (18) recommended that the owner/operator of a source
seeking to demonstrate compliance with some other control
scenario be allowed to establish an appropriate range for the
parameters, with the approval of the implementing agency;
operation precisely at the conditions established during the
performance test may not be practical for normal operating
conditions.
One commenter (06a) suggested that a facility should be
given the opportunity to validate a process and stay within set
operating parameters. The commenter's proposal incorporated an
early detection set point that would be established for emissions
controls which, in turn, would trigger an alarm notifying
personnel of the need for corrective action. The commenter added
that process validation cycles could be established annually.
The commenter stated that reliance on a continuous monitoring
system susceptible to delivering erroneous data could ultimately
lead to the unnecessary discontinuation of sterilization of
critical life saving medical devices and higher overall cost of
medical care. Two commenters (17 and 18) requested that
facilities employing an interlock system that shuts down the
entire system and prevents the sterilizer from being used in the
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event that the conditions in the catalyst bed are outside of the
acceptable range be exempted from the proposed monitoring,
recordkeeping, and compliance provision requirements. One of
these commenters (17) suggested that such facilities be required
to record incidences of interlock shutdown and recharging of the
bed.
One commenter (09) stated that the proposed monitoring
requirements would result in at least $100,000 in capital
expenditures for one of the commenter's facilities. The
commenter estimated that the monitoring and the submittal of
reports would result in approximately $50,000 in annual costs.
The commenter also stated that because they also rely on contract
sterilizers, their product costs would be significantly increased
by this regulation.
Response: The Agency has considered allowing interlock
systems in lieu of the monitoring requirements presented for
catalytic oxidizers. While the EPA wishes to encourage
innovative technologies such as interlock systems, the EPA has
insufficient information on the variety of designs and
applications of interlock systems to specify alternative
monitoring, recordkeeping, and compliance procedures that would
be appropriate for all such systems. Sources wishing to use
interlock devices may apply to the Administrator as described in
the General Provisions § 63.8(f) and in § 63.365(g) of the final
rule. In regards to establishing a set point that notifies
personnel of system malfunctions, the Agency does not believe
that it is appropriate to specify requirements for "triggers" in
the standards. Rather, the Agency believes that the
establishment of any such triggers or set points should be left
to the owners or operators of an affected source.
The Agency agrees with the commenters that compliance should
be measured during the initial compliance test and that the
source should be allowed to show compliance with the emissions
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standards through a control scenario of the source's choice. The
Agency has provided monitoring requirements and compliance
provisions for the most commonly used control devices (i.e., the
referenced control technologies) but has also incorporated
provisions for sources using alternative controls (§ 63.365(g) of
the rule and § 63.8(f) of the General Provisions). However, the
Agency believes that sources should not be allowed to establish
their own operating parameters and to monitor parameters of their
choice unless the source has applied to the Administrator for
approval of such plans. The parameters to be monitored under the
final rule for the referenced control technologies have been
selected by the Agency to assure compliance with the standards
and to standardize reporting of noncompliance. In instances
where a referenced control technology is used, the parameters
detailed in the rule should be used for monitoring. The Agency
understands that allowing sources to select parameters to be
monitored for compliance provides flexibility to the source; in
instances where the control scenario used at the source does not
match those referenced in the rule, the source must develop a
comparable compliance and monitoring plan and apply to the
regulating Agency for approval. However, the Agency believes
that the approval process that would ensue from the commenter's
suggested compliance program for all facilities would result in a
lessor indication of compliance with the standards, additional
time expended by sources for developing individual compliance
programs, and an additional review step in the regulating
Agency's approval process for these compliance plans. The Agency
believes that the additional step in the approval process would
overwhelm the regulating agencies.
The owner or operator of the commercial ethylene oxide
sterilization and fumigation operation seeking to demonstrate
compliance with the standards using an alternative control device
may submit a monitoring scenario utilizing a range for the
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monitored parameters, however, any such submittal will be subject
to review and possible modification by the Administrator.
Regarding the commenter's request that the Agency consider the
entire control device as a whole, the Agency asserts that this is
how the compliance determinations and monitoring requirements in
the proposed rule and final rule were determined. In evaluating
any submitted alternative compliance provisions or monitoring
requirements, the Agency will attempt to also consider the
control device as an entire unit. In regard to the commenter's
statement on the practicality of operation of the source at the
precise conditions as were established during the performance
test, the Agency is promulgating monitoring requirements in the
final rule that show compliance at all times of operation.
The Agency appreciates the information on the cost of
compliance submitted by the commenter. In the final rule, the
Agency has provided additional flexibility to affected sources
that the Agency believes will reduce the costs of compliance
without affecting the effectiveness of the monitoring program.
Comment: One commenter (19) agreed with EPA's proposed
point-by-point compliance scheme.
Response: The Agency appreciates the commenter's support.
2.5 TEST METHODS
Comment: Three commenters (04, 05, 11) made suggestions
regarding the test methods identified in the regulation. These
commenters (04, 05, 11) referred to background documents that
state high reactivity (04), low concentrations of ethylene oxide,
high temperature, and presence of moisture do not provide
reproducible, accurate results (04, 05, 11); one commenter (05)
stated that Method 18 is not practical for hourly sampling and
another commenter (11) stated that continuous monitoring of
ethylene oxide is not obtainable. One commenter (05) asked that
an alternative to Method 18, Section 7.2, for the aeration room
vent standard as specified in § 63.365(c) be identified due to
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these factors. Another commenter (11) suggested that the
requirement in § 63.365(a)(3)(ii)(A)(1) to have sample bags
analyzed within 8 hours should be consistent with
§ 63.365(a)(3)(ii)(B)(1) , which requires that samples be analyzed
within 24 hours.
Response: The Agency has included alternative compliance
provisions and monitoring requirements in the final rule to
provide affected sources with additional flexibility to assure
compliance with the standards. The Agency agrees that parametric
monitoring of the control device used for the aeration room vent
and chamber exhaust vent should be allowed as an alternative to
direct measurement of the ethylene oxide concentration in the
stream with Method 18, Section 7.2. Additional discussion of
this issue and the compliance test procedures is located in
Section 2.4. It is assumed that the commenter is referring to
§§ 63.365(a)(4)(ii)(A)(I) and 63.365(a)(4)(ii)(B)(I) of the
proposed rule (since the sections mentioned did not exist in the
proposed rule) [§§ 63.365(b)(1)(iv)(B)(I) (a) and
63.365 (b) (1) (iv) (B) (2.) (a) in the final rule] . However, the
sections mentioned by the commenter each indicate an 8 hour limit
on the time allowed before analysis should occur.
Comment: One commenter (17) suggested that under
§ 63.365(a), the flow rate and concentration be measured at both
the inlet and the outlet to the control device to avoid possible
errors including air leaks into the sterilization chamber, leaks
from the vacuum pump, and errors that could occur if the inlet
ethylene oxide concentration is measured directly but the flow is
not measured (i.e., the mass of ethylene oxide fed to the abater
must be derived, potentially not taking into account the
combustion air added to catalytic oxidizer units). Another
commenter (18) stated that the method for determining residual
mass of ethylene oxide in the sterilization chamber
(§ 63.365(a)(2), based on the ideal gas law) does not consider
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air leaking into the chamber during initial evacuation. This
commenter also stated that the total mass of ethylene oxide (Wi)
at the inlet to the control device is not measured directly, and
is therefore subject to error. The commenter recommended that
the concentration and flow rates be measured at the inlet and the
outlet.
Response: Section 63.365(b)(1) of the final rule allows the
source two options for calculating the total mass of ethylene
oxide at the inlet to the control device: (1) calculating the
theoretical mass charged to the chamber by utilizing one of
several techniques listed; or (2) by measuring the flow rate and
concentration of ethylene oxide by utilizing the techniques to be
used at the outlet of the control device. The Agency allowed the
use of theoretical calculations for inlet mass in order to
minimize exposure of the source tester to ethylene oxide.
Comment: One commenter (18) recommended that EPA provide an
expedited mechanism via Subpart E to approve alternative test
methods and monitoring protocols, or delegate approval of same to
State/local agencies for area sources.
Response: The Agency believes that facilities choosing an
alternative test method or monitoring method than those specified
in the standard should follow the requirements as specified in
§§ 63.7 and 63.8, i.e., apply for approval of such plans to the
Administrator, of the General Provisions. The Agency believes
the requirements as established in the General Provisions are
sufficient for approving use of alternative plans for this
regulation. Following the implementation of Part 70, the Agency
believes that States may be delegated the authority to implement
the provisions of Part 63 standards.
2.6 REPORTING AND RECORDKEEPING REQUIREMENTS
2.6.1 General
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Comment: One commenter (18) agreed with the limited
recordkeeping and administrative requirements for facilities that
qualify for the low usage exemption [i.e., sources <1 ton/yr].
Response: The Agency recognizes the burden recordkeeping
places on small sources and has therefore limited the
requirements for these sources to alleviate this burden. Many of
the requirements of the General Provisions are specific for major
sources, and some are not appropriate for area sources in this
source category. Several of these requirements, such as
construction/reconstruction requirements, performance test plan
requirements, and performance evaluation test plan requirements
for monitoring equipment, have been waived for area sources.
In addition to these exemptions, all sources (both major and
area) in this source category have been waived from the
requirement to develop a startup, shutdown, and malfunction plan
as specified in § 63.6 of the General Provisions. Due to the
batch nature of the industry, the Agency does not foresee
emissions associated with startup, shutdown, or malfunction
periods that would affect the source's compliance status. No
emissions are associated with startup of the process (i.e.,
introducing ethylene oxide into the sterilization chamber);
emissions associated with shutdown of the process are vented to
control equipment and, in the instance of a malfunction of the
control equipment, the process may be stopped (i.e., no ethylene
oxide emissions) until the malfunction has been corrected. While
the Agency has not required sources to develop a plan, a source
may choose to voluntarily develop a startup, shutdown, and
malfunction plan if they have a concern regarding the source's
compliance status due to ethylene oxide being emitted during
startups, shutdowns, and malfunctions.
2.6.2 Relationship to the General Provisions
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Comment: Two commenters (04, 05) stated that §§ 63.366(b)
and (c) should be modified to conform with § 63.9 (Notification
Requirements) of the final General Provisions.
One commenter (18) stated that the initial notification
should be required no sooner than 120 days after the effective
date in order to allow all facilities to receive and comprehend
the Federal Register notice containing the final rule.
Response: The General Provisions were finalized on
March 16, 1994, following the proposal of these NESHAP. The
recording and recordkeeping requirements of the final rule will
be made consistent with the General Provisions. A table
identifying the applicable, modified, and nonapplicable
requirements of the General Provisions has been included in the
final rule.
2.6.3 Reporting Frequency
Comment: One commenter (18) recommended that implementing
agencies be allowed to determine the frequency of reports based
on individual program needs and routine inspection schedules.
One commenter (13) recommended that an excess emissions and
monitoring system performance report be submitted every quarter,
and if there have been no exceedances, the facility should state
this.
Response: The Agency has determined that semiannual
reporting is appropriate for this regulation; however, a source
may be subject to more frequent reporting if the Administrator
determines it is necessary for a particular source. In addition,
excess emissions reports must be submitted semiannually even when
no excess emissions have occurred. The EPA recognizes the value
of reporting on a regular basis in that the source demonstrates
their attention to applicable standards. By requiring sources to
report violations on a regular basis, the enforcement authority
is able to identify potential violations in a timely manner.
Since penalties are calculated per day per violation, the timely
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identification of violations reduces a source's liability. More
importantly, timely identification allows the enforcement
authority to ensure that the cause of a violation has been
addressed, thereby reducing potential health effects of the
emissions. In addition, companies that have facilities in
several States could possibly be subject to numerous different
and confusing reporting schedules.
2.7 WORDING OF THE REGULATION
Comment: Three commenters made suggestions regarding the
wording of the regulation. One commenter (13) suggested that the
definition for the term "baseline ethylene glycol concentration"
be amended as follows: "baseline ethylene glycol concentration
means the maximum concentration of ethylene glycol in the
scrubber liquor of an acid-water scrubber control device beyond
which the scrubber achieves less than 99 percent control of
ethylene oxide emissions." This commenter also suggested that
§ 63.363(a), Compliance and Performance Testing, be reworded as
follows: "The emissions limits of this subpart apply at all
times except that, during periods of malfunction which might
increase emissions, no ethylene oxide shall be charged to the
affected sterilization chamber during the malfunction." Another
commenter (14) stated that the regulation should avoid confusion
between the terms "baseline temperature," "combustion
temperature," and "temperature of catalyst bed." An appropriate
definition of "baseline temperature" would be as follows:
"baseline temperature" means the temperature at the inlet of the
catalyst bed in a catalytic oxidation unit control device at
which the unit achieves at least 99 percent control of ethylene
oxide emissions. Another commenter (18) stated that the
definition for the term "chamber exhaust vent" should only refer
to a physical emissions point, not a time period during which
that point meets the definition. The standard for the chamber
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exhaust vent could include the time-frame during which the
standard applies.
Response: The definitions for baseline ethylene glycol
concentration and baseline temperature have been revised in the
final rule. The definition for chamber exhaust vent has not been
revised because reference to both the physical point and the time
period are significant in defining this term. Interchangeable
use of the different temperature terms has been eliminated and
the term baseline temperature is used consistently in the final
rule. Changes to the wording of § 63.363 for applicability
during malfunctions have been incorporated.
Comment: One commenter (18) suggested several
clarifications for § 63.360: (1) eliminate § 63.360(a);
(2) eliminate § 63.360(b) and include the language of this
exemption in the aeration room vent standard; and (3) rephrase
§ 63.360(c) to refer to sources that are subject to the standard
rather than those that are not. Another commenter (17) indicated
that a separate applicability threshold for aeration room vents
should be included in § 63.362(b), as follows: "Aeration room
vent. Each owner or operator of an existing or new sterilization
facility that uses 9,070 kilograms (kg) (10 tons) of ethylene
oxide within any consecutive 12-month period, shall reduce
ethylene oxide emissions to the atmosphere from each aeration
room vent . . .."
Response: Section 63.360 of the final rule identifies the
applicability of the regulation to specific commercial
sterilization and fumigation sources. Language has also been
added as suggested to the standards in § 63.362 of the final rule
to identify those sources that are subject to a specific
standard. The Agency believes that the applicability section and
the emissions standards in the final rule have been written
clearly.
2.8 MISCELLANEOUS
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Comment: Two commenters (07, 13) questioned why the
proposed regulation was not included along with the preamble in
the Federal Register. One of these commenters (07) also
questioned whether this form of notice satisfies EPA's
obligations for informed notice and comment for rulemaking. The
other commenter (13) stated that omission of the text of the
proposed regulation is not a good policy. This commenter
explained that requesting a copy of the rule from EPA through the
mail would take time out of the already limited comment period
and explained that downloading from the TTN requires access to a
computer, modem, and appropriate software. The commenter stated
that these methods of obtaining the actual text of the proposed
regulation could be difficult for some facilities, especially
small facilities, and added that it is critical that facilities
know when the proposal date occurs since the regulations will
apply to new sources from this date onward. This commenter also
suggested that until EPA revises this policy, the fact that the
actual proposed regulation is not included in the
Federal Register notice should be made very clear, and an EPA
contact person, their telephone number, and the TTN telephone
number should be included. One commenter (07) indicated that the
text of the proposed regulation is equally, if not more,
important than the preamble, and the other (13) stated that it
makes more sense to leave out the preamble and to print the
regulation.
Response: The Agency has reviewed its responsibility to
adequately inform the affected public of proposed actions. The
decision to reduce the amount of printed material in the
Federal Register and assure that the material, including the
proposed regulatory text of the proposed rule, is accessible for
public comment and judicial review does not conflict with the
statutory requirements of the Administrative Procedures Act
(APA), the Federal Register Act (FRA), nor the requirements of
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the Clean Air Act Amendments of 1990. Access to material that is
used as the basis of the proposed rule (officially located in the
Air Docket created by the CAAA) is identified in the preamble to
the proposals and promulgations of rules. Specifically, the
Agency clearly established and will continue to look for
additional connections and will include directions for obtaining
the text of information not printed in the Federal Register.
Currently, this information may be obtained through one of the
following sources: (1) the TTN's "Recently Signed Rule" bulletin
board; (2) directly from the Air and Radiation Docket and
Information Center; (3) distribution to trade associations;
(4) plaintiffs in court ordered regulatory actions; (5) contact
with small business ombudsman system in each State; and (6) if
necessary, through the contact person at the Agency. The
response to this approach has been positive as the process has
aged.
The proposal date is the date that the notice of the
Agency's action is signed by the Administrator and published in
the Federal Register. This has always been the case with the
Agency's rulemakings. The printing of the regulatory text does
not depend on the effective date of applicability as determined
by the date of Federal Register publication.
The Agency believes that all information that is developed
in the course of the development of a proposed and final rule is
important, however, EPA believes they have realistically and
responsibly addressed the need to publish information in the
Federal Register. The Agency will continue to review the issue
of extensive publishing in the Federal Register along with its
responsibility to adequately inform affected parties of our
proposed and final actions.
Comment: One commenter (03) suggested that the rule include
the standards in the form of a table.
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Response: The Agency agrees that providing the requirements
of the standards in tabular format is a convenient summary
method. Tables similar to those presented in the preamble to the
proposed rule have been included in the final rule to supplement
the regulatory text.
Comment: One commenter (02) requested that EPA promulgate
the final rule for this source category by November 15, 1994;
promulgation by the scheduled date is important to the States who
have the obligation of implementing and enforcing the NESHAP
standards and requirements.
Response: As a result of a Clean Air Act litigation suit,
Sierra Club v. Browner, the proposal and promulgation dates for
several NESHAP were agreed upon in a consent decree. The
commercial sterilization and fumigation facilities source
category was included in this consent decree and the
court-ordered deadline for promulgation of this NESHAP is
November 23, 1994. The EPA will promulgate this project on
schedule.
Comment: One commenter (10) stated that emissions averaging
does not address the possible health effects from exposure to
high concentrations of an extremely toxic substance for a short
time period.
Response: The EPA does not believe emissions averaging can
be used practically for commercial sterilization facilities and
has not included emissions averaging in the final regulation.
The Agency could not develop a credible averaging scheme and
requested comment in the preamble to the proposed rule on the
feasibility of emissions averaging for this industry and also
requested submittal of potential emissions averaging schemes from
commenters. None of the commenters submitted an averaging scheme
to the Agency.
Comment: One commenter (08) indicated support for the
stated positions of commenter 11.
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Response: The Agency appreciates this commenter's support
for statements made by commenter 11.
Comment: One commenter (06b) noted that CFC's and HCFC's
that are used as a diluent with ethylene oxide in commercial
sterilization inhibit the efficiency and can cause permanent
damage to catalyst in catalytic oxidizers. The commenter added
that there is typically a much higher proportion of CFC/HCFC's
relative to ethylene oxide in the sterilant gas. The commenter
also noted that the CFC/HCFC's will produce toxic byproducts
including phosgene at oxidation temperatures above 400°F.
Two commenters (17 and 18) stated that EPA should consider
the existence of multiple control units on a single vent. The
commenters were aware of a number of sources that have installed
membranes or condenser/compressor units (whose performance can
vary considerably) between the sterilization chamber and the
abatement device to collect ethylene oxide and CFC's. The
commenters specifically noted these devices as they relate to
varying ethylene oxide concentrations and hence temperature
responses when catalytic oxidation is used for abatement.
One commenter (19) stated that EPA should address the
implications of CFC phase out as it relates to potential
increased ethylene oxide emissions, especially from sources
falling below the proposed 1 ton/yr ethylene oxide use cutoff.
Response: The Agency is aware of the use of CFC's and
HCFC's as dilutants for ethylene oxide in commercial
sterilization and the potential impacts associated with catalytic
oxidation of CFC-EO mixtures. As noted in the Background
Information Document for these proposed standards, the Agency
does not believe that toxic CFC byproducts would be emitted
following catalytic oxidation because the CFC's do not react at
the temperatures typically occurring during catalytic oxidation
(150° to 180°C [300° to 350°F]). The Agency has also been made
aware that the use of EO-CFC gas mixtures has significantly
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decreased in response to increased regulation of CFC's. The
Health Industry Manufacturer's Association (HIMA) has informed
EPA that none of their members are currently using EO-CFC gas
mixtures.
Use of multiple controls, ex. installing membranes or
condensers prior to the control device, is at the source's
discretion as long as the control efficiency achieved by the
multiple control units is consistent with the applicable
standard. A source, however, would be required to apply to the
Administrator for approval of the monitoring plan for the control
scenario.
The EPA would like to point out that increased emissions of
ethylene oxide should not result from CFC phase out. Because the
sterilization process must be performed using a specified
concentration of ethylene oxide, the same amount of ethylene
oxide is used for a sterilization process whether pure ethylene
oxide or 12/88 is used. The Agency believes these NESHAP are
sufficient to control ethylene oxide emissions from all affected
area and major sources.
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TECHNICAL REPORT DATA
(Please read Instructions on reverse before completing)
1. REPORT NO.
2.
4. TITLE AND SUBTITLE
Ethylene Oxide Emissions from Sterilization/Fumigation
Operations—Background Information for Final Standards
7. AUTHOR(S)
Karen Schmidtke, David G. Hearne
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Midwest Research Institute
401 Harrison Oaks Boulevard
Gary, NC 27513
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Air Quality Planning and Standards
Office of Air and Radiation
U. S. Environmental Protection Agency
Research Triangle Park, NC 2771 1
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
November 1994
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D1-0015, WA96
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/200/04
15. SUPPLEMENTARY NOTES
Project Officer is David Markwordt, Mail Drop 13, (919) 541-0837
16. ABSTRACT
National emissions standards to control emissions of ethylene oxide from new and existing
sterilization/fumigation operations are being promulgated under Section 1 12 of the Clean Air Act. This
document contains information on the background and authority, a summary of public comments and Agency
responses, and a summary of changes to the regulation following proposal and the resulting environmental and
economic impacts.
17.
KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
Air pollution
Ethylene oxide
Pollution control
National emissions standards
Industrial processes
Hazardous air pollutants
Sterilization industry
Fumigation industry
18. DISTRIBUTION STATEMENT
Unlimited
b. IDENTIFIERS/OPEN ENDED TERMS
Air pollution control
Ethylene oxide
Stationary sources
19. SECURITY CLASS (Report)
Unclassified
20. SECURITY CLASS (Page)
Unclassified
c. COSATT Field/Group
13B
21. NO. OF PAGES
75
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION IS OBSOLETE
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TABLE 2-1. COMMENTS RECEIVED ON THE PROPOSED EO STERILIZATION
NESHAP
Docket Item3 Commenter and Affiliation
IV-D-01 David Driesen
Natural Resources Defense Council
1350 New York Avenue, Northwest
Washington, DC 20005
IV-D-02 John Walton
Tennessee Department of Environment and
Conservation
Tennessee Air Pollution Control Board
9th Floor, L & C Annex
401 Church Street
Nashville, TN 37243-1531
IV-D-03 Margaret Corbin
Puget Sound Air Pollution Control Agency
110 Union Street, Suite 500
Seattle, WA 98101-2038
IV-D-04 Ann Baldwin
Health Industry Manufacturers Association
1200 G Street, Northwest
Suite 400
Washington, DC 20005-3814
IV-D-05 Gary Wilson
COBE Laboratories, Inc.
Environmental Health and Safety
1185 Oak Street
Lakewood, CO 80215
IV-D-06ab Robert Wheeler
SIMS Concord/Portex
Technical Services
15 Kit Street
Keene, NH 03431
IV-D-06bb Allen Ammerman
Griffith Micro Science
200 S. Frontage Road, Suite 120
Burr Ridge, IL 60521-6916
IV-D-07 Michael Pucci
AT&T
Corporate Environment and Safety Engineering
Center
131 Morristown Road
Basking Ridge, NJ 07920
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TABLE 2-1. (continued)
Docket Item3 Commenter and Affiliation
IV-D-08 Raymond Connor
Manufacturers of Emission Controls Association
1707 L Street, Northwest
Suite 570
Washington, DC 20036-4201
IV-D-09 David Mixon
McCormick and Company, Inc.
18 Loveton Circle
Post Office Box 6000
Sparks, MD 21152-6000
IV-D-10 Thomas Allen
New York State Department of Environmental
Conservation
Division of Air Resources
50 Wolf Road
Albany, NY 12233-3254
IV-D-11 Gary Olson
Donaldson Company, Inc.
Chemical and Catalytic Systems
Post Office Box 1299
Minneapolis, MN 55440-1299
IV-D-12 Gerald Messerschmidt
C. R. Bard, Inc.
Scientific Affairs
730 Central Avenue
Murray Hill, NJ 07974
IV-D-13 William 0'Sullivan
New Jersey Department of Environmental
Protection and Energy
Air Quality Regulation Program
401 East State Street
Trenton, NJ 08625
IV-D-14 Michael Wax
Institute of Clean Air Companies
1707 L Street, Northwest
Suite 570
Washington, DC 20036-4201
IV-D-15 Barbara Morin
Rhode Island Department of Environmental
Management
Division of Air Resources
291 Promenade Street
Providence, RI 02908-5767
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TABLE 2-1. (continued)
Docket Item3 Commenter and Affiliation
IV-D-16 Patricia Leyden
South Coast Air Quality Management District
(SCAQMD)
21865 E. Copley Drive
Diamond Bar, CA 91765-4182
IV-D-17 Robert Colby
Donald Theiler
STAPPA/ALAPCO
444 North Capitol Street, Northwest
Washington, DC 20001
IV-D-180 Bay Area Air Quality Management District
(BAAQMD)
939 Ellis Street
San Francisco, CA 94109
Deborah Sheiman
IV-D-190 Natural Resources Defense Council
1350 New York Avenue, Northwest
Washington, DC 20005
aThe docket number for the commercial sterilization and
fumigation docket is A-88-03.
bThis designation for internal use only, these comments were
assigned identical docket numbers by EPA's Air and Radiation
Docket and Information Center.
cThis designation for internal use only, these comments were
received after the close of the comment period and have not been
assigned a docket number.
2-4
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