United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/3-89-007
March 1989
Air
Alternative Control
Technology Document -
Ethylene Oxide
Sterilization/Fumigation
Operations

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                            EPA-450/3-89-007
   Alternative Control
Technology Document -
     Ethylene  Oxide
Sterilization/Fumigation
       Operations
        Emissions Standards Division
     U.S. Environmental Protection Agency
     Region 5, Library (PL-12J)
    U.S. ENVIRONMENTAL PROTECTION AGENCY
        Office of Air and Radiation
     Office of Air Quality Planning and Standards
     Research Triangle Park, North Carolina 27711
           March 1989

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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, N.C.
27711, or from National Technical Information Services, 5285 Port Royal
Road, Springfield, Virginia 22161.
                                   n

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                              TABLE  OF  CONTENTS

                                                                       Page

 LIST OF FIGURES	   v

 LIST OF TABLES	   vi

 CHAPTER 1.   INTRODUCTION	   !_1

 CHAPTER 2.   SUMMARY      	   2-1

 CHAPTER 3.   ETHYLENE OXIDE STERILIZATION/FUMIGATION  PROCESSES  AND
               EMISSIONS	            3_!
             3.1  BACKGROUND  INFORMATION	     "*   3.1
             3.2  PROCESS DESCRIPTION	'*   3.3
                 3.2.1  Bulk  Sterilization	   3,3
                 3.2.2  Single-Item Sterilization System	   3.14
                 3.2.3  Beehive Fumigators	      3_15
             3.3  EMISSION SOURCES	    3_15
                 3.3.1  Sterilization Chamber Vents	    3_i;
                 3.3.2  Sterilization Chamber Vacuum Pump Drains...    3-17
                 3.3.3  Aeration Room Vent	    3_17
                 3.3.4  Equipment Leaks	!    3_17
                 3.3.5  Storage and Handling	"....          3.19
            3.4  EMISSION ESTIMATES	.'    3.19
                 3.4.1  Commercial  Sterilization Facilities..!!.*.*!!    3-19
                 3.4.2  Hospitals	       3_2i
            3.5  CURRENT REGULATIONS	!    3.22
                 3.5.1  Occupational Safety  and  Health Administra-     3-22
                          tion Standards	
                 3.5.2  State Regulations	       ""     3.22
            3.6  REFERENCES  FOR CHAPTER 3	!!!.*."!    3_25

CHAPTER 4.  EMISSION  CONTROL  TECHNIQUES	    4_i

            4.1  BULK  STERILIZATION  PROCESSES	    4.!
                 4.1.1  Sterilization Chamber  Vent Emissions	!    4-1
                 4.1.2  Sterilization Chamber  Vacuum  Pump  Drain
                         Emissions	    4_15
                 4.1.3  Aeration Room Vent Emissions	!!!!*    4.16
            4.2  OTHER STERILIZATION PROCESSES	    4_22
                 4.2.1  Single-item Sterilization	!    4.22
                 4.2.2  Fumigation with Portable Units	     *    4-22
            4.3  ALTERNATIVES  TO EO STERILIZATION	      "    4_22
            4.4  RETROFIT CONSIDERATIONS	     	    4 23
            4.5  IMPACTS OF A  CFC REGULATION ON EO EMISSION
                  CONTROLS	                   4 73
            4.6  REFERENCES FOR CHAPTER 4	!	    4 24
                                   111

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                       TABLE OF CONTENTS (continued)
CHAPTER  5.   EMISSION  CONTROL COSTS .................................    5_1
5.1
5.2
5.3

5.4
5.5
5.6
INTRODUCTION ................................
CONTROL COSTS FOR COMMERCIAL STERILIZATION
  FACILITIES
5.2.1  Description of Components Costed
5.2.2  General Assumptions ............ ,
5.2.3  Capital Costs ..................
5.2.4  Annual ized Costs ...............
CONTROL COSTS FOR HOSPITAL STERILIZATION
  CHAMBERS .............................. .....
CONTROL COSTS FOR OTHER STERILIZATION SYSTEMS
CONTROL COSTS FOR AERATION ROOMS .......
REFERENCES FOR CHAPTER 5
                                                                       5_1

                                                                       5_1
                                                                       5-1
                                                                       5.2
                                                                       5_3
                                                                       5.3

                                                                       5.3
                                                                       5-3
                                                                       5.4
                                                                       5-14
APPENDIX A.  FEDERAL AGENCY CONTACTS, CONTROL DEVICE VENDORS, AND
               ETHYLENE GLYCOL RECOVERY COMPANIES

APPENDIX B.  COST INDICES AND SAMPLE COST CALCULATIONS

APPENDIX C.  CONTROL DEVICE COSTS (CATALYTIC OXIDATION AND GAS/
               SOLID REACTOR SYSTEM)
                                   iv

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                              LIST OF FIGURES
                                                                       Page
 Figure 3-1.   Schematic of a gas  sterilizer	    3_5
 Figure 3-2.   Sterilization cycle for 12/88	    3_H
 Figure 3-3.   Sterilization cycle for pure EO	    3-12
 Figure 3-4.   Schematic of emission sources at commercial
                sterilization facilities	    3_16
 Figure 3-5.   Hydrolysis rates of dilute, neutral aqueous solutions
                of ethylene oxide	    3_18
 Figure 4-1.   Countercurrent packed bed scrubbing system	    4-5
 Figure 4-2.   Detoxification tower control system	   4.7
 Figure 4-3.   Catalytic oxidation system	   4-11
 Figure 4-4.   Condensation/reclamation system	   4-13
Figure 4-5a.   Once-through liquid-ring vacuum pump	   4-17
Figure 4-5b.   Recirculating  liquid-ring  vacuum  pump	   4.17

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                                LIST OF TABLES

                                                                       Page

 TABLE 2-1.   CONTROL COSTS FOR ACID HYDROLYSIS AT COMMERCIAL
                STERILIZATION FACILITIES	   2-3

 TABLE 3-1.   LOCATIONS OF COMMERCIAL STERILIZATION FACILITIES—EPA
                DATA BASE	   3.2

 TABLE 3-2.   NUMBER OF FACILITIES AND STANDARD INDUSTRIAL
                CLASSIFICATION (SIC)  PER INDUSTRY CATEGORY-EPA
                COMMERCIAL STERILIZATION DATA BASE	   3.4

 TABLE 3-3.   CHAMBER SIZES—EPA COMMERCIAL STERILIZATION
                DATA BASE	   3_6

 TABLE 3-4.   PHYSICAL AND CHEMICAL PROPERTIES  OF ETHYLENE OXIDE,
                DICHLORODIFLUOROMETHANE, AND CARBON  DIOXIDE	   3-8

 TABLE 3-5.   STERILANT GAS TYPE USAGE-EPA COMMERCIAL
                STERILIZATION  DATA BASE	    3.9

 TABLE 3-6.   AVERAGE EMISSIONS  FOR COMMERCIAL  STERILIZATION
                FACILITIES—EPA  DATA BASE	    3_20

 TABLE 3-7.   AVERAGE EMISSIONS  FROM HOSPITAL STERILIZERS	    3-23

 TABLE 3-8.    STATE  REGULATIONS  FOR ETHYLENE OXIDE EMISSIONS	    3-24

 TABLE 4-1.    ETHYLENE OXIDE EMISSION CONTROL DEVICES  FOR
               STERILIZATION CHAMBER VENTS—EPA COMMERCIAL
               STERILIZATION DATA  BASE	    4_2

 TABLE 5-1.    CONTROL COSTS FOR ACID HYDROLYSIS	    5.5

 TABLE  5-2.    COST OF DAMAS SCRUBBER MODELS (F.O.B.)	    5.5

 TABLE  5-3.    INCREMENTAL CAPITAL COSTS OF MANIFOLDING
               STERILIZATION CHAMBERS	   5.7

TABLE 5-4.   CAPITAL COST OF CHECK VALVE FOR CHAMBER	   5.3

TABLE 5-5.   MISCELLANEOUS OPERATING COSTS	   5.9

TABLE 5-6.   DATA USED TO CALCULATE CONTROL EQUIPMENT CAPITAL
               COSTS	   5_10

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                         LIST OF  TABLES  (continued)

                                                                       Page

TABLE 5-7.  DATA USED TO CALCULATE CONTROL DEVICE ANNUALIZED
              COSTS	    5_n

TABLE 5-8.  HOSPITAL EMISSION CONTROL COSTS	    5.43

TABLE A-l.  CONTACTS AT FEDERAL AGENCIES	    A-l

TABLE A-2.  CONTROL DEVICE MANUFACTURERS	    A-2

TABLE A-3.  ETHYLENE 6LYCOL RECOVERY COMPANIES	    A-3

TABLE B-l.  CAPITAL AND ANNUALIZED COSTS OF INSTALLING SCRUBBER....    B-6

TABLE C-l.  CATALYTIC OXIDATION	    C-l

TABLE C-2.  ACID-WATER SCRUBBER AND GAS/SOLID REACTOR  SYSTEM	    C-2
                                  vn

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                             1.0  INTRODUCTION

     The Clean A1r Act  (CAA) identified December  31,  1987, as the  latest
date for attainment of  the national ambient air quality  standard  (NAAQS)
for ozone.  As of this  writing, many areas of the country are not  in
attainment with the ozone NAAQS.  The U. S. Environmental Protection
Agency  (EPA) has proposed to require States that  have ozone nonattainment
areas to submit revised State implementation plans (SIP's) that describe
what steps will be taken to attain the standard (52 FR 45044, November  24,
1987).
     Under the proposed rule (52 FR 45044), to demonstrate attainment of
the NAAQS for ozone, emissions of volatile organic compounds (VOC's) must
be reduced to a level that will produce ozone concentrations consistent
with NAAQS as demonstrated by atmospheric dispersion modeling.  Once the
State has determined the VOC emission reduction required to meet the
NAAQS,  it must identify and select control measures that will produce the
required reductions as  expeditiously as practicable.
     In 1985, EPA published a Federal Register notice titled "Assessment
of Ethylene Oxide as a  Potentially Hazardous Air  Pollutant."  The
conclusion of that notice, based on the information available, was that
EPA intended to list ethylene oxide (EO) under Section 112 of the CAA if
emission standards were warranted.  Therefore, a  reduction in EO emissions
(which also is a VOC) contributes to attainment of the NAAQS for ozone and
reduces potential health risks from direct exposure to EO.
     This report presents technical information that State and local
agencies can use to develop strategies for reducing VOC (i.e., EO)
emissions for sterilization/fumigation facilities.  The information in
this document will  allow planners to (1) identify available control
alternatives and (2)  evaluate the VOC reduction and cost of implementing
controls.
     This document  provides information on sterilization/fumigation
processes,  EO emissions, and  emission reductions,  and  cost associated with
the application of  control  units.   Section 2.0 presents  a summary  of the
findings of this study.   Section 3.0 provides  a description of
sterilization/fumigation facility operations  and emission sources.
                                   1-1

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Section 4.0 provides a description of alternative control techniques for
the reduction of ethylene oxide emissions.  Section 5.0 presents a cost
analysis that includes a methodology for computing annualized equipment
and operating costs.
     A list of contacts at various Federal agencies who are knowledgeable
about sterilization/fumigation processes is presented  in Appendix A.
                                  1-2

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                                2.0  SUMMARY
      Ethylene oxide (EO) is used as a sterilant/fumigant in the  production
 of medical equipment supplies, in miscellaneous sterilization and
 fumigation operations, and at hospitals.  Available information  indicates
 that EO is used at over 200 commercial sterilization facilities  in the
 U.S. and at approximately 7,000 hospitals.  These facilities use EO as a
 sterilant for heat- or moisture-sensitive materials or as a fumigant to
 control microorganisms or insects.  A variety of materials are sterilized
 or fumigated with EO,  including medical  equipment (e.g., syringes and
 surgical gloves), spices, cosmetics, and Pharmaceuticals.  These materials
 may be sterilized at the facility that produces or uses the product or by
 contract sterilizers (i.e.,  firms under  contract to sterilize products
 manufactured by other  companies).  Libraries and museums use EO to
 fumigate books  and other historical  items.  State departments of
 agriculture control  diseases  of bees by  fumigating beehives with EO.
      Practically all of the  EO used  in sterilization/fumigation processes
 is estimated to be emitted from three sources:   (1)  the sterilizer vent(s)
 (i.e.,  the vent from the vacuum pump gas/liquid separator),  (2)  the vacuum
 pump drain,  and (3)  the aeration  room or  chamber.   Uncontrolled  emissions
 from these sources are  assumed to be 50 percent,  45  percent,  and  5  percent
 of the  EO  use,  respectively.   The total amount  of  EO used by  the
 203 commercial  sterilization facilities (i.e.,  not  hospitals) represented
 in the  EPA sterilization data  base is  2,270 Megagrams per year  (Mg/yr)
 (5 million Ib/yr).   Estimated  emissions from these 203  facilities are
 760 Mg/yr  (1.7 million  Ib/yr)  from sterilizer vents, 1,000 Mg/yr
 (2.2 million  Ib/yr) from vacuum pump drains, and 110 Mg/yr (0.25 million
 Ib/yr)  from aeration room vents.  The sterilizer vent emissions are less
 than 50 percent of the EO use because several of these 203 facilities
 control EO emissions from the sterilizer vent.  However, drain and
 aeration room emissions at these facilities are assumed to be
 uncontrolled.  Based on approximately 80  responses to a 1986 information
 request to Federal hospitals  and information in the 1988 American Hospital
Association data base,  EO use at hospitals is estimated to be
approximately 1,000 Mg/yr.  Because the majority of hospitals do not use
                                   2-1

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 £0 emission controls,  £0 emissions from hospitals are assumed to equal the
 £0 use of approximately 1,000 Mg/yr.
      Three primary techniques are applicable to the control  of EO
 emissions from sterilization/fumigation processes:   acid hydroysis (i.e.,
 acid-water scrubbers),  oxidation, and a gas/solid reactor system that
 chemically reacts EO and binds it to  the solid  reactor packing.   Control
 efficiencies for those  techniques range from 98.0 percent to 99.0 percent
 for sterilizer vent emissions.   However, the control  efficiencies of these
 devices have not been demonstrated for the low  EO concentrations from
 aeration processes.  Acid hydrolysis  and thermal  oxidation are applicable
 to the control  of sterilizer  vent emissions  from  the  larger  sterilizers
 (>2.8 m  [100 ft3])  at  commercial  sterilization facilities.   Several
 hospitals use catalytic oxidation or  scaled-down  acid-water  scrubbers to
 control  emissions from  hospital  sterilization chambers.   Catalytic
 oxidation and the gas/solid reactor system are  used by  several hospitals
 and  a few commercial sterilization facilities to  control  EO  emissions from
 aeration rooms  or aeration chambers.   Closed-loop recirculating  fluid
 vacuum pumps  can  virtually eliminate drain EO emissions by routing the
 gaseous  phase exiting the gas/liquid separator to the sterilizer  emission
 control  device.
      Federal  regulations for stratospheric ozone-depleting
 chlorofluorocarbons  (CFC's)  have been developed under EPA's Stratospheric
 Ozone  Protection  Program (SOPP).  The majority of commercial  sterilization
 facilities and almost all hospitals use a sterilant gas mixture known  as
 12/88, which  is 12 weight percent EO and 88 weight percent
 dichlorodifluorocarbon  (CFC-12).  The use of CFC's in sterilant gases  is
 one of the source categories subject to the CFC  regulations.   However, the
 requirements of a CFC regulation would not affect  the ability of a
 sterilization facility  to control EO emissions.
     The cost of controlling EO emissions from sterilizer vents at three
of the commercial sterilization facilities represented in EPA's data base
are presented in Table  2-1.   Acid hydrolysis  was chosen as the basis for
the cost calculations because  that control technique currently is
practiced at many commercial  facilities and has  been demonstrated at both
small and large commercial sterilization facilities.   Detailed cost
                                   2-2

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        TABLE 2-1.  CONTROL COSTS FOR ACID HYDROLYSIS AT COMMERCIAL
                        STERILIZATION FACILITIES4 b
Model
plant
Small d
Medium8
Large
Total
sterilizer
volume,
m3 (ft3)
2.8
(100)
28
(1,000)
168
(6,000)
Annual
EO use,
Mg
(lb/1,000)
0.18
(0.39)
3.9
(8.7)
109
(240)
Capital
costs, $
76,000
160,000
291,000
Annuali zed
costs, $
21,200
40,800
117,000
Annual emis-
sion reduc-
tion, Mg
(lb/l,000)c
0.17
(0.37)
3.7
(8.2)
102
(226)
 These cost .estimates are not applicable to hospitals because the acid-
 water scrubbers costed are not designed for the low flowrates from the
.vacuum pumps on hospital sterilizers.
DSee Chapter 5 and Appendix B for the methodology used to calculate these
 control costs.
Calculated as (0.99)x(0.95)(EO use).  Five percent of the EO use is
 assumed to be retained in the product after sterilization and emitted
.from the aeration room, which is assumed to be uncontrolled.
°The small model plant has one chamber and uses 12/88 (EO/CFC-12).
 Therefore, a model  100 scrubber (see Table 5-2) was chosen as the basis
 for the calculations.
8The medium model plant has one chamber and uses 12/88 gas.  Therefore, a
.model 400 scrubber  was chosen as the basis for the calculation.
 The large model plant has seven chambers and  uses  100 percent EO.  The
 sum of the volumes  of the two largest chambers is  2,000 ft .  Therefore,
 a model  500 scrubber (with explosion-proof valves) was chosen as the
 basis for the calculations.
                                    2-3

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estimates have not been developed for the control of EO emissions from
hospitals or aeration processes.  However, preliminary control cost
estimates for hospitals have been developed by EPA's Office of Research
and Development (see Chapter 5).  Also, the Office of Air Quality Planning
and Standards currently is developing control cost estimates for aeration
rooms, which should be available by June 1989.  (See Appendix C for
preliminary aeration control costs.)
     Possible alternatives to EO sterilization include radiation, chlorine
dioxide, gas plasma, hydrogen peroxide, ozone, X-ray (a new, developing
technology), deep freezing (museums and spice industry), and increased use
of disposable medical items in hospitals.   However,  none of these
alternatives can replace the use of EO in  all applications.
                                   2-4

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          3.  ETHYLENE OXIDE STERILIZATION/FUMIGATION PROCESSES AND
                                  EMISSIONS

 3.1  BACKGROUND INFORMATION
      Ethylene oxide (EO) is used as a sterilant/fumigant in the production
 of medical equipment supplies, in miscellaneous sterilization and fumiga-
 tion operations, and at hospitals.  Available information indicates that
 EO is used at over 200 commercial sterilization facilities in the U.S. and
 at approximately 7000 hospitals.1'3  These facilities use EO as a
 sterilant for heat- or moisture-sensitive materials or as a fumigant to
 control microorganisms or insects.  A variety of materials are sterilized
 or fumigated with  EO, including medical  equipment (e.g., syringes and
 surgical gloves),  spices, cosmetics, and Pharmaceuticals.  These materials
 may be sterilized  at the facility that produces  or uses the product or by
 contract sterilizers (i.e., firms under  contract to sterilize  products
 manufactured by  other companies).  Libraries  and museums use EO  to
 fumigate books and  other historical  items.  State departments  of agricul-
 ture  control  diseases  of bees  by  fumigating beehives with EO.
      Information about  facilities that use EO  as a sterilant/fumigant  was
 obtained from three sources:   (1)  a  survey of  medical equipment  suppliers
 conducted  by  the Health  Industry  Manufacturer's  Association (HIMA)  in
 1985,  (2)  an  information  request  submitted by  EPA  under  Section  114  of  the
 Clean Air  Act to miscellaneous  sterilizers and fumigators (identified
 during  an  extensive  survey  of potential  users) in  July 1986, and (3) an
 information request  in January  1986  to Federal hospitals and nine of the
 largest  non-Federal  hospitals.  A total  of 203 commercial sterilization
 facilities (i.e., not hospitals) responded to the  HIMA survey and the July
 1986 EPA information request.  Data from these responses comprise the EPA
 sterilization data base.  Approximately 80 hospitals responded  to the
January  1986 information request.
     As shown in  Table 3-1,  the facilities represented in the  EPA
commercial sterilization data base are located in 43 States  and Puerto
Rico.   These facilities were grouped by Standard  Industrial  Classification
(SIC)  into the following categories:
                                   3-1

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     TABLE 3-1.  LOCATIONS OF COMMERCIAL STERILIZATION FACILITIES—EPA
                               DATA BASE1'2
State
Arizona
California
Colorado
Connecticut
Delaware
Florida
Georgia
Illinois
Indiana
Iowa
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
No. of
facilities*1
3
21
3
6
2
5
4
8
4
3
5
9
8
6
2

Missouri
New Hampshire
New Jersey
New York
North Carolina
Ohio
Pennsylvania
Puerto Rico
Rhode Island
South Carolina
Tennessee
Texas
Utah
Virginia
Washington
No. of
facilities*
5
2
18
14
7
2
10
14
2
3
3
11
2
5
2
Subtotal
 89
Subtotal
100
The EPA data base includes one facility located in each of the following
States:  Alabama, Alaska, Arkansas, Hawaii, Kentucky,  Maine, Nebraska,
Nevada, New Mexico, North Dakota,  Oregon, South Dakota, Wisconsin, West
Virginia.
Subtotal

Total No. of
  facilities
 14

203
JDoes not include hospitals.
                                    3-2

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      1.  medical equipment suppliers;
      2.  Pharmaceuticals;
      3.  other health-related industries;
      4.  spice manufacturers;
      5.  contract sterilizers;
      6.  libraries, museums, and archives;
      7.  laboratories (research, testing, and animal breeding); and
      8.  State departments of agriculture.1*
 Table 3-2 shows the number of facilities in the EPA commercial
 sterilization data base for the eight categories listed above.  Table 3-2
 also shows the SIC codes represented by these industry categories.
 3.2  PROCESS DESCRIPTION
      There are two main types of EO sterilization processes:  (1)  bulk
 sterilization and (2)  single-item sterilization.  These processes  are
 described below.
 3.2.1  Bulk Sterilization
      Bulk sterilization is the more commonly used EO sterilization
 process;  98 percent of the commercial  sterilization facilities represented
 in  the  EPA data base use this process.1*2   The  products to be sterilized
 are placed in a sterilization chamber  and  are exposed  to a sterilant  gas
 at  a predetermined  temperature,  humidity  level,  and pressure.   The
 equipment,  sterilant gases, and  sterilization cycle used for bulk
 sterilization processes  are described  below.
      3.2.1.1   Equipment.   A schematic  of a gas  sterilizer  is shown in
 Figure  3-1.   The main  components of the sterilizer  are  the chamber and
 vacuum  pump.   Chambers used by commercial sterilization  facilities
 typically  range in volume  from 2.8 cubic meters  (m3) (100  cubic feet
 [ft3])  to  28 m3 (1,000 ft3).1'2  Table 3-3 presents  size data  for  the
 chambers  in the EPA  commercial sterilization data base.  Sterilization
 chambers at hospitals range from less than 0.3 to 2 m3  (10  to  70 ft3) but
 are typically about 0.6 to 0.8 m3 (20 to 30 ft3).5
     A vacuum pump is used to remove air from the chamber  before
 sterilization begins and to evacuate the sterilant gas after the
 sterilization cycle is  complete.  Typically, a once-through, water-ring
vacuum pump is used.  Oil-sealed vacuum pumps or vacuum pumps that  use
                                   3-3

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  TABLE 3-2.   NUMBER OF FACILITIES AND STANDARD INDUSTRIAL CLASSIFICATION
    (SIC) PER INDUSTRY CATEGORY-ERA COMMERCIAL STERILIZATION  DATA BASE'
 Industry category
  No. of
facilities3
 SIC
 Medical equipment  suppliers
 Pharmaceuticals
 Other health-related  industries

 Spice manufacturers
 Contract sterilizers
 Libraries, museums, and archives
 Laboratories (research, testing,
  and animal breeding)
State departments of
  agriculture
Total
    64
    40
    25

    25

    17
    13
    11
 3841,  3842
 2834,  5122,  2831,  2833
 3079,  3693,  5086,  2211,
 2821,  2879,  3069,  3569,
 3677,  3999
 2099,  5149,  2034,  2035,
 2046
 7399,  7218,  8091
8411,  8231
0279,  7391, 8071, 8922,
7397
     8         9641

   203
aDoes not include  hospitals.
                                    3-4

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                                        GAS LINE    llQUIHEUGAS
                                        FILTER      1O VAPORIZER
                          GAS
                          SOURCE
CO
I
01
                                                                                                CONTROI
                                                                                                PANEL
                                             VACUUM PUMP
                                                                            VAPOKI/ER
                                                                                                UOOR
          Figure  3-1.  Schematic of  a gas sterilizer.   (Courtesy  of Union  Carbide Corporation,  Linde  Division.)

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    TABLE 3-3.  CHAMBER SIZES—EPA COMMERCIAL STERILIZATION DATA BASE
                                                                      1  2
Size range,
m* (ft*)
<1.4 (<50)
1.5-2.8
(51-100)
2.9-14
(101-500)
15-28
(501-1,000)
29-57
(1,001-2,000)
>58 (>2,001)
No. of
chambers* Percent
87 20
29 7

111 26

130 29

60 14

10 2
Cumulative
No. of chambers
87
116

227

357

417

427b
Cumulative,
percent
20
27

53

84

98

100
j*Does not include hospitals.
 This number excludes four single-item sterilization units, one 55-gal
 drum user, and two facilities that did not report a chamber size.
                                    3-6

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 recirculated water also are used.  There are indications that some
 commercial sterilization facilities and hospitals are converting from
 once-through water-ring vacuum pumps to full sealant recovery vacuum pumps
 in order to meet the 1 part per million by volume (1 ppmv) Occupational
 Safety and Health Administration (OSHA) standard for EO and proposed State
 regulations.6'7
      3.2.1.2  Sterilant Gases.  Ethylene oxide is an extremely effective
 sterilant gas.  The EO penetrates product packaging (e.g., cardboard
 shipping box, plastic shrink wrap,  paper box, and final  product wrapping)
 and destroys bacteria and viruses on the product.  The product remains
 sterile until use because bacteria  and viruses  cannot penetrate the
 product wrapping.
      The most widely used sterilant gas is  a mixture of  12 percent  by
 weight EO and 88 percent by weight  dichlorodifluoromethane (CFC-12),
 referred to as 12/88.   Two other commonly used  sterilant gases are
 (1)  pure EO (i.e.,  100 percent EO)  and (2)  a mixture of  10  percent  by
 weight EO and 90 percent by weight  carbon dioxide (C02), referred to as
 10/90.  Other sterllant gas mixtures  that are used  include  20/80, 30/70,
 and  80/20 (weight percents  E0/C02).l»2   Gas  mixtures that contain
 20 percent or greater  EO (by weight)  are considered  flammable.  The  80/20
 (E0/C02)  mixture has the same  flammability range  as  pure EO.12  Physical
 and  chemical  properties of  EO,  CFC-12,  and C02  are given in Table 3-4.
 Table  3-5 shows  the number  of  commercial  sterilization facilities
 represented  in the EPA  data base that use a  particular gas type and  the
 amount of EO  used for each  gas  type.  Since many  commercial sterilization
 facilities operate more  than one sterilization  chamber,  the gas usage
 rates  in  Table 3-5 also  are presented on a chamber basis.1'2
 Seventy-five  percent of  the hospitals that responded to  the 1986
 information request use  12/88.  The rest use pure EO in the form of
 ampules or single-use cartridges.  At hospitals, pure EO is generally used
 only in very  small (<0.3m3  [10ft3])  chambers.
     The  12/88 mixture is the most popular sterilant gas  for several
 reasons.  Unlike pure EO, 12/88 is nonflammable  and nonexplosive.
Therefore, the use of 12/88 does not require explosion-proof rooms  and
additional safety precautions that are necessary when pure  EO  is used.
                                   3-7

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CO
oo
                      TABLE 3-4.   PHYSICAL AND CHEMICAL  PROPERTIES OF  ETHYLENE  OXIDE, DICHLORODIFLUOROMETHANE,
                                                             AND CARBON  DIOXIDE8-"
                                              Ethylene oxide
Other designations


Appearance


Chemical formula

Molecular weight

Vapor pressure at 20*C  (68*F)

Boiling point at 101.3  kPa
  (14.7 psi)

FlammabiIity  Iimits  in  air


Water solubiIity

Heat of  combustion,  vapor at
  25'C <77*F)

Threshold  limit  value (TLV)
  8-h time  weighted  average (TWA)
                                              1,2-epoxyethane, oxirane,
                                                dimethylene oxide

                                              Colorless liquid or gas
44.0

146.0 kPa (21.2 psia)

10.4'C (50.7'F)


Lower 3 percent by volume
Upper 80+ percent by volume9

Completely miscible

1.306 kJ/mol  (12,760 Btu/lb)


I  ppmv
                                                                              01chIorod i fIuoromethane
CFC-12, refrigerant 12,
  propel I ant 12

Colorless gas, readily liquified
  under pressure and/or  cooling

CC.2F2

120.9

567.6 kPa (82.3 psia)

-29.8*C (-21.6'F)


Nonflammable


Low solubiIity

111  kJ/mol  (396 Btu/lb)


1,000 ppmv
                                                                                                                   Carbon dioxide
                                                                      Carbonic  acid gas,
                                                                        carbonic  anhydride

                                                                      Colorless gas
                                                                                                                   co2

                                                                                                                   44.0

                                                                                                                   5,731.0 kPa  (831 psia)

                                                                                                                   -78.5'C (-109.3'F)


                                                                                                                   Non fIammabIe
                                                                                                                   5,000  ppmv

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CO
I
                    TABLE  3-5.  STERILANT GAS TYPE USAGE-ERA COMMERCIAL STERILIZATION DATA BASE1*2
No. of .
Sterllant gas facilities* b
12/88 (EO/CFC-12)
Pure EO
10/90 (E0/C02)
Other mixtures6
154
44
14
16
Percent of
facilities
76
22
7
8
No. of
chambers0
295
122
19
25
=SBS^==SSS=^==S=====
Percent of
chambers
68
28
4
6
EO use,
Mg/yr*
720
1,350
4
190
Percent of
total EO use
30
60
<0.01
10
K
bThere
 these
"" ""  ""•
                                                                                            » •••»•« "
        Amount of EO in the sterllant gas mixture.
         Includes mixtures of EO and C02 with a weight percent of EO ranging from 20 to 80 percent and custom

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 The 10/90 mixture also is nonflammable and nonexplosive.12  But, because
 10/90 is only 10 percent EO by volume whereas 12/88 is 27.3 percent EO by
 volume, 10/90 requires higher operating pressures to obtain an EO
 concentration that is sufficient for effective sterilization
 (approximately 304 kilopascals [kPal, or 44 pounds per square inch
 absolute (psial, for 10/90, as compared to 170 kPa [24.7 psial for
 12/88).    The chambers used for 10/90 sterilization must  be ASME-rated
 pressure vessels, (i.e.,  manufactured in accordance with Section VIII,
 Division I, of the ASME Pressure Vessel Code)  and are, therefore, more
 expensive to construct than the chambers used  with 12/88.   However,
 because of insurance requirements,  many commercial sterilization
 facilities use chambers that meet requirements for ASME-rated  pressure
 vessels when sterilizing  with 12/88 or with  explosive  mixtures below
 ambient pressure.
      3.2.1.3  Sterilization Cycle.   The typical sterilization  cycle
 consists of five phases:   (1)  presterilization conditioning,
 (2)  sterilization,  (3)  evacuation,  (4)  air wash,  and  (5) aeration.
 Figures  3-2 and  3-3  show  pressure/time  curves  for  the  first four  phases of
 the  12/88  sterilization cycle  and the pure EO  sterilization cycle,
 respectively.  Steps  1  through  4  typically require about 8 hours  at  larger
 commercial  sterilization  facilities, and about 2 to 4  hours at hospitals.
     3.2.1.3.1   Presterilization conditioning.  After  the products  have been
 loaded  into  the  chamber and the airtight door  sealed,  a partial vacuum is
 drawn inside the chamber.  This initial vacuum, or drawdown, prevents
 dilution of  the  sterilant gas.  Also, if flammable sterilant gases are
 used, the removal of air reduces the potential  for ignition.12  The
 chamber pressure is reduced to a pressure of about 6.9 to 69 kPa  (1 to
 10 psia) for 12/88 and 3 kPa (0.4 psia) for pure EO.  The initial drawdown
 takes from about 5 to 45 minutes, depending on the product  being
 sterilized.  Certain products require a longer drawdown time because they
 are damaged by sudden pressure changes.   The  chamber temperature is then
 adjusted to between 38°C (100°F) and 54°C (130°F).  A higher temperature
will  increase the diffusion rate of  EO into  the products and,  thus,  will
reduce the time the products must be exposed  to the sterilant  gas to
ensure proper sterilization.  Finally,  the  relative humidity  is raised  to
                                   3-10

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                                      HUMIOlflCAIlON
                                          &
                                      CONDI TONING
                    0 HOUR
                      1.  PRESTERILIZATION CONDITIONING
                      2.  STERILIZATION
                                                                                    8 HOUR
                                                     3.   EVACUATION
                                                     4.   AIR MASH
Figure 3-2.
Sterilization cycle for 12/88.   (Courtesy  of  Union Carbide Corporation, Linde Division.)

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OJ
I
ro
                                 0  HOUR
                               1.  PRESTERILIZATION CONDITIONING
                               2.  STERILIZATION
                                                                                              8  HOUR
3.   EVACUATION
4.   AIR WASH
            Figure 3-3.  Sterilization cycle for pure EO.   (Courtesy of Union Carbide Corporation
                                              Linde Division.)                                    '

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  about 45 percent by  injecting  steam.   Proper numidification is important
  to the process because the  susceptibility of microorganisms to the
  sterilant gas is increased  under moist conditions.12
      3.2.1.3.2  Sterilization.  The sterilant, which  is  supplied  as  a
  liquid, is vaporized and introduced into the chamber  to  achieve the
  desired concentration of EO.  The chamber pressure depends  on  the type  of
  sterilant gas used.  Pure £0 is used under a slight vacuum  at  pressures  of
  about 94 kPa (13.7 psia); the 12/88 mixture is used at pressures of  about
  170 kPa (24.7 psia).  The pressure is held for about 4 to 6  hours.   This
  exposure time is dependent on the temperature,  pressure, humidity level,
  type of sterilant gas,  and products being sterilized.  For example,  porous
  products require shorter exposures than nonporous products.  Also, some
  bacteria are more resistant to EO and take longer to destroy.
      3.2.1.3.3   Evacuation.  Following sufficient exposure time, the
  sterilant gas is  evacuated  from the chamber  with  a vacuum pump.  Typical
 evacuation pressures are  13 kPa (1.9 psia) for  12/88 gas and 3 kPa
  (0.4  psia)  for pure EO.   This postcycle vacuum  phase lasts about
 10 minutes.
      3.2.1.3.4  Air wash.   The  pressure  in the  chamber is brought  to
 atmospheric  pressure  by introducing  air  (when nonflammable sterilant  gases
 are used) or  either nitrogen or  C02  (when flammable  sterilant gases are
 used).  The combination of  evacuation and air wash phases is repeated from
 two to four times to  remove  as much of the EO from the  product  as
 possible.  The air  wash typically lasts 2 to 15 minutes.
     The purpose of the air  wash is to allow residual EO  to  diffuse from
 the product.  Removal of EO  from the product during the air wash helps
 meet Food and Drug  Administration (FDA) guidelines on residual  EO levels
 for medical devices, EPA residual tolerances  for agricultural products,
 and the OSHA standard for exposure in the workplace.
     3.2.1.3.5  Aeration.   After the last air wash, the chamber doors are
opened,  and the  sterile  products are placed in an  aeration room and kept
there  for several  hours  to days depending on  the product.  The purpose of
aeration  is  to allow further diffusion  of residual  EO from the products
prior  to  shipping  to comply  with the  FOA  and  EPA residual  EO guidelines.
Ethylene  oxide concentrations in the  aeration  room  are  maintained at
                                   3-13

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 relatively low levels by ventilating the room at a rate of about 20  air
 changes per hour.
      Recent information from industry contacts indicate that some
 commercial sterilization facilities are aerating some or all of the
 sterile products in heated enclosed aeration cells.  In comparison to
 traditional warehouse-type aeration rooms, these cells are smaller in
 volume (<70m3 [2500 ft3])  with much lower ventilation rates.
 Consequently, the EO concentrations are usually higher than the 1 ppmv
 OSHA standard.  However, worker exposure is reduced by not opening the
 door until the EO concentration drops and by limiting the  frequency of
 opening the door.  The main purpose of this type of aeration process is to
 increase the diffusion rate of EO out of the sterile product (by
 increasing the temperature)  and,  thus,  reduce the aeration time.
      Facilities  that sterilize products infrequently may aerate in  the
 sterilization chamber.   Two  basic chamber aeration  processes  are  used.
 The first process involves  cycling the  chamber between  atmospheric
 pressure and  a slight  vacuum pressure (i.e.,  a pressure of about  94 kPa
 [13.7 psia])  several times over a 12- to  24-hour  period.   The  length  of
 the cycles depends  on  the chamber size  and  vacuum pump capacity.  The
 second  process involves  drawing an extreme  vacuum (about 0.6 kPa
 [0.1 psia]) in the  chamber and holding  the  vacuum for 24 to 48  hours.
      Some  hospitals  and  commercial  sterilization  facilities with  smaller
 sterilizers (less than 1 m3  [40 ft3]) use aeration chambers (or cabinets),
 which are  similar to the sterilization chambers in size and design.
 Sterile products at hospitals are  aerated for about 24 hours.
 3.2.2 Single-Item Sterilization System
      Four  of the 203 commercial sterilization facilities (2 percent)  that
 responded  to the HIMA survey or the July 1986 EPA information request
 reported the use of a single-item sterilization system.1'2   Three of these
 facilities use the Sterijet® system manufactured by H. W. Andersen
 Products; one facility uses another patented system that is similar to the
 Sterijet®  system.   In contrast to the bulk sterilization chambers used by
most commercial sterilization facilities,  these systems  are designed to
 sterilize small individual  items (such as medical  equipment supplies)  in
 sealed pouches.  Marketing  of these systems is primarily focused on
hospital sterilization.15
                                   3-14

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       The single-item sterilization systems consist of (1) a machine that
  delivers the sterilant gas through a nozzle,  (2)  flexible plastic pouches,
  and (3) an aeration cabinet.   The process involves the following steps.
  The product to  be  sterilized  is  placed in a plastic pouch.   With the open
  ends of the pouch  sealed  around  the nozzle, a  slight vacuum is drawn in
  the pouch followed  by injection  of a premeasured  quantity of sterilant
  gas.  The amount of sterilant  gas injected depends on the size of the
  pouch.   After the gas is  injected,  the nozzle  is  automatically withdrawn,
  and the pouch is heat sealed.  The  sealed  pouches  are placed  directly  into
  an  aeration cabinet  or temperature-controlled aeration room.   The enclosed
  product is  sterilized prior to the  escape  of the gas  through  the  pouch,
  which  is  designed to  retain the  EO  long enough to  ensure  proper
  sterilization.  The products are  sterilized for approximately  12  hours  at
  about 50°C  (122°F)  and aerated for 36  hours.15
  3.2.3   Beehive Fumiqators
      The process for  beehive fumigators is essentially the same as bulk
  sterilization; however, a unique feature of the fumigators warrants a
 separate discussion.  Whereas  the sterilization processes described above
 are performed at one location,  six of the eight State departments of
 agriculture represented in the  EPA sterilization data base use portable
 chambers to fumigate beehives.2  These fumigators  are transported to and
 used at numerous and variable  locations in each  of the six States.  The
 State departments of agriculture  use an E0/C02  sterilant  gas  mixture.
 Typically, a garden  hose is connected to  the fumigation chamber and is
 placed  along the ground for venting  the sterilant  gas  during  the
 evacuation phase of  the sterilization cycle.  After the evacuation,  the
 beehive  is removed from the chamber  and aerated in  the open air.
 3.3   EMISSION SOURCES
      The three principal sources  of EO  emissions from sterilization/
 fumigation processes are (1) the  sterilizer vent(s)  (i.e., the vent on the
 vacuum pump gas/liquid  separator), (2)  the sterilization chamber vacuum
 pump  drain (assuming that a once-through, water-ring vacuum pump is used),
 and  (3)  the aeration room vent.   A schematic of  these emission sources is
 shown in Figure 3-4.   Other potential emission  sources are equipment leaks
and storage and handling.  For  the purposes of developing  emission
                                   3-15

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                                          (760 Mq/yr)
                                                         (1,000 Mg/yr>    no Mq/yr)
                                          VENT OR EMISSION
                                  VENT — CONTROL DEVICE
                               (GAS)
                                                                           VENT
                              SEPARATOR
                                             (LIQUID)
                                                          DRAIN
  ETHYLENE
  OXIDE
"900UCTS FOR
STERILIZATION
STERILIZATION
CHAMBER
                                            STERILIZED
                                            PRODUCTS
                                                   AERATION
                                                   300M
           Figure 3-4.   Schematic  of emission sources at  commercial
                             sterilization  facilities.
                           (Does not include  hospitals).
                                         3-16

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  estimates and because bulk sterilization processes are the main source of
  emissions, emission sources were assumed to be the same for both
  sterilization processes (i.e.,  bulk  and single-item).
  3.3.1   Sterilization Chamber Vents
      Sterilization  chamber vent emissions are associated with the chamber
  vacuum pump.   These vacuum pumps are typically once-through,  liquid-ring
  designs that  use water  as  the working fluid.   During the evacuation phase
  of the sterilization'cycle,  a mixture of chamber  gas and water is expelled
  from the pump to a  centrifugal  gas/liquid separator.   In the  separator,
  gas-phase EO  is directed to  a vent and  emitted  to  the  atmosphere.   The
  liquids  from  the separator are  directed  to  a  sewer drain.
  3.3.2   Sterilization Chamber  Vacuum  Pump  Drains
      Some  of  the EO that is released  from the chamber  during  the
  evacuation phase enters the liquid-phase  separator line with  the  vacuum
  pump water.  Although some EO may be  hydrolyzed to ethylene glycol, the
  conversion rate at ambient temperatures is extremely slow, requiring weeks
  for completion (see Figure 3-5).8  Also, EO is rapidly released from an
 aqueous solution when agitated.16  Therefore, virtually all of the EO that
 dissolves in the vacuum pump water is emitted from the  water.   The
 absorbed EO may be  released at the 1-inch air break between the liquid
 pipe  and drain (required by local plumbing codes)  or may diffuse into
 other areas of the  building as the water passes through the drain
 system.  Any remaining EO would  desorb into the head space of  the sewer
 pipes (possibly creating flammable mixtures  with air) and be emitted as  it
 passes  through the sewer or waste treatment  systems.6'8
 3.3.3   Aeration Room Vent
     All  emissions from  residual  EO in the product  are  referred  to as
 aeration room  vent emissions.  As  residual EO diffuses  out  of  the  sterile
 products  in the aeration room  or  is emitted to the sterilization room when
 the chamber door is opened, it is  emitted  to the atmosphere via room
 ventilation.  High ventilation airflow rates are used to maintain  EO
 concentrations below the OSHA  limit.
 3.3.4  Equipment Leaks
     Although equipment component counts (number of flanges, valves, etc.)
were not obtained for the commercial  sterilization  facilities,  observations
                                   3-17

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    100 r
    Figure 3-5.   Hydrolysis rates of dilute,  neutral  aqueous solutions
                            of ethylene oxide.
(Courtesy  of  Union  Carbide Corporation,  Ethylene Oxide/Glycol  Division.)
                                  3-18

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 made during site visits indicated that the number of components is
 small.  However, control of equipment leaks may be important to meet the
 1 ppmv OSHA standard.  For the purposes of this analysis, equipment leak
 emissions are assumed to be negligible.
 3.3.5  Storage and Handling
      Ethylene oxide at commercial sterilization facilities and hospitals
 is typically stored in pressurized cylinders rather than bulk
 containers.  Therefore, material  losses associated with loading and
 unloading bulk quantities of EO and storage tank breathing losses would
 not occur.  Although bulk storage of sterilant gas at sterilization
 facilities is rare, at least one  commercial sterilization facility stores
 bulk quantities of 12/88 in a pressure vessel.  During transfer of the
 12/88 from the tank truck to the  pressure vessel,  the vessel  and the tank
 truck are vapor balanced.   Therefore,  emissions during transfer are
 expected to be negligible.   Also,  because the storage tank is a pressure
 vessel,  no emissions should occur during  routine operation.   Consequently,
 commercial sterilization facilities  and hospitals  are likely  to have
 negligible storage and handling emissions.
 3.4  EMISSION  ESTIMATES
 3.4.1 Commercial  Sterilization Facilities
      The emission  estimate  for commercial  sterilization  facilities  is
 based on the facility-specific annual  EO  usages and emission  control
 levels reported  in  the 203  responses to the HIMA survey  and the July 1986
 EPA information  request.  Average  EO emissions  from these  commercial
 sterilization  facilities, based on total  sterilizer volume, are presented
 in  Table  3-6.  The  total amount of EO used by  the 203 commercial
 sterilization  facilities (i.e., not hospitals)  represented in the EPA data
 base  is 2,270  Mg/yr; approximately 16 percent  (i.e., 370 Mg/yr) of this
 amount is  controlled.  Therefore, the EO emission estimate for the
 203 facilities represented in the EPA commercial sterilization data base
 is  1,900 megagrams per year (Mg/yr).1'2  Of this amount, it is estimated
 that 760 Mg/yr are emitted from sterilizer vents, 1,000 Mg/yr are emitted
 from sterilization chamber vacuum pump drains, and 110 Mg/yr are emitted
 from aeration room vents (see Figure 3-4).  These estimates were developed
using the HIMA survey, the July 1986 EPA information request responses,
and the following assumptions:

                                   3-19

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 TABLE  3-6.  AVERAGE  EMISSIONS FROM COMMERCIAL STERILIZATION  FACILITIES-
                             FDA  nflTA  nacr1.2
EPA DATA BASE •
Total chamber
volume at
facility, m1 (ft3)
<11 (<400)
11-56 (400-2,000)
>56 (>2,000)
No. of
facilities3
88
77
38
Mean EO use,
kg/yr (Ib/yr)
660 (1,500)
7,600 (17,000)
43,000 (94,000)
Mean EO emissions,
kg/yr (lb/yr)b c
640 (1,400)
6,800 (15,000)
34,000 (75,000)
jjDoes not include hospitals.
 Mean emissions are less than mean EO use because of existing controls.
 Emissions from all sources (i.e., sterilizer vent, vacuum pump drain
 aeration).
                                    3-20

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       1.  All of the EO reported as used in the sterilization  process  is
 evacuated from the sterilization chamber or released  from the product
 during aeration.
       2.  Within each facility, EO emissions are distributed among three
 emission points.  The three emission points and the percentage of total EO
 emissions allocated to each are:
       a.  Sterilizer vent(s)—50 percent;
       b.  Sterilization chamber vacuum pump drain~45 percent; and
       c.  Aeration room vent(s)--5 percent.
 This  50/45/5 percent split is based on industry estimates, limited test
 data, and engineering judgment.17
      3.  For the 355 sterilization chambers in the EPA commercial
 sterilization data base that are uncontrolled, all of the EO that enters
 the chamber vent(s)  is released to the atmosphere.  For the
 79 sterilization chambers with  emission control  devices, the chamber vent
 emissions are controlled  at the efficiencies reported on the HIMA survey
 and EPA information  request responses.
      4.   At  each  facility,  all  of  the  EO that  dissolves in the vacuum  pump
 water and subsequently  enters the  drain is  assumed to be emitted
 uncontrolled  to the  atmosphere  at  an outdoor ground-level drain near the
 facility.  This assumption  is consistent with  test data that suggest EO  is
 rapidly released from an  aqueous solution when agitated.16
      5.   At each facility,  all of the EO that  enters  the  aeration room
 vent  is released uncontrolled to the atmosphere.
 3.4.2  Hospitals
     The  EO emission estimate for hospitals is based on data from the
 approximately 80 responses to the 1986  information request to  hospitals
 and information in the 1988 American Hospital  Association (AHA) hospital
 data base.  Linear regression analyses of the  1986 data indicated that the
 annual EO use correlates better with the number of hospital  beds (r2 =
 0.77)  than with the number of surgical  procedures (r2 = 0.68).18  A
 nationwide EO use rate of  approximately 1,000 Mg/yr was obtained by
extrapolating the 1986 data to  the  1988 AHA data base, which  contains
hospital-specific information on the number of  beds for
7064 hospitals.19   Because the majority  of  hospitals do not use EO
                                   3-21

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 emission  controls,  EO emissions  from  hospitals are  assumed  to  equal  the EO
 use  of  approximately 1,000 Mg/yr.  Average EO emissions  for hospitals,
 based on  the  number of hospital  beds,  is presented  in Table 3-7.
 3.5  CURRENT  REGULATIONS
 3.5.1   Occupational Safety and Health  Administration Standard
     In 1984, OSHA established a permissible exposure limit  for
 occupational  exposure to EO of 1 pprav  determined as an 8-hour  time-
 weighted  average (TWA)  concentration.  In addition, an action  level  of
 0.5 ppmv  as an 8-hour TWA was established as the level above which
 employers must monitor employee exposure.20  In April 1988, OSHA
 established a short-term excursion limit (EL) for occupational exposure to
 EO emissions of 5 ppmv  averaged over a 15-minute sampling period.21
 3.5.2  State Regulations
     Existing State regulations for EO are summarized in Table 3-8.
Several  States are currently regulating EO or developing air toxics
          22_28
programs.
                                  3-22

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 TABLE 3-7.  AVERAGE  EMISSIONS  FROM  HOSPITAL STERILIZERS
3,19
Hospital
size range
Small (<200 beds)
Medium (200 to 500 beds)
Large (>500 beds)
No. of
hospitals
4,907
1,645
512
Mean EO use,
kg/yr (lb/yr)d
70 (150)
200 (430)
790 (1,740)
aBecause most hospitals do not control EO emissions, the EO
 emissions are assumed to equal the EO use.
                              3-23

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        TABLE  3-8.   STATE REGULATIONS FOR  ETHYLENE  OXIDE EMISSIONS
                                                             22.26
  State
 Florida3
 Michigan3
 Missouri
 New  Jersey

 New  York3
Ok Iahoma
Puerto Rico

Rhode Island3

Tennessee
Texas
Utah
Vermont
Virginia
Wyomi ng
                    Regulatory description
 California         • Developing air toxics program but a regulation may not be proposed  fo~
                      i y0sr•
                    • South Coast—groposed rule for new (or modified) sources based on
                        maximum 10 * nsk level, including aeration processes.
                    • Bay Area—draft rule for new and existing sterilizers; no drain
                        emissions; 99.5 percent control of vent emissions if EOTuse exceeds
                        250 Ib/yr:  exemptions—steriIizers smaller than 250 ft3 and aeration
                        procssscs.
 Colorado           • Regulate as a volatile organic compound (VOC).
 -     ...  ^        * Reasonably available control  technology (RACT) required for new source
 Connecticut        . Best avaiIabIe control  technology (BACT)  required for  alI  new "r
                        mod,f,«d sources exceeding  a maximum allowable stack concentration
• MASC is calculated using exhaust gas flow rate, stack height, and the
    distance from the discharge point to the property line.  MASC would be

    cycles.  Therefore,  BACT required on^ew^o/modff ied^sources'°"
    Existing sources exceeding the maximum allowable ambient concentration
    of 0.01 ppm have 3 years to comply with orders given by the
    Connecticut Department of Environmental  Protection
• Maximum risk level  of  10'° for new or modified  sources.
• BACT for all  new sources.   Requires emissions be indectable or subjected
    to risk analysis  (maximum allowable risk level  is 10~6)    For
    industrial  sterilizers using typical  sterilization  cycles,  a control
    erriciency  based  on  a  risk assessment analysis would be greater than
    99 percent  by weight.
• Regulate as a VOC.
• Regulate as a VOC.
• BACT requfred for new  or modified  sources.
' 2?Hr0x  l"od!fied sources  must receive  99 percent  control or  greater  or
  BACT (also at permit reviews)                               grearer, or

'  l?AAiir«*TJ£lJm/P¥t,  must."ot e,x.?eed guideline Acceptable  Ambient Level
  (AAL) of  6.67 yg/mj (a revised AAL of 0.019 yg/m7 is  anticipated for  the
  next edition  of  Air Guide-1  [to be  released by 01/901
•  Certificate of  operation  includes the following statement-
    Should  significant  new scientific evidence from a recognized
    institution result in  the  decision by DEC that  lower ambient levels
   must  be  established, it may  be necessary to reduce emissions from this
   source prior  to the expiration of this Certification of Operation."
  Maximum ambient  air concentration at property line is 1/100 of TLV.
  Regulate as a VOC.
  Emission control.s required for emissions greater than  3 Ib/h or 15 lb/d
  Maximum risk  level of  10'6 for new and existing  sources
  If BACT  is used, nay consider  10~3 risk level.
  Regulate under standards  for process and nonprocess emissions.
  BACT required for all  new sources.
 BACT required for alI  new or modified sources.   BACT requirements to go
  into effect for existing  sources.
  Following the programs  developed in New York.
 Regulate as a VOC.
 For any 24-hour concentration exceeding 1/100 of  the TLV-TWA both
   ^ffln3 KndJ!e"1,faC.M!ties are re
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 3.6  REFERENCES FOR CHAPTER 3
  1.  Letter and enclosures from J. Jorkasky, Health Industry Manufacturers
      Association (HIMA), to D. Markwordt, EPA:CPB.  February 21,  1986.
      Survey responses from HIMA members.
  2.  Responses to July 1986 Section 114 information request regarding the
      use of ethylene oxide by miscellaneous sterilization and fumigation
      facilities.
  3.  1988 Abridged Guide data base.  American Hospital Association, 840
      North Lake Shore Drive,  Chicago, Illinois  60611.
  4.  Commercial Sterilization Standard Industrial Classification  (SIC)
      data base.  Research Triangle Institute.  July 1987.  SIC
      designations for facilities in the EPA commercial sterilization data
      base.
  5.  Responses to the January 1986 Section 114 information request to
      hospitals that use ethylene oxide as  a sterilant.
  6.  Letter from Buonicore, A.,  Chemrox,  Inc.,  to Markwordt,  D.,
      EPA:CPB.   August 27,  1984.   Comments  on the  sources  of  ethylene oxide
      emissions draft report.
  7.  Responses to  July 1988 information  request to commercial
      sterilization  facilities  regarding  chamber operating parameters,
      current controls,  vacuum  pumps,  and aeration rooms.
 8.   Ethylene  Oxide  Product Information  Bulletin.   Union  Carbide  Corp.,
      Ethylene  Oxide/Glycol Division.   1983.
 9.   Ethylene  Oxide:   Material Safety  Data Sheet.   General Electric.
      April  1983.
10.   Dichlorodifluoromethane:   Material Safety  Data Sheet.  Genium
      Publishing Corporation.  February 1986.
11.   Handbook of Chemistry and Physics.  67th Edition.  CRC Press, Boca
      Rotan, Florida.  1986.
12.  Gas Sterilants.  Product  information brochure.  Union Carbide Corp.,
      Linde Division.  Undated.
13.  Telecon.  Taylor, G., MRI, with Conviser, S.  and Woltz,  C.,  Union
     Carbide Corp., Linde Division.  July 31, 1987.  Discussion of
     operating  pressures for sterilization  chambers.
14.  Letter from Burley, R., Environmental  Tectonics Corp., to Wyatt, S.,
     EPArCPB.   August 25,  1987.  Comments on draft BID  Chapter 3  for
     ethylene oxide NESHAP.
                                   3-25

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 15.  Mitigation of Worker Exposure to Ethylene Oxide.  Goldqraben,  R   and
      Zank, N.  The Mitre Corp.  1981.

 16.  Conway, R., Wagg, G., Spiegel, M., and Berglund, R.  Environmental
      Fate and Effects of Ethylene Oxide.  Environmental Service and
      Technology.  1983.  17(2):107-112.

 17.  Abrams, W., McCormick and Company, Inc.  Project No. 075320
      Treatment of Spices-EtO Mass Balance.   Final Report.  November 26,
      1985.

 18.  Memorandum.  Nicholson, B. and Srebro,  S., MRI, to Patel, N.
      EPA/OAR.  Baseline Freon 12* Emissions  from Hospital Sterilization
      Processes.   September 30, 1986.

 19.  Memorandum.  Markwordt, 0., EPA/CPB.  Documentation of Human  Exposure
      Model Parameters for Ethylene Oxide Emissions from Hospitals
      January, 1989.

 20.  Ethylene Oxide.   Occupational  Safety and  Health Administration
      Promulgated on June  22, 1984.  49  FR 25797.   Office  of  the Federal
      Register. Washington,  D.C.                                  	

 21.  Occupational  Exposure  to Ethylene Oxide.   Occupational  Safety and
      Health Administration.   Promulgated on April  6,  1988.   29 CFR
      Part  1910.  Office of  the Federal Register.  Washington, D.C..

 22.  Summary  of  Regulations  Pertaining to Ethylene Oxide by  State.
      Chemrox,  Inc.  Bridgeport,  Connecticut.  Undated.

 23.   Air Pollution Control.   The Bureau of National Affairs, Inc
      Washington, D.C.  January 1987.

 24.   Telecon.  Shine, B., MRI, with Vincent,  R., California Air Resources
      Board.  February 14, 1989.

 25.   Telecon.  Shine, B., MRI, with Glenn,  J.,  Florida Department of
      Environmental Regulation, Division of  Air  Resources Management.
      February 14, 1989.

 26.  Telecon.  Shine,  B., MRI, with Schleusener, P., Michigan Department
     of Natural Resources, Air Quality Division.  February 14,  1989.

27.  Telecon.   Shine,  B.,  MRI, with Wade, E., New York Department of
     Environmental  Conservation Division of Air Quality.   February  14,
     1989.

28.  Telecon.   Shine,  B.,  MRI, with Morin, B.,  Rhode Island  Department  of
     Environmental  Management, Division  of Air  and Hazardous  Materials
     February  14, 1989.
                                   3-26

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                        4.   EMISSION CONTROL TECHNIQUES

  4.1  BULK STERILIZATION PROCESSES
       The three principal  sources of ethylene oxide (EO) emissions from
  bulk sterilization processes are:
       1.  The sterilizer vent(s) (i.e., the vent on the vacuum pump
  gas/liquid separator);
       2.  The sterilization chamber vacuum pump drain; and
       3.  The aeration room vent.
       The following sections describe  the techniques available to control
  EO  emissions from these three  sources.   Table A-2  in  Appendix A presents  a
  list  of the  emission  control devices  and manufacturers.
  4.1.1  Sterilization  Chamber Vent  Emissions
       Three primary techniques  are  used to  control  EO  emissions  from
  sterilizer vents:  hydrolysis,  oxidation,  and  condensation.  Ethylene oxide
  is catalytically  hydrolyzed to form ethylene  glycol;  oxidation decomposes
  EO into carbon dioxide and water; and condensation allows the recovery of
  the sterilant gas mixture.  A fourth control  technique for sterilizer
  vents is a gas/solid reactor system that chemically reacts EO and binds it
 to the solid packing of the reactor.1
      Table 4-1 shows the emission control techniques and devices used by
 the  203 commercial sterilization facilities (i.e.,  not hospitals)
 represented in the EPA data base (refer to Chapter  3 for a description  of
 the  contents  and  origin of the  data base).   Twenty-seven of  these
 203  commercial  sterilization facilities  (13 percent) reported  the use of a
 control  device  for sterilizer vent  emissions.   Nineteen  of these
 27 facilities use  one  emission  control device  for multiple chambers by
 manifolding the chamber vents and staggering the evacuation of the
 sterilant gas from the chambers.  The remaining eight  facilities  control
 emissions from single chambers.2'3
     Nine additional commercial  sterilization  facilities reported the use
of a neutral-water scrubber to control  EO vent emissions.  Neutral-water
scrubbers reduce EO vent emissions by "washing" a portion of the EO to the
drain (facilities  reported  20 to 100 percent of the  total EO emissions
from  the sterilizer chamber were "controlled" by a neutral-water
                                   4-1

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-pi
I
                              TABLE 4-1.   ETHYLENE OXIDE EMISSION  CONTROL DEVICES  FOR STERILIZER
                             	VENTS-EPA COMMERCIAL STERILIZATION DATA BASE5*3

Emission control technique and device
Hydrolysis
Packed scrubber
Reaction/detoxification tower
Caustic scrubber
Oxidation
Flare

Catalytic oxidizer
Condensation
Condensation/reclamation system
TOTAI ' 	

"Control efficiencies are those reported
Control
ef f iciency ,
percent3

99. Oc
99.0
30.0 and 95.0


98.0
99.0

50.0 - 86.0

-•
by the 203 comnu
No. of
facilities
(percent)6

14 (7)
2 (1)
1 (0.5)


2 (1)
1 (0.5)

7 (3)

27 (I3)e
«=-«>-=-="=»=
arcl al <;t»r i i i , =.
No. of
chambers
(percent)b

45 (10)
4 (1)
2 (0.5)


5 (1)
1 (0.2)

20 (5)

77 (18)f
======

Chamber
size, m3 (ft3)
	
4- HO
(140-6,000)
4-27
(140-960)
32 and 60
(1,150 and 2,120)

2-77
(60-2,720)
4
(130)
5-45
(190-1,580)
=S==s=^=i^='S5^*=SBHSSSS^^S^B^K

EO usage/
facility, Mg/yr (Ib/yr)
— 	 . 	 .
0.9-59
(2,000-130,000)
4 and 57
(9,500-126,000)
44
(98,200)

34 and 80
(74,200 and 176,000)
0.4
(1,000)
7-46
(15,000-100,800)
790 (1,750,000)
                                  EPA-sponsore "
                   'a' ^-^IS ol'S^^^                                       efficiencies  ranging from 96.0  to
                         that Can be achieved o« a continuous JLs4          "rubbers  .ndicates that  99.0 percent is the  maximum

                         ^^                                                             efficiencies of 99.0 and 99.7 percent
      eachive at least 98 percent destruction efficienc! §PeC'fled con<"tions of waste  gas heat content  and  flare exit velocity wilt
      f Total number of facilities = 203.
       Total number of chambers = 434
      R.,r.S.n,s 35 p.rcen, ., ,„. tofa, E0

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            2  3
  scrubber).  »   Some  cf  the  £0  that  is washed  to  the drain may  be  converted
  by hydrolysis to ethylene glycol; however, the conversion rate of EO  to
  ethylene glycol in neutral  water at ambient temperatures  is  extremely
  slow, requiring weeks for completion.*3  Since EO  is rapidly  released  from
  an aqueous solution when agitated, the vast majority of the  EO washed to
  the drain will off-gas uncontrolled from the air  break in the  drain line,
  sewer lines, or the waste treatment system.s~8  Because the  use of
  neutral-water scrubbers merely changes the EO emission source,  they are
  not discussed here as a control technique.
      The majority of hospitals do not control  EO emissions from sterilizer
 vents.  However,  some hospitals use emission controls because of State and
 local  regulations.   Catalytic oxidation  and the gas/solid reactor system
 are two  techniques  that are  known to be  used  by hospitals to control  EO
 emissions from sterilizer vents.9"11
      4.1.1.1  Hydrolysis.  Hydrolysis  is  the most common  EO emission
 control  technique used  by  commercial  sterilization facilities.2'3   This
 technique is  applicable  for  both  pure  EO and EO/inert gas  mixtures such  as
 12/88  (12 percent by  weight  EO  and 88  percent  by  weight dichlorodi-
 fluoromethane  [CFC-12])  and  10/90 (10  percent  by  weight EO and  90  percent
 by weight carbon dioxide).   The majority of commercially available
 hydrolysis control devices are not designed for the  low flow  rates
 associated with chamber volumes less than 1.4 m3  (50 ft3)  and are,
 therefore, not applicable to the control  of most hospital  sterilization
 chambers.  However, two manufacturers have designed  scaled-down  acid-water
 scrubbers for flow rates less than 0.3 cubic meters  per minute  (m3/min)
 [10 cubic feet per minute (ft3/min.)].1l*12
     Ethylene oxide can be hydrolyzed under relatively mild conditions to
ethylene  glycol products (without  affecting the inert gas)  as shown in the
following reaction:
     C2H,0 +  H20    	»    HOCH2CH2OH     +    HO(CH2CH2)nOH
                  H+  or  OH-                               n

                           Ethylene glycol      Polyethylene glycols
                                   4-3

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  Ethylene oxide  will  hydrolyze in neutral  water,  but this  reaction is very
  slow.   (The  half-life  of  EO  in neutral  water at  ambient temperatures is
  approximately 14 days.)8   The reaction  rate  is  increased  in  an acidic or
  basic  solution.  The reaction is approximately two  orders  of magnitude
  faster under acidic conditions than under basic  conditions,  making  acid
  hydrolysis the preferred method.  Sixteen of  the 203 commercial
  sterilization facilities represented  in the EPA data base  reported  using
  acid-water scrubbers; one  facility reported using caustic  scrubbers  to
  control  EO emissions.2'3
      4-1-1-1.1  Packed scrubbers.  Figure 4-1 is a schematic of a packed
  scrubbing system used to control EO emissions.  The system consists of  a
  countercurrent packed tower,  a reaction vessel,  and a holding tank.   In
  the countercurrent tower,  the sterilant gas is contacted with an acidic
 water solution,  generally  aqueous sulfuric acid.   Because  EO is extremely
 water soluble, most of  the EO is absorbed into the scrubber liquor.  Next,
 the liquor is sent  to the  reactor vessel,  which  is a small  storage tank
 operated at atmospheric pressure, to  complete the hydrolysis  of EO.   After
 the reaction  is  complete,  the liquor  is  sent  to the  storage vessel.   The
 liquor  in the storage vessel  is recirculated  to operate the tower  until
 the concentration of  the ethylene glycol  in the liquor reaches  a predeter-
 mined weight  percentage, past which point  the  scrubber efficiency
 declines.   Manufacturers of packed scrubbing  systems suggest  that  the
 scrubbing liquor is spent when the solution is 30 to 40 percent  by weight
 ethylene glycol. I3*l
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                                                    H20/H2SOH/ETHYLENE GLYCOL SOLUTION
STERILIZER
          VACUUM PUMP
               LIQUID-GAS
                SEPARATOR
                            LIQUID
    HEAT
  EXCHANGER
           Figure 4-1.   Countercurrent packed  scrubbing system.

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  sterilization facilities ranges from 0.9 Mg/yr (2,000 Ib/yr) to 59 Mg/yr
  (130,000 Ib/yr).2'3
       Manufacturers of countercurrent packed scrubbers designed to control
  EO emissions from sterilizer vents claim EO removal efficiencies greater
  than 99 percent. 1'13'15  For a 12/88 sterilant gas mixture,  the average EO
  removal efficiency for three tests was  99.0 percent by weight (individual
  test results were 99.0, 98.7,  and  99.4  percent).16  These  tests were
  conducted  using  a scrubber that was designed to achieve  an EO removal
  efficiency of 99 percent.  A representative of the manufacturer of  the
  tested  acid-water scrubber stated  that  the  company can design scrubbers  to
  achieve virtually any  EO removal efficiency with any  type  of  sterilant
  gas.     The  results of an EPA-sponsored test on another acid-water
  scrubber designed  by this company  indicated  an EO  removal  efficiency
  greater than 99.9  percent for 12/88.18  For  pure EO,  the EO removal
  efficiency was greater^than 99.98 percent for each of four tests performed
  at two  facilities.16'19  However,  a detailed review of the available test
 data indicates that 99.0 percent is the highest EO removal  efficiency that
 can be achieved on a continuous basis."*
      4-1-1-1.2  Reaction/detoxification  towers.  Another acid hydrolysis
 scrubbing technique for EO  emission control  is a reaction,  or
 detoxification, tower.   A schematic of this  system  is  shown in
 Figure 4-2.  This system consists of a tank  that  holds the  scrubbing
 liquor,  which is  a sulfuric acid solution  at a  pH of 0.5  to 2.5.   The
 sterilant gas is  bubbled upward through  the  liquor.  The  EO is absorbed
 into  the liquor where it hydrolyzes  to ethylene glycol.  The gas  stream
 then  flows  through  the  liquid surface  and  a  demister.  The  demisting  pad
 prevents acid  mist  from exiting with  the scrubbed gas  and provides a  final
 hydrolysis  reaction site for any EO remaining in the gas stream.  Inert
 gases  (i.e., CFC-12 and C02) are exhausted unreacted to the atmosphere.
 After ethylene glycol builds up in the stream to a maximum recommended
 level^of  60 percent, the scrubber liquor is neutralized and  disposed or
 sold.     (See Section 4.1.1.1.3 for  a more detailed  discussion of waste
disposal.)  Possible methods of determining the scrubbing  liquor changeout
point include (1)  liquid level indicators,  (2) specific gravity detectors,
and (3) measuring the amount of EO charged  to the sterilizer.   Reaction
                                   4-6

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                   STERILIZER
                                                                           SCRUBBED
                                                                           GAS
-p-
i
                                                           I
                                                           I
                                                           I
                                                           L
                          HEAT
                         EXCHANGER
1
DETOX-
IFICATION
TOWER






DEHISTER

AQUEOUb 1
ACID /
SOLUTION <
r
1





IQUEOUS
U.KALINE
SOLUTION

I

HAItK
SUPPLY
                                       Figure 4-2.   Detoxification tower control  system.

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   towers  are effective  for chambers  ranging  from 1.4 m3 (50 ft3) to 45 m3
   (1,600  ft ).   •     Two  of the  203  commercial  sterilization facilities
   represented in EPA's  data base use reaction towers to control  EO emissions
   from sterilizer vents.   The sterilizers at these  two  facilities  range in
   volume from 4 m  (140 ft3) to 27 m3  (960 ft3).  One of these facilities
   uses 4 Mg (9,500 Ib) of  EO per year; the other uses 57 Mg  (126,000  Ib)
   annually. »
       Manufacturers of reaction/detoxification towers  claim 99+ percent EO
  removal  efficiency by weight.21'22  Third-party laboratory test results
  indicate that  EO  emission reductions  greater than 99.8 percent can be
  achieved with  reaction towers.23   However,  a detailed review of the avail-
  able test data indicates that 99.0  percent  is  the highest EO removal
  efficiency that can  be achieved by  acid  hydrolysis techniques  on  a
  continuous basis.**
      4.1.1.1.3  Waste  disposal.  The  spent  liquor  from acid hydrolysis of EO
  is typically 40 to 60  weight percent  ethylene  glycol and  has a  pH  of 0 5
  to 2.0.  Because of the  low pH, the solution is considered  a hazardous
 waste and, thus, requires  special  handling procedures  for shipping if  not
 neutralized.   However, the spent liquor can easily  be  neutralized with
 sodium hydroxide (caustic) prior to disposal.
      Two  recovery  companies have been  identified that are willing to
 purchase  the  aqueous  ethylene  glycol solution.2
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      4.1.1.2.1  Thermal oxidation.  Ethylene oxide, wnich  has  a  high
 heating value, a relatively low ignition temperature, and  a  very wide
 range of mixtures combustible in air (see Table 3-4), can  be easily and
 efficiently destroyed by thermal oxidation using flares.   Thermal
 oxidation of EO produces carbon dioxide and water as follows:
                 2 CjH.,0+5 02	*4 C02+4 H20
                              thermal oxidation
      Two of the 203  commercial sterilization facilities represented in the
 EPA data base  reported using flares to  control  EO emissions from the use
 of pure EO as  a sterilant gas.2   One of these facilities has one 76.7-m3
 (2,710-ft )  chamber  and uses 80  Mg (176,000 Ib)  of EO per year.  The other
 facility has three chambers  ranging in  size from 75.2 to 76.9 m3  (2,655 to
 2,715 ft )  and  one smaller 1.7-m3  (60-ft3)  chamber;  this facility uses
 98 Mg/yr (215,600 Ib/yr)  of  EO.2   Because of difficulties with  sustaining
 combustion,  commercially  available  flares are not  applicable  for
 facilities emitting only  small amounts  of EO.
      A manufacturer of  flare burners for the  control  of  EO  emissions
 claims greater  than 99  percent control  efficiency for pure  EO but no data
 were  provided to substantiate this  claim.27   The EPA's position is that
 flares operated within  specified conditions of waste gas  heat content and
 flare exit velocity will achieve at least 98 percent destruction  efficiency.
     Flares can also be used with E0/C02 sterilant gas mixtures (e.g.,
 10/90) but are not designed for use with EO/CFC-12 mixtures (e.q.
       2728
 12/88).  »    The EPA has not in the past and does not now recommend the
use of flares to control emission streams containing halogenated compounds
 (e.g., CFC-12)  because corrosive or toxic by-products may form.   As shown
below, thermal  oxidation of CFC-12 may produce the following corrosive or
toxic by-products at  the high temperatures  (400°  to 800°C [800°  to
1500°F1)  associated with the  use  of flares:
     CF2C12+02	»   COC12 Phosgene
                thermal  oxidation   COF2 Carbonyl  fluoride
                                    HC1   Hydrogen  chloride
                                    HF    Hydrogen  fluoride
                                    CF,,   Carbon  tetrafluoride
                                    C12   Chlorine
                                    CO    Carbon monoxide
                                   4-9
5

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      4.1.1.2.2   Catalytic oxidation.   Catalytic  oxidation of  EO  occurs  in
 the presence of  a  solid-phase catalyst as follows:
               2 CzM+S 02	»4 c,02+4 H20
                            catalytic oxidation
 This control technique is applicable to pure EO, E0/C02 mixtures, and
 EO/CFC-12 mixtures.  The CFC-12 does not react at the temperatures (150°
 to 180°C [300° to 350°F]) that occur during catalytic oxidation, and,
 therefore, the toxic CFC by-products that result from the higher
 temperatures associated with thermal oxidation are not produced.  During
 an EPA-sponsored test of a catalytic oxidation unit, no CFC decomposition
 by-products were detected; the detection limit was 200 parts per billion
 (ppb)  for the analyte chloride ion.  The maximum operating  temperature of
 the unit during testing was  155°C (311°F).12
     A schematic of a catalytic  oxidizer is  shown in Figure  4-3.   The
 spent  sterilizer gas is first mixed with  a large  volume of  air to reduce
 the control  device inlet  EO  concentration  to 5,000  ppmv or  less.   This
 dilution prevents excessive  cataTyst bed temperatures  (which can  damage
 the catalyst)  from occurring  during the oxidation of EO.  The  gas stream
 passes  through  a filter for  dust  removal and then is preheated to the
 reaction temperature with  steam or  electricity.   The gas then  enters the
 catalyst bed(s)  where the  EO  is oxidized.  Part of the exiting  gas stream
 may be  recycled  for  heat recovery before being vented to the atmosphere.
 One manufacturer  also sells a catalytic oxidizer  that uses excess
 catalyst, instead of diluent air, to absorb  the heat of oxidation.29
 Because  of cost considerations, the excess-catalyst system has been used,
 thus far, only for chambers less than 1 m3 [40 ft3]) in volume.29
     Recent information indicates that the use of catalytic  oxidation to
 control  EO emissions  is increasing, particularly for hospital sterilizers
                         Q 1 A
 and other small chambers.  •    In general,  the large amount  of  diluent air-
 required for most catalytic oxidation systems has  limited the use of this
 technique to smaller, hospital-size chambers.  Also,  some of  the
manufacturers of hospital  sterilizers are developing  sterilizers that  are
evacuated with air ejectors instead  of a vacuum pump.30   The  emissions  are
then routed to a catalytic oxidizer.30
                                   4-10

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  STERILIZER
TO ATMOSPHERE
ON FAILURE  	L
     AIR
  1,500 CFM
FILTER
STEAM
COIL
                   CATALYST
                     BED
                                            STEAM
                                            9 PSIG
                                                   HEAT RECOVERY
                                                                            FAN
                                                                                                    TO ATMUbPIII HI
                               Figure 4-3.  Catalytic oxidation system.

-------
      Only one of the 203  commercial  sterilization  facilities  represented
 in the EPA data base reported the use of a catalytic  oxidizer in  1986  to
 control EO emissions from the chamber vent.2  This facility has one 4-m3
 (130-ft ) chamber and uses 0.4 Mg/yr (1,000 Ib/yr) of EO  in an E0/C02
 sterilant gas mixture.2   However, data obtained in 1988 indicated that at
 least one additional commercial sterilization facility has installed a
 catalytic oxidation system to control EO emissions from a larger
 industrial-size sterilizer (17 m3[600 ft3]); the EO concentration to the
 control unit is regulated by throttles.31
      Because catalytic oxidation is applicable to the control  of low EO
 concentrations,  many facilities manifold other EO emission sources (e.g.,
 aeration chambers or room, sterilizer hood  and door vent,  and  the gas
 cylinder room)  to the control  device.  In addition, if the catalytic
 oxidizer requires diluent air,  these low-concentration emission sources
 can  provide  part or all  of the  necessary diluent.
      Manufacturers  of catalytic oxidation units  claim EO destruction
 efficiencies  greater than 99.9  percent.32'33   Third-party  testing  and  an
 EPA-sponsored test  support these claims  for  small  (<30 ft3)
 sterilizers.12'32
      4.1.1.3  Condensation/Rec1amation Systems.  Recovery  of sterilant  gas
 mixtures  is possible using a reclamation  system.  The  sterilant gas
 mixtures will condense under conditions of reduced  temperature and
 increased pressure,  but  precautions  are necessary to avoid explosions.
      Figure 4-4  is a schematic of a  sterilization chamber room and a
 condensation/reclamation system for  a 12/88 sterilant gas mixture.   (See
 Table 3-4 for physical and chemical  properties of CFC-12.)   After each
 sterilization cycle, the 12/88 gas is withdrawn and passed through one of
 the two desiccant beds next to the chamber.   (One of the desiccant beds is
 regenerated while the other is in use.)   The dried 12/88 gas then passes
 to a compressor where it is compressed to 50 psig to improve condensation
           3 u
 efficiency.    The compressed gas is piped to a separate explosion-proof
 room where it passes through a pressurized condenser that  is  chilled  by
 ethylene glycol  to about -18°C (0°F).3l+   The  liquid  12/88 mixture  is
collected in  a pressurized, chilled  holding  tank.   The noncondensed gas is
recirculated  to  the chamber and  back through  the  condenser.   The liquid
                                   4-12

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-fa
I
                STERILIZER
                                      DESICCANT
                                        BEDS
                                                                              CONDENSER
                                                                 COMPRESSOR
                                                                                                       TO STORAGE TANK
                                                                                               HOI DING
                                                                                                 TANK
                                                                                                                 R[Ul ENDING
                                                                                                                    TANK
                                                    RECYCLE
                                           Figure 4-4.   Condensation/reclamation  system.

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 collected in the holding tank is transferred to a pressurized reblending
 tank where the liquid is mixed and its composition determined by infrared
 analysis.  The liquid is then adjusted to the 12/88 (weight percent) ratio
 by adding the necessary amount of EO or CFC-12.  When the correct ratio is
 obtained, the liquid is transferred to a pressurized storage tank in the
 chamber room.
      Although the reclamation cycle could be continued indefinitely,  the
 amount of EO recovered declines to the point where it is not cost
 effective to continue the reclamation cycle after about three passes
 through the system (i.e., typically 60 to 90 minutes).  The majority of
 the EO (80 to 85 percent) is recovered during this time.   Also, increasing
 the reclamation time  would require that products spend additional  time in
 the sterilizer and could  affect the plant's operating schedule.  However,
 even if the reclamation time was increased, this system is not designed
 for low EO concentrations.   Therefore,  if this  type of control  system is
 used,  add-on controls  (e.g., catalytic  oxidation or a small  scrubber)  need
 to  be  considered  for  the  EO  remaining  in  the chamber  after the  reclamation
 cycle  is  complete.
     Seven of  the  203  commercial  sterilization  facilities  represented  in
 the  EPA data base  reported the  use  of condensation/reclamation  systems;
 three  of  these  facilities reported  an 85  percent  EO recovery efficiency,
 three  reported  80  percent, and  one  reported  50  percent.2'3  These seven
 facilities  recover E0/C02 and EO/CFC-12 sterilant gases.  Six of these
 facilities  each use over 23 Mg/yr (50,000 Ib/yr) of EO.  The seventh
 facility uses just over 6.8 Mg/yr (15,000 Ib/yr).2'3  The chamber sizes
 range from  5 to 45 m3   (190 to 1,580 ft3) at these seven facilities.2'3
     The condensation/reclamation systems currently available are designed
 for the high volumetric flow rates of larger, industrial-size chambers.
The systems are not technically or economically feasible for use with
smaller chambers or at facilities that use small amounts of EO.  In
addition, the safety hazards (i.e., explosion potential) associated with
this control technique preclude its use in hospitals.
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       4.1.1.4   Gas/Solid Reactor.   A fourth control  technique that is used
  by  some  hospitals to control  vent  emissions (after  acid-water scrubbing)
  is  a  dry,  solid-phase system  that  chemically converts EO and then binds
  the product to the solid packing.1   The  system operates at room
  temperature.   There are no  liquid waste  streams produced;  the vendor
  handles  the disposal  of the solid waste  that is produced.35   Although  the
  gas/solid  reactor can handle  EO concentrations in the percent range  (i.e.,
  >100,000 ppmv)  for brief periods of  time,  it is designed for low  (ppm
  range) concentrations such as the exhaust  from an acid-water scrubber.
  The manufacturer  of this device markets  a  two-stage control  system,  which
  consists of an  acid-water scrubber and the  gas/solid  reactor.   (The
  company also sells  the  stages separately.)   The majority of  the EO is
  removed by the  scrubber, which is specifically  designed for  the small
  sterilizers (<2 m3  [70  ft3]) used at hospitals.  The gas/solid reactor
  removes the residual  EO  exiting the scrubber and, because  it  is designed
 for low EO concentrations, can also be manifolded to other emission
 sources (e.g., aeration chambers,  sterilizer hood and door, and gas
 cylinder storage room).
     The manufacturer of this  system claims greater  than 99.9 percent
 efficiency for the gas/solid reactor.1   However, this  efficiency is based
 on a test performed with an  inlet  EO concentration of  140,000 ppmv, which
 is much higher than the concentration of  the scrubber  outlet  stream.   In
 another test,  no EO was detected  (with  a  lower detection limit of
 0.1  ppmv)  in the gas/solid reactor outlet stream when  the  inlet stream
 (i.e.,  scrubber outlet stream) was 2  ppmv EO.35  Because of the innate
 problems  associated with measuring  low  EO concentrations, the actual
 efficiency  of  the  system under normal operating conditions  presently
 cannot  be determined.   (See Section 4.1.3  for a more detailed  discussion
 of measuring low EO  concentrations.)  However,  the maximum  removal
 efficiency  that  the  gas/solid reactor can achieve on a continuous basis  is
 assumed to  be 99.0 percent.
 4-1-2  Sterilization Chamber Vacuum Pump.Drain Emissions
     Ethylene oxide drain emissions result from the use of vacuum pumps
 that use once-through water as  the working fluid.  (Some of the
manufacturers of hospital sterilizers are developing  sterilizers that are
                                   4-15

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 evacuated by air ejectors instead of vacuum pumps.)30   Ethylene  oxide  is
 infinitely soluble in water, and, therefore, a portion  of the  EO evacuated
 from the chamber enters the drain with the vacuum pump  water  (see
 Figure 4-5a).  The EO that enters the drain with the vacuum pump water  is
 subsequently released uncontrolled from the air break in the drain line,
 sewer lines, or the waste treatment plant.6'8
      The EO drain emissions can be controlled by replacing the existing
 once-through vacuum pump with a closed-loop (recirculating) vacuum pump.
 The recirculating fluid (sealant) can be water, oil or ethylene
 glycol.     In this closed-loop system,  the water or liquid from  the
 liquid-gas separator is cooled in a heat exchanger and recirculated
 through  the vacuum pump (see Figure 4-5b).  Because ethylene oxide is not
 soluble  in oil  or ethylene glycol and will off-gas from water as it is
 recirculated,  nearly all  of  the EO will  be emitted through the liquid-gas
 separator (chamber)  vent.   (Techniques  for control  of  chamber vent
 emissions are  discussed above.)  In  addition, mechanical seals are used to
 eliminate leakage (and,  thus,  any EO emissions)  from the pump.37
      Because the  sterilization  cycle operates under  humid conditions, some
 water will  be  condensed  in the  liquid-gas  separator  and, thus,  mix with
 the liquid  sealant  in the  pump.   An  overflow collection  tank  is used  to
 maintain  a  constant amount of sealant recirculating  in the pump.37 If
 ethylene  glycol is used as the  sealant, the contaminated  glycol will
 eventually  need to be disposed  and replaced with a fresh  charge.35
 However,  if oil is used as the  sealant, the condensed water can be drained
 off the bottom with minimal oil  loss because of the  immiscibility of oil
   ,    .   as
and water.
4.1.3  Aeration Room Vent Emissions
     4.1.3.1  Aeration Rooms.  Most commercial sterilization facilities
aerate the sterile products in large, warehouse-type aeration rooms that
are typically 280 to 2,800 m3 (10,000 to 100,000 ft3) in volume but may be
larger than 14,000 m3 (500,000 ft3).31  The ventilation rates are,
generally, in the range of 112 to 560 m3/min (4,000 to 20,000 ft3/min) but
may be as high as 1,680 m3/min (60,000 ft3/min).31  These large flow rates
are necessary to maintain a low EO concentration in the room to comply
with the Occupational Safety and Health Association (OSHA)  standards (see
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                                                              4  :U:SS::.NS
                                  VACUUM
                                   PUMP
 EVACUATED GAS  FROM
STERILIZATION CHAMBER
                      WATER
      SEPARATOR
VACUUM PUMP WATER
EO  DRAIN EMISSION
            Figure 4-5a.   Once-through  liquid-ring  vacuum pump.
    EVACUATED GAS  FROM
  STERILIZATION CHAMBER
             RECIRC'JLATED
                «ATER
                                                                EO VENT
                                                                EMISSIONS
                                                                    LI3UIO-GAS
                                                                    SEPARATOR
                                                                 VACUUM PUMP
            Figure  4-5b.   Redrculating liquid-ring vacuum pump.
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 Section 3.5).  Data from a cross-sectional  survey  (44 facilities) of  the
 203 commercial sterilization facilities represented in EPA's data base
 indicated an average 8-hour time-weighted average  (TWA) EO concentration
 of 2.5 to 3 ppmv in aeration rooms.31
      Two issues of concern regarding the control of aeration room
 emissions are:  (1) most EO emission control devices are impracticable for
 the low-concentration, high-flow-rate exhaust streams from aeration rooms;
 and (2) the lower detection limit of most analytical methods makes it
 impossible to determine the true control efficiency of the low EO
 concentrations (<1 ppmv) found in most aeration rooms.   Hydrolysis,
 thermal oxidation, and condensation/reclamation presently have not been
 demonstrated to be practicable control  techniques for low-concentration,
 high-flow-rate gas streams.   However, catalytic oxidation and the
 gas/solid  reactor system have the potential  to  control  aeration room
 emissions.   Catalytic  oxidation units are  commercially  available to  handle
 flow rates  from less than 1 m3/min (40  ft3/min)  to  approximately
 340 m3/min  (12,000 ft3/min).9'38   The catalytic  oxidizers  are modular, and
 systems can  be designed  to handle higher flow rates; however, the
 increased size of  the  system  for  high flow rates  can restrict  its
 practical use.  Gas/solid reactors  are  being used for flow rates  up  to
 42  m /min (1,500 ft /min), and  systems  can be designed to handle  any flow
 rate; however,  as with catalytic  oxidation,  the system size can become
 impractical.39
      The manufacturers of the catalytic oxidizers and of the gas/solid
 reactor claim  EO destruction efficiencies greater than 99.9 percent and
 offer the results of third-party  tests to support these claims.35»1+0»1*1
 However, test data on the efficiencies of the control units operating
 under conditions (i.e., low concentrations and high flow rates) that are
 typical of aeration room exhaust  streams are not available.
     Generally, the control  units are tested by sending the control device
 a stream of EO with a much higher concentration (e.g.,  100 to
 140,000 ppmv) than that associated with  normal  operating
conditions.   »l|0>ltl  The results of these tests  are  the  efficiencies
reported by the manufacturers.  However, these  test  results  are
 inconclusive because (1)  it  has not been demonstrated whether the control
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 units perform at the  same  efficiencies under  normal  operating  conditions
 (i.e., very  low inlet concentrations) as during  test conditions  (i.e.,
 controlled flow, high concentration); (2) EPA has  not verified the
 available test data;  (3) there has not been an EPA-sponsored test of  these
 control devices with aeration room emissions;  and  (4)  a test reference
 method has not been developed (but is being developed) to evaluate the
 efficiencies of these control devices with aeration  room emissions.
      The lower detection limits of most analytical procedures that are
 used to measure EO concentrations are approximately  0.5 ppmv to 1 ppmv,
 which is equal to or greater than the EO concentrations in many aeration
 rooms.  Although one testing laboratory reportedly used a method with a
 detection limit less than 0.1 ppmv, the test data have not been verified
 by EPA, and it is unknown whether this method can be applied to high flow
 rates.  (The flow rate tested was 14 m3/min [500 ft3/min].)M   Also,
 because of the reactivity of EO,  the validity of detection limits below
 1  ppmv,  and particularly below 0.5 ppmv,  is  questionable/2   Because the
 detection Limits  of the  analytical methods  (in ppmv)  are  so  close to the
 room concentrations,  testing under normal operating conditions  may yield
 an efficiency that  only  can be calculated to  be equal to  50  percent  or
 less.
      Three  possible techniques  for reducing EO emissions from aeration
 rooms  are  (1)  recirculate the air  from the aeration room control  device  to
 the  aeration  room,  (2) replace the warehouse-type aeration rooms with
 smaller, heated aeration  cells, or (3) modify  the evacuation and air wash
 phase  of the  sterilization  cycle.  The first two  techniques  increase the
 EO concentration in the aeration room and lower the flow rate, which makes
 both control of the emissions and  testing of the  control efficiency more
 practical.  The third alternative  lowers the EO emissions from the
 aeration room by decreasing the residual  EO in the product prior to
 aeration.  These techniques are discussed in more detail below.
     The first alternative refers  to routing the aeration  room air through
 an emission control  device and back to the aeration room.   A  small amount
of makeup air is added to the control  device exit stream to regulate  the
room temperature.   This practice increases the room temperature  and,
therefore,  increases the  diffusion  rate of EO  from the product,  producing
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 a higher EO concentration  in the room.  (Worker  exposure and compliance
 with the OSHA standards will need to be considered  if frequent worker
 access to the room is required.)  Catalytic oxidation and the gas/solid
 reactor are more applicable to the increased EO  concentrations and
 decreased flow rates associated with this process than to typical aeration
 room emissions.  (In addition, increasing the room temperature reduces the
 energy costs of preheating the inlet stream to the catalytic oxidizer.)
 Hydrolysis, thermal oxidation, and condensation/reclamation are not
 applicable because the EO concentrations are too low (<20 ppmv) for these
 techniques to be practicable.   Because the room air is recirculated and
 not  vented to the atmosphere,  this technique eliminates  practically all
 aeration room emissions; only  a small  amount of the emissions from the
 control  device are vented to allow fresh makeup air to enter the  room.
 This practice of recirculating the aeration room air is  used by two of the
 203  commercial  sterilization facilities  represented in the  EPA  data
 base.    The aeration  rooms  at  these  two  commercial  facilities are each
 approximately 140 m3  (5,000 ft3)  in  volume.31   These 2 facilities
 manufacture synthetic rubber products, which retain a large  amount of
 residual  EO and,  therefore, require  a  longer aeration period than the
 majority of products  that are  sterilized with EO.   The facilities
 installed  the recirculating system to decrease  the  aeration time  and the
 residual  EO  concentrations  in the products."*3   A  catalytic oxidation
 system is  used to control the EO emissions  and  to provide hot air  to heat
 the  room.1*
     Another alternative is to replace the  large, warehouse-type aeration
 rooms with smaller  (70 m3 [2,500 ft3] or less), heated aeration cells and
 control the emissions from the cell.  In this process, instead of  storing
 the  sterile products  in a warehouse and aerating at normal room
 temperatures, the products are  aerated in heated (>43°C [110°F]) insulated
 cellular units.  The emissions  from these cells can be controlled  by
 catalytic oxidation or the gas/solid reactor system.  Emissions  from the
 control unit can be recirculated to the aeration cell or  vented  to the
atmosphere.  The cells can be filled  approximately 40 to  75  percent full
and still allow sufficient air  space  for  off -gassing. "»'"'   The  cell  is
heated either with supplemental  heat  or hot air  from the  control device if
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 catalytic oxidation  is used.   Several  commercial  sterilization facilities,
 particularly contractors,  are  aerating at  least part of  the  sterile
 products in heated,  cellular units.3t'3a   Structures used  for  aeration
 include insulated shipping containers,  modified walk-in  coolers  (which  are
 heated instead of cooled), and manufactured units designed specifically
 for the heated aeration process."*5"1*7   Most of these facilities  have
 installed these units to reduce the aeration time or the residual  EO
 concentration in the products.  The heated cells are similar to  the first
 technique described above (i.e., the practice of recirculating the
 aeration room air) in that the EO concentration in the cell will increase
 due to elevated temperature.
      Another strategy for reducing aeration room emissions is modifying
 the evacuation/air wash phase of the sterilization cycle.  Residual EO  in
 the product can be reduced by performing additional  sterilization chamber
 purges.  However,  this procedure does require additional  time in the
 sterilizer  and  could  affect plant operating schedules.   The potential
 reduction  in residual EO  with evacuation-phase modifications  is product
 dependent.   Results from  tests  performed at one facility  that fumigates
 spices showed an average  reduction in residual  EO  of 26 percent for four
 different spices following  evacuation-phase modifications.19   Some
 facilities  aerate  in  the  sterilizer,  with or without cycle
 modifications.    Aeration  emissions  from the  sterilizer  can  be sent to
 the  sterilizer control device.  However, the removal efficiencies of the
 hydrolysis techniques  have  not  been determined for the low  inlet
 concentrations associated with  aeration  emissions.  Also,
 condensation/reclamation would  not be practicable for controlling these
 low concentrations.
     4.1.3.2  Aeration Chambers.  Many hospitals and some commercial
 sterilization facilities use aeration chambers instead  of aeration
 rooms.  These chambers are similar in appearance and size (<1 m3  [40 ft3])
 to the sterilization chambers used at hospitals.  However, the flow rate
 is much lower from  the chambers than from aeration  rooms.   Therefore,
catalytic oxidation and the gas/solid reactor are applicable to the
control of EO emissions from aeration chambers.   Several  hospitals and
small commercial  sterilization facilities use catalytic oxidation or the
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 gas/solid reactor system to control aeration chamber  emissions,  and  at
 least one commercial sterilization facility uses an acid-water scrubber to
 control these emissions.9'10'31  However, as stated in Section 4.1.3.1,
 the control efficiencies of these techniques have not been determined  for
 the low concentrations from aeration processes.
 4.2  OTHER STERILIZATION PROCESSES
      There are no demonstrated EO emission control devices for single-item
 sterilization processes or for portable fumigation units.  The problems
 associated with controlling EO emissions from these sources are discussed
 below.
 4.2.1  Single-Item Sterilization
      Single-item sterilization systems do not use a chamber evacuated with
 a vacuum pump.   (See Section 3.2.2  for a description of single-item
 sterilization.)   Instead,  the  EO is  allowed  to  diffuse from products  while
 they are inside  an aeration room or  cabinet.  The EO from facilities  using
 single-item sterilization  systems is,  therefore,  emitted  from one major
 source,  the  aeration room/cabinet vent.   Because  there is no  evacuation
 phase,  the  EO concentration in the gas  stream from  single-item
 sterilization systems is higher than the  concentration of EO  in aeration
 rooms.   However,  the concentration is  sufficiently  low such that  catalytic
 oxidation or the  gas/solid  reactor system may be  viable control options.
 4.2.2   Fumigation with Portable Units
     Because of problems with  transporting an emission control device,
 there are no practical controls of EO emissions from the  portable units
 operated by State departments  of agriculture to fumigate  beehives.
 However, one State Department  of Agriculture is working on the development
 of an acid-water scrubber for  portable fumigation units.3
 4.3  ALTERNATIVES TO EO STERILIZATION
     In some cases, radiation  sterilization can  replace EO sterilization.
 Radiation sterilization is used for  about half of the products sterilized
           u a
 in the U.S.    However,  not all products can  be  sterilized with radiation;
plastics can become broken,  discolored, or malodorous,  and Teflon® and
acetyl delrin are damaged  by radiation.<+a»'19   According to industry
representatives,  most of the commonly used plastics  have  been  or are in
the process of being reformulated to  withstand radiation.50'51  Therefore,
the potential  use of this  alternative will probably  increase.

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      There  are  several  chemical  alternatives  to EO  sterilization  (e.g.,
 chlorine dioxide,  gas plasma,  hydrogen  peroxide,  and  ozone).   However,
 these chemicals do not  necessarily offer  environmental  improvements  over
 EO.  Other  alternatives  include  X-ray (a  new,  developing technology), deep
 freezing (museum and spice  industry), and  increased use of disposable
 medical items in hospitals.  However, none of  these alternatives can
 replace the use of EO in all applications.
 4.4  RETROFIT CONSIDERATIONS
      All of the control devices discussed above can be retrofitted to
 existing EO bulk sterilization chambers.  However, the use of flares in
 urban areas is  prohibited because of safety hazards.  There are no
 retrofit problems  associated with the replacement of once-through vacuum
 pumps with closed-loop recirculating vacuum pumps for control of drain
 emissions.
 4.5  IMPACTS OF A CFC REGULATION ON EO EMISSION CONTROLS
      Federal regulations for stratospheric ozone-depleting
 chlorofluorocarbons (CFC's)  have been developed under EPA's  Stratospheric
 Ozone Protection Program (SOPP).   The use of CFC's in sterilant gases is
 one of the  source categories subject  to  these regulations.   The most
 popular sterilant gas mixture,  12/88, contains 88 percent by  weight
 dichlorodifluoromethane  (CFC-12),  which  is an ozone-depleting CFC.  Nearly
 all  hospitals  and 75 percent of the 203  commercial sterilization
 facilities  represented  in the EPA  data base  use 12/88  at least  part of the
 time.  »   The  requirements of a CFC regulation  would not affect  the
 ability  of  a sterilization facility to control  EO emissions.  The
 explosion-proof  condensation/reclamation system discussed above  recovers
 CFC-12 emissions in addition  to EO emissions.   However, if this  control
 device is used,  add-on controls (e.g., catalytic oxidation or a  small
 scrubber) need to be considered for the EO remaining in the chamber after
 the reclamation  cycle is complete.  Also, a nonexplosion-proof
 condensation/reclamation system that recovers only CFC-12 could follow the
 acid-water scrubbing of EO to ethylene glycol.52  Some facilities may
 switch to sterilant gases that do not contain CFC-12  (such  as 10/90 and
 pure EO), in which case, the EO  control  techniques discussed  above still
would be applicable.
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 4.6  REFERENCES FOR CHAPTER 4

  1.  Safe-Cell™ product brochure.  Attachment to letter from Kruse, R.,
      Advanced Air Technologies, Inc., to Farmer, J., EPA.  May 31, 1988.

  2.  Letter and enclosures from J. Jorkasky, Health Industry
      Manufacturer's Association (HIMA),  to D. Markwordt, EPArCPB.
      February 21, 1986.  Survey responses from HIMA members.

  3.  Responses to July 1986 Section 114  information request regarding the
      use  of ethylene oxide by miscellaneous sterilization and fumigation
      facilities.

  4.  Memorandum.   Srebro,  S.,  MRI, to Markwordt, D., EPA/CPB.  Examination
      of Ethylene  Oxide Control  Efficiencies.   Attachment to Effect on the
      Maximum Individual Risk from an  Increase in the Ethylene Oxide
      Removal  Efficiencies.   October 5, 1988.

  5.  Organic  Chemical  Manufacturing Volume 4:   Combustion Control
      Devices.   EPA-450/3-80-026.   December 1980.  Control  Device
      Evaluation:   Flares and the  Use  of  Emissions as Fuels.   p.III-2.

  6.  Ethylene  Oxide  Product  Information  Bulletin.   Union Carbide  Corp.,
      Ethylene  Oxide/Glycol Division.   1983.

  7.   Letter from  Buonicore,  A., Chemrox,  Inc.,  to Markwordt,  D.,
      EPA:CPB.  August  27,  1984.   Comments  on  sources of  ethylene oxide
      emissions draft report.

  8.   Conway, R., Waggy, G.,  Spiegel, M.,  and Berglund, R.  Environmental
      Fate and  Effects  of Ethylene Oxide.    Environmental  Science and
      Technology.   17(2):107-112.  1983.

  9.   Telecon.  Nicholson, R., MRI, with Olson, C., Donaldson Company,
      Inc.   May 12, 1988 and June 13, 1988.  Discussion about applicability
     of catalytic oxidation to large aeration rooms and  location of
     facilities using the EtO Abater™.

10.  Contact report.  Srebro, S.,  MRI, with Meo, D., DM3 Incorporated.
     December 9, 1988.

11.  Telecon.  Nicholson,  R., MRI, with Kruse, R., Advanced Air
     Technologies, Inc.  June 14,  1988.   Discussion  about the Safe-Cell™
     gas/solid reactor.

12.  Ethylene Oxide Control  Technology Development for Hospital
     Sterilizers.   Meiners,  A.,  MRI.  EPA-600/2-88-028.   May  1988.

13.  Questionnaire for  Croll-Reynolds  Ethylene Oxide Scrubber—Customer
     Specifications.  Droll-Reynolds Company.   Westfield, New Jersey.
     October 1985.
                                   4-24

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 14.  Telecon.  Newton, 0., MRI, with Urban, T., Chemrox, Inc.
      February 13, 1986.  Discussion about disposal of scrubber liquor
      containing ethylene glycol.

 15.  Newsletter about EO control.  Chemrox, Inc., Bridgeport, Connecticut
      Volume 1, No. 1.  October 1983.

 16.  Certification Testing Report.  BCA Project No. 85-260.  Chemrox Inc.
      Bridgeport, Connecticut.  October 29, 1985.

 17.  Letter from Desai, P., Chemrox, Inc., to Wyatt, S., EPA:CPB.
      September 17, 1987.   Comments on draft BID Chapter 4 for ethylene
      oxide NESHAP.

 18.  "Sampling/Analytical  Method Evaluation for Ethylene Oxide Emission
      and Control  Unit Efficiency Determinations."   Final Report.   Radian
      Corporation, Research Triangle Park,  North Carolina.   April  5,  1988.

 19.  Desai,  P.   Performance Test Report:   DEOXX™ Ethylene Oxide
      Detoxification  System.   Chemrox Project  No.  85-260. October 1985.

 20.  Memorandum.   Srebro,  S.,  MRI,  to Markwordt,  D.,  EPA:CPB.  Capital
      cost,  annualized cost,  and  cost effectiveness  of reducing ethylene
      oxide  emissions  at commercial  sterilization  facilities.  March  20
      1987.   80 p.

 21.   Product Data Sheet.   Environmental Tectonics Corporation.  Enclosure
      to  letter from Peters,  J.,  Environmental Tectonics  Corporation, to
      Nicholson, B., MRI, June  10,  1987.

 22.   Meeting Minutes.   Beall,  C., MRI, to Markwordt, D., EPA:CPB.  Damas
      Corp. and Johnson  & Johnson.  April 30, 1986.  9 p.

 23.   Letter  and attachments from Smith, D., Damas Corp., to Wyatt, S.,
      EPA:CPB.  September 21, 1987.  -Comments on draft BID Chapter 4 for
      ethylene oxide NESHAP.

 24.   Telecon.  Srebro, S., MRI, with Hoffman, J., Med-Chem Reclamation,
      Inc. (formerly B&D Industries).  March 6, 1989.  Discussion about
      recovery of ethylene glycol from ethylene oxide scrubbing liquor.

 25.  Telecon.  Srebro, S., MRI, with Duvow, J.,  Chemstreams,
      Incorporated.  March 16, 1989.  Discussion  about recovery of  ethylene
     glycol from ethylene oxide scrubbing  liquor.

 26.  Telecon.  Srebro, S.,  MRI, with Dalton, K., High Valley Chemicals.
     March 16,  1989.   Discussion about recovery  of ethylene  glycol from
     ethylene oxide scrubbing liquor.

27.  Letter and attachments from Smith,  S.,  John Zink  Company,  to
     Coronna, B.,  MRI.  October 3,  1986.   Information  about  the John  Zink
     EO flare.
                                   4-25

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 28.  Telecon.  Soltis, V., MRI, with Duck, 3., John link Company.   July  8,
      1987.  Discussion about EO sterilant gas mixtures and the  use  of
      flares.

 29.  Telecon.  Srebro, S., MRI, with Meo, D., DM3 Incorporated.
      January 13, 1989.  Discussion about CATCON catalytic oxidation
      systems.

 30.  Telecon.  Srebro, S., MRI, with Ames, G., South Coast Air Quality
      Management District.  March 10, 1989.  Discussion about hospital
      sterilizers that use air ejectors to send emissions to a catalytic
      oxidizer.

 31.  Responses  to July 1988 information collection request regarding
      chamber operating parameters, current controls, vacuum pumps, and
      aeration rooms.

 32.  Letter and attachments from Olson, C.,  Donaldson  Company,  Inc., to
      Markwordt, D.,  EPA/CPB.   March 21, 1988.   Test  data for EtO Abater™
      for sterilizer  chamber emissions.

 33.  Telecon.   Srebro,  S.,  MRI, with Meo,  D.,  DM3  Incorporated.
      December 2,  1988.   Discussion about the CATCON  catalytic oxidation
      systems.

 34.  Memorandum.   BeaTl,  C.,  MRI,  to Markwordt, D.,  EPArCPB.  Trip
      Report:  Sterilization Services of Tennessee, Memphis,  Tennessee,  on
      March 18,  1986.

 35.   Letter and attachment  from Hammer,  D., Consulting Engineer,  Advanced
      Air Technologies,  to Markwordt,  D., EPA/CPB.  June 22,  1988.
      Transmitting  test  data for the  Safe-Cell™ system.

 36.   Buonicore, A.  In-Plant  Programs to Reduce Ethylene Oxide Worker
      Exposure Levels.   Chemrox,  Inc., Bridgeport, Connecticut.  August
      1984.

 37.   EO-VAC" Closed Loop Vacuum Product Information Sheet.  Chemrox, Inc.
      Bridgeport, Connecticut.  May 1987.

 38.   Letter and  attachments from Meo, D., DM3 Incorporated, to Srebro, S.,
      MRI.  January 13, 1989.  Transmitting information about the CATCON
      system.

39.   Letter and  attachments from Kruse,  R., Advanced  Air  Technologies,  to
      Nicholson,  R., MRI.  June 15,  1988.  Transmitting  information about
     Safe-Cell"  system.

40.   Letter and  attachments from Olson,  C., Donaldson Company, to
     Srebro, S., MRI.   November 9,  1988.  Transmitting  test  data  for the
     EtO Abator".
                                   4-26

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 41.   "Report of Air Pollution Source Testing Conducted at lolab
      Corporation."  Engineering  Science,  Incorporated, Pasadena,
      California.  Seotember 27,  1988.   Attachment to letter from  Meo, D.,
      DM3,  Incorporated, to Srebro,  S.,  MRI.   December 16, 1988.

 42.   Analytical  Chemistry.  Volume  60.   1988.   pp.  24-54 to 24-60.

 43.   Telecon.   Shine,  B.,  MRI, with Cutright,  L., Seamless  Hospital
      Products.   October 20,  1988.   Discussion  about the  catalytic oxidizer
      used  to control aeration room  emissions at Seamless.

 44.   Telecon.   Friedman, E.,  MRI, with  Shumway,  R.,  Medronic,
      Incorporated.  January  18,  1989.   Discussion about  the heated
      aeration cells at Medronic.

 45.   Memorandum.   Srebro,  S., MRI,  to Markwordt,  D.,  EPA/CPB.   Site
      visit:  Medtronic,  Incorporated, Anaheim,  California,  on December 9
      1988.

 46.   Memorandum.  Srebro,  S., MRI,  to Markwordt,  D.,  EPA/CPB.   Site
      visit:  lolab, Incorporated, Claremont, California, on December  9,
      1988.

 47.   Product brochure.  Chemrox,  Incorporated.  Hot Cell™ heated aeration
      unit.

 48.  Telecon.  Soltis V., MRI, with Jorkasky, J., Health Industry
     Manufacturers Association.  March 2, 1987.  Discussion about trends
      in the sterilization  industry.

 49.  Telecon.  Beall, C., MRI, with  Chin,  A., Radiation Sterilizers,
      Inc.  February 22, 1986.  Discussion about gamma radiation.

 50.   "Cobalt-60 Growth from 1978  to  1988."  Chin, A., Radiation
     Sterilizers, Incorporated.  Presentation at the Health  Industry
     Manufacturers' Association (HIMA)  "Sterilization in  the 1990's"
     Conference in Washington, D.C., on  October 31,  1988.,

51.  "Radiation and Plastic:   Friend or  Foe."  Apostolou, S.,  POLY-
     FOCUS.  Presentation at HIMA conference  on October 31,  1988.

52.  Telecon.  Srebro,  S.,  with Desai, P., Chemrox,  Incorporated.
     January 20,  1987.   Discussion about the  FREOXX™ CFC-12  reclamation
     system.
                                  4-27

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                         5.   EMISSION CONTROL COSTS

 5.1  INTRODUCTION
      This chapter presents a summary of the methodology to develop
 emission control cost estimates.  Costs presented in this chapter are in
 December 1984 dollars.  A method for estimating EO emission control costs
 at commercial sterilization facilities is presented in Section 5.2.
 Limited cost information has been obtained about emission controls for
 hospital sterilizers, single-item sterilization systems,  and aeration
 rooms;  these costs are discussed in Sections 5.3 through  5.5,
 respectively.
 5.2  CONTROL COSTS FOR COMMERCIAL STERILIZATION FACILITIES
      This section describes a method for estimating emission control  costs
 for sterilizer vent(s)  and  the vacuum pump drain at commercial  sterilization
 facilities.   Acid hydrolysis (i.e.,  acid-water scrubbing)  was chosen  as  the
 bas-is for the costing procedure because that control technique  currently is
 practiced at several  commercial  sterilization facilities  and  has  been
 demonstrated at both  small  and  large commercial  facilities.   A  detailed
 review  of the available  test data  indicated  that 99.0 percent  is  the maximum
 EO  removal efficiency that  acid  hydrolysis techniques can  achieve on a
 continuous basis.1  Therefore,  99.0  percent  was  used to calculate the
 emission  reductions.
      The  costing  procedure  presented  in this  section has been used to
 develop emissions control costs for  the 203  commercial  sterilization
 facilities represented in the EPA data base.2  (See Section 3.1 of this
 report for a  description of  how the data base was developed.)  The results
 of this cost  analysis for three actual commercial sterilization facilities
 are presented in Table 5-1.   Detailed sample calculations  for another
 commercial sterilization facility are given in Appendix B.
 5.2.1  Description of Components Costed
     The following components were costed:  (1) an acid-water scrubber,
 (2) a water-sealed vacuum pump with closed-loop recirculation for each
sterilizer, (3) piping for manifolding all chambers at  a facility to one
scrubber, (4) operating materials (i.e., chemicals  and  chlorine  filters),
(5)  scrubber  waste disposal, and (6)  labor.
                                   5-1

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      Scrubber prices are listed in Table 5-2.  The capital costs of the
 piping system for manifolding and the installed cost of the vacuum pump  are
 presented in Tables 5-3 and 5-4.  The costs of operating materials, as well
 as the shipping charges used for computing disposal costs for the spent
 scrubber solution, are presented in Table 5-5.2
      Costs reported in Tables 5-2 through 5-5 are in fourth quarter 1984
 dollars.   The prices for the scrubbers,  vacuum pump, chlorine filters, and
 chemicals were obtained from the manufacturer and suppliers and were
 originally in 1986 dollars.  These prices were converted to fourth quarter
 1984 dollars using the CE Plant Cost Index (for the equipment) and the
 Current Business  Indicators (for the chemicals)  in Chemical
             3 '*                                    ~~~~~~~~~~
 Engineering.  '   The labor costs were calculated from the Economics
 Assessment Branch (EAB/EPA) control  cost  manual  and from the  CE Plant  Cost
       •*  5
 Index.  »    The indices used and the  conversion factors  obtained are reported
 in Appendix B.
 5.2.2  General  Assumptions
      Chamber  volume was  used  as the  basis  for  scrubber  sizing.   The rela-
 tionship of chamber volume  to scrubber size  is presented in Table  5-2.2
      If a  facility  has three  or more sterilization chambers,  the scrubber
 costed was  chosen based  on  the  sum of the  volumes  of  the two  largest
 chambers at that  facility.  This methodology simulates  the cost  of
 controlling emissions  from  a  facility if two chambers at that  facility were
 to be evacuated simultaneously.   If  a facility has  two  chambers, the
 scrubber was  selected  based on  the volume of the larger chamber.  For
 facilities with two chambers, it was assumed that the sterilization cycles
 could be staggered  so that  the chambers would not be evacuated
 simultaneously.2
     For the purposes of this cost analysis, it was assumed that the
 ethylene glycol would be accepted by a recovery facility on a no cost/no
 credit basis, except for shipping charges.  Therefore, the disposal cost for
 the aqueous ethylene glycol solution produced by the acid-water scrubbers
was computed as the cost .to ship the solution,  either in 55-gallon  drums or
 in a tank truck, depending on quantity,  to a recovery facility.
Transportation costs were calculated by assuming that commercial
 sterilization facilities are within 1,000  miles of one of the  three known
                                   5-2

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 recovery facilities.2  However, these disposal costs may not be applicable
 to all sterilization facilities.  If a recovery facility is not available to
 accept the liquor, it may be necessary to neutralize the scrubbing liquor
 and then have it hauled to a landfill or incinerator, which may increase the
 waste disposal costs.
 5.2.3  Capital Costs
      The fixed capital costs for a particular facility represent the initial
 investment and installation charges for control equipment.   The cost data
 presented in Table 5-6 were used to calculate capital cost  estimates for
 each of the facilities.2
 5.2.4  Annualized Costs
      Annualized costs for a particular facility represent direct operating
 costs such as  labor costs,  cost of materials,  and  disposal  costs,  as well  as
 indirect operating costs such  as overhead  charges, tax/insurance charges,
 and capital  recovery costs.  The cost data presented  in  Table  5-7  were  used
 to estimate  plant-specific  annualized costs.2   .
 5.3  CONTROL COSTS FOR HOSPITAL STERILIZATION  CHAMBERS
      Detailed  cost estimates have  not been developed  for EO  emission
 controls at  hospitals.   Only a  small  percentage of hospitals control  EO
 emissions  to the  atmosphere.  Emission controls used  at  hospitals  include
 acid-water hydrolysis,  catalytic oxidation, and the gas/solid reactor system
 discussed  in Section  4.1.1.4 of  this  report.6'9
      Because only a few control devices are in  place  at  hospitals, the cost
 data  available  are  limited and, therefore, should  be  used cautiously.
 Table  5-8  presents a  range of the approximate costs of using catalytic
 oxidation  to control  EO emissions from hospitals.  The capital costs  and
 annual operating  costs for catalytic oxidation were obtained from two
 hospitals.10  Additional control cost estimates for hospitals have been
 obtained from vendors and are given in Appendix C.
 5.4  CONTROL COSTS FOR OTHER STERILIZATION SYSTEMS
     There are no demonstrated  EO emission control  devices  for single-item
 sterilization processes or for  portable fumigation  units. Therefore,
 emission cost estimates have not been developed for these processes.
However, the EO concentration and flow rate from single-item sterilization
units is low enough that catalytic oxidation or the gas/solid reactor system
                                   5-3

-------
may be  viable control options.  See Appendix C for vendor-supplied  cost
estimates for these control devices.
5.5  CONTROL COSTS FOR AERATION ROOMS
     The potential control of aeration emissions is being evaluated by EPA,
and the preliminary cost analysis should be available by June 1989.
Catalytic oxidation and the gas/solid reactor system may be applicable to
the control of aeration emissions particularly from aeration chambers and
the heated, cellular structures to which some facilities are switching.  See
Appendix C for vendor-supplied cost estimates for catalytic oxidation and
the gas/solid reactor system.
                                  5-4

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             TABLE 5-1.  CONTROL COSTS  FOR ACID  HYDROLYSIS* b
Model
plant
Small d
Medium6
Largef
Total
sterilizer
volume,,
m3 (ft5)
2.8
(100)
28
(1,000)
168
(6,000)
Annual
EO use,
Mg
(lb/1,000)
0.18
(0.39)
3.9
(8.7)
109
(240)
Capital
costs, $
76,000
160,000
291,000
Annuali zed
costs, $
21,200
40,800
117,000
Annual emis-
sion reduc-
tion, Mg
(lb/l,000)c
0.17
(0.37)
3.7
(8.2)
102
(226)
 These cost estimates are not applicable to hospitals because the  acid-
 water scrubbers costed are not designed for the  low flowrates from the
.vacuum pumps on hospital sterilizers.
 See Appendix B for the methodology used to calculate these control costs,
"-Calculated as (0.99)x(0.95)(EO use).  Five percent of the EO use  is
 assumed to be retained in the product after sterilization and emitted
 .from the aeration room, which is assumed to be uncontrolled.
 The small model plant has one chamber and uses 12/88 (EO/CFC-12).
 Therefore, a model 100 scrubber (see Table 5-2) was chosen as the basis
 for the calculations.
 The medium model plant has one chamber and uses 12/88 gas.  Therefore, a
fmodel 400 scrubber was chosen as the basis for the calculations.
 The large model plant has seven chambers and uses 100 percent EO.  The
 sum of the volumes of the two largest chambers is 2,000 ft .  Therefore,
 a model  500 scrubber (with explosion-proof valves) was chosen as the
 basis for the calculations.
                                    5-5

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en
i
en
                                   TABLE  5-2.  COST OF DAMAS SCRUBBER MODELS  (F.O.B.)1
                                              (4th Quarter 1984 Dollars)
Model
No.
100
200
300
400
500
600
a
Chamber 0
size, m3 (ft3)3
<11.3 (<400)
11.3 to 17.0 (400 to 600)
17.0 to 22.7 (600 to 800)
22.7 to 45.3 (800 to 1,600)
45.3 to 56.6 (1,600 to 2,000)
>56.6 (>2,000)
Conversion capacity
of scrubber,
kg (Ib) of EO
908 (2,000)
1,816 (4,000)
2,724 (6,000)
3,632 (8,000)
4,540 (10,000)
5,448 (12,000)
Automated
scrubber
cost, $
47,250
68,250
89,250
99,750
141,750
157,500
Cost of explosion-
proof valves
for scrubber, $b
12,180
13,195
14,210
15,225
17,255
18,270
         The  size  of  sterilization  chamber that can be served by the model number, assuming  the  smallest
         appropriate  vacuum pump  1s used.

         'Explosion-proof  valves are necessary  If the sterilization chamber that  is vented  to the scrubber  uses  a
         gas  mixture  greater than 20 percent by weight EO.

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            TABLE 5-3.   INCREMENTAL CAPITAL COST$  OF  MANIFOLDING
                          STERILIZATION CHAMBERS1

                                                                      Cost,
 Item                                                                 1984  $

 Opening in explosion-proof wall*

   Adjustable sheetmetal sleeve                                         2b
   Labor costs at $18.05/hour                                          93
   Overhead costs at $8.35/hour                                        43

 Drill  holes for pipe hangersc

   Labor costs at $19.40/hour                                         146
   Overhead costs at $15.06/hour                                      113

 P1p1ngd

   100  ft,  2 in.  diameter,  40 standard  carbon  steel pipe              240?
   90°  elbows,  3  at  $4.19                                              13b
   Tee  with full-size outlet                                           14b
   Swing check  valve                                                  350b
   Bolts and gaskets,  two sets at  $6.76                                14b
   Pipe hangers,  1 carton of 50 hangers                               140°
   Labor costs  at $20.50/hour                                         576
   Overhead  costs at $12.71/hour                                      357

Total  installed cost  for piping system

   Total  direct costs6                                              1,588
   Total  indirect costs:
    Overhead costs                                                    513
    Administration9                                                   159
    Taxes              .                                               39
  Total  installed cost1                                     '       2,299

Total  installed cost  for recirculatinq vacuum pump                 4,935

TOTAL CAPITAL COST                                                 7j234

j*Requires 5.15 labor-hours.
"Equipment cost.
^Requires 7.5 labor-hours.
^Requires 28 labor-hours.
-Sum of all labor and equipment costs.
 Sum of all overhead costs.
'Ten percent of total direct costs.
.Five percent of total equipment costs.
 (Total direct costs)+(total indirect costs).
                                     5-7

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           TABLE 5-4.  CAPITAL COST OF CHECK VALVE FOR CHAMBER1
 Cost  item                                                      Cost, 1984 $
 Swing check  valve                                                 350a
 Installation costsb
  Labor costs  at $20.50/hour                                       23
  Overhead costs at $12.71/hour                                    14
 Total direct costs0                                               373
 Administration:  10 percent of total direct costs                  37
 Taxes:  5 percent of equipment cost                                18
 Total indirect costsd                                              69
 Total installed cost6                                             442
Annualized capital recovery costf                                  74
^Equipment cost.
 .Requires 1.1 labor hours to install.
jjSum of all labor and equipment costs.
°Sum of overhead costs, taxes, and administration.
"(Total direct costs)+(total indirect costs).
rCalculated as 0.16275x(total installed cost), for an interest rate of
 10 percent and a 10-year recovery period.
                                    5-8

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                TABLE 5-5.  MISCELLANEOUS OPERATING COSTS1
 Item description
 Cost,  1984 $
Operating materials

1.  50 percent H2SOm electrolyte-grade

2.  50 percent NaOH, industrial grade:
      <2 drums
      3-9 drums
      >9 drums

3.  Chlorine filters:
      Filter housing
      Filter
      Installation

Shipping charges for waste disposal

Weight of solution for disposal:
    <42,000 Ib (drums)
    >42,000 Ib (bulk)
0.069/lb
0.108/lb
0.0787/lb
0.0738/lb
41.50 each
15.00 each
20.00 each
0.096/lb
0.059/lb
                                    5-9

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    TABLE 5-6.  DATA USED TO CALCULATE CONTROL EQUIPMENT CAPITAL COSTS1
                        (4th Quarter 1984 Dollars)
 Item
Cost  factor
Automated scrubber
Explosion-proof valves for scrubber
Chlorine filter house
Scrubber installation
Chlorine filter installation
Taxes
Freight
Vacuum pump(s)
Manifolding of chambers (includes
  check valve)
($41.50 each)x(No. of tanks)c
50 percent of scrubber cost
($20.00)x(No. of tanks)0
5 percent of total equipment cost
5 percent of total equipment cost
$4,935 per pump
^Function of chamber size (see Table 5-2).
 Explosion-proof valves are necessary if the chamber that is vented to the
 scrubber uses a gas mixture greater than 20 percent (by weight)  EO.
 Number of scrubber tanks required = scrubber conversion capacity divided
 .by the conversion capacity of one tank (2,000 pounds of EO).
°See Tables 5-3 and 5-4.
                                    5-10

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                   TABLE 5-7.   DATA USED TO CALCULATE CONTROL DEVICE  ANNUALIZED COSTS1
                                        (4th Quarter  1984 Dollars)
 Item
Cost factor
Direct operating costs
Labor
Materials:
  50 percent H2S04
  50 percent NaOH
  Chlorine filters
  Taxes
  Freight
Compressed air
Disposal of ethylene glycol
Indirect operating costs
Overhead
Property tax, Insurance,
  and administration
Capital recovery costs
$3,177+($11.60)x(16 person-hours)x(No. of scrubber regenerations)* b
($0.069/lb)x(594 lb/drum)x(No. of drums required)
(Cost/lb)x(700 lb/drum)x(No. of drums required)
  c d
c, e, f
                        »                •
($15/filter)x(No. of tank regenerations)0 9
5 percent of materials cost
5 percent of materials cost
Oh
  1
(O.S)x(labor costs)
4 percent of total capital costs
(0.16275)x(total capital costs)j
                                                                                             (continued)

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                                                TABLE  5-7.   (continued)
tn
       aNumber of scrubber regenerations = amount of EO to be treated divided by the conversion capacity of the
       .scrubber (See Table 5-2).
        The $3.177 Is for visual Inspection of the system 15 minutes per shift.  3 shifts per day,  365 days per
        year at 511.60/person-hour.  It was assumed that each regeneration of the scrubber solution would
       crequ1re two people at 8 person-hours each, Independent of scrubber size.
        /Tnno °f S5rubber ^nks = scrubber conversion capacity divided  by the conversion capacity of one tank
        (<>,uoo pounds of EO).  Number of tank regenerations = number of  scrubber regenerations multiplied bv
        .the number of scrubber tanks.
        Each tank regeneration requires one 55-gallon drum of 50 percent H?SO/,.
        Each tank regeneration requires 250 pounds of NaOH for neutralization.
        Cost basis for 50 percent NaOH (350 pounds NaOH per drum):
        If No. of drums >9, cost/lb = $0.0738
        If No. of drums = 3 to 9, cost/lb = $0.0787
        If No. of drums <2, cost/lb = $0.108
      chlorine filter can dechlorlnate  approximately 200  gallons  (one  tank)  of  H90;  replace  filter  at
.each tank regeneration.                                                        *
Jhe cost of 10 seconds of In-house compressed  air  per  cycle  1s considered negligible.
 Un t cost of disposal was calculated by  multiplying the  total number  of  tank regenerations  by  the
 "page B-3]*         regeneration,  approximately  4.845  Ib (see Example Calculation No.  3  1n  Appendix B

 If the total weight <42,000 Ib,  disposal  cost  =  (we1ght)x($0.096/lb).
 If the total weight >42,000 Ib,  disposal  cost  =  (we1ght)x($0.059/lb).
JAssumes an Interest rate of 10 percent and  a 10-year recovery period

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         TABLE 5-8.   HOSPITAL EMISSION CONTROL COSTS
                                                    10
                                                   Annual
Control device         Capital  costs, $a    operating costs,  $b


Catalytic oxidation      30,000-50,000          6,000-16,000

aTotal installed capital  costs.   (Does not include modifying
.vacuum pump)
 Direct operating cost and  annualized catalyst and prefilter
 replacement.
                             5-13

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 5.6  REFERENCES FOR CHAPTER 5

  1.  Memorandum.   Srebro,  S.,  MRI,  to  Markwordt,  0.,  EPA/CPB.   Examination
      of  Ethylene  Oxide Control  Efficiencies.   Attachment to  Effect on the
      Maximum Individual  Risk from an  Increase  in  the  Ethylene  Oxide Removal
      Efficiencies.   October 5,  1988.

  2.  Memorandum.   Srebro,  S.,  MRI,  to  Markwordt,  D.,  EPA/CPB.   Capital  cost,
      annualized cost,  and  cost  effectiveness of reducing ethylene  oxide
      emissions  at commercial sterilization facilities.   March  20,  1987.
      80  p.

  3.   Chemical Engineering.   Economic Indicators.   February 18,  1985.  p.  7.

  4.   Chemical Engineering.   Economic Indicators.   June 23, 1986.   p.  7.

  5.   Neveril, R., Capital  and Operating Costs of Selected Air Pollution
      Control Systems.  GARD, Inc.  Miles, Illinois.   Publication
      No. EPA-450/5-80-002.  December 1978.  p. 3-11,  12,  16.

  6.   Responses  to July 1988 EPA information request regarding chamber
      operating  parameters, vacuum pumps, current controls, and aeration
      rooms.

  7.  Telecon.   Nicholson, R., MRI,  with Olson, C., Donaldson Company, Inc.
     May 12, 1988 and June 13,  1988.  Discussion about applicability of
     catalytic oxidation to large aeration rooms and location of facilities
     using EtO Abaters™.

 8.  Contact report.  Srebro, S., MRI,  with  Meo,  D., DM3, Incorporated.
     December 9, 1988.

 9.  Telecon.  Nicholson, R., MRI, with Kruse,  R., Advanced Air
     Technologies, Inc.  June 14, 1988.  Discussion about Safe-Cell™
     gas/solid reactor.

10.  Ethylene Oxide Control Technology  Development for Hospital
     Sterilizers.   Meiners, A.,  MRI.  EPA  600/2-88-028.   May  1988.
                                    5-14

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                    APPENDIX A.

FEDERAL AGENCY CONTACTS, CONTROL DEVICE VENDORS,  AND
         ETHYLENE GLYCOL RECOVERY COMPANIES

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                                TABLE A-l.  CONTACTS AT FEDERAL AGENCIES
 Agency  name  and  address
 Food  and Drug Administration
 Division of  Compliance
 8757  Georgia Avenue
 Silver Spring, Md.  20910

 Occupational Safety and Health
  Administration
 200 Constitution Avenue
 Washington,  D.C.  20210

 U. S. Environmental Protection Agency
U. S. Environmental Protection Agency
Global Change Program
401 M Street, S.W.
Washington, D.C.  20460

U. S. Environmental Protection Agency
Office of A1r Quality Planning and
  Standards
Research Triangle Park, N.C.   27711
 Item of concern
Sterility compliance
  (e.g., switching
  steMlants)
Worker exposure (e.g.,
  aeration rooms)
Sterilant registration
  (e.g., switching
  sterllants)

Chlorofluorocarbon
  regulations
Economics
Emission test method
                                        Health risk assessment
                                        Standards development
                                          (EPA Lead Engineer)
                                                                   Contact name
                       Phone
Virginia Chamberlain    (301) 427-7194
Melody Sands
John Lee
Karla Perri
Tom Walton
John Margeson
  (Office of Research
  and Development
Nancy Pate
David Markwordt
(202) 523-9308





(703) 557-5339



(202) 475-7496
(919)  541-5311
(919)  541-2848
                                                  (919) 541-5347
                                                  (919) 541-0837

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                     TABLE A-2.   CONTROL  DEVICE MANUFACTURERS3
 Company name and address
 Control  types
 Emission source applicability
 Advanced Air Technologies, Inc.    Scruober
 710  S. McMilIan Street
 Owosso, Michigan 48867
 (517) 723-2171
 Chemrox,  Incorporated
 217 Long Hill Crossroads
 SheI ton, Connecticut 06484
 (203) 926-9081

 CrolI-Reynolds
 Post Office Box 668
 Westfield, New Jersey 07091
 (201) 232-4200

 Oamas Corporation
 8 RomanelIi  Avenue
 S. Hackensack, New Jersey 07606
 (201) 489-0525

 DM3, Incorporated
 1530 E. Edinger Avenue
 Santa Ana, CaIiforn i a 92705
 (714) 543-1312

 Donaldson Company, Inc.
 Post Office  Box 1299
 Minneapolis, Minnesota 55440
 (612) 887-3155

 John Zink
 4401 South Peoria Avenue
 Post Office  Box 702220
 Tulsa,  Oklahoma  74170
 (918)  747-1371

 Environmental  Tectonics, Inc.
 County  Line  Industrial Park
 Southampton, Pennsylvania 18966
 (215)  355-9100

Vacudyne, Inc.
375 E.  Joe Orr  Road
Chicago Heights,  Illinois 60411
 (312) 757-5200
 Gas/sol id reactor
 Scrubber

 CFC reclamation  system
   (after EO  removed)

 Scrubber
Scrubber
Catalytic oxidation
Catalytic oxidation
Flare
Scrubber
EO reclamation system
  (for use with 12/88)
 Scrubber—vent (small  and large
   chambers)

 Gas/solid reactor—vent (after
   scrubbing); aeration chamber
   or room; sterilizer  door;
   hood;  si ngIe-itern ster iIi za-
   tion units

 Vent
                           Vent
                          Vent
Vent  (low  flows,  small  chambers)
Aeration chamber  or  room
Single-item  sterilization  units
Vent (low flows, small chambers)
Aeration chamber or room
Single-item sterilization units
                          Vent (large chambers; pure EO)
                          Vent
Vent (large chambers)
 This information  is  provided for the convenience of the reader and does not  imply product
 endorsement  by  EPA.
                                             A-2

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        TABLE A-3.   ETHYLENE  GLYCOL RECOVERY COMPANIES3

Mr. Jerry Duvow
Chemstreams
3501 River Road
Matthews, North Carolina  28106
(704) 821-6727

Mr. Keven Dalton
High Valley  Chemicals
1151 S. Redwood Road
Suite 105
Salt Lake City, Utah  74104
(801) 973-7966

Mr. John Hoffman
Med-Chem Reclamation, Inc. (formerly B&D Industries)
7900 N. Kolmar
Skokie, Illinois  60076
(312) 673-1441

aThis information is provided for the convenience of the
 reader and  does not imply product endorsement by EPA.
                             A-3

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      APPENDIX  B.



    COST INDICES AND



SAMPLE COST CALCULATIONS

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                    COST  INDICES  AND  CONVERSION  FACTORS
      The prices  for the scrubbers,  vacuum pump,  chlorine fiHars, and
 chemicals were obtained from the  manufacturers  and suppliers and were
 originally  in 1986 dollars.   These  prices were  converted to 4th quarter
 1984 dollars using the  following  indices  from Chemical  Engineering;
                            February  1986     October  1984:
                                                              Conversion
                                                              factor
 CE  Plant Cost  Index
Scrubber
Vacuum pump
Explosion-proof valves
Chlorine filters
Current Business Indicators
319.2
418.6
377.1
344.1

335.1
413.1
382.9
334.7

1.05
0.987
1.015
0.98

Industrial  chemicals
                              340.0
334.7
0.98
     The labor costs were calculated using the Economics Assessment Branch
(OAQPS/EAB) Control Cost Manual and the annual CE Plant Cost Indices in
Chemical Engineering:
CE Plant Cost Index
  1978
  1984
Conversion factor
EAB Conrol Cost  Manual'
Labor for calculations
                             218.8
                             322.7
                             1.47
                             $7.87/person-hour
                             $11.60/person-hour
                                   B-l

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                   EXAMPLE  CALCULATIONS  FOR  CONTROL COSTS"
                                Sterilization chambers at; the facility

Size, ft3
Gas type
EO USE, Ib
EO-EMIT, Ib
MEO-EMIT, Mg
EO-FAC, Ib
MEO-FAC, Mg
EO-TOT, Ib
MEO-TOT, Mg
CON-EM, Mg
REDUCE, Mg
No. 1
667
100
28,000
26,600
12.07
141,740
64.30
149,200
67.7
0.64
63.66
No. 2
667
100
28,000
26,600
12.07






No. 3
1,200
12/88
1,200
1,140
0.52






No. 4
1,334
100
46,000
43,700
19.82






No. 5
1,334
100
46,000
43,700
19.82






      1.   The  size,  gas  type, and EO use are those for an actual  commercial
 sterilization facility  represented in the EPA data base.   (See Section 3.1
 of  this  report for  a  description of how this data base was developed.)
 The other values were calculated using the following assumptions:
      a.   EO-EMIT (Ib) = EO (Ib) emitted annually from an individual
 sterilization chamber to the vacuum pump drain and to the atmosphere.
 Sterilizer vent emissions and vacuum pump drain emissions were assumed to
 be  50 percent and 45  percent of EO use (Ib), respectively.  Residual EO  in
 the sterilized product prior to aeration was assumed to be 5 percent of
 EO-USE (Ib).  This  5  percent of the EO use is not included as part of
 EO-EMIT  (Ib).
     b.   MEO-EMIT (Mg EO) = EO-EMIT (lb)/2,204.6
     c.   EO-FAC (Ib)  and MEO-FAC (Mg)  are the amount of EO released
 annually  by the facility to the vacuum pump  drain and to the atmosphere,
 i.e., the  sum of EO-EMIT and the sum of MEO-EMIT, respectively.
     d.   EO-TOT (Ib)  is the total  amount of  EO (Ib)  used annually by the
facility,  i.e., the sum of EO use.   MEO-TOT  (Mg)  = EO-TOT (lb)/2,204.6.
     e.  CON-EM (Mg) is the amount  of  EO that  would  be  released  annually
after control, i.e., MEO-TOT*(1-0.99)*0.95.   Note that  the  5  percent
residual  EO in the  sterilized product,  which  is  later released from the
aeration room vent,  is excluded from this  calculated  emission estimate.
                                   B-2

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       f.  REDUCE (Nig)  is the incremental amount of EO that would be reduced
  if controls are implemented,  i.e.,  (MEO-FAC)-(CON-EM).
       2.  For all  calculations,  a conversion efficiency of 99.0 percent was
  assumed for the scrubber.
       3.  Each tank  of the  scrubber  initially holds 198 gal  H20 and
  19.8  gal  H2SO^.  The  manufacturer recommends that the tank  be  regenerated
  (i.e.,  drained, rinsed,  and refilled)  after 2,000 Ib EO have been  treated.
       a.  19.8 gal H2SOk  =  1.42  kg-mole H2SO^ (p  = 1.834;  MW =  98.08)
  2NaOH+H2S0lt  * Na2S
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      6.   Find number of regenerations  of  scrubber required per year:
      a.   Number of scrubber tanks  =  scrubber model/100 = 6 (scrubber
 consists  of  modular tanks).
      b.   Conversion capacity of scrubber  =  (no.  of  tanks)x2,000 Ib =
 12,000  Ib
      c.   Number of scrubber regenerations =  EO-FAC  (lb)/12,000, i.e.,  the
 amount of EO (Ib)  to be treated per year  divided  by the conversion
 capacity  of  the scrubber.
          141,700/12,000 »  11.81 scrubber  regenerations/yr
      d.   Number of tank regenerations  = (No.  of scrubber
 regenerations)/(No.  of  tanks per scrubber) =  (11.81)x(6)  = 70.87.
      7.   Cost of chlorine  filter housing  = (41.50)x(no.  of tanks)  =
 $(41.50)x(6) =  $249.
      8.   Installation costs:
      a.   Scrubber  installation  = (O.S)x(cost  of scrubber)  = $78,750
      b.   Chlorine  filter housing installation = (20)x(no,.  of tanks)  =  $120
      9.   The incremental capital costs of manifolding are  presented  in
 Table 5-3 of this  report.
      10.  Vacuum pumps.  A  closed-loop recirculating water vacuum pump is
 required on each of the five chambers.   The cost of modifying the first
 vacuum pump is  included in  the cost of the scrubber; the cost of modifying
 the other four vacuum pumps  is $4,935 each.
      11.  Calculate direct operating costs:
     a.  Labor = 3,177+(ll'.60)x(16)x(no.  of  regenerations).  The $3,177 is
 for general inspection of the system 15 minutes/shift, 3 shifts/day,
 365 days/yr at $11.60/person-hour.   For the  purposes of these cost
 analyses,  it was assumed that each  regeneration  of the scrubber would
 require 2  people at 8 person-hours  each,  independent of scrubber size.
 System inspection was also assumed  to be  independent of scrubber size.
     b.  Sulfuric acid (50 percent  H2SOu-electrolyte grade).
Assumed:   1 55-gal  drum of 50 percent H2SO\,  i.e.,  19.4 gal ^SO^,  per
 scrubber tank.
     No. of drums required = No. of tank regenerations = (No. of scrubber
regenerations^ (No. of tanks per scrubber) =  70.87
        Cost of acid =  (no. of  drums)x(594 lb/drum)x($0.069/lb)
                                   B-4

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      c.   Caustic (50 percent NaOri-incustrial  grade).   First, the unit cost
 of NaOH  was calculated.
          NaOH required  per year = [No.  of tank regenerations]x[NaOH (Ib)
 required per tankj  = 70.87x250 = 17,718 Ib/yr
          Total  drums/yr  required by  facility  = total  NaOH  (lb)/350 Ib per
            drum;  total drums =50.6
          If total drums  >9,  cost/1b  = 0.0738
          If total drums  =  3  to 9,  cost/1b = 0.0787
          If total drums  =  <2,  cost/lb = 0.108
          Cost of  caustic = (No.  of drums)x(cost/1b)x(700 Ib/drum)
     d.   Cost of  chlorine  filters.   Each  filter can dechlorinate -200  gal
 H20  (or  1 scrubber tank);  replace at each scrubber regeneration.
     Cost =  (No. of  scrubber regenerations^ (No. of tanks)x($15/filter)
     e.  Disposal.   Unit cost  of disposal was calculated by multiplying
 the total number of  tank regenerations by the weight of a tank at the  time
 of regeneration, including rinse water  (see 3.f).
         Total wt - 70.87x4,844 Ib/tank - 343,943 Ib/yr
         If total wt <42,000 Ib, disposal cost = wt (lb)x($0.096/lb)
         If total wt >42,000 Ib, disposal cost = wt (lb)x($0.059/lb)
     f.  Compressed air.   The cost of 10 seconds of in-house air per cycle
was considered negligible and was not computed for  these cost analyses.
     12.   The capital and annualized  costs are reported in  Table  B-l.
                                  B-5

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      TABLE B-l.   CAPITAL AND ANNUALIZED COSTS OF INSTALLING SCRUBBER1
                         (4th Quarter 1984 Dollars)

       Item                                                           Cost

   I.   CAPITAL COSTSa

         Installed equipment  costs,  1984,  $

         Automated scrubber13                                        158,000
         Explosion-proof  valves for  scrubber0                        18,300
         Chlorine filter  house                                          249
         Installation of  scrubber6                                   79,000
         Installation of  chlorine filters                               120
         Taxes:  5 percent of equipment  cost                          8,850
         Freight:  5fpercent of equipment  cost                        8,850
         Vacuum pump                                                 19,700
         Manifolding of chambers (includes check valve)9              9,560
         Total capital costs, 1984,  $                               303,000

 II.  ANNUALIZED COSTS3

         Direct operating costs, 1984, $

         Laborh                                 '                      5,370
        Materials
          50 percent H2SOJ                                          2,900
          50 percent NaOhH.                                           2,620
          Chlorine filters                                           1,060
          Taxes:   5 percent of materials cost                         329
          Freight:   5 percent of materials cost                       329
        Compressed air1                                                  0
        Disposal  of ethylene glycol"1                               20,300

        Indirect  operating costs,  1984,  $

        Overhead:   0.80  x labor                                     4,300
        Property  tax,  insurance,  and administration"               12,100
        Capital recovery costs                                     49,300
        TOTAL ANNUALIZED COSTS,  1984, $                             98,600

III.   COST EFFECTIVENESS

      Reduce, Mg  EO  yr                                               63.66
      Cost effectiveness, 1984,  $/Mg EO                              1,500
                                                               (continued)
                                     8-6

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                          TABLE B-l.   (continued)
 *Costs  rounded to three significant  figures.
 °8ased  on total  volume of  two  largest  chambers.
 JjOne  set  per scrubber  at $18,300  each.
 °0ne  per  tank; six tanks;  $41.50  each.
 -Fifty  percent of scrubber cost.
 The  cost of the first vacuum  pump is  included  in  the  installation  cost of
 the  scrubber; therefore,  cost is for  remaining  four pumps at  $4,935  each.
 ySee  Table 5-4 of this report.  Manifold  four chambers  at $2,300 each plus
 $355 for a check valve for the first  chamber.
 "Labor  was calculated  for  0.25 person-hours/shift, 3 shifts/day,
 365  days/year for system  inspection and  16 person-hours for each
 regeneration of the scrubber  at $11.60/person-hour.  No. of scrubber
 regenerations = (annual EO use at facility)-*-(2,000)x(No. of tanks  in
 .scrubber).
 ^he  cost  of  acid  is calculated, (annual  EO use at facility)*(2,000)x
 .(594)x($0.069).
 JThe  cost  of  caustic is calculated, No. drum = (EO use/yr at
 facilityH2,000)x(250)*(350).  No.  drum = 50.62; therefore, unit cost =
 $0.0738.  Total cost = (No.drums)x(700)x(0.0738).
 Chlorine  filter cost is (annual EO use at fac1l1ty)x(l5)+(2,000).
 The cost  of  10  seconds of house-supplied compressed air per cycle was
 considered negligible.
 Disposal  cost is (annual EO use at facility)*(2,000)x(4,845)x(0.059).
"Calculated as 4 percent of total  capital  costs.
Calculated as (0.16275)x(total capital costs)  for an  interest  rate  of
 10 percent and a 10-year recovery period.
                                    B-7

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REFERENCES FOR APPENDIX B

1.  Chemical Engineering.  Economic Indicators.  June 23, 1986.  p. 7.

2.  Chemical Engineering.  Economic Indicators.  February 18, 1985.  p. 7.

3.  Neveril, R., Capital and Operating Costs of Selected Air Pollution
    Control Systems.  6ARD, Inc.  Niles, Illinois.  Publication
    No. EPA-450/5-80-002.  December 1978.  p. 3-11, 12, 16.

4.  Memorandum from Srebro, S.,  MRI, to Markwordt, D., EPA/CPB.  March 20,
    1987.  Capital  cost, annualized cost, and cost effectiveness of
    reducing ethylene oxide emissions  at commercial sterilization
    facilities.
                                  B-8

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                   APPENDIX C.



               CONTROL DEVICE  COSTS



(CATALYTIC OXIDATION  AND GAS/SOLID  REACTOR SYSTEM)

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               TABLE C-l.  CATALYTIC OXIDATION1
Flow rate,
m /mina (ft3/min)
1.4 (50)
3.5 (125)
14 (500)
28 (1,000)
84 (3,000)
168 (6,000)
252 (9,000)
336 (12,000)
Cost, $b c
15,000
23,000
37,000
60,000
97,000
140,000
192,000
240,000
 The catalytic oxidation units are modular.  The sizes listed
.are available currently.  Larger sizes can be designed.
 These costs are for catalytic oxidation systems capable  of
 handling sterilizer and aeration emissions simultaneously.
 Costs were not provided for a system to handle only aeration
 emissions.
 Cost includes heat exchanger (70 percent heat recovery),
 preheater, and prewiring.   Installation and ducting costs  are
 facility-specific  and were  not provided.
                            C-l

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 TABLE  C-2.  ACID-WATER SCRUBBER AND GAS/SOLID  REACTOR  SYSTEM2

 Sterilizer volume                                Cost, $a  b
<0.6 m3 (20 ft3)                             30,000 to 35,000


0.6 to 1.2 m3 (20 to 40 ft3)                 40,000 to 45,000


Two 0.8 m3 (30 ft3) sterilizers              45,000 to 50,000


One 2 m3 (72 ft3) sterilizer                 50,000 to 55,000

dThese are "budget" costs for a complete two-stage system
 (i.e., acid-water scrubber and the gas/solid reactor).  Costs
.were not provided for the gas/solid reactor separately.
"Includes installation costs, wiring, and ductwork.
                             C-2

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REFERENCES FOR APPENDIX C

1.  Telecon.  Nicholson, R., MRI,  with Olson, C., Donaldson Company,
    Inc.  May 12, 1988, and June 13, 1988.   Discussion regarding the EtO
    Abater™ catalytic oxidation system.

2.  Letter from Kruse, R., Advanced Air Technologies, Inc., to
    Nicholson, R., MRI.  June 13,  1988.  Transmitting information about
    the Safe-Cell™ two-stage system.
                                  C-3

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 t
       TECHNICAL REPORT DATA
?'.ssse reia insi*uciior.s on tne reverse oeiore co
  i REPORT NO.
   EPA-450/3-89-007
                                Z. RECIPIENT'S ACCESSION NO.
  <*. TITLE AND SUBTITLE
  Alternative Control  Technology Document
  Ethylene Oxide Sterilization/Fumigation Operations
                                5 REPORT DATE

                                !   i larch 1989
                                6. PERFORMING ORGANIZATION CODE
  7. AUTHOR(S)
                                                              8. PERFORMING ORGANIZATION REPORT MO
 9. PERFORMING ORGANIZATION NAME AND ADDRESS
  Midwest Research  Institute
  401 Harrison  Oaks Boulevard
  Gary, North Carolina  27513
                                10. PROGRAM ELEMENT NO.
                                11. CONTRACT/GRANT NO.

                                    68-02-4379
  12. SPONSORING AGENCY NAME AND ADDRESS
  U.  S.  Environmental  Protection Agency
  Emission Standards  Division
  Office of Air Quality  Planning and Standards
  Research Triangle Park.  North Carolina   27711
                                                               13. TYPE OF REPORT AND PERIOD COVERED
                                14. SPONSORING AGENCY CODE
  15. SUPPLEMENTARY NOTES
  ESD Work Assignment Managers:  David Markwordt (MD-13)  (919) 341-0837
 16. ABSTRACT
  This  document contains  the data and methodology which  EPA believes most  accurately
  describes  alternative control  technologies  for ethylene  oxide emissions  from
  steril-ization facilities.
 7.
                                 KEY WORDS AND DOCUMENT ANALYSIS
                   DESCRIPTORS
                                                b.IDENTIFIERS/OPEN ENDED TERMS  c. COSATI Held/Group
  Ethylene Oxide
  Ethylene Oxide Sterilization
  Sterilization
  Chlorofluorocarbons
  Volatile Organic Compound  (VOC)  Emissions
M3. DISTRIBUTION STATEMENT
1  Release (Jnl imited.
                 19. SECURITY CLASS iTItis Reoorti
                   Unclassified
:i. NO. OF PAGES
  00
                                                ;0. SECURI Tv CLASS i This
                                                    Unclassified
                                             :2. PRICE
 EPA Form 2220-1 (Rev. 4-77)   Devious EDI TION i s OBSOLETE

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U S. Environmental Protection Agency
Region 5, Library (PL-12J)
77 West Jackson Boulevard, 12th Floor
Chicago,  IL  60604-3590

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