EPA-450/2-75-009 b
              STANDARD SUPPORT

                     AND

       ENVIRONMENTAL IMPACT STATEMENT

           VOLUME 2:  PROMULGATED ,

              EMISSION STANDARD

                     FOR

               VINYL CHLORIDE
 Emission Standards and Engineering Division
    U. S. Environmental Protection Agency
     Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
               September 1976

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This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers.  Copies are
available free of charge to Federal employees, current contractors and
grantees  and nonprofit organizations - in limited quantities - from the
Library Services Office (MD-35) , Research Triangle Park, North Carolina
llll-L °T B    f   '   m the National Technical Information Service,
5285 Port Royal Road, Springfield, Virginia 22161.
                 Publication No. EPA-450/2-75-009b

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  Final Standard Support and Environmental Impact Statement

     Vinyl Chloride Emissions from Ethylene Dichloride-

        Vinyl Chloride and Polyvinyl Chloride Plants

               Type of Action:  Administrative
                         Prepared by
Director, Emission Standards and Engineering Division
Environmental Protection Agency
Research Triangle Park, N. C.  27711
(Date)
                         Approved by
(Date)
Assistant Administrator for Air
and Waste Management
Environmental Protection Agency
401 M Street, S. W.
Washington, D. C.
Final Statement Submitted to Council on Environmental Quality

                              on

                      _October 1976

                           (Date)
Additional copies may be obtained at:

Public Information Center (PM-215)
Environmental Protection Agency
Washington, D. C.  20460
                                 m

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                          Table of Contents
                                                                  Page
Chapter 1.  Summary of the Environmental Impact of the
            Emission Standard for Vinyl  Chloride                  1-1
Chapter 2.  Summary of Public Hearing and Comments .  .            2
            2.1   List of Commentators. .                          2-1
            2.2   Rationale for Regulating Vinyl  Chloride
                 Under the Authority  of  Section  112 of
                 the Clean Air Act  ......                     2-5
                 2.2.1   Decision  to List  Vinyl Chloride as
                        a  Hazardous Air  Pollutant   m               2-5
                 2.2.2   Approach  for  Regulating Vinyl
                        Chloride  Under Section 112                 2-17
           2.3  Selection of Source  Categories .....           2-28
                2.3.1   §61.60  ............             2-28
           2.4  Emission Limits
                                  ............. • •  •    2-33
                2'4'1  ^M2!a)'  61-63(a)> and 61.64(a)(l),      9 „
                       (b), (c)9  and  (d)  .......         ,   ^~66
                2.4.2  §61.62(b)
                                    ...........  ...   2-36
                2.4.3  §61.64(a)(2)
                                    ..............   2-37
                2.4.4  §61.64(e) ............  ^         2^38
                2.4.5  §61.65(a) ...........             2_47
                2.4.6  §61.65(b)(l) ....  .......         2-50
                2.4.7   §61.65(b)(3) ...........         2_52
                2.4.8   §61.65(b)(4) ...  ........         2-54
               2.4.9   §61.65(b)(5) ...
                                           ....... ...   £-00
               2.4.10  §61.65(b)(6).  . ............   2_58
               2.4.11  §61.65(b)(7)                            .

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                                                          Page


     2.4.12   §61.65(b)(8) "•"•'.  •  •  •  • .	  2-61

      2.4.13   §61.65(b)(9)  	  .........  2-64

      2.4.14   §61.66	2-6C


2.5   Testing, Reporting, Recordkeeping  	   2-67

      2.5.1  §61.67	   2-67

      2.5.2  §61.68	   2-70

      2.5.3  §61.69	   2-71

2.6   Test Methods	   2-73

2.7   Economic Impacts	   2-82

2.8   Environmental Impacts  	   2-94

2.9   Process and Control Technology (Chapters
      3 and 4 of Volume I of the Standard
      Support and Environmental Impact
      Statement) ........... 	   2-'01

2.10  Comments on Quantitative Risk Assessment
      for Community Exposure to Vinyl
      Chloride	   2-107

2.11  Miscellaneous	   2-112

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         CHAPTER I.  SUMMARY OF THE ENVIRONMENTAL IMPACT
           OF THE EMISSION STANDARD FOR VINYL CHLORIDE
Background:  On December 24, 1975, the Environmental Protection Agency
(EPA) proposed a national emission standard for vinyl chloride under
the authority of section 112 of the Clean Air Act.  At that time, EPA
requested public comments on the proposal.  Fifty comment letters were
received from environmental groups, industry, State and local air
pollution control agencies, and individual citizens.  On February 3, 1976,
EPA held a public hearing on the proposed standard in Washington, D. C.
Both the written comments and the comments made at the public hearing as
well as EPA's responses to these comments are summarized in this document.
The summary of comments and responses serves as the basis for revisions
which have been made to the standard between proposal and promulgation.
     EPA decided to regulate vinyl chloride because it has been implicated
as the causal agent of angiosarcoma and other serious disorders, both
carcinogenic and noncarcinogenic, in people with occupational exposure
and in animals with experimental exposure to vinyl chloride.  Reasonable
extrapolations from these findings cause concern that vinyl chloride may
cause or contribute to the same or similar disorders at present ambient
air levels.  The purpose of the standard is to minimize vinyl chloride
emissions from all known process and fugitive emission sources in
ethylene dichloride-vinyl chloride and polyvinyl chloride plants to the
level attainable with best available control technology.  This will have
the effect of furthering the protection of public health by minimizing
the health risks to the people living in the vicinity of these plants
and to any additional people who are exposed as a result of new construction.
                                 1-1

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  Alternatives  to the Proposed Action:   The  alternatives  to the  proposed
  action  are discussed in  detail  in  Chapter  5  of Volume  I  of the
  Standard  Support and Environmental  Impact  Statement  (SSEIS,  Vol.  I.).
  These alternatives  concern  the  quantity of energy  required to  incinerate
  the emissions from  the oxychlorination process  in  ethylene dichloride-
  vinyl chloride  plants and the degree to which  EPA  should  require
  developing  technology for controlling emissions from the  processing of
  dispersion  resins in polyvinyl  chloride plants.  These alternatives
  remain unchanged since the standard was proposed.
  Environmental  jmgact of the Standard:  Changes in  the standard since
 proposal do not affect the level of control required.  Therefore, the
 environmental  impacts for the promulgated standard and alternative •
 control  levels are essentially the  same as  described  for the proposed
 standard in Chapters 1  and 6 of the SSEIS,  Vol. I.  There is one exception.
 Based  on data  submitted by the Society  of  Plastics  Industry, Inc.  (SPI),
 the impact on  water  consumption  (SSEIS,  Vol.  1) was overstated.   In-
 estimating the impact on  water consumption, EPA based its  -estimates on
 worst case conditions.  That  is, EPA assumed  that those control  systems
 with the greatest water usage would  be employed and that  there would be
 no recycling of water.  There  is no  regulation  which would require water
 recycling.   According to SPI, the control system utilizing  the most
water will not be used generally by  the industry and economics will
cause plants to recycle much of  the water.   Therefore, the  impact of the
standard on water consumption will  be negligible.  A more detailed

                               1-2

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discussion of the water consumption impact can be found in the first
comment in Section 2.8 of Chapter 2 of this document.
     A summary of the environmental impact of the promulgated standard
is as follows:
     The primary environmental impacts of the standard are beneficial
and will consist of reductions in vinyl chloride emissions from
ethylene dichloride-vinyl chloride and polyvinyl chloride plants,
and consequently, corresponding reductions in ambient air concentrations
of vinyl chloride and risks to health in the vicinity of these sources.
Although the standard will not eliminate all vinyl chloride emissions,
it will further the protection of public health by minimizing emissions.
For a typical average-sized ethylene dichloride-vinyl chloride plant,
the standard will reduce hourly vinyl chloride emissions from 176 kg to
10 kg.  This is approximately a 94 percent reduction.  For a typical
average-sized polyvinyl  chloride plant, the hourly vinyl chloride
emissions will be reduced from 330 kg to 16 kg, or by approximately
95 percent.  Percentage  numbers for both source categories are based
on an estimated 90  percent reduction  in fugitive  emissions and 1974
emission  levels.
     There  are several potential secondary environmental  impacts
of the  standard.  These  include increased  atmospheric emissions  of
hydrogen  chloride,  lowered pH of inprocess wastewater due  to hydrogen
chloride,  small  increases in  the quantity  of  vinyl chloride  released
into  inprocess wastewater, increased  solid waste  disposal  due  to
carbon  used for  adsorption, and increased  energy  consumption.  The
types  and degree  of the  secondary  impacts  resulting  from the standard
                                1-3

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 will vary from plant to plant depending on the type of control
 selected to meet the standard.
      The potential secondary environmental impacts of the standard
 are either insignificant or will be minimized without additional
 action, except for one adverse impact.  Hydrogen chloride is already
 emitted by process equipment at ethylene dichloride-vinyl chloride
 plants and by other petrochemical, plants in the complexes where
 ethylene dichloride-vinyl  chloride plants  are typically located.  An   '
 incinerator used to attain the standard at an ethylene dichloride-vinyl
 chloride plant could increase hydrogen chloride emissions by several fold.
 Typically,  however, due to the corrosion problems which would otherwise
 occur both  on plant property and in the community, plants use scrubbers •
 to control  already  existing hydrogen chloride emissions.   Hydrogen
 chloride emissions  resulting from control  of  vinyl  chloride  emissions
 are expected  to  also  be controlled  for the same reason.   If  even a
 moderately efficient  scrubber (98 percent  control)  were  used to  control
 the hydrogen  chloride emissions  resulting  from incineration  of vinyl
 chloride  emissions, the increase  in  hydrogen  chloride  emissions  from a
 typical  ethylene dichloride-vinyl chloride plant  due to  the  standard
would be  reduced to 35  percent.   However,  EPA  plans to further evaluate
 the  need  to control hydrogen  chloride emissions,  since diffusion model
results indicate that under  "worst-case" meteorological conditions, the
hydrogen chloride emissions from  the process equipment and the incinerator
combined would cause maximum ambient concentrations of hydrogen chloride
in the vicinity of ethylene dichloride-vinyl chloride plants to be in
the same range or somewhat higher than existing foreign standards and
National Academy of Sciences (NAS) guidelines  for public exposure.
                                 1-4

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Economic Impact of the Standard:  In accordance with Executive Order
11821 and OMB Circular A-107, EPA carefully evaluated the economic and
inflationary impact of the proposed standard and alternative control
levels.  The economic analysis is contained in Chapter 7 of the SSEIS,
Vol. I.  Since changes in:the standard since proposal do not affect the
level of control required,  the economic impacts of the promulgated
standard and alternative control levels are essentially the same as
described for the proposed standard.  There is one exception.  EPA
estimated that there would be four plant closures as a result of the
promulgated standard.  Of the four plants identified as possible
closure candidates, one (Occidental Petroleum Corporation's polyvinyl
chloride plant in Hicksville, N. Y.) has given notice that it no longer
produces polyvinyl chloride, and the other three (Jennat Corporation's
plants in Somerset, N. J., Torrence, Calif., and Tucker, Ga.) have
indicated that they do riot intend to close as a result of the standard.
     A summary of the economic impact of the promulgated standard is
as follows:
     The total capital cost for existing plants to meet the standard
is estimated to be $198 million, of which $15 million is for ethylene
dichloride-vinyl chloride plants and $183 million is for polyvinyl
chloride plants,.  EPA estimates that these plants will have to spend
$70 million per year to maintain the required emission levels.  In
addition, total capital cost for existing plants to meet the EPA's  1983 water
effluent guideline limitations is $83 million and the total annualized
operating cost is $17 million.  The costs to the industry of meeting
                              1-5

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  the OSHA standard cannot be quantified at this time, but they are
  expected to overlap to some degree with the costs to meet EPA's
  fugitive emission regulations.  The costs of meeting the fugitive
  emission regulations are included in the total costs cited
  above for meeting the promulgated regulation.   Broken out separately,
  the capital  cost of meeting the fugitive emission regulations  is
  $37 million  and the  annualized cost is  $25  million.
       The  promulgated standard  is  not expected  to  deter construction
  of  new ethylene dichloride-vinyl  chloride plants  or  most  types  of
  new polyvinyl chloride plants.  For one  type of polyvinyl  chloride
  plant (dispersion process) that represents  13  percent  of  the industry
  production, the standard would significantly deter the construction
 of smaller plants.
      It is estimated that the price of polyvinyl chloride resins
 would rise by approximately 7.3 percent in order to maintain
 precontrol profitability and also to recover the total annualized
 control  costs necessitated by the  standard at ethylene dichloride-
 vinyl chloride plants and polyvinyl  chloride plants.   This increase
 is estimated  to  translate into  a maximum consumer  price increase in
 goods fabricated from polyvinyl  chloride  resins of approximately
 3.5  percent.  Recovery of effluent annualized costs plus maintenance
 of precontrol profitability is estimated  to  add approximately 2
 percent to polyvinyl  chloride resin  prices and  result  in an additional
maximum consumer price increase of 1 percent.
                                  1-6

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Relationship -Between Local Short-Term Uses of Man's Environment
and the Maintenance and Enforcement of_ Long-Term Producti on:   By
taking steps now to establish standards based on best available
control technology to minimize vinyl chloride emissions, EPA will be
able to minimize exposure and prevent severe illnesses and deaths
which may have occurred in future years as a result of prolonged
community exposure to vinyl chloride.  Therefore, the standard
may curtail industrial  expansion on a short-term basis, as a
result of funds being diverted from support of industrial expansion
to support of installation of process changes and control systems to
attain the standard; but it will enhance the long-term productivity
of man and his environment.
Irreversible and Irretrievable Commitments of Resources:  Irreversible
and irretrievable resources which would be committed to reduce ambient
concentrations of vinyl chloride include energy and the materials
to construct incinerators, boilers, monitoring equipment, carbon
adsorption units, etc.   If incineration were used to meet the
standard, additional energy and materials would be needed for
operation of an absorption unit to abate hydrogen chloride emissions.
                                 1-7

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                            CHAPTER 2
             SUMMARY  OF  PUBLIC  HEARING  AND  COMMENTS
     2.1  List  of Commentators

Comment No.

     VC-1


     VC-2


     VC-3


     VC-4


     VC-5


     VC-6



     VC-7


     VC-8


     VC-9



   1  VC-10


     vc-n


     VC-12



     VC-13


     VC-14
          Commentators

Robert A. Fine
Hooker Chemical Corporation

Constance Panchuk
PARKLABREA

Mr. and Mrs. F. B. Minnock
(U. S. Resident)

Marilyn E. Sadowski
(U. S. Resident)

Dr. Martin Wersba
(U. S. Resident)

Dr. John F. Finklea
National Institute for Occupational
  Safety and Health

Susan Howard
(U. S. Resident)

Gayle and Herb Weaver
(U. S. Resident)

Dr. Peter F. Infante
National Institute for Occupational
  Safety and Health

June Armstrong
(U. S. Resident)

Robert H.  Collom, Jr.
Department of Natural Resources (Georgia)

Harry H. Hovey, Jr.
N. Y.  State Department of Environmental
  Conservation

R. W.  Laundrie
The General  Tire and Rubber Co.

R. E.  Hiding
PPG Industries, Inc.
                                2-1

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Comment No.

    VC-15


    VC-16


    VC-17


    VC-18


    VC-19


    VC-20


    VC-21


    VC-22


   VC-23


   VC-24


   VC-25


   VC-26


   VC-27


   VC-28


   VC-29


   VC-30
        Commentators

 Allan J. Topol
 Covington & Burling  (for Tenneco Chem.)

 Ed Light
 West Virginia - Citizen Action Group

 F. V. Prus
 The Goodyear Tire and Rubber Co.

 David A. Kuhn
 Continental Oil Co.

 Flynt Kennedy
 Continental Oil Co.

 Lee E.  Jager
 Department of Natural Resources (Michigan)

 W.  W. Madden
 Firestone Plastics Co.

 W.  C. Holbrook
 B.  F. Goodrich Chemical  Co.

 Barry I.  Castleman
 Environmental  Defense Fund

 Harvey A. Rosenzweig
 Borden,  Inc.

 R.. N. Wheeler, Jr.
 Union Carbide  Corporation

 J. M. DeVoe
 Allied Chemical

 R. E. Van Ingen
 Shell Chemical Co.

 Gary L.  Ford
Stauffer Chemical Co.

Ralph L.  Harding, Jr.
The Society of the Plastics Industry, Inc.

Earl R.  Smith
Dow Chemical U.S.A.
                                  2-2

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Comment No.
       Commentators
    VC-31


    VC-32


    VC-33



    VC-34


    VC-35


    VC-36


    VC-37


    VC-38


    VC-39


    VC-40

    VC-41


    VC-42


    VC-43


    VC-23a


    VC-44
Robert W. Hill
Diamond Shamrock Corporation

Richard Fleming
Air Products and Chemicals, Inc.

R. A. Abramowitz
R. A. Fine
Hooker Chemical Corporation

Mitchell R. Zavon, M.D.
Ethyl Corporation

John C. White
EPA - Region VI

Jack Jaglom
The Pantasote Company of New York, Inc.

Professor Benjamin Linsky
West Virginia University

Sidney M. Wolfe, M.D.
Health Research Group

Kip Hewlett                        ,
Georgia-Pacific Corporation

Keysor-Century Corporation

John M. Daniel, Jr.
State Air Pollution Control Board (Virginia)

Charles R. Barden, P.E.
Texas Air Control Board

Dr. Thomas A. Robinson
Vulcan Materials Co.

Barry I. Castleman
Environmental Defense Fund

George P. Ferreri
Bureau of Air Quality and Noise Control
(Maryland)
                                  2-3

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 Comment  No.

     VC-45


     VC-46


     VC-47


     VC-48



    VC-49


    VC-50
         Commentators

James  F. Coerver
Louisiana Air  Control  Commission

Sidney R. Galler
U.S. Department of Commerce

James  C. Miller.Ill
Council on Wage and Prfce Stability

Stephen C. Urman
Occupational Safety and Health
  Administration

Stanley D. Doremus
U.S. Department of the Interior

Edward F.  Ferrand
Environmental Protection Administratiop (N.Y.)
      Chapter 2 contains  a summary of the public comments  on  the
 proposed standard and EPA's  responses to them.   The comments  are
 divided into sections.   The  first section discusses the rationale
 for regulating vinyl  chloride  under the  authority  of section  112
 of the  Clean Air  Act;  i.e. EPA's  decision to  list  vinyl chloride
 as a hazardous air pollutant and  the approach used for regulating
 vinyl chloride under  section 112.   The next three  sections discuss
 the selection of  source  categories,  the  emission limits,  and
 testing,  reporting, and  recordkeeping requirements.   The  comments
 in these  three sections  are  organized to  correspond with  the
 different^section  numbers  in the  proposed  standard.   The  remaining
 sections  include comments  on the  test methods,  economic and environ-
 mental  impacts, process  and  control  technology, and  the Quantitative
gjsk Assessment for Community  Exposure to  Vinyl Chloride.   Comments
 "  ... Scient'lf'lc a"d Technical Assessment Report  for Vinvl Chloride
    £2imnyl  Chloride are included  in section  2.27Ton~EPA's decision
    ist vinyl  chloride as a hazardous air pollutant
                                  2-4

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     2.2  Rationale for Regulating Vinyl Chloride Under the Authority
of Section 112 of the Clean Air Act.

     2.2.1. Decision to List Vinyl Chloride as a Hazardous Air Pollutant.

     (Except for commentators VC-32, VC-23, and VC-46, the comments
contained in this section generally did not contest EPA's decision to
list vinyl chloride as a hazardous air pollutant.  However, they did
argue that EPA has placed great and sometimes unwarranted emphasis on
factors suggesting the possibility of a health risk while "playing down"
or not even mentioning factors which suggest that there may be no
significant risk at all.  Examples cited by the commentators are listed
below).

     1.  VC-22, VC-27, VC-29, VC-32

Comment:  The U. S. worker EPA discussed as having been exposed
to vinyl chloride levels lower than those usually encountered in
polyvinyl chloride production has been dropped from the National Institute
of Occupational Safety and Health's listing of workers with angiosarcoma.

Response:  Table 6.18, page 73, of the Scientific and Technical Assessment
Report (STAR) includes the data which were available at the time of
publication, documented by the Center for Disease Control.  Dr. John T. Herbert,
Center for Disease Control,, was contacted by telephone on March 29, 1976.
Dr. Herbert, on that date, stated that the information in Table 6.18,
including the footnotes was still correct.  He also stated that four
additional cases from Canada had been added to the list.  There are
questions concerning the level of exposure of those cases not involved
directly in polyvinyl chloride and vinyl chloride production, and in
some cases the pathology.  These uncertainties are stated in the appropriate
footnotes to table 6.18.  However, in spite of these uncertainties, in
view of the possible exposure patterns, these cases cannot be ignored in
the evaluation of the potential public health problems.

     2.  VC-22, VC-29, VC-27, VC-32, VC-46

Comment:  EPA has not summarized the results from the more extensive
ambient monitoring program but stated that the results from the more
extensive ambient monitoring program are generally in the same range
as found in previous studies except for peak concentrations.  The more
recent data actually show significantly lower ambient concentrations
of vinyl chloride than previously measured.

Response:  A report entitled "EPA Programs of Monitoring Vinyl Chloride
in Ambient Air" summarizing the data from the more extensive monitoring
program was made available by EPA.  A detailed analysis comparing the
results from the two monitoring programs has not been performed by EPA.
The sampling procedures, placement of samplers, extent of sampling, and
quality of analysis were not the same in the two programs.  Only one of
the plants monitored in the second program was also monitored in the
first program.

                                   2-5

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       3.   VC-22,  VC-29
  Comment:   EPA has  stated that "Occupational  exposure  studies have
  strongly  implicated vinyl  chloride  as  a  human  chemical  carcinogen  ...".
  It should be noted that these studies  were  conducted  at relatively high
  levels compared to ambient concentrations now  being detected.

  Response:  _It is still  true,  however,  that  occupational  exposure studies
  do indeed implicate vinyl  chloride  as  a  human  carcinogen which manifests
  itself in  liver angiosarcoma, and suggest that it may also manifest
  itself in  multiple tumor sites.  Because of the rarity  of angiosarcoma,  .
  the cause-effect relationship has been clearly demonstrated.  Vinyl chloride
  is one of the few  industrial  carcinogens for which confirmatory animal
  studies have been  positive.

       4.   VC-22,  VC-27,  VC-29,  VC-32, VC-36

  Comment:   The preamble  and  Volume I of the  Standard Support and
  Environmental  Impact Statement  (SSEIS, Vol.  I) refers to "some occasional
  PeaFconcentrations  as  high as  33 ppm."  The STAR document correctly
  states  that  there  was one  instantaneous  value  of 33 ppm which was
  f SaTd f  a d1Sta^C5  ?f  °'5  km from the center of thPe plant and
  saS, V?irf?rJX fShedJ. P,PnU  The data  from the 24-hour integrated
  1974 study/'             9     ValUe t0 be °'55 ppm for the N°vember

 Response^ Jhere was only one peak value of  33 ppm and it occurred


      5.  VC-22

 Comment:  EPA states that approximately 4.6  million  people  live within
 a 5-mi lie radius of  ethylene di chloride/vinyl chloride  and polyvinyl
 hll2r«JnISn!! !CtU""?  Cities.   The implication  that these people  are
 being exposed to vinyl  chloride is questionable.   The  basis  for using  a
 5-mile radius is questionable  since  EPA has  done no  sampling  beyond a
 rnl le-Ia  rUS-  Accord,!n9 to the "Quantitative  Risk  Assessment for
 Community  Exposure  to Vinyl  Chloride,"  approximately 1.7 million
 people live within  a 3-mile radius of such plants.

 Response:   Dispersion model  calculations  indicate that vinyl  chloride
 hSSS  £atTS-?f 91ater than  ] part Per b1111on  (PPb)  can be found
 beyond  the  5-mile radius.   The  five miles was chosen as  a practical
 matter  since  population  estimates were available for that distance.
 The average concentration calculated depends  only slightly on radius.

     6.  VC-22, VC-32, VC-46
                          t0 the Pr°P°sed standard and in Chapters 1 and
                           1S Stated that "^asonable extrapolations
™Hh                   C°"C?rn that Vlnyl chlon'de may cause, or may
contribute to, the same or similar disorders ...". There is no reference
nor6?* ?npr???rtH^e^lain/5a^ suct! reasonable extrapolations were, .
nor is specific data presented to substantiate such concern.
                                 2-6

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Response:  Section 112 of the Clean Air Act defines the term "hazardous
air pollutant" as "an air pollutant to which no ambient air quality
standard is applicable and which in the judgment of the Administrator
may cause, or contribute to, an increase in mortality or an increase
in serious irreversible, or incapacitating reversible, illness."
The sentence in question refers to the factors the Administrator considered
in his judgment that vinyl chloride should be listed as a hazardous air
pollutant.  These factors include:

     (1)  Data from occupational exposure studies indicate that
vinyl chloride is a carcinogen, and possibly a mutagen and teratogen.

     (2)  Data from animal exposure studies demonstrate that vinyl
chloride is a carcinogen and a teratogen.

     (3)  Data from microbial systems indicate that vinyl chloride
is a mutagen.

     (4)  Vinyl chloride has been measured in communities surrounding
ethylene dichloride-vinyl chloride and polyvinyl chloride plants.

     (5)  The threshold for effects has not been demonstrated.  In
absence of proof to the contrary, EPA believes that it is prudent to
assume that there is no no-effect level.

     (6)  There is an expected latency period of 20 years or more from
the time of community exposure to vinyl chloride and the appearance of
effects.

     7.  VC-17, VC-22, VC-27, VC-29, VC-32, VC-46.  Public Hearing Record-
Presentation of P. J. Gehring of Dow Chemical, p. 87.

Comment:  EPA has implied that vinyl chloride is "an apparent non-threshold
pollutant."  Laboratory data on metabolism has been developed under
Manufacturing Chemists Association administered research study.  The
data indicate that there are at least two different metabolic routes for
destroying vinyl chloride, and therefore, raise questions as to the
validity of the EPA stated assumption.

Response:  The results of the recent studies by Dr. P. J. Gehring are
indeed significant; however, they are not sufficient to resolve the
issue of a biological threshold, or to establish such a value.  Dr. Gehring's
studies reflect a short-term response to relatively high levels of
exposure (one hour of 50-1,000 ppm).  Studies by Dr. Selikoff on industrial
workers exposed to vinyl chloride for more than five years reveal that
the substance bioaccumulates, and is not excreted or otherwise metabolized
after five weeks of non-exposure.  Thus, one short-term response to high-
level exposure is irrelevant in terms of long-range responses to chronic
low-level exposure.
                                 2-7

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       8.  VC-27
  Comment:   Human cases  of cancer alleged  to  be  associated with  vinyl
  A^^^r^n" S!e U1ted States  are 1im1ted  to  only  foL
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Response:  The statement from the Quantitative Risk Assessment for
Community Exposure to Vinyl Chloride is taken out of context.  The
following is an extract from the subject document:

     "This survey has produced no evidence that living around vinyl
chloride plants is a factor in the occurrence of liver angiosarcoma.
This conclusion is far different than saying that living around plants
is not a risk factor for several reasons:  (1) This type of survey
of a disease with a latent time from first exposure to diagnosis of
17 years reflects exposures that started at some time before 1957, when
the quantities of vinyl chloride produced were much smaller than the
current production levels.  (2)  This survey did not include the
place of occupation of the currently suspected collection of liver
angiosarcoma cases.  Therefore, it underestimates the risk of being near a
vinyl chloride plant.  (3)  This survey might not have detected all
existing liver angiosarcoma cases, although the number we have is
consistent with the national statistics.  The circumstantial evidence for
this is that there was not substantial overlay between the three sources
of case information.  If the data sources had been complete, the
information collected by CDC from the National Center for Health
Statistics would contain all the cases reported by both the Armed Forces
Institute of Pathology arid the state health department.  (4)  In over
90 percent of the cases traced in this survey, the only information
available was the residence at the time of death and in some cases, the
residence of the spouse or parent only.  This information is only a
crude indication of where the individuals spent most of their lives.
(5)  In contrast with our expectation when the survey was started, there
is a significant rate of changes in diagnosis after the slides are
confirmed by the National Cancer Institute.  The 286 cases currently
on file cannot be regarded as definitely established liver angiosarcoma.

     11.  VC-22, VC-32

Comment:  Chapter 6 of the STAR document includes an extensive
bibliography on vinyl chloride monomer toxicology and epidemiology.
There are at least three additional scientific documents which have
become available that are pertinent and should be made a part of the
EPA hearings docket.

     (a)  "Report on Mortality Data Collected by Organization
Resources Councilors, Inc., Concerning the Effects of Vinyl Chloride
Exposure in PVC Fabrication."  (Available from ONC, 1625 I Street, N. W.,
Washington, D. C.  20006).

     (b)  "Metabolic Studies in Vinyl Chloride as a Function of Concentration"
by Dow Chemical Company under Manufacturing Chemists Association administered
research study.  (Available from MCA, 1835 Connecticut Avenue, N. W.,
Washington, D. C.  20009).
                                   2-9

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       (3)   "Inhalation Toxicity of Vinyl  Chloride"  by Industrial  Bio-
  Test Laboratories,  Inc.,  under Manufacturing  Chemists  Association  administered
  research  study.   (Available  from MCA,  1825  Connecticut Avenue, N.  W ,
  Washington,  D.  C.   20009).

  Response:   It  is  stated in the Preface of the STAR-document  that
  information  available through  June  1,  1975, was  generally  considered,
  and  further  that  references  cited did  not constitute a  complete
  bibliography.   The  more recent references cited  by the  commentator are
  pertinent, and  are  incorporated  into the bibliography  by referencina
  them in this document.

       12.  VC-46

  Comment:  There are speculative  statements made  by  EPA which should be
  qualified as such.  EPA stated that the "latency period can possibly be
  longer for lower levels of exposure."  Also that "EPA will  be able to
  reduce substantially  the risks, that severe illnesses and deaths will
 occur in the future as a result of the present and prolonged community
 exposure to vinyl  chloride."

 Response:   In the  first sentence, the words "can possibly"  qualify the
 sentence so that a reader would not think that there is proof that the
 latency period would be longer for lower levels of exposure.   The second
 sentence states that the EPA  regulation would decrease risk of severe
 illness and not necessarily the severe  illness.

      13.   VC-46

 Comment:   The terms  "non-threshold pollutant"  and "apparent non-
 threshold  pollutant" are not  proper  and are  inappropriately applied to
 vinyl chloride.

 Response:   The  paragraph referred to explains  that  data are available
 which make  it clear  that vinyl  chloride is hazardous within the definition
 of  section  112  at  higher levels of exposure.   However,  since  there  are
 no  dose-response data  on health effects of vinyl  chloride at  lower
 levels  of exposure (below  50  ppm), a  threshold level  of effects cannot be
 defined for exposure levels of  vinyl  chloride  found in  the  ambient  air.
 There is no conclusive evidence that  there is  a threshold concentration
 of  vinyl chloride below which cancer  does not  occur.  Therefore as  a
 matter of prudence,  EPA assumes  that  some risk exists for any level
 of  vinyl chloride exposure, and  proposes to reduce  this  risk with the
 current regulation.

      14.  VC-21, VC-26, VC-27,  VC-29, VC-32, VC-34

 Comment:  EPA has not  taken sufficient  cognizance of either the cost of
 or the improvements from, efforts made  to comply with the Occupational
Safety and Health (OSHA) standard.  A principle reason these effects are
 uncertain  is that the Agency has made no effort to measure them.  Some
                              2-10

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of the efforts are complimentary, others are totally separate, and the
costs are not altogether overlapping.  Ventilation contributes only an
insignificant reduction in the vinyl chloride levels in the work place
and, therefore, any concern that the emissions found in 1974 would
continue are completely unfounded.  Any justification as to the need for
an emission reduction should be based on those emissions found after
completion of all projects designed to comply with the OSHA regulation.

Response:  EPA stated in the preamble to the proposed standard
t'hat the OSHA standard is expected to "indirectly reduce atmospheric
emissions to some degree, but that the degree is unknown.  In the
SSEIS, Vol. I, the reason that the degree is unknown is explained.  The
OSHA standard requires that employee exposure be reduced to 1 ppm.  It
does not prescribe the means for doing this.  It does require that
employers institute feasible controls to the fullest extent possible and
to continue to improve and apply engineering controls until full compliance
is achieved.  Some of the engineering controls used to meet the OSHA
standard can also be used to meet EPA's standard.  Since a plant owner
knows both what OSHA and EPA expect he can plan so that he can use some
of the same controls to meet both standards.  OSHA did not prescribe any
deadlines for compliance through engineering controls.  The plants are
expected to use some combination of respiratory protection, ventilation
techniques, and emission reduction.  The plants are not expected to be
uniform in what they use.  OSHA does not require submittal of a formal
plan describing what the plants plan to use.  Therefore, in order to
find out how much emission reduction the OSHA standard is achieving, EPA
would have to send to each plant a request for information on the
controls they are using, the controls they plan to use, and how much
these controls will reduce emissions.  This does not seem to be necessary,
since it is not likely to change EPA's standard.  If the plants are
using engineering controls rather than ventilation and respiratory
protection to meet the OSHA standard, this is achieving both OSHA and
EPA goals.  On plant visits EPA has observed that engineering controls
have been employed to a large extent, but that ventilation practices are
still employed to some extent.  An example would be open-sided buildings.

     With regard to cost, EPA has always been interested in
obtaining figures on the cost of the OSHA standard.  During the
February 3, 1976, public hearing Susan Wyatt of EPA asked Ralph Harding  .
of the Society of Plastics Industry  (SPI) how much of the cost to meet
EPA's standard can also be attributed to meeting the OSHA standard.
(Public Hearing Transcript, p.69).  Mr Harding replied that he did not
know and that it is a premature number at this time.  He continued by
saying that he thought they were interrelated, but that he didn't think
the industry was ready to ascribe  "which costs to which standard."  In
order to get information on the costs of the OSHA standard, EPA would
have to request each plant to submit cost figures for both present and
future controls.  The benefits from  this exercise are not apparent.

                                   2-11

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       15.  VC-21, VC-32, VC-34

  Comment:  Ventilation used to meet the OSHA standard dilutes  emissions
  and decreases ambient concentrations.

  Response:   Ventilation can reduce ambient concentrations,  although
  not necessarily.   An example would be  an  open-sided  building    EPA
  considers^technology for reducing emissions  as  a  more  reliable  method
  for reducing ambient concentrations.

       16.   VC-27,  VC-29,  VC-32,  VC-34

       The emission  levels  reported in the  supporting  documents are
  overstated.   Fugitive  emissions in  particular are overstated
  because  they are based on  a  materials  balance and because  poly-
  vinyl chloride solids  were incorrectly included in the fugitive
  vinyl chloride losses.  The  fugitive emissions reported for 1974
  have  been substantially reduced since  that time because of the
  OSHA  standard.  Stack  emissions have also been reduced since 1974
  These overstated emission levels were  used in diffusion calculations,
  and so the maximum ambient concentrations reported by the diffusion
 model are also overstated.

      Furthermore, the maximum ambient  concentrations  do not
 present a realistic picture of what is occurring around the
 plants.   Worst conditions are assumed in the modeling.   The maxima
 occur within 80 to 220 meters of the model plants  which is  still
 well within the plant limits for all but the smallest plants.

 Response:  All emission levels reported in the preamble and supporting
 documents are based on 1974 data.   This qualification is  stated  in
 all  places  where  emission data are presented.  EPA recognizes  that
 emissions have been reduced since  that time,  and has  so stated in
 the  preamble to the proposed standard.   EPA has  decided not to gather
 more recent data  on emission  levels, because  these emission levels
 are  expected to continue  to change,  and gathering  the data  would take
 considerable time  both  on  the part of  EPA  and on the  part of industry.
 Since  the purpose  of the  standard  is to minimize emissions,  these
 more current data would not affect the  standard  itself.   In  other words,
 |PA_s  purpose is  to  apply  best control  technology, not  to reduce
 fugitive  emissions  by 90 percent.  More current data  on emission levels
 would  reduce  the relative  impact of  the standard on the ambient  air
 concentrations which  are presented in the  chapter  on  environmental
 impacts.  All  diffusion modeling data contained in the environmental
 impact chapter are qualified  by stating that  they  are based on 1974 data.

   t  EPA did  include  polyvinyl chloride solid losses  in the fugitive
 emission estimates.   This was  based  on  a discussion with plant
 engineers from one company who described unaccounted for polyvinyl
 chloride losses as "very, very small."  The fugitive emission estimates
 include only  unaccounted for polyvinyl  chloride losses.   In EPA's
judgment polyvinyl chloride solid losses are more easily accounted
                                   2-12

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for than vinyl chloride gaseous losses.   Polyvinyl chloride collected
in baghouses or cyclones can be weighed.  The efficiencies of these
collection devices are known, so the loss from them can be calculated.
Polyvinyl chloride discharged into wastewater settles out and can be
weighed.  This is not true for vinyl chloride gas.  If it were assumed
that 50 percent of the emissions were solid as was suggested by the
commentator, a typical 68 million kilogram per year plant would lose
nearly 2000 kg of polyvinyl chloride per day.  Because polyvinyl chloride
losses are more easily accounted for, they are considered to be lower
than this.  Thus, EPA assumed that all unaccounted for losses were vinyl
chloride monomer.

     With regard to diffusion modeling, it seems reasonable to
estimate the worst atmospheric concentrations that are to be
expected.  It should be emphasized that these estimates were
based on worst, but realistic conditions.  Eighty to 220 meters
from the center of the plant would in many cases be on plant
property.  At one plant that was monitored, a sampler was located
across the street from a plant and was about 200 meters from the primary
emission point.  In EPA's modeling, all emissions were assumed to
occur from the center of the plant property.  In fact, emission
sources, particularly at polyvinyl chloride plants are located
more diffusely on the plant property.  Fugitive emission sources,
in particular, are likely to be located closer to plant property
lines than assumed.   For this reason they may have a larger impact
outside  of the property lines than indicated by the diffusion.modeling.

     Although the estimated maximum concentrations of vinyl
chloride were given in the SSEIS, Vol.  I, EPA also states in the
Quantitative  Risk Assessment Document that an average exposure of 17  ppb
was estimated to exist within a 5-mile radius of an average plant.  This
figure was also based on 1974 emission levels.

     17.  VC-32, VC-34, VC-46

Comment:  Available health data are not sufficient to justify
regulating vinyl chloride  under section  112.  Section 112 of the
Clean Air Act allows  the Administrator  to regulate those
substances which may  cause or contribute to  an increase in
mortality, or an increase  in serious  irreversible or incapacitating
reversible  illnesses.   In  the  case  of vinyl  chloride, none of  these
requirements  had been  reported  outside  of the plant which can  be  traced
directly to any  plant or to  any manufacturing use of vinyl chloride
or the  formation of polyvinyl  chloride  products.

Response:   As  implied by the commentator, no community  cases of
angiosarcoma  have  been  verified as  being caused by ambient
exposure to vinyl  chloride.  Thus,  there is  no proof that vinyl
chloride ambient concentrations cause  cancer, teratogenesis, and
mutagenesis.   The  data  base  showing that vinyl chloride  causes

                                2-13

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  these effects as a result of occupational  exposure  is  a very  strong
  one.   The latency period for developing cancer due  to  vinyl chloride
  exposure is indicated to be at least 20 years.   Section 112 defines
  a hazardous pollutant as one which  "may cause  or contribute to     "
  (emphasis added) rather than one  which  has  been proven  to  cause""
  or contribute to certain effects.   As stated in the  preamble  to
  the proposed standard,  EPA has concluded that  it should take  action now
  to reduce exposure levels  to vinyl  chloride before  retrospective
  evidence of risk is  allowed to show itself.

       18.   VC-32

  Comment:   Standards  for  vinyl  chloride  should be  set under the
  authority of section  109 or 111 of  the  Clean Air  Act.   Although
  the preamble to  the  proposed standard asserts that section 109 treatment
  of vinyl  chloride would  be  inappropriate "because vinyl chloride is a
  localized  problem and section  109 is usually more appropriate for
  regulating pollutants whose presence in the ambient air is ubiquitous,"
  ;EV5i!ence  ?f Clusten'n9 °f incidences of  liver  angiosarcoma demonstrates
  that the  problem is not localized.  Moreover, the recent joint
  publication  of the American Health Foundation and the National Cancer
  Institute suggests that vinyl chloride may well be ubiquitous
 in the ambient air because of the combustion of vegetation.

      EPA has implicitly accepted that an ambient concentration aot
 exceeding 1 ppb vinyl chloride is  sufficient to provide an  ample
 margin of safety to the public health.   An   ambient  air standard  under
 section 109 to this effect would properly protect the public    We
 also support an appropriate new source standard for  vinyl  chloride
 under  section 111.

 Response:  The reason for not using  section  109 is not  related to
 whether there is  a clustering of angiosarcoma cases.  Section  109
 is usually not used for pollutants which are emitted  from a
 relatively small  number of source  types  of which there  are  a
 n;la*uVel£ t^plants<   EPA has stated that  it  d°es  not  know what
 the threshold level  of effects  for vinyl  chloride  is, and thus does
 hot know what level would provide  an  ample margin  of  safety.

     EPA has  left open  the  option of  setting standards in the
 future  for new sources  under section  111.  Such  standards could
 require  increased control of the oxychlorination process or more
 stringent stripping limitations.  As  an  alternative to section 112,
 however,  EPA  concluded that  section 111  is not the best  mechanism
 for controlling vinyl chloride.  Specifically, the length of time
 required  under section lll(d) from State to  State, State-granted
 variances  that may be based  only on cost considerations, and standard
 development as a State rather than a  Federal process  are all
 features that make section 111 unacceptable for a substance
which fits the definition of a  "hazardous air pollutant."

                                   2-14

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     19.  VC-6

Comment:  "This letter is in regard to the most recent assessment
of health problems which may follow exposures to vinyl chloride.  It
is our hope that this assessment may be of some assistance to your
Agency in discussion of standards to limit vinyl chloride emissions
into the ambient air.  Two studies that are conducted by NIOSH and CDC
personnel which directly bare on this issue of community effects are
those which Dr. Infante of NIOSH performed while he was at the Ohio
Health Department and subsequent investigations by the Division of
Cancer and Birth Defects of the Bureau of Epidemiology in Atlanta.
Enclosed are copies of these two studies.

     "Our scientists may differ in their interpretation of particular
studies in relation to vinyl chloride exposure and teratogenesis.
They are, however, in complete agreement that while the issue is not
yet resolved, the potential public health ramifications remain a cause
for concern.  Please note that we are speaking only of vinyl chloride
monomer-VCM, and not of polyvinyl chloride plastic.

     "The points raised in conversations with your office dealt specifically
with the issue of teratogenicity of VCM among humans.  Neither the
Infante nor the CDC study resolve the matter.  Dr. Infante's study used
available birth and fetal death record information and identified three
areas with increased rates of central nervous system  malformations.
The CDC investigation followed up cases in one city and found no
parental association between VCM exposure and plant employment.  There
also appeared to be no differences between cases and  controls with
respect to location of residence relative to the plant in Painesville.
In this circumstance no association could be established with VCM.
However, the authors stated, "This study clearly does not rule  out the
possibility that vinyl chloride may be teratogenic."  Because of  the
small numbers of cases involved, there still might be an effect that
was not detectable  in Painesville.

     "It is important to  remember  that the possible effects  of  VCM
exposure also  include mutagenicity.   Mutagenesis and  carcinogenesis
are sufficiently correlated  that demonstration  of one is cause  for
concern  about  the other.  The carcinogenicity of VCM  in  humans  is
well demonstrated via the NIOSH cohort mortality study and  by
various  animal  studies.   There are also  data to demonstrate  VCM-induced
transplacental  carcinogenesis in rats.   In the  past year, several
reports  have  indicated  that  VCM  is mutagenic via the  microbial  test
system,  and  that  VCM metabolities  have induced  mutations  in  the
mammalian  cells.  Likewise,  four  independent reports  from four  different
countries  have  shown an  excess of  chromosomal aberrations in lymphocytes
of workers  exposed  to VCM as compared to controls.   I should also note
that  NIOSH  is  participating  in a  collaborative  study  with a  university

                                  2-15

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 vn             •  D I!0? lab°r and "anagement of workers exposed to
 vinyl chloride  in Pottstown, Pennsylvania which should provide
 additional information on the mutagenic potential of vinyl chloride
 We anticipate that a preliminary report of this study will be
 available in the near, future, and we will transmit a copy of this
 report to you hopefully before completion of your public hearings and
 commentpenod.   Thus, while no conclusive data are available
            mutaf nesis J" the n""ian setting, such animal and laboratory
          suggest a need for caution with respect to human exposures."

 Response:  EPA appreciates  the information submitted by the commentator.

      20.   VC-9

 Comment:   The commentator submitted the  following five  papers  dealing
 with  vinyl  chloride.


 Pv-^c1;. /Te1]er'.,Ri9hard  J" et  al->  "Neoplastic  Risk  Among Workers
 Exposed to  Vinyl  Chloride,"  Annals  New York  Academy  of  Sciences.
MTfKu     +n*            " et al"  "Genetl'c Risks of Vinyl Chloride,"
NIOSH, Post Office Building, Room 515, Cincinnati, Ohio 45202'
January 28, 1976.  (Prepublication Copy)

     3.  Infante, Peter F. , "Oncogenic and Mutagenic Risks in   -
Communities with Poly vinyl Chloride Production Facilities."

     4.  Waxweiler, Richard J. , "Vinyl Chloride:  More Than An
'Occupational' Hazard?", APHA,  November 1975.

,nH ,»' iES?"d-:i 4r^ D" et  al" "Congenital Malformations
and Vinyl  Chloride,"  The Lancet,  November 29, 1975, p.  1098.'
                               2-16

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     2.2.2.  Approach for Regulating Vinyl Chloride Under Section 112.

     1.  Proceedings of the Public Hearing, Presentation by
Barry Castleman of the Environmental Defense Fund, p.9; VC-23,
VC-10, VC-2, VC-7, VC-16.

Comment:  The standard should be based on a cost/risk analysis rather
than best available control technology.  In other words, a socially
acceptable risk should be determined.  The socially acceptable risk
should be justified by the social importance, that is, the benefits
to society of the article, whose production entails the risk.  EPA
did not seriously evaluate the desirability of continuing all existing
uses of vinyl chloride.  The Environmental Defense Fund (EOF) pointed
out several uses of vinyl chloride for which EPA named no substitutes
if polyvinyl chloride were banned.  One of these was credit cards.
Credit cards are also one of the fastest growing uses of polyvinyl
chloride.

     A 95 percent reduction of vinyl chloride emissions should reduce
risk of adverse health effects,  but will  not necessarily minimize health
risks.  Section 112 requires more protection of public health than the
proposed standard will provide, especially in view of the evidence that
polyvinyl chloride products also cause adverse health effects.  An
example is hydrogen chloride fumes from burning polyvinyl chloride
products.

     A zero emission limit should be established for vinyl chloride.
Vinyl chloride should be phased out.  Vinyl chloride usage should be
banned now for products for which substitutes are available.  Substitutes
should be developed for the remaining uses of vinyl chloride, and all
vinyl chloride usage should be banned eventually.

Response:  In the preamble to the proposed standard EPA named its
reasons for not setting a zero emission limit for vinyl chloride,
as follows:  (1) There are beneficial uses of vinyl chloride products
for which desirable substitutes are not readily available, (2) there
are potentially adverse health and environmental impacts from
substitutes which have not been thoroughly studied,  (3) there are a
number of employees, particularly in the fabrication industries,
who would become at least temporarily unemployed, and  (4) control
technology is available which is capable of substantially reducing
emissions of vinyl chloride into the atmosphere.

     EPA agrees that substitutes do exist or could be manufactured
for most vinyl chloride or polyvinyl chloride uses.  However, in
general, these substitutes do not have some of the more desirable
characteristics of polyvinyl chloride, such as nonflammibility.
If vinyl chloride and polyvinyl chloride were banned, other substitutes
with these more desirable characteristics would likely be developed.
                                    2-17

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 EPA presently has no direct control over which substitutes are developed
 or used.  There is a risk that these substitutes would also have
 adverse health or environmental effects.   Since control measures
 are available which can reduce emissions  by 90 percent or more, it
 does not seem prudent to reduce emissions by the remaining 10 percent
 and take the risk of introducing new untested chemicals into the
 environment.

      2.   VC-3, VC-4, VC-5, VC-8, VC-41

 Comments:   These commentators  favor the approach and standard
 adopted for vinyl  chloride.

 Response:   No response  is required.

      3.   VC-17

 Comment:   There  are no  readily available  substitutes for polyvinyl
 chloride products.   Any imposed substitution of other materials
 for polyvi-nyl  chloride  products without consideration of the
 possible adverse consequences  that  may  result,  may  have a dramatic
 impact  on  our way  of life, including  the  curtailment of new  developments
 in  such  areas  as medicine, communication,  automotive manufacturing,
 aircraft and building industries  and  fire  retardation and safety
 equipment.   The  substitution for polyvinyl  chloride  products  may
 have  a greater adverse  and detrimental  effect on  both the environment
 and the  general  public's  health than  the present  polyvinyl chloride
 products.

 Response:  This  appears to be  a response to  the comments  made by the
 Environmental  Defense Fund at  the public hearing.  No response  is
 required by  EPA.

     4.  VC-46

 Comment:  Reference is made that the immediate original impact
of a ban would be felt primarily in areas of Southwest  Texas and
Southern Louisiana where fourteen of the seventeen plants are located.
 Commentator VC-46 believes this statement should be qualified since it
is entirely possible that communities within these areas  could conceivably
be in the total state of unemployment if such a ban were  to be enforced.

Response:  The fourteen of seventeen plants referred  to are
ethylene dichloride-vinyl chloride 'plants, and these  plants are
located mainly in Southwest Texas and Southern Louisiana.  These
plants are typically located in large petrochemical  complexes.
                                   2-18

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It is very doubtful  that a ban on vinyl  chloride would cause the
cities of New Orleans, La.; Houston, Tx.; Baton Rouge, La.; and
Long Beach, Calif, to be in a total state of unemployment.   Polyvinyl
chloride and fabrication plants are more widely dispersed throughout the
country.
     5.  VC-16
                                                                More
Comment:  The vinyl chloride standard is not stringent enough.
stringent restrictions could include (1) no variances on time
schedules to install the best available controls, (2) zero emission
limits for substitutable uses of polyvinyl chloride plastics after
one year, and (3) zero emissions for all sources of vinyl chloride after
three years.

Responses:  A response to suggestions 2 and 3 can be found under
comment #1 in section 2.2.2.  In regard to the first suggestion, the
Clean Air Act allows for a waiver period of up to two years after the
standard is promulgated to comply with the standard, provided that EPA
"finds that such period is necessary for the installation of controls
   11.  Variances will not be granted unnecessarily.  In many cases it
takes much longer to install control equipment than the 90 days that the
Clean Air Act allows for compliance.  Waivers will be granted only for
the time that is necessary to install controls.  The standard requires
control of several  emission points.  It is probable that control
equipment can be installed on some points sooner than others.  Compliance
for each different  point will be required as expeditiously as practicable.

      6.  VC-29, VC-31, VC-32,

Comment:  Industry  suggests that EPA expend more effort  on  the
fine  tuning  of  the  cost/benefit ratio.  There are  several
requirements  in  the proposed standard which offer  little benefit
in terms  of  emission reduction  for  the  costs  required.   They are:
requiring replacement  of single seals  on  rotating  equipment with
double  seals; installation  of car unloading purge  units  at
plants  where monomer delivery by rail  car is  infrequent;  the
requirement for stripping  all dispersion  resins  to 2000  ppm;
excessive recordkeeping, and a  gasholder.

      The risk of vinyl  chloride exposure  appears  to be  entirely
 limited to  workers in polyvinyl chloride  plants.   There  is  no  basis
 for  the prohibition of vinyl chloride  and polyvinyl  chloride,  as  some
 demand, or  for  a standard  which requires  expenditures  bearing  no
 reasonable  relationship to the  benefits obtained.
                               2-19

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  Response:  Section 111 of the Clean Air Act provides for the
  development of standards based on best control technology

        ^TLTh5]-  -Ve" fder SeCt1°n 1]1' however' "^ndards are not
        on a fine balancing of costs versus benefits.  Instead  costs arp
                      °f ^ affo^ability of the controTtecto ogf   "
  POSS be   and      * Z™" J11"101? 1evel  and the economic impact of
  possible standards on the industry in question.   Unlike section' 111
  ifloSld clar? "ot.exP11cit^ Provide for consideration of cSsi  'so
  unde? sect on H2 th^aPPr?ST^ t0 C°nsider costs to a 9™ter extent
  unaer section 112 than would be done under  section 111    As discusspd
  in the preamble to the proposed standard for vinyl ch oride  EPA believes
  costs may be  considered  under section 112,  but only to a very iVmi ted
  extent;  i.e.,  to assure  that the  costs  of control  technology are not
  grossly  disproportionate  to  the amount  of control  achieved    Requirinq  a
                       "6  t0  S0!^1  ^atively small  emissions  ?rdme
                   •<-   appeared to  be  a cost which would  be grossly dispro-
               The 'tems ment1oned  by  the commentators  do not fit in
       f  ?9
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in its determination of whether controls are needed, particularly
in the absence of any conclusive medical evidence that vinyl
chloride emissions have a detrimental effect on the general public
living in the neighborhood of such plants.

Response:  EPA realizes that the costs to install and operate
control systems are generally nonproductive.  This is the reason
EPA does an economic impact study.  Installation of controls does
have some positive impact on costs to the plant in that more vinyl
chloride is recovered.  This is also considered in EPA's economic
s tudy.

     9.  VC-46

Comment:  Three alternatives are proposed in the report.  One
alternative would accomplish a 90 percent emission reduction in the
entire plant; another 94 percent; and another 97 percent.  The
reason for selecting the 94 percent emission level is unclear,
and this selection should be carefully and thoroughly explained
since the reduction difference between the three options is only
7 percent and the difference between the lower and middle option is
only 4 percent.

Response:  It is assumed that the commentator is discussing the
alternatives for the oxychlorination process in ethylene dichloride-
vinyl chloride plants,,  The reasons for the selection of these three
alternatives is explained thoroughly in Chapter 5 of the SSEIS, Vol. I.
The reason that the relative degree of difference between the reduction
levels for the three alternatives is relatively small is that the
oxychlorination process is only one of several emission points in an
ethylene dichloride-vinyl chloride plant and on the average it represents
only 10 percent of the emissions  from the plant.  The alternatives
actually represent a range in emission reduction for the oxychlorination
process from 0 to 99 percent.

     The reason that the 94 percent  level was selected  is explained
in detail in section 8.2.1 of Chapter 8 of  the SSEIS, Vol.  I.  In
summary, the 97 percent reduction level was not selected because of the
large energy expenditure required.   The 94  percent  reduction  level would
achieve some degree of emission reduction without incurring the  large
energy expenditure.
                               2-21

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      10.  VC-26

 Comment:  IF OSHA allows 1 ppm (8-hour average) as safe to the
 health of workers then likewise an ambient air concentration should
 be considered rather than an emission standard.

 Response:  The level of the OSHA standard is not derived from a health
 data base.  Response to comment VC-32 (page 16) states why EPA did not
 choose the ambient standard approach.

      11.  VC-18

 Comment:  A standard for ambient concentrations of vinyl chloride can
 be based on OSHA's standard.   The OSHA action level  is 0.5 ppm for
 8 hours a day, 5 days a week exposure.  An equivalent safe maximum
 24-hour environmental exposure would be 119 ppb (8 hr * 24 hr x 5 days
 * 7 days X 500 ppb).

 Response.   Same as for 10.

      12.   VC-46

 Comment:   The  statement is  made that "Congress  never  discussed the
 particular problems  associated with  apparent non-threshold pollutants."
 If Congress  did not  discuss  these  problems,  it  is  difficult to justify
 EPA's  attempt  to regulate substances  which  they consider non-threshold
 pollutants without more justification than  is presented in this  section,

 Response:   Congress  clearly intended  for  EPA to regulate substances
 which  "in  the  judgment  of the  Administrator  may cause,  or contribute
 to an  increase  in  serious irreversible, or  incapacitating reversible,
 illness."  EPA  has determined  that vinyl  chloride  is  such  a substance
 for the  reasons  stated  in response to comment #6 in section 2.2.1.  The
 fact that sufficient data are  not available  to  delineate a threshold
 level of effects for vinyl chloride does  not mean  that  it should  not be
 regulated.

     13.  VC-46

 Comment:  EPA should  clarify whether  worst case effects were
 assumed in establishing the proposed  standard.

 Response:  The proposed standard is based on best available control
 technology and is intended to minimize emissions and risk.  The
meaning of the comment is not clear.   Worst case effects has no
 apparent relationship to the basis of the standard.

     14.  VC-46

Comment:  In the preamble to the proposed standard and on pages 8-38
and 8-39 of the SSEIS, Vol.  I,there is discussion about the reasons for
                                2-22

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stating the emission levels for sources following the stripper in two
different ways.   This discussion seems to infer that the regulation is
proposed for the sake of regulation and enforcement rather than for
accomplishing safety in the surrounding communities.

Response:  The goal of the standard which is, as suggested, "the
safety in the surrounding communities" is achieved through the
amount of emission reduction required.  Both ways in which the standard
for sources following the stripper is written achieve essentially
the same degree of emission reduction.

     15.  VC-32

Comment:  The proposed standard is unnecessary to provide an ample
margin of safety to protect the public health because the margin of
safety which EPA has implicitly accepted as ample has already been
achieved by industry as a result of the OSHA standard for vinyl chloride
and industry's increasing awareness and understanding of the health
hazard of high level exposure to vinyl chloride.

Response:  EPA is  aware that emissions have been reduced as a result  of
the OSHA standard  and industry's awareness of the vinyl chloride problem.
EPA's standard will  further reduce emissions.  Since the threshold level
of effects for vinyl chloride is unknown, EPA has determined that it  is
prudent  to minimize  emissions by requiring this  additional control.

      16.   Proceedings of  Public Hearing, Presentation at the
Public  Hearing by  Barry Castleman, p.16.

Comment:   EPA should have declared vinyl chloride as a  hazardous    .
air pollutant in  June  1974.  That way the final  standards would have
been  due by  June  1975.  The public would have been  spared  an
additional year of unregulated  emissions.   EPA  compiled a  best
available  technology standard  after  observing the industry through  1974.
Through almost  all of  1975, the standard was  reviewed by  industry,
the public and  other government agencies.   It is important to  try
to  put regulations out  and shorten  this  review  process.

Response:   EPA  also favors expeditious rulemaking.   However,  for
the vinyl  chloride standard there  were many-technical details  and
issues that needed to  be  resolved  before  the standard could  be
proposed.   Preparation  of environmental  and  economic impact  statements
for the standard  is time-consuming but has  beneficial effects  in
 decision-making and in  understanding the impact a standard will have.
 EPA's policy of having a recommended standard reviewed  by other
 groups within EPA, other federal  agencies,  interested  parties, and
 public .advisory committees before  it is proposed or promulgated is
 also  beneficial  to the quality of the standard.

                                 2-23

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       17.  VC-42

 Comment:  EPA should provide for a continuous ambient monitoring
 program for vinyl chloride in those cases where densely populated
 areas are located within five miles from affected plants.  Although
 ambient standards for vinyl chloride have not been set, historical
 ambient data for this air contaminant should be collected because
 of strong implications that it is a human chemical carcinogen.
 Without ambient monitoring the efficacy of emission controls will not
 be known if and when carcinogenicity is confirmed at low ambient
 levels.

 Responses:  Ambient monitoring after the standard goes into effect
 would be useful  for the reasons  suggested by the commentator.   EPA
 may establish such an ambient monitoring program as resources  and
 other priorities  permit.

      18.   VC-24

 Comment:   The following section  should  be added  to the standard:

      "The  Administrator may waive  application  of the  foreqoinq
 regulations  (Sections  61.62 -61.65,  Sections 61.67 -  61.70) when
 the owner  or  operator  of a  vinyl chloride plant  or polyvinyl chloride
 piant_demonstrates  to  the Administrator  that emissions  of vinyl
 chloride from the  plant  undergo  dispersion sufficient to provide
 adequate dilution  of the  concentration of vinyl  chloride insuring
 an  ample margin of safety.  In making this determination the
 Administrator may  consider:

      (1)  ambient monitoring data
      (2)  the location of persons living  around  the plant site
      (3)  other relevant  information"

 Response:  EPA has stated that sufficient data is not available
 to establish a threshold  level of effects for vinyl chloride.
 For this reason,  EPA has not been able to identify a numerical
ambient concentration which would provide an ample margin of safety.
Furthermore, Section 112 provides for the establishment of emission
standards.   It does not provide for establishment of an ambient air
quality standard  which can be  met by dilution.
                                 2-24

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     19.   VC-22

Comment:   In the second paragraph of page 1-6, it is noted that
the standard would be applicable to an existing process, as well  as
"any other process developed in the future."  This statement is far-
reaching and conjectural.  It is not clear how EPA could realistically
regulate specific emission limitations on a future process yet even
to be developed, particularly when the basis for the current limitations
stems from the application of the best available control technology
currently existing.

Response:  The statement on page 1-6 refers to the fact that EPA
does not want to limit the standard to existing polymerization
processes by name, because a new variation on the polymerization
process could be developed and not be covered by the standard only
because it was not specifically named.  The control technology
required for the existing polymerization process is essentially
the same and is likely to apply to new types of polymerization.
Existing processes vary depending on whether water is used, how
much detergent is used, etc.  The equipment used in the various
processes is similar.

     20.   VC-23

Comment:  EPA should make a formal commitment to conduct a complete
review of the standard one year after promulgation.  EPA should
keep pushing for improved technology to reach the ultimate goal
of zero emissions.  EPA should review all new construction to see
that best control technology available at the time is installed.

Response:  It is EPA's policy to review the need to change standards
as new technology is developed.  Priorities would determine when a
standard is revised.  Priorities are determined by 'the amount of
impact a new standard or revised standard for a particular pollutant
would have in comparison to setting or revising standards for
another pollutant.

     21.  VC-42

Comment:  EPA should push the development of improved stripping
technology by setting a two-phase standard.  The first phase would
require stripping to 400 ppm as proposed.  The second phase would have
a plant-wide fixed-point emission standard of 100 kg vinyl chloride
per million kg of polyvinyl chloride in any product, averaged over
any calendar day.  The second phase standard could be achieved in
5 years.

Response:  EPA also favors development of improved stripping technology.
Section 112 of the Clean Air Act doesn't directly provide for a two-
phase standard.   It states that a plant must meet a standard

                                2-25

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 within 90 days  of promulgation,  unless  a  waiver of compliance
 is  obtained.   If a waiver is  obtained,  the  plant must meet  the
 standard within two years of  promulgation.   EPA can revise  the
 standard at a later date.

      EPA's requirement  for stripping  to 400 ppm does  not preclude
 the States from setting more  stringent  standards.   Technology is
 being developed which can reduce  the  stripping  levels  below 400 ppm
 for many resins.   States  may  decide to  require  plants, particularly
 new plants,  to  adopt this new technology  and reduce emissions even
 more.   The 400  ppm limit should not be  considered an  end-point in
 the development of improved stripping technology.

      The basis  of the 100 kg  vinyl chloride per million kg  product
 is  unclear.   The  controls which would be  used to attain this
 level  were not  described  in the comment.

      22.   VC-24

 Comment:   The technology  necessary to achieve compliance with the
 proposed regulation  is  untried.   There  are  some  indications that
 compliance with  the  regulations may create  other equally troublesome
 problems.  As an  example,  recovered vinyl chloride  monomer  has been
 found  to contain  certain  polyperoxides which  are percussion
 sensitive  thereby  creating  an  explosion hazard.   If these by-products
 of  emission control  create  significant  health hazards, the  regulations
 should provide  a mechanism  whereby the Administrator can modify
 the regulations on an emergency basis.

 Response:  All  the technology  required by the standard has  been
 used.  The industry  has been recovering vinyl chloride in the past for
 economic reasons and that a problem with polyperoxides exists has
not been mentioned previously.

     23.   VC-44

 Comment:  The standard should  include a specification for plume dispersion
hardware to preclude the possibility  that the dryer stream may be
discharged at near ground level.  The concentration of vinyl chloride
in the dryer exhaust may well   exceed  10 ppm and  be  carried at this
level for some distance'if  no  stack is used.  In fact, air flow
calculations for a polyvinyl chloride dispersion plant in Maryland
indicate that there would be a possible maximum  ambient concentration
in excess of 1.0 ppm across the property line after the plant has
met the provisions of the proposed regulations.
                                    2-26

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Response:  In order to require plume dispersion hardware, since
a number of plants would be involved, EPA would have to specify
an ambient air quality goal for vinyl chloride.  EPA has not
done this because there is not sufficient data on health effects
to establish a numerical threshold of effects for vinyl chloride.

     In visiting polyvinyl chloride plants, EPA has observed that
dryer stacks are generally 15 meters high and discharge horizontally.
Concentration levels of 1. ppm are of concern.  States may find
that they want to require dispersion hardware to further reduce ambient
concentrations.  The fact that EPA has not required dispersion hardware
does not preclude States from doing so, nor should it discourage them
from doing so.

     24.  VC-42

Comment:  The standard should include a limit on the mass emissions
allowed per unit time.  Otherwise, the total emissions will simply
grow as plant size increases.

Response:  There are advantages to a mass per unit time standard.   It
could be used to limit growth as suggested.  It would also clearly
preclude dilution as a means of attaining the standard.

     EPA, however, did not propose a mass emission limit for two
reasons:

     (1)  The standard is based on best available control technology
rather than an ambient air quality goal.  If the ambient air quality
goal approach had been used, EPA would have calculated an emission
rate for the entire plant which would allow the plant to meet the
ambient air quality goal under worst case conditions.  The emission
rate in kg/hr would have been adopted as the standard.

     (2)  The air volumes and mass emissions from specific emission
points, particularly at polyvinyl chloride plants, fluctuate.  There
are a number of pieces of equipment at each plant.  The configuration
for ducting the emissions from the different pieces of equipment varies
from plant to plant.  Reactors and strippers at most plants are batch
processes.  Capture and ducting of fugitive emissions to a control
device is intermittent.  Sufficient information is not available
for developing a mass emission standard which  could be applied
to all plants.
                                   2-27

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       2.3.   Selection of Source Categories

       2.3.1   §61.60
  Comment:   Research  and  development  facilities  should  be exempted  from
  regulation.   Research,  testing,  and pilot  plants  are  important  tools
  in  developing new products,  improving  productivity, devising new
  procedures to achieve lower  emissions, and enhancing  safety.  Such work
  involves  reactions  of vinyl  chloride in small  glass vessels, miniature
  reactors  set  up on  a laboratory  bench  and/or small reactors.  These
  facilities are operated on a  "need  to  investigate" basis and therefore
  operate intermittently.  To  require that each  reaction or other
  experiment be fully equipped with the  various  required control devices
  to meet a 10  ppm maximum concentration would be extremely burdensome
  as well as delay needed work to  advance emission and safety control
  technology.

      Many experimental  equipment set-ups are not permanent installations.
  in fact, a particular set-up may involve only one experiment.   To
 comply with the proposed standard, the operator would have to conduct
 emission tests, prepare an initial operating report and a semi-annual
 report, and maintain records of emissions for two years.

     _In addition  to  testing and reporting,  the  requirements  in  the
 section on fugitive  emissions become quite  cumbersome  in  pilot  operations
 The  sample flask  system  on  a small  reactor  becomes almost as large as
 the  reactor itself.   Pilot  size pumps are simply not available with
 double mechanical  seals.   Finally,  a formal leak detection and
 elimination  procedure would be burdensome,  and  stripping  of  waste
 water to 10  ppm vinyl chloride concentration  seems  excessive in
 this  case.

      The current data in Table I, collected from 14 members  of
 SPI  representing 75  percent of the nameplate  poly vinyl  chloride  capacity
 in the United  States illustrates  that estimated emissions from 113 test
 sources  account for  less than 0.06 percent  of the  total monomer emissions
 from  all sources before control and  1.0 percent after  all model plant
 controls are in use.

      The vessels used for these experiments range from  under 3.78  1
 (1 gal)  to 4158 1 (1100 gal).  The ninety vessels of 189 1 (50 gal)
 and below represent more than 50  percent of these emission sources
 Commentator VC-29 recommends  that vessels 1890  1 (500 gal) and under
 be exempt from all emission standards because of the aforementioned
 data and because OSHA guidelines  adequately protect the workers.    Vessels
over 1890 1 (500 gal) should be required to limit emissions to 5 kg
 (5 Ib) vinyl chloride monomer per 100 kg (100 Ib) of polyvinyl  chloride
produced.
                                    2-28

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Table I. EMISSION DATA  ON LABORATORY  AND PILOT FACILITIES  USING  VINVL  CHLORIDE
                                                              Estimated
 Company        Reactor       Number        Produced      Total Emissions
   Code           Size        of Units         Rate           per Year	      Resin Use
    A
    B
    C
    D
     K

     L

     H
     N
  (gal.)

   50
    0.4
    3.25
  300
   50
    0.5
    0.8
    0.8
   15
   30
   30
 1100

  300

    5
   10
                      .5
                   10
                   50
                 .5 to 2
                 50 to 100
                  750
  200
   15
   10
   50
  200
  220
  500
1,000
    5
   30
  300
    2.5
   10
   12.5
  200
   30
   10

   30

    0.5
    1
   10
  100
  500
  600
2
6
1
1.
1
I
4
2
6
1
2
2
                                 3
                                 1
                 1
                 2
                 2
                11
                 5
                 2
1
1
1
7
1

*-
1
4
1
1
1
1
4
i
2
2
                                 1
                                 7
                                 2
                                 1-
                                 1
                                 1
(Ib/yr)

 30,000
.  1,084
    987
 36,450
 17,000
    192-
  2,112
    600
 23,100
    960
 28,800
666,000

113,812

    400-
    100~
                380-
             27,338
            136,687
             16,000
             10,000
             50,000
 72,900
  5,468-
    608-
 75,634
  2,430-
 12,029
  7,594-
 33,413
     76
  5,285
 31,894
  1,823
    606
 15,480
 24,000
 34,172
 66,582

 24,698

  1,200
  1,063
    304
  6,075
  1,519
364,500
   400
    89
   100
 5,000
 2,800
    48
   697
   878
   240
   240
   266
10,656

10,000

 6,075
 3,038
                    25
                 1,600
                10,800'
                   225
                   500
                 2,000
17,045.
   928
   100
 4,870
   192
 3,110
    60
   460
     8
   321
 2,582
   100
    30
 1,548
 2,400
   375
21,920

 2,740

 1,700
   350
    50
 1,000
   100
 4,000
   Testing and scrap
   Experimental
   Experimental
   Tests, trials in
      lab and to
      customers
   Sold as off grade
   Scrap
   Scrap
,   Scrap
   Scrap
   Scrap
   Scrap
   Scrap
   Divided between:
1. Experimental
   evaluation & tests
2. Customer samples
3. Remainder is
   placed in landfill
    (about 80%)
   Experimental
   Experimental
"   "Experimental
   Scrap
   Scrap
   Customer Sampling
      and scrap

   Testing
   Testing
   Testing
   Testing
   Testing
   Testing
   Testing S sampling
   Testing & sampling
   Testing & scrap
   Testing & scraj?
   Testing S scrap
    Product research
    Blending and/or
       scrap
    Blending and/or
       scrap
    Testing
    Testing
    Testing
    Testing
    Testing
    Testing & blending
       into normal
       production
                                               2-29

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     Other cut-off points were suggested by other commentators.
VC-13 wants to exempt all research and pilot plant facilities.
VC-40 wants to exempt reactors with a capacity of 7560 1 (2000 gal)
or less.  This would also essentially exempt all research and development
facilities.  Commentator VC-27, the operator of an ethylene dichloride-
vinyl chloride plant, requested that quality control facilities be
exempted from the standard.

Response:  As stated in the preamble to the proposed standard, EPA
recognizes that some small research and development facilities may
exist where the emissions of vinyl chloride are insignificant and
covering these facilities under the standard would be unnecessary and
inappropriate; however, EPA did not have sufficient information available
to clearly define which facilities should be excluded from the standard.
The standard has been revised so that it exempts polyvinyl chloride
reactors and associated process equipment from applicability of the
standard if the reactors are used^for research and development and have
a capacity of no more than 0.19 m  (50 gal).  The figure 0.19  (50 gal)
was selected because it distinguishes between research and development
equipment that is generally found in the laboratory and that which is
found in pilot scale facilities.  The emissions from the laboratory
scale facilities are relatively small and application of the controls
required by the standard would be impractical and expensive. ^Reactors
greater than 0.19 m  (50 gal) in size but no more than 4.07 m  (1100 gal)
are required to meet the 10 ppm emission limits for reactors, strippers,
monomer recovery systems, and mixing, weighing, and holding containers.
Research and development equipment in this size range would encounter
technical problems in meeting other parts of the standard.  For most
resins meeting the reactor opening emission limit involves reducing
the number of reactor openings.  In research and development the reactors
have to be opened after every batch for thorough cleaning.  With regard
to the stripping requirements, one of the purposes of research and
development is to gain an understanding of the conditions.which need to
be carried out during the stripping operation for a particular resin to
meet the standard.  The first part of the research involves development
of a marketable product.  A later phase involves development of the
stripping conditions for the resin.  Each batch in a research and
development reactor could not be expected to meet the stripping limitations,
Averaging would not help because typically only one or two batches are
made daily.
                      o
     The figure 4.07 m  (1100 gal) was selected as an upper cut-off
limit because there are no commercial reactors below this size.

     An exemption for research and development equipment in ethylene
dichloride-vinyl chloride plants is not needed.  Most research at
these plants involves the oxychlorination process.  Requiring pilot
scale oxychlorination processes to meet the stack standard is consistent
with requiring research and development equipment in polyvinyl
chloride plants to meet the 10 ppm limits.  The fugitive emission
limits apply only to equipment "in vinyl chloride service."

                                 2-30

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Since the equipment in the oxychlorination process is not "in vinyl
chloride service," the fugitive emission requirements would not
apply to the research and development equipment.

     Quality control facilities dp not need to be exempted, because
they are not covered by the standard.  Equipment which is not specifically
named by the standard (e.g., reactors, strippers, oxychlorination
process, etc.) would not have to be controlled.

     2.  VC-25

Comment:  Copolymer resin plants manufacturing resins with less than
a 50 percent vinyl chloride content should be regulated as any other
polyvinyl chloride resin plant is regulated.  EPA should, however, clarify
the application of the proposed standard to operations involving
vinyl chloride use on an intermittent basis.  On any given day, our
plant may manufacture copolymers containing vinyl chloride or it may
be manufacturing an unrelated material.  Vinyl chloride monomer will be
stored on the premises permanently though use is intermittent.  EPA
should not require records, tests, and reports for the whole operation
of the plant, except when vinyl chloride is being used.  Each production
run of a latex containing vinyl chloride should not be counted as a
new source and a reactor line should not have to be requalified via
emission tests and an initial report each time a production run is made.
                                  2-31

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 Response:  On days when vinyl  chloride is being stored and not used,
 the only part of the regulation which would appear to apply would be
 the Requirement for detection  and elimination of leaks from the storage
 equipment.   Any reports and records  would simply indicate which days
 vinyl  chloride was or was  not  being  used.   The plant would not be
 considered  a new source each time it started producing a  vinyl  chloride-
 containing  product.

     3.   VC-25

 Comment:  Solution resins  should  be  exempted from  the  standard,  because
 emissions from manufacturing solution  resins  compose only  0.028 percent
 of  the total,  EPA doesn't  understand the solution  process,  and  the
 proposed  standard does  not adequately  consider solution polymerization
 technology.

 Response:  There  is only one plant making solution resins   This
 explains, at least in part, why the  emissions  are  relatively low
 and why EPA did not concentrate more time on this process.  The
 fact that only one plant makes  solution resins  is not a reason for
 exempting the plant from regulation.   The number of plants in other
parts of.the country is irrelevant to the effects of the solution
resin plant in the community surrounding it.  The information presented
the standard          indicated that  this plant is capable of Meeting
                               2-32

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     2.4  Emission Limits

     2.4.1  §61.62(a), 61.63(a), and 61.64(a)(l),(b),(c),  and (d).

     1.   VC-14, VC-18, VC-21S VC-22, VC-29

Comment:  It has not been demonstrated that incineration,  carbon
adsorption, and solvent absorption can achieve the proposed emission
limit of 10 ppm under different production conditions at all sources.
It is arbitrary for EPA to base a standard on the operation of
experimental or infrequently used control devices required by the
standard to operate at their best efficiency 100 percent of the time.
Some thought should be given to alternate actions in case these devices
prove unworkable.

     Commentator VC-18 also stated that carbon adsorption is not
attractive for vinyl chloride plants because impurities in the
recovered vinyl chloride prevent putting it back into the production
line.  Commentator VC-18 also pointed out that the results from the
test EPA conducted on an incinerator showed higher emissions from
the HC1 scrubber following the incinerator than from the incinerator
itself.  He recommended changing the standard to 50 ppm now and
revising it later to reflect best available control technology as it
is verified and demonstrated.

Response:  EPA has acknowledged that relatively .little data exists
on the emission levels achievable for carbon adsorption, solvent
absorption, and incineration at ethylene dichloride-vinyl chloride
and polyvinyl chloride plants.  During the development of the proposed
standard, these control techniques were being used by only a few plants,
so little .testing was done.  EPA did test one incinerator.  The outlet
concentration averaged over six runs was 4 ppm.  Thus, the proposed
standard is set higher than the average measured concentration to allow
for a variation in conditions among plants.  Furthermore, EPA feels
that the 10 ppm limit has been demonstrated from incinerators on
similar streams to those in ethylene dichloride-vinyl chloride and
polyvinyl chloride plants.

     Furthermore, conditions of the stream that is to be treated at a
particular plant  are  taken into account  in designing a control device
to meet the standard.  The standard accounts for normal fluctuations in
emissions by permitting  averaging of emissions.  Compliance with the
10 ppm  limit is to be determined by averaging together  the  results
of these  runs.   Each  run consists of sampling for  a minimum of an
hour.

     If carbon  adsorption is not a  feasible control  technique for a
vinyl  chloride  plant, incineration  is a  viable option.  There is no
apparent  reason  to  increase  the 10  ppm limit to  50 ppm  based on  the
data that are  available.

                                  2-33

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      EPA does not know why the vinyl chloride concentration from the
 HCL scrubber outlet was higher than the concentration going into
 the scrubber.  The water used in the scrubber was from a wastewater
 sump, so there is a possibility that it did contain vinyl  chloride.
 Water samples were taken from the scrubber and were reported to
 contain no vinyl  chloride.  However, the water samples may have
 been taken improperly.   At the time of this test, EPA had not specified
 a method for measuring  vinyl  ch-loride in water.  If the container used
 to obtain the sample was not  completely filled with water, then vinyl
 chloride in the water could.have escaped into the air space in the
 container above the water so  that it was not measured.  The test discrepancy
 does not detract  from the figure of less than 10 ppm for the exit stream
 from the incinerator.

      2.   VC-14

 Comment:   Sections 61.62(a) and 61.63(a) prohibit the discharge of
 exhaust gases which contain 10 ppm vinyl chloride or greater from
 "any equipment."   As worded,  these sections apply to fugitive emission
 sources  as well as stack emissions.   These sections should be amended
 to limit their applicability  to stacks  and vents used specifically
 for purposes  of discharging vinyl  chloride-containing gases from the
 process  equipment.

 Response:   The fact that Test Method 106 is to be used to  determine
 compliance with §§61.62(a) and 61.63(a)  and that Test Method 106
 is a stack testing method with a minimum sampling time of  an hour
 indirectly excludes  fugitive  emissions  such as leaks  from  valve stem
 packing  and flange gaskets from applicability of the  10 ppm standard.
 Adding a  statement to the effect that only "stacks  and vents used
 specifically  for  purposes of  discharging vinyl  chloride-containing
 gases" could  result  in  additional  uncertain!'ties.   For example,  the
 specific  purpose  of a stack may be  to vent ethylene dichloride,  but
 vinyl chloride may  also  be a  pollutant  in  the gas  stream.   Or the
 primary purpose of a vent may be  to  remove heat.

      3.   VC-26

 Comment:   The  10  ppm maximum  vinyl  chloride  emission  limits  for the
 low  volume  ethylene  dichloride  purification  and vinyl  chloride  formation
 and  purification  stacks  are not  realistic.   To get  down  to  10 ppm
would require at  a minimum the  use of carbon  adsorption.   Since  EPA
 uses a cost benefit  ratio to  justify the 0.02  lbs/100  Ibs  of product
 for  the oxychlorination  process, it  seems  more  realistic to  apply this
same weight standard to  all of  the.stacks.

Response:  The primary reason for making the  standard  for  the oxy-
chlorination process less stringent  than for  the other emission points
is the large energy expenditure that would  be  required at many plants
to reduce the oxychlorination process emissions  to  10 ppm.   Little, if
any  fuel, is required for incineration of  emissions from the ethylene
dichloride purification and vinyl chloride formation and purification
processes.  Furthermore,  the  uncontrolled  emissions from these two

                                2-34

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processes are a much larger percentage of the total  emissions from an
average plant than those from the oxychl or i nation process^  The incinerator
tested by EPA is controlling the ethylene dichloride PuriflcjJ10
vinyl chloride formation and ourification process and meets  the 1
limit.

     4.  VC-18

Comment:  During formation of vinyl chloride, there is a column to
separate by-product HC1 from the vinyl chloride.  The HC1 overhead
in this column  is ducted to the oxychl ori nation process.  During
upsets of this  system, HC1 must be vented to the atmosphere   This
stream contains about 30 ppm of vinyl chloride. _ We es t™ate th ^
venting occurs  about five times per year releasing 12. Ib kg  U/ IDS;
of vinyl chloride oer year.  Removing this small amount of vinyl chloride
will  increase the cost of our control device $500,000.  This stream
should be exempted from  §61.63(a).
 Response:   EPA has  discussed  this  problem with  two      ,huere
 Both  of  these  comoanies  avoid venting  the HC1 stream to the atmosphere
 by  operating the  cracking  furnaces  only when  the oxychlorination process
 is  operating.

      5.   VC-35

 Comment:  The  10  ppm limit for  vinyl  chloride emissions from  the     _
 various  control equipment  should specifically mention  that it is to  be
 determined prior  to mixing with other gases.

 Response:  On  October 14,  1975  (40 FR 48299)  §61.17 was added to
 Subpart A - General Provisions  of Part 61.   Section 61.17 (entitled
 "Circumvention")  prevents  an owner or operator  from building, erecting,
 installing, or using any article, machine,  equipment,  Process, or
 method, the use of which conceals an emission which would otherwise
 constitute a violation of an applicable standard.   Dilution would
 be a method of concealing an emission which would otherwise constitute
 a violation of an applicable standard.

      6.  VC-18, VC-21, VC-25, VC-29, VC-34

 Comment:  An  averaging time of  30 days should be provided for the
 10 ppm  limit  for stack emissions.  Otherwise multiple back-up systems
 will have  to  be employed  at a grossly disproportionate cost  in order
 to meet the 10 ppm  limit  on an  instantaneous basis.

 Response-  The standard does provide  for an  averaging time of at
 least three hours.   Section 61.67  states that  an emission test is
 to consist of three runs.  Each run  is to  be an hour  in  length.
 The  continuous monitor  provides an  indication  of instantaneous
 emissions, but will not be used to  determine compliance.
                                  2-35

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      2.4.2  §61.62(b)

      1.  VC-23

 Comment:  EPA proposed a less stringent standard than can be met
 by incineration for the oxychlorination reactor because of the
 large fuel penalty that would be incurred to incinerate the
 emissions from that source.  Afterburners designed especially for
 these plants can attain substantial heat recovery, and catalytic
 afterburners offer energy savings by being able to operate at lower
 temperatures than conventional units.   The use of afterburners (and
 scrubbers) to control  emissions from oxychlorination reactors should
 be required.  The price of fuel will be sufficient incentive for
 plants to install well-designed systems.

 Response:  EPA recognizes that two plants are using afterburners
 for control  of the oxychlorination reactor.   In both cases, the
 plants are reducing the large volume gas  stream and thus  the high
 energy costs by recycling the process  gas stream and using oxygen
 instead  of air to feed into the process.   Although the cost of fuel
 does  provide incentive to install  this  kind  of system, there are
 several  types  of oxychlorination reactors and EPA does not know
 whether  this system could be  adapted to all  the reactor types within
 the time available for compliance.   A  catalytic oxidation  unit has
 been  used in a  pilot study  for the  oxychlorination process,  but it
 has not  been used commercially.   It should be emphasized that energy
 is  only  one  factor in  EPA's decision.   At most plants  the
 oxychlorination  reactor is  a  relatively small  portion  of the  total
 emissions.   At  the  one plant  where  the  oxychlorination reactor has
 relatively significant emissions,  the incineration  may have  to be
 used  if  a change  in  process variables will not  result  in the  plant
 meeting  the  standard.

      2.   VC-28

 Comment:  To meet the  0.02 kg/100 kg limit, more  than  a change  in
 process  variables will  be required.  The standard should be set
 slightly higher to avoid the  use of incinerators or an additional
 reactor  in the oxychlorination process.

 Response:  The additional  reactor in the oxychlorination process,
which is being used by several plants, does not require a large
expenditure of energy as 'does an incinerator.  If the additional
reactor  is required to meet the .02 kg/100 kg requirement,  there is  no
apparent reason why it should not be used.
                                  2-36

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     3.  VC-27

Comment:  The preamble to the proposed standard states that "...  as
technologies using less energy for controlling the oxychlori nation reactor
are developed, EPA will evaluate the desirability of proposing standards
which would require a higher degree of control at all plants."  The
possibility of more stringent regulation as technologies might develop
forces serious evaluation of the prudence of current prompt investment
and emission control efforts which might be rendered obsolete in
the future, without due consideration of ambient air emission levels
then existent and further assessment of the results of substantial
efforts now underway to quantify health risks at very low exposure
levels.                                               ,

Response:  It is EPA's responsibility to examine new technology
as it is developed and revise its standards accordingly.  If EPA
developed a more stringent standard for the oxychlorination reactor,
it would also look at the impact of adopting that standard for
existing plants.  Depending on these impacts, EPA may apply the
standard only to new plants by developing the standard under
section 111 of the Act.

     2.4.3  §61.64(a)(2)

     1.  VC-29, VC-22

Comment:  The inclusion of the words "is open and" in the last
sentence of §61.64(b), (c), and  (d) is inconsistent with the wording
"before opening" in  §61.65  (b)(6)(i) to which this sentence applies.
For clarity and to resolve this  discrepancy,  the last sentence of
§61.64(b) should be  reworded as  follows:   "This requrement  does not
apply  to equipment that meets the requirement in §61.65(b)(6)(i)."

Response:  The commentator's suggestion does  not appear to  clarify
the sentence.  This  is exemplified  by  inserting his  suggestion in  the
last sentences of  §§61.64(b),  (c),  and  (d).   They would then  essentially
read as follows:   "The 10 ppm requirement  does not apply to equipment
that before it is  opened the quantity  of vinyl chloride is  to be  reduced
so that the equipment  contains  no more  than  2.0 percent by  volume  vinyl
chloride  ...  etc."  The intent of the  last  sentence of §61.64(b),  (c),
and  (d) is  to say  that the  10 ppm requirement does not  apply  to equipment
that^ i^ open  and has  already met the  requirement in  §61.65(b)(6)(i)
before it was opened.  In other words,  the standard  does not  apply to
equipment which is  not in operation.   In the  promulgated standard,  the
last sentence in the proposal  §61.64(b) has  been  changed to:   "This
requirement  does not apply  to equipment that is open and out  of operation
and  that met  the  requirement  in §61.65(b)(6)(i) before  it was  opened."
                                 2-37

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       2.   VC-13,  VC-21,  VC-25,  VC-29,  VC-33,  VC-34

  Comment:   The  reactor opening  emission  limitation should be changed to
  permit averaging all reactor openings over a 30-day period.  In the case
  of  the reactor opening  limitation, the  requirement that each reactor
  opening must meet the limitation is burdensome and, in addition, may
  cause hazardous  situations.  EPA has  discussed in the SSEIS, Vol  I
  on  page 4-71 its  logic  in developing  the standard.  It requires that

            ?YU?.an av^age Of 3'5 batches before opening and cleaning.
             Ruling and/or the need for cleaning varies from one resin
            a"othe.r'  Traditionally, on the completion of each batch, the
       op   ato*;.has made a judgment based on inspection, heat transfer,
         K  £°"dltl°u °r history as to whether the reactor should make
         5   ? °^ whether u sh°uld be cleaned.   Failure to clean at the
            +h    -  ° ^h1gh Percentage of runaway reactions and emergency
                air'   C1*amn9 to° °ften ^ costly and results  in higher
                      5^ standard requires multiple  batches between each
                     ;  thus,  a plant operator with a  reactor that fouls
      .     •     must choose  between violating the standard or  operating
 a reactor in an unsafe manner.
           «n»                f°r reactor opening  has  not been  increased
              9a?   stand?rd-   In  ^e  SSEIS,  Vol.  I several ways  of
             rCt°r  pem"g em1ssio"  limit were mentioned.   One  of these

                                                       1s  t0  evacuate the
     3.  VC-21, VC-22, VC-29
                1? ai?/rror 1n calculating the emission factor for
shon!H    ™   C512rlde m?nomer in reactor openings.  The concentration
deHved   C°nVerted to weight percent before the emission factor is


Response:  The calculation was provided by a company and should
have been converted to a weight basis.   Recalculation gives a

rhwfSi0" S1SSl°n/aSt?r °f °-°°2 kg  Vlnyl  chloride/100 kg polyvinyl
chloride.  The standard has been changed to reflect this correction.

     2.4.4  §61.64(e)

     1.   VC-22,  VC-24, VC-28,  VC-29
              PSSed  s*andard  requiring  that dispersion  resins
               ?°°°-Ppm ""?  t00 stn""gent.   EPA recognized  the
            icul^J "s^PPing  dispersion resins  and  the
         state of technology  relating  to stripping of  dispersion
                                2-38

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resins.  EPA also recognized in the preamble to the proposed standard
that achievement of the requirements for dispersion resins depends
on development of more advanced control technology in the period
subsequent to the promulgation of the standard and prior to the
effective date of some of its provisions.

     Extensive scientific research is presently being conducted
to develop this control technology and these efforts have been
successful for many dispersion resin products.  However, after more
than ten months of concentrated research, there still remain several
dispersion resin products which cannot be stripped to 2000 ppm
residual vinyl chloride.  Stripping capability for these dispersion
resins range from 3000 to 10,000 ppm residual vinyl chloride.  It
now appears uncertain that sufficient time remains to allow development,
engineering, equipment procurement, installation, and demonstration of
the necessary stripping equipment within the maximum compliance time.
Due to these factors, EPA should give additional consideration to
the standard for dispersion resins prior to promulgation of the final
standard.

     Specifically, the industry requests the allowable residual
vinyl chloride content of certain dispersion resins to be set at
6,000 ppm.  The specific dispersion resins to which this 6,000 ppm
limit should apply shall be based on a manufacturers demonstration
that specific resins cannot be stripped on a commercial scale of
2,000 ppm.  The industry pledges its efforts to continue researching
methods of stripping all dispersion resins to a residual
level of 2,000 ppm or less and invites EPA to reevaluate
dispersion resin stripping technology in mid-1978 and to
regulation as appropriate.
vinyl chloride
the status of
amend the
Response:  EPA also recognized in the preamble to the proposed standard
that some grades of resins are more difficult to strip than others.
Therefore, rather than requiring that each grade of dispersion resins
be stripped to 2,000 ppm, the proposed standard permits industry to
average different grades of dispersion resins together over a 24-hour
period.  Only one of the eight manufacturers of dispersion resins
specifically commented that the dispersion resin standard should
be made less stringent.  Only two of several grades of dispersion resins
made by this company cannot meet the 2,000 ppm limit.  In considering
this information and the information obtained prior to proposal of the
standard, EPA has decided that making the standard less stringent is not
warranted.
                                  2-39

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       2.   VC-44

  Comment:   The proposed standard for dispersion resins is not stringent
  enough.   There appears to be a technical  inconsistency in the fact
  that the  dispersion resins cannot be stripped to less than 2 000
  ppm and yet they are easily "stripped"  in the dryer with the monomer
  discharging into the air.   Since the mass transfer of monomer through
  the polymer is,  undoubtedly,  the limiting factor in each case,  it
  would  seem that  additional  product exposure  time in the  "stripper"
  could  produce a  concentration lower than  2,000 ppm.   The conclusion
  drawn  by  EPA that 2,000  ppm will  reflect  the  best available  control
  technology in "2 1/2 years"  seems  pessimistic.   If this  limit
  is  set at 2,000  ppm, there will  be no incentive to reduce it further.  :

  Response:   The primary difference  between  the  polymerization  of
  dispersion  resins  and other resins  is the  relatively large amounts of
  emulsifying  agent  used in  the  polymerization of  dispersion resins
  The emulsifying  agent combined with  strong agitation  prevent
  coalescence  of the polymer particles.  This results  in smaller particles
  than are  obtained by other polymerization processes.  High temperatures
  cannot be used in the stripping process because  this would cause
  coalescence  of the particles and thus degradation of  the final product
  Prolonged stripping  causes discoloration of the  final product.

      There is a difference in the conditions between the stripper
 and the dryer which affects the transfer of vinyl chloride out of
 the resin.  In the stripper the resin is surrounded by water which
 tends to  inhibit the release of the vinyl  chloride from the resin
 The vinyl  chloride would have to move out of the resin into the
 water and  then into the vapor space above  the water.  The drying
 of dispersion resin takes place in a spray dryer, where the small
 resin particles are atomized.   Each particle is therefore exposed
 to a large surface area in the dryer. The water is evaporated
 off the particle.  This eases  the escape of vinyl chloride from the
 particle.

      3.  VC-20

 Comment:   It is not clear how  the residual  amount of vinyl  chloride
 in the  dispersion resin has  a  significant  bearing on stack emissions
 from process  equipment.   It would appear that  steps  can be taken
 without significant  additional  cost to reduce  stack  emissions  from
 process equipment for dispersion  resins  to  the  same  levels as  the other
 resins.

     EPA should emphasize the  importance of special  handling  required
  nn  isPf^sion ^sins  which  have  a  2,000 ppm vinyl chloride content.
 EPA should also announce a schedule  requiring industry to  reduce vinyl
 chloride levels in dispersion resins.

 Response:   The emissions from stacks on dryers, silos, and other process
equipment following the stripping operation are due to residual vinyl
                                    2-40

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chloride in the dispersion resin.  These emissions can be controlled in
two ways.  Either more vinyl chloride can be stripped out of the resin
or control equipment can be placed on the stack.  As explained in the
preamble to the proposed standard, dispersion resins are more difficult
to strip than other resins.  Also, a different kind of dryer is used in
the manufacture of dispersion resins than is used for other resins.
This dryer uses larger volumes of air than the other dryers.  A
control device reducing the effluent to a given concentration therefore
does not reduce the mass emissions from a dryer at a dispersion resin
plant as low as at other resin plants.  At dispersion resin plants, add-
on control devices achieve about the same degree of emission reduction
as stripping to 2,000 ppm.  So there is no advantage to requiring add-on
controls.  The cost of add-on controls at an average dispersion plant
is significantly higher than improved stripping.  For improved stripping,
the installed capital cost is $3,319,000 and the total annualized cost
is $1,363,000.  For incineration, the installed capital cost is $5,287,000
and the total annualized cost is $4,892,000.

     EPA investigated the possibility of reducing the air volume from
dispersion resin dryers by a recirculation system.  This does not appear
to be a practical solution.

     In regard to special handling for dispersion resins, when the
processing (drying) of dispersion resins is completed, the product
contains no more residual vinyl chloride than other resin types.  There
is no provision under section 112 of the Act for setting up a schedule
for reducing vinyl chloride levels in dispersion resins.  EPA can,
however, review the status of control at a later time and revise the
standard as appropriate.

     4.  VC-40

Comment:  Allowing averaging of different resin grades is unfair
to a small polyvinyl chloride plant that makes only one resin grade.
The resin made by this company is a copolymer and is more difficult
to strip than homopolymer.  Other producers have the flexibility
of being able to average together homopolymers and copolymers.

Response:  EPA agrees that the averaging concept does favor the larger
plant making a variety of resin grades.  However, EPA contacted another
company which manufactures the same copolymer as the commentator.  This
copolymer is essentially the only resin produced at one of its plants.  The
company reported wide variations among batches with regard to the degree
of stripping that is achieved.  However, over a 24-hour period there are
a large number of batches produced and the average of all batches consistently
meets the 400 ppm limit.  Differences in recipes used at different plants,
however, can affect the stripping levels achieved.  Considering this
information and the fact that the averaging concept does provide needed
flexibility for the industry as a whole, EPA has not removed the provision
for averaging from the standard.
                                    2-41

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     5.  VC-25

Comment:  In the preamble to the proposed standard, EPA stated that
"since stripping technology is currently in the development stage, it is
possible that lower levels of emissions will be achievable before
promulgation of the proposed standard.  Interested parties are invited
to submit during the comment period factual data on the status of
stripping technology."  Commentator VC-25 believes that EPA should not
lower the 400 ppm proposal for stripping for two reasons:

     (1)  It would disrupt the industry's on-going plans to comply
with the proposal.  It takes time and major new capital investment
to design, purchase, and construct necessary equipment and facilities.
In many cases the two-year statutory limit for waivers is not adequate
to carry out a major change.

     (2)  There is a lot of variation in the degree to which resins can
be stripped.  The company represented by the commentator has directed
its own research organization to seek improvements in its stripping
technology and has actively sought information on various technologies.
While many of these technologies offer some advantages in special areas
and products, there is no universal technology for all plants, products,
and processes.  Within the commentator's own processes and plants, he
has observed a variation in stripping of residual vinyl chloride monomer
from 5 ppm to 600 ppm, exclusive of the dispersion resins which meet the
2,000 ppm limit proposed in the standard.  The commentator is experiencing
great difficulty in achieving the 400 ppm limit for copolymer resins.
Currently, these are in the 400 ppm to 600 ppm residual vinyl chloride
range.

Response:  EPA has decided not to reduce the 400 ppm limit at this
time.  It appears that some resins can be stripped to much lower
levels than others.  Copolymers appear to be more difficult to strip
than homopolymers.  Because of this variation, data on stripping
levels for different products would have to be obtained.  Substantial
reduction in the 400 ppm limit would probably require reproposal of
the standard for public comment.  This would delay the implementation
of any standard.  EPA has decided that revision to the 400 ppm limit,
if any, will take place at a later date after promulgation of the
400 ppm limit.  EPA's decision to not reduce the 400 ppm limit in no
way suggests that States are to be discouraged from doing so as newer
technology is developed.

     6.  VC-42

Comment:  The proposed level of 400 ppm may be satisfactory in the
initial control; however, it should be pointed out that information
available in the literature indicates that residual concentrations
considerably below 400 ppm are achievable in some types of polyvinyl
chloride resins.  Diamond Shamrock and B. F. Goodrich report
achievable levels which indicate that the figure 400 ppm could be
lowered to 100 ppm or less for some resins.
Response:  Same as #5.
                                      2-42

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     7.  VC-28

Comment:  The preamble to the proposed standard suggests that
stripping technology can be developed within two years following
promulgation of the standard.  This assumes that a plant can get a
waiver of compliance.  There is no guarantee that an existing plant
can obtain a waiver.  Also, newly constructed plants cannot obtain
waivers and would have to meet the 2000 ppm limit within 90 days of
start-up.  This would deter construction of new plants.

Response:  It is true that there is no guarantee that a waiver
would be granted to allow the development of stripping technology
for dispersion resins.  However, it is likely that EPA would grant
resin manufacturers the maximum two years to comply with the stripping
part of the standard if they complied with the other provisions of
the standard and reduced the vinyl chloride levels in the resin as
much as possible in the two year period.  This was a consideration
in EPA's decision to base the standard on developing technology
rather than on technology available at the time that the standard
was being developed.

     With regard to newly constructed plants, it is true that
section 112 does not provide for waivers of compliance.  A "new source"
is defined in §61.02 of the General Provisions as a stationary source,
the construction or modification of which is commenced after the
proposal of the standard.  The owner or operator constructing a new
source would therefore be aware of the requirements of the standard
before construction is commenced.  Whereas the owner or operator
of an existing source would have to retrofit a plant to meet the
standard, it would appear that the owner or operator of a source
undergoing construction can more readily design that source to meet
the standard.  It seems appropriate to prohibit newly constructed
sources from operating out of compliance with the standard.

     8.  VC-13, VC-18, VC-21, VC-29

Comment:  The intent of the standard is that once the polyvinyl
chloride resin has been stripped to 400 or 2000 ppm, as appropriate,
all of the emission  requirements from that point on in the process
have been met.  Two  changes in wording should be made to make
the standard consistent with this  intention.

     First, after the resin has been stripped to 400 ppm or 2000 ppm,
the plant owner or operator should be able to open the stripper with
the resin in it without having to  meet the "opening of equipment"
requirement in §61.65(b)(6).  The  vinyl chloride which escapes
from the resin into  the vapor space above the resin should be exempted
from meeting the "opening of equipment" requirement.
                                    2-43

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  _    Second, the standard now requires that the resin be sampled "as it
  is transferred out of the stripper."  This phrase should be removed so
    5 +S P J   uVner °r °Perator can measure the resin in the stripper
  and then be able to carry out additional  functions in the stripper
  without_meeting additional emission requirements before transferrina
  the resin out of the stripper.

  Response:  EPA agrees that the  intention  of the standard is to limit
  n^n^T/tn^Y11  °Perat1°nS followin9 tne stripping operation to 0.04
  or 0.2 kg/100 kg product,  as  appropriate.   Therefore, the standard has
  been  revised so that^samples  of the resin  are  to be  taken immediately
  Ann61" ^nnn   PPing 1S  comPleted-   If the  sample contains no more  than
  400 or 2000 ppm,  as appropriate, operations  beyond the stripping opera-
  tion  are  in compliance  with the  standard even  if those operations  take
  place in  the stripper.  Also, after the stripping  is  completed,  if the
  stripper  is to  be opened,  the vapor space  above  the  resin  in the stripper
  must  not  exceed  "the  opening  of  equipment  standard."   After it  has  been
  established that the  resin meets the  400 or  2000 ppm  requirement,  vinyl
  chloride  escaping into  the vapor space  will  not  have  to meet the openinq
  of  equipment  standard.  In the case where  stripping is done in  the
  reactor,  the  same principle applies,  except  that the  vapor  space above
  the resin has to meet the  "reactor  opening"  requirement immediately
 after stripping.                                                  J

      9.  VC-34

 Comment:  A paragraph should be added to §61.64(e) to permit the
 use of control devices in lieu of stripping to meet the requirement
 for sources following the stripper in polyvinyl chloride plants.

 Response:   This provision has  already been made in §61.64(e)(2).

      10.  VC-12

 Comment:  The vinyl  chloride emission sources following the stripper
 should also  have vinyl chloride  emission limits in  addition to
 residual vinyl chloride  limits in the processed vinyl  chloride  resin
 Emission sources  following  the polyvinyl chloride resin stripper
 account for  46 percent of a polyvinyl  chloride  plant's vinyl chloride
 emissions.   It is  important to have  emission  standards that can  be
 readily measured  and enforced  for these  emission  sources.

 Response:  Stripping the residual vinyl  chloride  content of dispersion
 resins  to  2000 ppm and other resins  to 400  ppm  achieves essentially
 tne_same amount of emission reduction  from  sources  following the
 stripper as  installing add-on control  devices.  Therefore,  there is
 no benefit in  requiring add-on control devices  as well  as  stripping.

     With regard to  the enforcement  aspects,  there  are multiple stacks
on the sources following the stripper.   Essentially all the emissions
from these stacks are due to vinyl chloride left in the resin after  it
                                    2-44

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 is stripped.   Measuring the residual  vinyl  chloride in  a sample of
 stripped resin is  much easier than measuring the emissions  from
 multiple sources  following the stripper,  and provides  the same
 information.

      11.   VC-21,  VC-22, VC-25, VC-29,  VC-31, VC-35

      The proposed  standard requires that  in the  case where
 continuous stripping  is used, "one representative sample of
 polyvinyl  chloride resin is to be  taken for each grade  of resin
 processed or  at intervals of 8 hours  for  each grade of  resin  which is
 being processed, whichever is more frequent."

      VC-21, VC-22, and VC-29 request  that the 8  hour requirement
 be changed to 24 hours.   The rationale for  this  request is  that
 instrument charts  for a continuous stripper reflect adequately  the
 degree of control  attained over the process, and in a system  operating
 properly,  a single sample per day  is adequate.

      VC-25 requests that for batch stripping one sample be  taken
 at random  for each eight hours  of  operation.   The rationale for
 this  request  is that  the proposed  standard  discriminates  against
 a  plant which strips  batchwise  as  opposed to a plant which  has
 continuous stripping.   The plant with  batch stripping would have
 to analyze more samples.

      VC-31  requests that samples be required only once  per  day.

      According  to  VC-35,  there  are no  criteria or guidelines
 provided for  determining the  number of strippers  and samples
 and the types  and  grades  of resin  to be sampled  for each
 individual plant.   Therefore,  the  standard  is  vague and may be
 1 eft  open  to  negoti ati on.

 Response:  The proposed  standard requires that the  vinyl  chloride
 in the  stripped slurry  samples  be  measured  both  during  the  initial
 emission testing within  90  days  of the effective  date (unless a
waiver  of  compliance  is  obtained)  and  on  a  continuous basis.  There
 are no  criteria or guidelines provided for  determining  the  number
 of strippers  and samples  and  the types and  grades of resin  to be
sampled during the initial  testing  period.   At one  time,  EPA considered
 requiring  one sample  of  each  grade  and type  of resin manufactured  at
the plant.  However,  this  could be  disruptive to  production schedules
and does not  seem  necessary because of the  continuous sampling required.
 For the continuous sampling,  there  are specific  requirements.   One
sample  is  to  be taken for each batch of each grade  and  type of
resin stripped.  One  sample is  required for each  batch  of resin
stripped because the  degree of emission reduction achieved  through
stripping  is primarily dependent on the procedures  carried  out rather
than a -control device.  The vinyl  chloride  levels in the stripped
resins are permitted  to be averaged over a 24-hour  period.  A daily
resin sample would give no assurance that the 24-hour average level
was being met on a continuous basis.

                                     2-45

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      12.  VC-25, VC-29, VC-34

Comment:  Increase the averaging time for stripping from 24 hours
to 30 days.  With the 24 hour averaging time, a plant manager would
have to balance production based on meeting the standard rather than
on what customers had ordered.

Response:  As stated in the preamble to the proposed standard, EPA
rejected the option of extending the averaging time to a month
because this would permit higher peak emission levels than averaging
on a 24-hour basis.   EPA has already provided the industry with
considerable flexibility by allowing an averaging time of 24 hours
                              2-46

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     2.4.5  §61.65(a)

     1.  VC-21, VC-26, VC-29, VC-31

Comment:  A zero emission limit is proposed for relief discharges which
can be prevented.  According to the preamble to the proposed standard,
operator error is to be considered preventable.  This statement goes
beyond normal legal responsibility based on, negligence.  A plant manager
may be held responsible only if an operator is improperly trained.
Errors in human judgment, however, are beyond complete prevention.


Response:  Whether an operator error will be considered preventable
or not will have to be decided on an individual basis depending on the
surrounding circumstances.  Examples of preventable operator errors
would be errors due to lack of training or negligence.

     2.  VC-42

Comment:  It is recommended that §61.65(a) on relief valve discharges
be amended to require that all relief valves in vinyl chloride service
in ethylene dichloride, vinyl chloride, and polyvinyl chloride
plants be required to discharge to flares capable of combusting all
vinyl chloride received.

Response:  There are several ways of limiting relief valve discharges
to the atmosphere.  One of these is flares.  EPA is concerned only
that these discharges are eliminated.  If a plant successfully employs
other methods to prevent the discharges, there is no apparent reason
to require flares in addition to the other methods.

     3.  VC-20

Comment:  EPA should require the owner or operator to report by
telephone any emergency discharge into the atmosphere from relief
valves immediately rather than within 10 days, to be followed by a
complete written report of the accident within 10 days.

Response:  There is no apparent benefit to be gained by requiring the
plant to immediately report a discharge.  This would not result in
reduced emissions or reduced community exposure.  Enforcement action
would await the written report in 10 days anyway.

     4.  VC-18

Comment:  Thermal relief valves activate very seldom and emit little
vinyl chloride when they do.  Some of these are located in remote
parts of the plant and can be tied into a control device only with
difficulty.  The benefit for doing this will be insignificant.  EPA
                                  2-47

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 should  exempt these remote thermal  relief valves  from the
toallrelifv         Sta"dard  f°r  rel1ef  valve  discharges  applies
to ail relief valves on equipment in  vinyl chloride  service    FPA
                                                     '


                                                                others .
d      a
                       2-48

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     5.  VC-24
damage occurring as a result
should not be subject to the
Comment:  §61.65(a) should be amended to clarify that the term
"emergency relief discharge" includes steps necessary to repair
                             of such discharges and that such steps
                             emission limitations contained in the
regulations.   For example, a rupture disk will be damaged as a
result of a discharge from an emergency system.  Steps taken to replace
the rupture disk could involve evacuation of a portion of the vinyl
chloride remaining in the equipment.  The limitation upon emissions
from opening of equipment should not apply to this situation.

Response:  Steps necessary to repair damage occurring as a result of
emergency relief discharges are not exempt from emission limitations
contained in the regulations.  Emergency relief discharges are
discharges which cannot be prevented.  Steps taken to repair damage
after a discharge are deliberate and planned and the emissions can
be prevented or at least reduced.

     6.  VC-39

     The proposed standard defines "emergency relief discharge" as a
discharge which could not have been avoided by taking all available
measures to prevent the discharge."  (Emphasis added)  Our contention is
that our facility contains sufficient features to satisfy the "all
available measures" provision.  The following is a summary of the features
in our polyvinyl chloride plant which collectively prevent reactor
relief valve discharges.

1.  Computer control with automatic transfer to back-up computer.

2.  Total back-up analog instrumentation with the "bumpless" transfer.

3.  Two sources of electric power.

4.  Two emergency generators.

5.  Automatic restart of critical motors following a power interruption.

6.  A 200,000 gallon reservoir of refrigerated water for controlling
    reactor temperature.

7.  Inverter powered control of instruments and computer.

8.  Computer actuated chemical system for stopping the polymerization
    reaction.

9.  Computer controlled peak shaving system for reduction of excess
    reactor pressure.

10. Use of a reactor size vessel in the  recovery system for collection
    of  gas surges and thus prevention of reactor over-pressuring.

                                    2-49

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 11.  Computer monitoring and alarm of pressure and temperature for
 abnormal conditions.

 12.  Computer automatically starts maximum cooling water to the reactor
 if the pressure reaches a specified level.

 13.  Computer shuts off all reactor charging operations if a high level
 occurs.

 As can be seen from the above list, we feel we have provided many
 features not mentioned in the regulations.

      In §61.65(a) "necessary" should be substituted for "all available"
 as follows:

      "An emergency relief discharge means a discharge which could not
 have been avoided by taking (all  available) necessary measures to
 prevent the  significant likelihood of a discharge.

 Response: The standard has been  revised by deleting  "all  available"
 measures."   EPA has listed several  methods which  it expects a plant to
 take in preventing discharges.   EPA's primary concern is that the
 discharges are prevented.   If a  company has alternate methods which do
 prevent discharges,  these  are acceptable to EPA.

      2.4.6   §61.65(b)(l)

      1.   VC-21,  VC-24

 Comment:  The  emissions from loading  and unloading  lines are insignificant.
 Section  61.65(b)(l)(i)  imposes too  stringent  a  limitation  upon emissions
 from loading and unloading  lines.   VC-21  states that  the allowable  vent
 from three cars  a  day at an  average-sized polyvinyl chloride plant  with
 small cars will  be 0.09 kg  (0.2 Ibs).   Using  7.6  meter (25  foot)  connecting
 hoses with three cars  a day  the vent  at  760 mm  pressure  would be  less
 than  0.9  kg  (2  Ibs)  per day.  The extra  handling  necessary  with valve-
 to- valve  coupling  at the car is hardly worthwhile.  VC-24  states  that
 the  necessity  for  connecting the unloading  line to  a  pressure or  vacuum
 source  in order  to comply with the  proposed standard  creates  increased
 danger of an uncontrollable  discharge of  vinyl  chloride.

 Response:  The quantity of emissions from each fugitive  emission  source
 may appear to be relatively  small,  but is being regulated because
when the emissions from all  the sources are considered together,  they
 are relatively large.  EPA feels that best  control  technology  has
 been considered  in developing this  section  of the proposed  standard
and that the increased danger of vinyl chloride monomer  discharge is
minimal.
                                   2-50

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     2.  VC-31

Comment:  The requirement for loading and unloading lines should
not be applied to pipeline delivery of vinyl chloride.  To
obtain a residual of as little as 0.0038 m  (0.13 ft ) of vinyl
chloride in a substantial length of pipe would be exceedingly difficult.
Moreover, it does not seem necessary since they are not disconnected
and opened with each loading and unloading.

     Before opening a pipeline to make repairs (necessitated by a
leak or corrosion, for example), the line is purged and drained of
its contents to eliminate fire hazards.  This is done by evacuating
the residual vinyl chloride vapor in a long pipeline below 2 percent
of its volume, except by venting to the atmosphere.  Achieving the
0.0038 m  residual level would require the installation of a number of
valves.  Proper design, however, requires that the number of
valves be kept at a minimum, since valves are a principal source
of fugitive emissions in a pipeline.

     The standard for unloading lines and loading lines should be
changed so that the vinyl chloride has to be reduced to 0.0038 m  or
2 percent, whichever is greater.

Response:  Since pipelines are not opened on a routine basis, the
standard has been revised to exclude them from meeting the
requirement for unloading and loading lines in §61.65(b)(l).  When
pipelines are opened, they are required to meet the opening of
equipment standard in §61,65(b)(6).
                                  2-51

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       3.   VC-36

  Comment:   Unloading lines  from river barges  should  be  given  special
  consideration  due  to the greater volume  of vinyl  chloride  unloaded
  h°L5 5argeBc?m2c/uwVw^a  rail  car or truck"   A  sentence  should
  be  added  to  §61.65(b)(l)(i) so that  the  vinyl  chloride,in  unloading
  lines from barges  would have  to be reduced to  0.0038 m6  (0.13  ft3) at
  standard  temperature and pressure  per 225,000  kg  (500,000  Ib)  of vinyl
  chloride  unloaded.

  Response:  The standard is based on  best  control  technology  to
  minimize  emissions.   The standard as  a whole will result in  greater
  emissions  from a larger plant  than from a small plant.  The  same
  principle  applies  to  unloading  lines.""

      2.4.7  §61.65(b)(3)

      1.   VC-21, VC-25, VC-29

 Comment:   No account has been  taken of the use of reciprocating com-
 pressors  which are widely used in the industry.  Section 61.65 (b)(3)(iii)
 should be retitled "Rotating Compressors" and a new paragraph (b)(3)(iv)
 should be inserted entitled "Reciprocating Compressors" with  wording
 essentially the same as paragraph (b)(3)(ii).

 Response:   This provision  has  been added  to  the promulgated standard.

      2.   VC-24

 Comment:   §61.65(b)(3) should  contain additional  language to  the
 effect^that direct  venting  of  gases from  seals  to  a  control device
 is equivalent to  utilization of double mechanical  seals.   The
 general provisions  for demonstration  of equivalent emission control
 equipment  would require a decision  by the  Administrator for each
 plant.  This process  is cumbersome  and unnecessary.

 Response:   The  two  are not  equivalent.  Control devices control
 to around  10 ppm while  a properly operated double  mechanical  seal
 would have essentially  no emission losses.

     3.  VC-25, VC-27

 Comment:   EPA should withdraw the requirement of using double
mechanical  seal pumps  in place of single seal pumps now used.
According  to VC-25, this could be done by limiting the requirement
for double mechanical seals to pumps handling liquids containing
more than  50 percent vinyl  chloride by weight (rather than 10  percent,
as proposed).   This should be done for several reasons:
                                   2-52

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      (1)  The emissions  from a single mechanical seal pump are
very  small.  An average  single pump with a single mechanical seal
and handling refined vinyl chloride would emit only 0.0033 percent
of the  16 kg/hr which  EPA calculates an average plant will emit
after the standard is  in effect.  A single pump with a single
mechanical seal pumping  a liquid containing 10 percent by weight
vinyl chloride would emit 0.00033 percent of the target 16 kg/hr.

      (2)  Single mechanical seals have a reliability factor of
0.90  -  0.95, if properly fitted for vinyl chloride service.  Double
mechanical seals and their attendant flush holders, filters and
gauges  are estimated to  have an overall system reliability of
0.70  -  0.80.  To insure  the integrity of the overall unit, redundancy
of such pump systems would be required, with comparatively insignificant
reduction of vinyl chloride emissions estimated to result.

      Mechanical seal systems on resin slurries and solutions are
even  more prone to failure than average because the resinous
materials tend to foul the pressure springs and the moveable seal
face  preventing proper automatic wear adjustment.  The proposal
to limit the use of double mechanical seals for liquids containing
50 percent or more vinyl chloride would exempt resin slurry or
solution pumps from regulation.

      (3)  In the case of pumps required to transfer specification
quality vinyl chloride through pipelines in the process unit or
in loading operations, the inclusion of minute quantities of
"an environmentally acceptable fluid such as ethylene dichloride"
designed to flow into the pump, not out of the pump," would
obviously contaminate the product and require purification facilities
to remove such impurities or the use of alternate means to preclude
the possibility of product contamination.   Such measures would
be expensive and create operation monitoring parameters now not
envisioned, with further high costs attendant with them.

Response:   EPA is aware that each fugitive emission source, such
as one pump, taken by itself causes relatively small  emissions.
Fugitive emissions considered as a whole are a significant source
of emissions, and the goal  of the standard is to reduce these.

     The 10 percent figure was selected as a means of distinguishing
between equipment which handles vinyl  chloride and that which does
not.

     Double mechanical  seal  pumps are used industry-wide for emission
reduction.   Where these pumps are not applicable, seal!ess pumps have
been  used.
                                2-53

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      2.4.8  §61.65(b)(4)

      1.   VC-29,  VC-22

 Comment:   Section 61.65(b)(4) requires the installation of a
 rupture  disc preceding the relief valve on equipment in vinyl
 chloride  service.  The preamble to the proposed standard states  that
 "an equivalent method of control  would be to connect the discharge
 line from a relief valve to process equipment or to a recovery
 system."   This stated equivalent  method should be included as
 part of  the regulation so that the regulation would be complete
 in itself and not be  dependent on the preamble for interpretation.

 Response:   In accordance with this suggestion, §61.65(b)(4)  has  been
 modified  as follows:   "Vinyl  chloride emissions due to leakage from each
 relief valve on  equipment in  vinyl  chloride service are to be  minimized
 by installing a  rupture disc  between  the equipment and the relief  valve,
 or by connecting the  relief valve discharge to a process  line  or recovery
 system, or equivalent as provided in  §61.66."

      2.   VC-25,  VC-26

 Comment:   The requirement in  §61.65(b)(4)  for  installation of  rupture
 discs between relief  valves and the equipment  served by the  relief
 valve should be  removed,  or revised to  provide for the alternative  of
 having a  formal  program of relief valve testing and  maintenance.  This
 should be  done for  several  reasons.

      (1)   A properly  selected,  installed and maintained relief
 valve is  less  likely  to  leak  than  a rupture  disc.

      (2)   The  rupture  disc prevents the relief valve  from  suffering
 premature lifting  and also eliminates  the  chatter or sporadic
 relief that can  occur  when the vessel is near  relief  pressure  and
 the valve  doesn't reseat  properly.  However, when  the rupture  disc
 fails, pieces of the failed disc  could  more  than likely wedge  the
 relief valve open and  cause relief  valve failure.  This, then, would
 cause  the  emission  of  more vinyl  chloride than  chattering  or premature
 relief which can  be cured  by  dropping system pressure.

      (3)   A dangerous  situation will arise if  the  rupture  disc
 slowly leaks vessel pressure  into the space between  it  and the relief
valve, thus effectively raising the relief pressure by  100 percent.
Venting the space between the rupture disc and  relief valve will
avoid this situation,  but creates another potential emission source.

Response:   The proposed requirement for rupture discs  is not being
changed.   There  is apparently a difference in opinion as to whether
relief valves leak more than rupture discs.  Routine maintenance  of
                                2-54

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relief valves may reduce leaks.  However, in EPA's judgement relief
valves do tend to leak more than rupture discs, and the addition of the
rupture discs will reduce emissions.  Preventing the leaks frpm
relief valves in the first place appears to be a more efficient way
of reducing emissions than detecting the leaks after they have
already occurred.

     In regard to the second point that pieces of a fragmented rupture
disc can wedge relief valves open, modern rupture discs are designed
so they do not fragment.  Knife blades can be placed above the disc
or the disc surface can be scored.  When pressure is exerted on the
disc, the disc divides into equal pie-shaped sections .without
fragmenting.

     A slow leak between the rupture disc and the relief valve can be
detected with a pressure gauge or by venting the space between the
disc and valve and checking for leaks from the vent.  Venting the
space between the rupture disc and relief valve does create another
potential source of emissions.  However, since the rupture discs are
less likely to leak than relief valves, the emissions from the vent
are less than if there were no rupture disc.

     3.  VC-35

Comment:  In addition to requiring the installation of a
rupture disc between the equipment and the relief valve, a
pressure gauge is recommended to be required between the rupture
disc and the relief valve so that rupture disc leaks or ruptures
are readily apparent, especially where relief valves may not
relieve, yet leakage could occur and go undetected.

Response:  The use of a pressure gauge between the rupture disc
and the relief valve is recommended in the SSEIS, Vol. I.  Pressure
build-up between the rupture disc and relief valve could prevent the
relief valve from relieving when it should.  Therefore, the pressure
gauge is needed  to protect the equipment that is serviced by the relief
valve.  Since the pressure gauge is needed primarily for safety
reasons rather than emission control, EPA has highly recommended
it but does not  require it.
                                    2-55

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       2.4.9   §61.65(b)(5)

       1.   VC-14,  VC-18,  VC-21,  VC-25,  VC-26,  VC-27,  VC-28,  VC-29,  VC-34

  Comment:  A  provision for emergency manual venting  should  be added to
  §61.65(b)(5).  Discharges from relief valves in polyvinyl  chloride
  plants are controlled by methods including,  but not limited to,
  proper instrumentation, injection of  chemicals, and the manual venting
  of gases  to  the  monomer recovery system or other stand-by  methods.
  Use of these techniques is the primary response to  a reaction upset.

      When these  actions fail to establish desired temperature and
  pressure, a hazardous condition is created.  As pressure and temperature
  rise toward relief ratings, the rate  of reaction more than doubles for
 every 10 C rise  and the degree of being out of control becomes a geometric
 progression.   For this reason the quantity of vinyl chloride evaporated
 in order to gain control of the reaction at burst pressure is significantly
 greater than  that needed to regain control at lower pressures and temperatures
 via the manual  technique.

      Use of manual  venting to the atmosphere recognizes this problem
 and relies on vinyl  chloride evaporation to cool  the reactor contents.
 Manual venting  can  permit  the reactor to be brought under control
 more quickly.  Since the manual valve can  be  completely closed,  a
 lower total quantity of vinyl  chloride will  be  emitted to the
 atmosphere.   Once a  relief assembly,  including  rupture disc and
 relief valve, functions  it is  not certain  that  the  relief valve
 will  reseat;  this would  permit continuing  emissions  of vinyl  chloride.
 It is  estimated that manual  venting will  reduce potential  emissions
 by 50  to  80 percent.

     The  proposed standard prohibits manual venting  of vinyl  chloride
 to the atmosphere, even  in cases  of extreme emergency.   It  is
 conceivable that  there will  arise on very  infrequent occasions the
 necessity  for doing  this.  An  example  could be  in the  case  of
 failure of abatement  equipment  or very severe weather,  such as a
 tornado, which  has so badly  damaged the plant that the  installed
 safety equipment  is inoperable, and manual venting of a small part of
 the reactor charge could prevent the uncontrolled venting of the
 entire charge.  Such occurrences are not expected to happen more than
 once in a  few years, but when they do, operators should not be
 forbidden  to exercise good judgment.   The  required reactor  chart
 record will show  when this has  happened, and  the owner should report
 the occurrence, just as in the  case of a relief valve release.

     Accordingly, the use of manual venting to the atmosphere should
 be permitted after all normal controls have failed,  but prior to
the use of the last resort, the emergency relief device.  It must
be understood  that this assembly is a primary device for preventing
a major catastrophe,  the rupture of a reactor.
                                 2-56

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     It is not practical to construct a gasholder or abatement
device large enough to handle all of the monomer from all of the
reactors in a plant or even one Targe reactor.

     VC-25 gave an example of how mahual venting was use'd to
control the pressure arid temperature in a vinyl acetate copolymer
reactor when the short stop addition system failed to function.  The
reactor became uncontrollable at 6:20 a.m.  Two additions of
refrigerated water failed to restore control.  At 7:35 a.m., with
the pressure at (195 psi) a'nd rising sharply, tire reactor 'was
vented to the air.  The reactor rupture disc Would have failed at
220 psi anyway and no later than, 7:40 a.m. based on the slope of
the pressure curve.  The material discharged from the vent was
semi-solid; thus, any vent recovery system would shortly haVe
been inoperative and the operating status of relief valves Highly
questionable.

Response.  The standard has been revised to allow emergency
manual venting.  Emergency manual venting could be used in
situations like the one where a tornado damaged the safety
equipment in the plant, but not in situations like the one
described by commentator VC-25.  In the situation described by
commentator VC-25, the reactor contents could be vented to a
gasholder.
                                  2-57

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      2.4.10  §61.65(b)(6)

      1.   VC-29

 Comment:  EPA discusses vacuum as a means of meeting the opening of
 equipment standard.  The assumption that larger pressure vessels will
 withstand vacuum is incorrect.  Many will not, despite a substantial
 pressure rating; this leaves water purge as the only practical method of
 gas removal.   This can be very difficult on a remote tank in cold weather.

 Response:  These statements are correct.  Even though these problems do
 exist, EPA feels that technology does exist for meeting this part of the
 standard and  it should be used.  Plants have several options for meeting
 the standard  including the ones named and also purging with nitrogen.

      2.   VC-20

 Comment:   Fugitive emission sources are the largest sources of
 emissions to  the atmosphere.   We therefore question the rationale
 of the proposed standard which requires that the vinyl  chloride
 concentration in process equipment greater than or equal  to 5,500
 liters in volume be reduced to two percent by volume at standard
 pressure  and  temperature before the equipment is opened to  the atmos-
 phere, and 110  liters  of vinyl  chloride at standard temperature and
 pressure  for  reactors  smaller  than 5,500 liters.   There appears to be
 incongruity in  logic  to  allow  such high emissions  from  fugitive sources,
 the most  important  source,  and  only 10  ppm for other sources.   EPA
 should also clarify how  these  measurements  are to  be made.

 Response:  There  are  three  points  made  in  the comment.   The
 responses  to  these  are as follows:

     1.   The  cut-off point  of 4.75  m3 (5,500  liters)  was  chosen
 for several reasons which were  explained  in the  preamble  to  the
 proposed  standard.  However, the cut-off point does  not apply
 to  reactors.  Since reactors have  traditionally  been  opened much
more frequently than other  process  equipment,  a  separate
standard was  proposed for the opening of reactors  in  §61.64(a)(2).

     2.  The  10 ppm limit and the limits for  opening  of equipment
are each based on best control  technology.  The  10 ppm  limit is
to be met through installation  of control devices.  The limits for
opening of equipment are to be met by procedures such as evacuating
or purging the vinyl chloride out of the equipment.  The vinyl chloride
removed from the equipment must also be treated  in a control device
                                   2-58

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and meet the 10 ppm requirement.  The overall mass emissions from
opening of equipment will be smaller than the emissions
from stacks meeting the 10 ppm requirement, because the equipment
is opened on an infrequent basis for insnection a,nd maintenance.

     The emissions from opening of equipment can be calculated.  If
vacuum is used, for example, the calculation would be based on the
number of evacuations, the vacuum involved, and the volume of gas
in the vessel.   If the vessel is purged, the vinyl chloride concentration
in the equipment can be measured and the total vinyl chloride emissions
calculated based on the volume of gas in the vessel.
                                  2-59

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      2.4.11  §61.65(b)(7)

      1.  VC-21, VC-22, VC-25, VC-26, VC-27, VC-29

 Comment:  The use of the word "no" in §61.65(b)(7) is inappropriate
 because the prohibition is impractical, if not impossible to enforce.
 However, there is no argument with the spirit of the provision, and the
 following revision is suggested:

      "(7)  Samples:   Unused portions of vinyl chloride samples
      shall  be returned to the process or to an abatement device,
      and sampling techniques shall be such that sample containers
      are purged into a closed process system."

 Response:  The suggested change has essentially been incorporated  into
 the promulgated standard.   This revision is only a change in wording and
 does not represent a change in the level of control  required to meet the
 standard.

      2.   VC-18

 Comment:  This  part  should be changed to allow the plant to  take vinyl
 chloride  samples  any way they choose so  long  as  vinyl  chloride emissions
 are minimized for instance by scrubbing  them  in  a proper control device.

 Response:   The  purpose  of  this  section  is  to  prevent emissions  during the
 collection  vinyl  chloride  samples.   It  is  unclear how a  control device
 could be  used to  achieve the  same  goal.

     3.   VC-29

 Comment:  The standard  for sample  flasks  is applicable only  to  liquid
 chemicals such  as  vinyl  chloride monomer sampling  in  vinyl chloride
 plants.   Consideration  should be given to  routine  and non-routine
 sampling.   EPA  should consider  limiting  the scope  of  this control to
 routine samples containing  20 percent or more  vinyl  chloride monomer by
weight.

 Response:  The standard  has been revised to cover  samples containing
 10  percent or more vinyl chloride by weight.   This is consistent
with the other fugitive emission regulations which apply to
equipment "in vinyl chloride service."
                                  2-60

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     2.4.12  §61.65(b)(8)

     1.   VC-43

Comment:  A plant operated by the commentator produces a
dry, unrefined ethylene dichloride product and any vinyl chloride
produced is basically a minor by-product.   The requirement for
a continuous leak detection system, as described in §61.65(b)(8)
(i-iii)  is felt to be unnecessary and would serve a very limited
function when compared to its cost, installation and maintenance^
A periodic, manual monitoring program would be a more equitable
alternative.

Response:  The leak detection program is required only for equipment in
vinyl chloride service.  "In vinyl chloride service" means that a piece
of equipment contains or contacts either a liquid that is at least TO
percent by weight vinyl chloride or a gas that is at least 10 percent by
volume vinyl chloride.  EPA has discussed this provision with the
commentator.  There is no equipment in this particular plant which is
"in vinyl chloride service."

     2.   VC-31

Comment:  The proposed standard does not give a clear definition of
leak.  By inference, any measurement by the vinyl chloride detection
equipment which shows a higher background level than normal is
construed to indicate a leak.  A better proposal would be to
define a leak as a measurement of greater than 25 ppm.  This would
minimize the continuous search for very small leaks which do not
materially increase emissions.

Response:  EPA considered including a definition for leak in the
proposed standard.  From an enforcement viewpoint this would be
a preferable approach.  However, the background concentrations in
plants are expected to vary depending on the size of reactors, the
age of the plant, the layout of the plant, and whether the plant
is open or enclosed.  The background concentrations are expected
to decrease as engineering controls are implemented to meet the
Occupational Safety and Health Administration standard.  The higher
the concentration defined as a leak, the less regulation of the
smaller leaks.  Twenty-five ppm is relatively high.  EPA visited
one newer plant which defined 0.5 ppm as a leak detection level.  It
is doubtful that this background concentration will be achieved
at all plants by the time the standard is promulgated.  Therefore,
EPA has decided to  define leak on a individual basis at each plant
depending,,on the measured background concentrations.
                                  2-61

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      3.   VC-31

 Comment:  It is recommended that leak patrols  using the portable monitoring
 system be done on a regularly scheduled basis  rather than  continuously.
 A weekly patrol should be adequate for this  function with  the detection
 equipment doing the monitoring between patrols.

 Response:  Both the proposed and promulgated standard require only
 that the portable hydrocarbon detector be  used routinely rather than
 continuously to find small  leaks.

      4.   VC-26
                        r                         ''
 Comment:  Preparation and submittal  of a specific  leak detection and
 elimination system within 45 days  is a very  short  period.   It should
 be extended to at least 120 days.   The establishment of new
 monitoring points,  assembly of equipment and training of laboratory
 personnel will  require at least 4  months.

 Response:  The proposed and promulgated standards  require  only  that
 a  description  of the leak detection  and elimination  program be
 submitted to EPA within 45  days after promulgation  of the  standard.
 This will allow EPA to review the  program  and  approve or disapprove
 it before it has  to be implemented.   The program has  to be  implemented
 90 days  after  the standard  is  promulgated.

     5.   VC-18

 Comment:   In  §61.65(b)(8)(vi)  the  standard has a provision  for  each
 operator to  develop  a  definition for a  leak  using some  measure  of
 vinyl chloride  concentration  above background  levels  in  the fixed
 point monitoring  system.  This  approach  is inoperable  because
 (1) changes  in  wind  direction  and  other  weather conditions will  cause
 the background  levels  at  some  monitoring points to fluctuate widely
 and (2)  the  intermittent  batch  nature of normal polyvinyl chloride
 operations will cause wide  variation  of  vinyl  chloride  concentrations
 depending on what operations  are occurring.  This will  cause the
 background variation to be  similar to the vinyl chloride increment
measured when  a leak occurred,  so it would  be difficult to separate
 a  leak from fluctuation of  the  normal background.  EPA should delete
this section and  let each plant handle how leaks shall be detected.

Response:  In  EPA's judgment,  the fact that  leak will be defined
on an indivudual basis for each plant provides  the flexibility
needed to account for these variations.
                                  2-62

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      6.   VC-20

 Comment:   EPA should  specify  that  companies  are  required  to  keep
 permanent records of  the  leak detection  results.  There should  also
 be  scheduled service, maintenance  and calibration of  leak detection
 equipment.  These records must be  subject  to inspection upon
 request.   EPA should  also establish a level  of vinyl  chloride not
 to  be exceeded and  require reporting violations  by  the owner or
 operator  when they  occur.

 Response:  EPA requires that  the records of  leak detection results
 be  kept for two years.  The purpose of the leak  detection program
 is  to ensure that emissions from leaks are minimized  by detecting
 them and  correcting them as soon as possible after  they occur.
 Keeping the leak detection results for longer than  2  years would
 not serve this purpose.

     Section 61.65(b)(8) of the proposed standard requires that each
 leak detection program include a calibration  and maintenance schedule
 for the leak detection program which is acceptable  to the Administrator.

     In the promulgated standard a sentence  has been  added which
 specifies  that the continuous monitoring system is  to be  calibrated
 daily using the same calibration gases which  are required for
 Test Method 106.

     The  reason EPA has not established a level of  vinyl  chloride
 not to be  exceeded is explained in comment number 2 in this section.
 The standard does not require the owner or operator to call EPA when a
 leak is detected for several   reasons.   First, the purpose of the program
 is to find sources of leaks and redesign equipment  to reduce leakage
 from these sources and to correct leaks that  do occur as  soon as possible.
A plant owner does not violate the intent of  the standard by having a
 leak, but  by not correcting the leak.   EPA expects  leaks  to occur.
Also, leaks occur relatively  frequently and  it would  be burdensome for
both the plants and EPA if all the plants called EPA when a leak occurred.
                                  2-63

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       2.4.13  §61.65(b)(9)


       1.   VC-14,  VC-17,  VC-18,  VC-21,  VC-22, VC-26, VC-28, VC-29

  Comment:   It is  recommended, that the  first sentence of this
  section be changed  to read as  follows:
                         °f Vlnyl Ch1on'de In each inprocess waste-
                         9re^er than 10° Ppm vinyl c^lon'de measured
            n             a Piece of equipment shall be reduced to
  less  than  10 ppm by weight before being mixed with any other inprocess
 wastewater stream which is 10 ppm or less; before being exposed to
                                     ged to a wastewate? treatment
                                     U"treated as a "abater.   This
 stand-1! pr°P°s!d to Clar1fy the standard.   Presently  the
 standard can be interpreted to require stripping all wastewater
 streams separately.  The intent to prohibitPLpliancrthrough

 thai ihe Inn"™31!!  ,h" ^ r^^ wrd^-   Jt ** a^o  requested
 has to be treated       cut-°ff P°lnt that determines which wastewater
        nf th                  -         ^eded to be clarified.  The
 intent of the standard was  to  prevent  dilution rather than require
 has bLn ^±ef °f 1ndiv1dual s^eams.  The promulgated standard
 if retlinld       aS  suggested' excePt that the 10 ppm cut-off point


      2.   VC-13, VC-21

 Comment:  According to  commentator VC-13, the definition of
 HpJfnpf^  wastewater" would be more clear and concise if it was
 defined  as  water which contains greater than 10 ppm of vinyl chloride
 as  it  eaves  any piece of equipment."  VC-21  suggests removing
              C°nde  f™                    '^process  wastewater"
vinyl  hlride."
                      -
                        9
                                 definition of

                                    SayS
                                                             containing
Response:  The purpose of the  rather  complicated definition of
          ^hn-f^^15^0 d1st1n9"ish  ^tween wastewater that is
          K 5   standard  and wastewater which is discharged to a
            »P ?nd.ls,suWect  to  EPA's  effluent guidelines and
             Polyvmyl  chloride"  is included in the definition

                                     chlor1de aiways contains at
     ta
standards.
                               2-64

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     3.  VC-23

Comment:  EPA proposes to limit the concentration of vinyl chloride
in inprocess wastewater to 10 ppm or less.  However, EPA has not
sufficiently investigated the more attractive possibility of recycling
inprocess wastewater.

Response:  The 10 ppm limit provides incentive for recycling because
of the cost involved in treating the water.  See Section 2.8, Comment
No. 1.

     4.  VC-14

Comment:  As noted in the preamble, steam stripping is the most
suitable device for reducing vinyl chloride in inprocess wastewater.
Section 61.65(b)(9) requires that the overhead from the stripper be
routed to a furnace for further treatment.  Neither does the data
contained in the SSEIS, Vol. I support, nor do we know of
any data which supports, the achievement of a 10 ppm bottoms stream
from a stripper which is also producing an overhead product suitable
for incineration.  The standard should be revised to require the
concentration of vinyl chloride be reduced to 25 ppm instead of 10 ppm.

Response:  If the overhead from the stripper alone cannot support
combustion, it can be blended with concentrated hydrocarbon wastewater
streams or supplemental fuel.  It is not apparent how revising the
standard to 25 ppm would solve this problem.

     5.  VC-37

Comment:  Activated carbon is available as a method for reducing
vinyl chloride concentrations in wastewater.  A reliable manufacturer
of resins who develops systems on a proprietary basis has informed
me that a pilot plant has been effective in cleaning up ethylene
dichloride (a closely related material) from water.  With 0.2 percent
(2000 ppm) in the intake wastewater they were able to clean the water
up to 0.05 ppm and steam off the catch for reuse of the product gas
and reuse of the resin.  Because no bench or pilot tests have
been run with vinyl chloride in wastewater, it is important that
work be done at once with vinyl chloride.

Response:   EPA appreciates the information provided by the commentator.
Before making the emission limit for inprocess wastewater more
stringent, and in effect requiring activated carbon as the control
measure, as suggested by the commentator, EPA would have to conduct
studies on the effectiveness of activated carbon on reducing vinyl
chloride concentrations in water.  This would delay standard setting.
EPA may conduct these studies at a later date.  Meanwhile plants
could employ activated carbon instead of waste stripping to meet the
standard.
                               2-65

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      2.4.14  §61.66

      1.  VC-32

 Comment:  The right to use equivalent methods should be indicated
 clearly in the standards without reliance on reference to the
 preamble.  This is especially true in the area of analytical
 methods, where no two laboratories ever follow precisely the
 same techniques, and in methods used to reduce fugitive emissions.
 Insistence on a single method discourages innovation in the
 development of improved technology.

 Response:  Provision for equivalent control  methods for fugitive
 emissions is included in §61.65(b) and §61.66 of the proposed standard.
 Provision for equivalent test methods is included in §61.67(g).

      2.  VC-24

 Comment:  The standard should include guidelines that the Administrator
 will  use in determining that a proposed control  method produces an
 equivalent emission reduction.  A procedure  for  contesting this
 determination should also be specified.

 Response:   Since there are many parts of the standard where equivalent
 methods are allowed and because the nature of the equivalent methods
 is unknown at this  time,  it would be difficult to write guidelines
 which would be  applicable to all  situations.  -Providing for a procedure
 for contesting  EPA's determination could indefinitely delay the
 installation  of controls.

      3.   VC-18

 Comment:   A sentence should be added  to  §61.66 indicating  that if
 EPA does  not  act  upon  a  request for an equivalent control  method
 within  90  days,  the  requesting operator  should be allowed  to
 proceed with  his  alternate.

 Response:   If an  owner or operator  chooses to  request  to use an
 equivalent  method of control  for  initial compliance with the standard,
 he  must do  so within 30 days  of  the effective date.  He should at the
 same  time  submit a request  for waiver of compliance pursuant to section
 112(c)(l)(B)(ii) of  the Act.   The request for waiver of compliance
 should provide for the case where a control method is determined  not
 to  be equivalent, and time  is  required to install another type of
 control.  The two year deadline cannot be exceeded in any event.

     Of course, an owner or operator can request  to use an equivalent
method sometime in the future  to replace the method he used  for
 initial  compliance.  In this case,  there is no deadline for
submitting a request for using an equivalent method.  The old method
of control can be used until EPA determines whether the new method
 is equivalent.

                              2-66

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     2.5  Testing, Reporting, Recordkeeping

     2.5.1   §61.67

     1.  VC-13, VC-21, VC-26, VC-27, VC-29

Comment:  Section 61.67(c) of the Emission Tests should be amended
to eliminate the requirement that emission tests be conducted
under the maximum production rate at which the equipment will be
operated.  The reason for the requested change is that the maximum
production rate of a plant under optimum conditions may not be
feasible or safe at the time of the test.  Flexibility under conditions
existing at the time must be allowed to insure that operator safety
and public welfare is protected.  Unique operating constraints may
also require that tests be performed at levels well below maximum
rates, owing to individual processes, which would require the
Administrator's approval.

Response:  The only scheduled emission test is the initial test
that is required to show that the plant is in compliance.  After
that, tests are performed only at the request of EPA.  Since tests
are likely to be required relatively infrequently, it does not seem
unreasonable to request a plant owner to schedule his operations as
required for the test.  The purpose of the test is to observe whether
the control equipment is sufficient to keep the emissions below the
standard when it is operating at its peak load.  If the standard
is met under these conditions, it can be more readily assumed
that the standard is being met on a continuous basis.  It should
be noted that testing is not required during maximum operation of
the equipment, but only "while the equipment being tested is operating
at the maximum production rate at which the equipment will be_ operated."
(emphasis added)

     2.  VC-11

Comment:  In regard to the 10 ppm concentration standard for several
of the stack emission sources, including the specifications for averaging
time, oxygen content, and moisture content would clarify compliance
determination.

Response:  The averaging time is specified indirectly through Test
Method 106.  Section 61.67(a)(g)(1) specifies that Test Method 106 is to
be used for those emission points that have a 10 ppm concentration
limit.   Test Method 106 requires that an integrated bag sample be collected
for a minimum of one hour three times.   This means that the emissions
are averaged over a period of at least three hours.   A specification has
been added to the promulgated standard which would require that a time-
weighted average be used, if the three runs are of different length.
In the proposed standard, the concentration of vinyl  chloride was to
be corrected to 10 percent oxygen (wet basis) if combustion were used
as the control measure.   In the promulgated standard, this requirement
has been expanded to all  control measures.
                                  2-67

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       3.  VC-20, VC-25
  S°?!!!!"t: .The frequency of emission  testing  should be specified.
  circumstances      ** 9ranted U^SS  there are  overriding or extenuating
    nnv
       y
                      mef urei?e^s  a™  required on a continuous basis
                      3-d ?tnPPin9 levels.  For other stack emissions,
  90 davn    h       e"lssl°n  tef  1s the 1n1«al test required within
  nShP^Lc^-     effectTve date  (unless a waiver is obtained).  Any
  other  testing  required is at the  discretion of EPA.  For example  EPA
  may require  an  emission test for  the monomer recovery system ?n a
  polyvinyl chloride  plant if emission excursions are repeatedly measured
  by the continuous monitor.  Waivers of emission testing are  ikely to
  tha?ro"-cd-°nly 1n.cases,where EPA has other substantial evidence
  that emission requirements are being met.
ic -Kn4;  VC~2°* uComment:
 ines   EPAr?hnh?/m?Unt-
lines.   EPA should also i
                           EPA should clarify how the owner or operator
                            -Vlnyl Chl°ride in Ioad1n9 or unloading
                            icate how this will  be enforced.
                        u          to meet the ^quirement  for  loading
    ^           lines.   The method for meeting  the  requirement is  to
 to EnpA°rP?hf stdanHnt°Ha Standard °Perat1ng P'ocedure'wh'ch  ?s available
 on a  rontJnp h«?c  I   °Peratln9 Procedure is  required  to be available
 SroLSS   uhS;L^hthoSS».p5rsons  resP°nsl'ble ^r carrying out the
 procedure.   Whether the method  used  meets the emission requirement can
                           0n-   EP^ can enforce the sSndSd Sr^Sjh
 of hP   nm'nn             operating procedure, through inspection
 Sit She  procedure     '  "     °U9h Observat1on of Persons  carrying

      5.   VC-25
witin   rhinH      WHeth?r Cont1nuo«s measurement of emissions
with a vinyl chloride detector is required or not.  If an acceptable
automatic vinyl chloride detector is in operation at a par??cu?ar
plant, emission tests should be waived.                particular

Response:  Continuous measurement of emissions with a vinvl  chloride
detector is required for the reactor; stripper; mixing^e ghing  and

SSrdf??at?nnaiv?rSi; ^^ re*COVery System; ethylene d1chl5r1dl
?eacSr-  InSVhl rlS ?ride-f°rmati°2 and Purification;  oxychlori nation
The vinvl ?MnHHfHor\-deV1.Ce USed for caPtured fugitive emissions.
it is ?n  HP .cln   dete?tSr 1S  not a standardized reference  method;
                    ™ lndlca*or of emission levels.   Test Method 106

                                                                1t  is
                               2-68

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     6.  VC-13, VC-18, VC-21, VC-22, VC-26, VC-27, VC-29

Comment:  Section 61.67(e) requires that emission test results are
to be determined within 30 days after the emission test and that
the determinations are to be dispatched to EPA by registered mail
the day following receipt of the determinations.  This requirement
should be changed so that the determinations are required to be
reported to EPA by U. S. mail postmarked within 15 days following
the determination.  There is no urgency in reporting such data and,
given the present state of our postal delivery system, there is no
reason for registered mail.

Response:  A source is supposed to be in compliance with the standard
within 90 days of the promulgation of the standard.  The proposed
standard requires that the emission tests be done within the 90 day
period, and permits an extra 30 days for determination of results.
It seems unnecessary to allow two more weeks to mail the results.
The purpose of using registered mail is to document the fact that
emission data have been sent and received.  This way if the results
are lost in the mail, there will be no question that they were sent.

     7.  VC-13, VC-21, VC-22, VC-26, VC-27, VC-29, VC-30

Comment: . It is recommended that paragraph (c) be changed so that a
general rather than a detailed description of the method used or the
procedure adopted to insure compliance with the standard is required.
For many abatement systems employed in the industry, detailed
descriptions of the equipment, the operating conditions, and the
functional characteristics of the equipment are trade secrets and,
in many cases, patentable technology.  The use of this technology
by other parties should be on a technology-fee basis which is established
by the company developing the abatement equipment.  If EPA would like
additional information concerning the system, a section 114 request
under the Clean Air Act would be an appropriate approach.

Response:  The promulgated standard has been revised to require a
"description" rather than a "detailed description."  EPA agrees that
a detailed description is not necessary in the initial report.
Additional information can be gathered as necessary under section 114
of the Act or through inspection.  If EPA does request information
of a proprietary nature, the Clean Air Act does provide for an owner
or operator to request confidential treatment of that information.
                                  2-69

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      8.  VC-27

 Comment:  Section 61.67(g)(l)(i) should be amended to take cognizance
 that it is impossible to sample the exit of a flare.  Sampling of a
 flare should not be required if it can be demonstrated that such
 a control  flare is actually operating.

 Response:   EPA is aware that the exit of a flare cannot be tested
 with Method 106.   EPA, however, has no data which indicates that
 a flare is as effective as an incinerator in controlling vinyl
 chloride emissions or that a flare can meet the 10 ppm requirement.
 Therefore, a blanket exemption for testing cannot be granted.   If an
 owner or operator could provide data__to EPA that showed that a
 flare could meet the standard, a waiver of source testing could be
 granted on an individual  basis.

      9.   VC-17,  VC-29

 Comment:   In the  regulation, the only mention of the option of using
 a portable hydrocarbon detector for measuring reactor opening  emissions
 is §61.67(g)(5)(i)(B).   Section 61.67(g)(l) should also state  that
 the portable hydrocarbon  detector can be used for the testing  required
 in §61.64(a)(2).

 Response:   Section 61.67(g)(l) outlines the testing procedures to
 be used  for stack  emissions.   The test methods  to be used for
 reactor  opening emissions  are outlined in  §61.67(g)(l)(i)(B).
 Test Method 106 only is  to be used  for stack emissions.

      2.5.2  §61.68 as  proposed or §61.69 as promulgated

 1.   Comment:  The  Agency must realize the  tremendous  task it has  set for
 both itself and industry  in  attempting to  take  all  the  readings for
 determining compliance on  all  source  points,  preparing  the  necessary
 reports, requests  for  variances,  compliance programs, and approved
 procedures,  forwarding these  to the Administrator,  receiving his  reply,
 and  acting on the  reply all within  90 days  of promulgation.  Total
 confusion  will result from even the slightest lack  of coordination
 in all of  these frantic activities at 50 or so  plants,  and  in  the
 Administrator's office.  It may be wise  to  omit  this original  report,
 or delay it for 90  to 180  days.

 Response:   Section  112 of  the  Clean Air  Act  requires that a  plant
 be in compliance with the  standard within 90 days of promulgation,
 unless a waiver of  compliance  is  obtained.   This  is the basis  for
 requiring  that emission tests  be  conducted within 90 days.   Several
 commentators have  indicated that  they will  request  a waiver  of compliance.
 If these results for waivers are  granted, the number of emission tests
will be reduced.  The regional  offices rather than  the Administrator's
office will be handling these various  reports.
                                 2-70

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     2.5,3  §61.69 as proposed or §61.70 as promulgated

     1.  VC-13, VC-21, VC-27, VC-29

Comment:  Section 61.69(b)(l) requires a report 180. days after the
effective date, while §61.68 requires a very comprehensive initial
report 90 days after the effective date.  The magnitude of these two
reports is such that the allowable time Is insufficient, and it is
unlikely that all the facilities and procedural approvals required
for the semi-annual report will be available imme.dtately after the
effective date.  It is requested, that §61.69(b)(l). be amended so
that the first semi-annual report is due 270 days after the effective
date or 180 days after the initial report, whichever comes first.

Response:  The standard has been revised §p that the first semi-
annual report will not be due for at least'180 days after the initial
report.  All semi-annual reports will be due on March 15 and
October 15.  The first semi-annual repprt will be due after the
first full semi-annual repprt period has past since the initial report
was received.  As an example, if the initial report is received by
EPA on September 15,the first semi-annual report will be due the
following March 15.

     2.  VC-29

     Comment:  To clarify the intent of the standard, §61.69(c)(2)
should be changed by substituting the words:

     "(2)  The owner or operator shall inplude a summary of the analytical
results on the stripped resin.  Test Method 107 or equivalent is to be
used."

Response:  Clarifying changes have been made to this paragraph.

     3.  VC-23

Comment:  The monitoring and record-keeping requirements in the proposed
rules appear to be adequate.

Response:  No response necessary.

     4.  VC-13, VC-22, VC-29

Comment:  The standard requires that the vinyl chloride levels in
stripped resin be measured for each batch.  It also requires that
the vinyl chloride in reactors be measured each time they are to be
opened.  The preamble to the proposed standard suggested that for
both reactor opening and improved stripping, it is possible over
time to establish a relationship between the emissions measured and
certain operating parameters..  The general provisions and the
proposed standard orovide for waiver of emission tests and use of

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alternative or equivalent methods.  The preamble stated further that
under the authority of these provisions, EPA could, on an individual
basis, permit a plant to record certain operating parameters
rather than measure emissions.  The alternative of recording
operating parameters should be included in the standard rather
than mentioned in the preamble.

Response:  EPA is preparing an enforcement guidelines document.  It
will recommend that the appropriate enforcement officials accept
recording of operating parameters as an alternative test method
after a plant has clearly demonstrated a relationship between
measured vinyl chloride levels and certain .operating .procedures.
Recording of operating parameters is not included in the standard as an
alternative test method procedure because of the individual
differences among plants and resins.  For improved stripping, for
example, specific operating conditions have to be established
for stripping each different kind of resin at each different
kind of plant.  Establishment of the operating conditions
to be used for each resin at each plant are best handled on  an
individual  basis.
                                 2-72

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     2.6  Test Methods

     1.  VC-13

Comment:  Method 106 was designed for isokinetic sampling of dusts and
mists, not for sampling of gases.  Appropriate changes are in order.

Response:  Apparently, the commentator failed to read Method 106,
as it ,has nothing to do with isokinetic sampling.

     2.  VC-14, VC-44

Comment:  Test Method 106 is a very detailed testing procedure,
capable of determining mass emission rates from equipment.  The
use of this elaborate procedure where only a concentration 'determination
is required is burdensome and unnecessary.

     A properly calibrated detector for vinyl chloride can make this
determination with greater ease and equal precision for purposes of
this section.  We request that this section be modified to allow
emission concentration limits to be measured with a calibrated
vinyl chloride detector where emission limits are prescribed in section
61.62(a), 61.63(a) and from the control system.

Response:  Method 106 yields an emission concentration only, not a
mass emission rate.

     Specification of Method 106 implies that an averaged emission
concentration determination is required for a minimum period of one
hour for each of three runs.  Since it would be difficult to specify the
correct number of instantaneous readings necessary to replace a single
averaged value for each of the great variety of sources covered by the
vinyl chloride standards, the integrated sample approach must remain the
reference method.   However, it is envisioned that individual sources may
wish to develop data to substantiate the equivalency of instantaneous
sample data for their processes.  This data would consist of enough
duplicate instantaneous/integrated sample data to be able to statistically
determine how many instantaneous data points spread over a minimum
period of one hour would be required for the average to not be statistically
different from the integrated average values at the 95 percent  confidence
level.   The conditions set forth in §61.67{g) would still apply with
regard to any subsequent dispute over equivalency.
                             2-: 73

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       3.   VC-17,  VC-26,  VC-29

  Comment:   Tedlar bags  are expensive ($91  each)
  bags  ($6  each)  as alternates.
We recommend Saran
  Response:   While  EPA has  no  direct  experience  with  Saran  bags  for
  vinyl  chloride  testing, data have been  published which  indicate  a
  Dag  of this material  could have  a significant  loss  of vinyl  chloride
  The  only bag material which  is acceptable  in place  of Tedlar is
  aluminized  Mylar.

      4. VC-17,  VC-29

  Comment:  Section 4.3.1 of Test  Method  106 specifies a  strip chart
  recorder for the gas chromatograph, while section 6.4 calls  for measure-
  ment of peak area with an automatic integrator.  We believe  that the
  strip  chart_recorder is adequate for this use  and that  the automatic
  integrator  is unnecessarily  elaborate and expensive ($5200) when peak
  height, triangulation and disc integrators are sufficiently accurate for
  ufi 1S US6•

  Response:   "... automatic integrator" has been changed to "disc
  integrator.    For a laboratory that processes a larger number of
 samples, an automatic integrator may be a worthwhile investment, and
 would of course be acceptable.

      5.  VC-17,  VC-27, VC-29

 Comment:  Most gas chromatographs are  designed  to  use  hydrogen  and
 air for their flame  detectors.  When so used,  they are capable  of
 detecting  0.5 ppm  vinyl  chloride  in  air.  This  seems to  be sensitive
 enough  to monitor  the 10 ppm  limit  that the standard calls for    The
 replacement  of air by oxygen  in  the  combustion  gas  therefore  seems
 unnecessary.

 Response:  "Oxygen"  will be changed  to  "air or  oxygen, as  required
 by the  detector.

      6.  VC-17,  VC-29

 Comment:  The integrator recorder specified in  section 5.3.6  of Test
 Method  107 seems unnecessarily elaborate as the measuring  device
 Here, especially, the vinyl chloride peak is so sharp that any measure-
 ment other than  peak height would be difficult.  A strip chart recorder
 With a  sensitivity of 1 millivolt full scale is adequate for  this use.

 Response:  If sample injection time is varied for some purpose, peak
 J2Sd?"ing mcy °^ur'  Accordingly, it is preferable to measure
 peak area.   For^the number of  samples that most facilities will  be
 analyzing, the integrator recorder specified in 5.3.6 would seem
 to be a wise  choice.   However, manual techniques may prove to be
acceptabIe.
                                  2-74

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     7.  VG-17, VC-29

Comment:  Regarding 5.3.2,in Test Method 107, Supelco, Inc., Supelco
Park, Ballefonte, Pennsylvania 16823, recently announced that they are
discontinuing Carbopack A.  However, they say that 0.2 percent Carbowax
1500 on Carbopack C gives the same separation of vinyl chloride as 0.4
percent Carboway 1500 on Carbopack A.

Response:  Carbopack C will also be listed in 5.3.2.

     8.  VC-17

Comment:  Regarding 7.2., 1 and 8.1 of Test Method 107, we cannot see why
water is added to dry resin samples and to the calibration vials.  It
seems more logical to run the calibration standards and dry resjn
samples without water and to use Equation 107-4 when water is present in
samples.

Response:  If any water is present in the sample, the water elutes
from the gas chromatograph column in a broad band, encompassing the
time the vinyl chloride is eluted.  As the water affects the sensitivity
of the flame ionization detector, it was thought best to add enough
water to every "dry" sample to have a water vapor saturated gas sample
for the gas chromatograph thus insuring a reproducible amount of water
vapor in each sample.

     9.  VC-17

Comments:  The constants in Equations 107-3 and 107-5 of Test Method
107 could not be generated from Equation 107^2 and 107-4, respectively.
                                                             M
Response:  A value for V  of 23.5 was used instead of 23.5 - ^—.
as published.           9                 .                   K4

     The equations were correct as published, except brackets were
missing in Equation 107-5 (See comment number 21 in this section).

     10.  VC-18, VC-27

Comment:  Concerning §61.61(n), the definition of portable hydrocarbon
detector, the two recommendations are to relax the sensitivity requirement
from the proposed 5 ppm to 10 and 20 ppm, respectively.

Response:  The definition of portable hydrocarbon detector has been
revised to relax the sensitivity requirement to 10 ppm.  Based on
information supplied by Commentator VC-27, analyzers with a sensitivity
of 5 ppm "are extremely delicate and require a high level of maintenance
and considerable redundancy of units would be required."  The standard
requires that a portable hydrocarbon detector be used to detect leaks and
measure vinyl chloride concentrations in equipment before opening it.
In both cases an instrument with a sensitivity of 10 ppm will be
adequate.

                                   2-75

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      11.   VC-26

 Comment:   In the drawing on page 59550 (Figure 106-1) valves should be
 provided  for the sample bag; otherwise the method cannot be used.

 Response:   The ball  check in the single bag female quick connect
 seals the bag when the sample line male quick connect is removed.

      12.   VC-27

 Comment:   The suggested technique in Test Method 106 is to sample  into a
 Tedlar bag at ambient conditions and analyze the bag contents.   Any
 stream which contains large amounts of water, or saturation ethylene
 dichloride at process temperature, will  cause erroneous numbers  for
 vinyl  chloride due to condensation.  This would  result in serious  errors
 in steam  vent analysis.   Assuming 1 percent inerts,  one can postulate  a
 100-fold  concentration of vinyl  chloride into the vapor cap.   For
 saturated  ethylene dichloride streams at 100°F,  taken to a laboratory  at
 70°F,  the  condensation results in a 10 percent decrease in the volume;
 however,  in a 100-liter sample about 40  cc of liquid EDC would be
 present.   This will  dissolve vinyl chloride from the vapor cap,  and thus
 one would  not measure the true vinyl  chloride concentration.

     A suggested better sampling technique would be  to cool  the
 sample to  -4°F and analyze  the liquid contents.   The total  sample
 would  then be a combination of the liquid condensed  and gas
 volume which can be  accurately measured  in the laboratory.

 Response:   No steam  vent analyses  are contemplated.

     EPA investigated the possibility of water condensation  causing
 errors in  the bag  sample vinyl  chloride  concentration,  due  to condensation
 of vinyl chloride  with  negative  results.   Since  all  bag samples would  be
 analyzed at room temperature,  it is  expected  that  the  vinyl  chloride
 concentrations  would  be  automatically normalized to  the corresponding
 water_vapor saturation  concentration.  The bag concentration of vinyl
 chloride is  finally  reported  on  a  dry basis,  corrected  for  that water
 vapor  concentration.

     The importance of  the  reported  effect of condensed ethylene
 dichloride  on  the  vinyl  chloride  concentration is  still  being investigated,
 but no actual  case where  the  suggested situation exists  has  been found.
 However, if  such a case  does  occur,  the  suggested  technique  should  prove
 to be  acceptable.

     13.  VC-27

 Comment:  The use of  a reverse "S"  type  pi tot  tube for  flow measurement
as described  in Test Method 106  is adequate for  highflow rates like
those  in the vent scrubber  stack;  however,  for tank vents, vents on
vessels, and other low flows  (less than  10  fpm)  the "S" type pitot  tube
does not give adequate flow measurements.

                                 2-76

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Response:  Currently there are no low flow (less than 10 fpm) streams
which are required to be tested.  If this problem should arise in the
future, it can be resolved at that time.

     14.  VC-27

Comment:  The isothermal method of operation in Test Method 106
is fine for "air samples" but in analyzing vent streams up to 2 hours
would be required for one analytical run.  Analyzing each sample to +_ 5
percent might require 6-8 hours of analysis to get a repeat on one
sample.  For several samples taken the same day there would be an
inordinate amount of time for analysis.  We would suggest duplicate runs
in a temperature-programmed mode of operation.

Response:  With proper care, temperature programming of the gas
chromatograph operation should facilitate analysis, and is not meant to
be precluded by absence of a description in the test method.

     15.  VC-27

Comment:  The daily calibration curves required by Test Method 106
are unnecessary.  A calibration curve run once for linearity and one
standard daily check should maintain quality control on the instrument.
Our experience has shown that vinyl chloride factors on a flame detector
are valid for several months.

Response:  If Method 106 tests are run on a routine basis, experience
may show that daily calibration is unnecessary; however, for
limited applications, the daily calibration would be advised.

     16.  VC-27

Comment:  The leak-proof rigid containers described in 4.1.5
of Test Method 106 are the size of a 40 gallon drum and would be
extremely difficult and hazardous to move to the top of a vent scrubber,
out of a tank farm, etc., and would pose serious operator problems for
sample-point logistics.  Alternative considerations should be reviewed.

Response:  Since Method 106 is only rarely used, the on-site disadvantages
of the bag container should not constitute a major problem.  For
discussion of replacement of the integrated sample procedure, see
comment VC-14.

     17.  VC-27

Comment:  Only one specific column material is allowed in 4.3.2
of Test Method 106.  This should be revised to permit use of any column
which results in adequate resolution and determination of the vinyl
chloride peak.

Response: Chromosorb 102 is the only column which EPA has investigated
to determine possible interferences, etc., for the analysis of vinyl

                                 2-77

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  chloride.   It is expected that other columns may work equally well   but
  substantiating data must be provided to EPA before equivalency can'be
  determined.   The method has been revised to include a secondary column

  SomhvinyiechloHdet0 ^^ acetaldeh-yde> if Present, in the sample,'

       18.   VC-29

  Comment:   Why is it not possible to use a portable hydrocarbon analyzer
  in place of  Method 106 in all  cases where Method 106 is specified?

  Response:  Specification of Method  106  implies  that a specific
  determination of only vinyl  chloride (i.e., not to include any other
  substance) be made.   Method 106  is  a reference  method,  by  which
  the appropriateness  of other methods for specific  applications
  can be judged.

       19.  VC-29

  Comment:  "The use of a  heated sample loop  and  automatic sample
  valve (Section 4.3.1)  is  not necessary  since the bag  sample is
  not heated.   A gas tight  syringe  is  adequate for transferring  the
  sample from the  bag  to the  gas chromatograph."

  Response:  Because of  the relatively small  surface area/volume  ratio
  of  the heated sample  loop and automatic  sample  valve, heating
  produces favorable results  insofar as peak  resolution and sharpness
  are concerned.  Use of an automatic sample  valve, as opposed to
  a syringe,  greatly improves  the repeatability of analysis.

      20.   VC-29

 Comment:   Equilibrium data for the vinyl chloride-water system.
 are available which conflict with the EPA K-value of 5.0 x  10~6
  (p. 59552,  Column 2).  Air Products  reports a value of 1 3  x 10
•which is  more consistent with a value of 0.9 x 10"5 determined by
 Ethyl Corporation 	 the constant  in equation 107-5 (2.066 x 10~3)
 depends  on  the K-value for water and should be corrected accordingly.

 Response:   The K value for a 1  cc water  sample of 5.0 x 10"6 was
 derived  through careful study by B.  F.  Goodrich.  The other K values
 apparently  are for larger water volumes.

      21.  VC-29

 Comment:  Brackets have been omitted from equation  107-5.

 Response:  Brackets  have  been added.

      22.  VC-2

 Comment:  The  last paragraph  under 9.2 of Test Method  107 is not
 applicable to  equation  107-5.   Equation  107-5 applies  only  to water

                                   2-78

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samples, where TS =  0.   Reference  to  107-5  should  be  deleted  and  the
paragraph  relocated  after equation  107-4.

Response:  .This comment  is correct; the  changes  noted have  been made.

     23.   VC-35

Comment:   Detailed performance specifications  should  be  given
for the vinyl chloride detector, and  should be similar to those
given where monitoring is required  in Part  60  (Standards of
Performance for New  Sources).

Response:  The promulgated standard requires that  the monitoring
system consist of a  gas  chromatograph; or if it  is assumed  that all
hydrocarbons measured are vinyl chloride, infrared spectrophotometry,
flame ion  detection, or  an equivalent method may be used.   The
standard included this flexibility so that  if  a  plant has purchased a
monitoring system for purposes related to the  OSHA standards, it  would
not have to purchase a new system  to meet the  EPA standard.  A gas
chromatograph is 100 percent accurate if calibrated properly.  EPA has
developed  some criteria  for judging the adequacy of a plant's calibra-
tion and maintenance schedule for  the monitoring system.  These will
be included in an enforcement guidelines document.

     24.   VC-35

Comment:   The sampling procedure in paragraph  6.1 of  Test Method
106 is not clear.  The description of the sampling procedure in paragraph
6.1 and the drawing  in Figure 106-1 do not  include correct  instructions
for purging the sample line prior to sampling.   If the instructions are
followed as proposed, erroneous results will be obtained .because  the
purged air will be drawn into the sample bag.  Paragraphs 4.1.3 and 6.1
and Figure 106-1 should  be changed.

Response:  The procedure is correct as written.  While the  sample
line is purged into  the  bag, the bag is subsequently  evacuated
before sampling commences.

     25.   VC-35

Comments:  Four typographical errors are noted.

Response:  These corrections have been made.

     26.  VC-42

Comment:  A specialized procedure is described in §61.67(g)(l)(i)
for use in sampling the emissions due to purging of vinyl chloride
from reactors after a batch is completed.

Response:  EPA calls this reactor opening emissions and has specified
a method separate from the stack test method for testing these
emissions.   See §61.67(g)(5).

                                  2-79

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       27.   VC-42
      ocnt  lh  §61:67(d)  the  average  of three  runs  may not  be  adequate  to
  represent  the emissions.   It  is  recommended  that  EPA require the  source
  operator to supply  technical  evidence that the  average  of the three
  adequately represents the total  emission  rate for each  source tested

  Response:  Most of  the  regulations  in Parts  60  and 61 require that
  three runs be conducted for each test.  There is  no  apparent
  reason for making the testing for vinyl chloride  different.   It is
          JM! S^rCS °Perator would "s"PPly  technical evidence that the
        h        5re? ^nns adequately  represents the  total emission rate
    t !C A I — *- test*d  .W1'thout doing  additional  tests.   EPA  believes
  that a definitive endpoint on the number of  runs  conducted is necessary.

      28.   VC-42

 Comment:   With regard to Test Method  106 we  recommend the use of

             f •" ,tUb^9 and tedlar bags-to minimize the absorption and
     1075A?  1975)              by the PlaStl'CS  ($ee Analytical  Chemistry.
            Te-la!I ?ugs are sPecified.   Aluminized Mylar bags can also
    used,  provided that the samples are analyzed within 24 hours of
 S2ni!2m°n; *    ofuTeflon tubing is monitored through labeling and
 replacement for each new set of samples.

      29.   VC-44
           Commentator  VC-44  fails  to  see  the  need  for taking  a  vinyl
          sample  at  a rate which  is  proportional  to the gas  stream  flow
            -oncentration variation  is  not necessarilv nrnnnrfinnai  tn
mass flow  and  the sampling can be  stopped between  batches^if necessary.
Response
to
           Use of Method 106 implies  that a time averaged sample is
                     1nstancwhe^ a  Proportional sample would no i
                                      conce"tration was proportional
                     !8 not done proportionally, then the burden
,,+      that proportional sampling was not necessary will lie
vntn those doing the testing.
                                 2-80

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     30.  VC-50

Comment:  Commentator VC-50 has found that on a Chromosorb 102 column
using helium carrier gas, acetaldehyde has the same retention time as
vinyl chloride and vinyl chloride cannot be distinguished from acetaldehyde
unless the effluent from the column is fed into a mass spectrometer.  It
is therefore recommended that unless acetaldehyde is positively known to
be absent from the stack gas, a different column be used.

Response:  Section 3, "Interferences," of Test Method 106 will be
reworded to include specific precautions regarding acetaldehyde
interference.
                                2-81

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      2.7  Economic Impacts

      1.  VC-17

 Comment:  Imposed substitution of other materials for polyvinyl
 chloride products may have adverse economic effects.

 Response:   Substitutes for polyvinyl chloride are not being imposed
 upon the industry.   Polyvinyl  chloride products will still be free to
 compete in the marketplace with substitute products on the basis of
 price and  performance characteristics.   It is believed that the price
 increase in polyyinyl chloride resins resulting from the standard will
 not cause  appreciable substitution of other products.

      2.  VC-22

 Comment:   The decrease in  demand for polyvinyl  chloride during 1973-74
 stated  as  2.4 percent should be 0.4 percent and referred to as a decrease
 in  consumption,  not  demand.

 Response:   The figure'for  decrease in consumption of 2.4 percent
 was  based  upon an estimate of  1974 sales.   Final  1974  figures  now
 available  indicate that  the actual  decrease was 0.5 percent.   It
 is agreed  that "consumption" is  a  better term than "demand".

      3.  VC-26

 Comment:   EPA's  estimated  installed  capital  cost  of $524,000 for
 the  oxychlorination process incineration is  too low.   The  commentator
 estimates  the  cost to  be $2,200,000.

 Response:  EPA did not estimate  the  cost of  the oxychlorination
 incinerator to be $524,000 but rather 524,000 times  the  volume of
 the  stream to  be incinerated raised  to the 0.53 power.  At  the
model plant volume of approximately  6100 SCFM this  results  in a
capital estimate of $1,369,000 (Table 7-7,  page 7-78).  The basic
algorithm that was used for cost estimating purposes was based
upon information submitted by five vinyl chloride producing
                                    2-82

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 firms  and one EPA contractor.   The commentator's  estimate was  one of the
 estimates used by EPA to develop  the  basic algorithm.

     4.   VC-26

 Comment:   The description "Allied Chemical/Geismar"  used in
 Tables  7-24  through  7-32 should be changed to  "Allied  Chemical/
 Baton  Rouge".   The production  capacity  attributed to Allied
 Chemical  in  the STAR document  is  incorrect.
 Response:   No  response  necessary.
 correction.

      5.  VC-26
This comment serves as a
Comment:   EPA estimates  for  control  costs  at  the Allied  Chemical/
Baton Rouge facility are  lower  than  current company  estimates.

Response:  The total cost for the Baton  Rouge plant  is obtained  by
adding the costs incurred at the ethylene  dichloride plant  (Table 7-17)
with the costs incurred  at the  vinyl chloride plant  (Table  7-24).   If
this is done the total air pollution control  costs are estimated to
amount to  $889,000 and total water pollution  control  costs  are estimated
at $1,775,000 for a grand total of $2,664,000 versus  the  company estimate
of $2,260,000.

     6.  VC-27   '

Comment:  The view that  large,  integrated  petrochemical and chemical
companies would supposedly have access to  sufficient capital to
invest in control devices is inappropriate without consideration
of other company projects competing for  capital.

Response:  Consideration  of  the capital  demands for  competing
products has been recognized.  The background document states:
" ... firms that own the  various ethylene  dichloride  plants are
generally large, integrated  petrochemical  and chemical companies that
would supposedly have access to sufficient capital to invest in  the
additional control equipment.  Whether a firm would  actually choose
to invest those funds in  control devices, however, cannot be
predicted with any degree of certainty particularly  for those firms
that are experiencing post-control decreases  in profitability compared
to the pre-control case."  (Page 7-27)   The intent of this  statement
was to point out that even though firms would probably have access
to sufficient capital to  invest in control devices they still might
not choose to do so for profitability reasons.
                                 2-83

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      7.   VC-27,  VC-29

 Comment:   Rates  of return,  profitability,  and pricing  parameters  are
 predicted on TOO percent operating rates  rather than a more
 realistic 85 percent rate.   The economic  impact would  be  dramatically
 altered  if 85 percent was used.

 Response:  An operating  rate of 100 percent  was .arbitrarily  selected
 due  to the difficulty in estimating expected operating rates.   The
 use  of this rate,  however,  does  not alter  the economic impact  of
 the  standard.  The percent  price increase  that would be required  in
 order to  recover control  costs  and maintain  pre-control profitability
 would be  essentially the same whether  100  percent  or 85 percent was
 used as the basic  operating rate.

      8.   VC-27

 Comment:   Incineration costs for the model ethylene dichloride-vinyl
 chloride  facility  are understated.

 Response:   EPA does  not  believe  that costs for the model  ethylene
 dichloride-vinyl chloride plant  are understated.   EPA  is  aware of
 the  incinerator  costs claimed for  the  commentator's plant and
 believes  that these  costs include  items that would not be found in
 a typical  facility.

      9.   VC-29

 Comment:   Production  decreases in  1975 caused depression  in prices
 and  profits which  reduced the capability of  the industry  to obtain
 capital or raise prices.

 Response:   Whereas conditions in the polyvinyl  chloride industry
were  depressed in  1975, a return to more normal  conditions is
 expected  for  the industry.   Since  it is not  possible to develop a year-
 by-year impact analysis based upon  projected  industry  performance it
must  be assumed that  normal  conditions will  prevail in  the long run.

      10.    VC-29

Comment:    No adjustments  for  inflation to 1976  and 1977 conditions
were made  in the cost estimates.

Response:  All financial  information, control  costs included, was
adjusted to reflect conditions as of a certain  date.   The assumption
has been made that product prices will  generally rise along with
increases  in costs so that profitability will  be unaltered over time.
Given this assumption it is unnecessary to adjust costs and revenues
for inflation since their increases essentially cancel  each other out.
                                    2-84

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     11.  VC-29

Comment:  The estimate of capital requirements for a carbon
adsorption system in the model suspension process polyvinyl chloride
plant is understated.

Response:  The polyvinyl chloride model plant carbon adsorption costs
were based on data obtained from four sources of information:  three
polyvinyl chloride companies and one EPA contractor.  The installed
costs, when scaled to the model plant volumetric flowrate, ranged from
$140,000 to $545,000.  The $333,000 figure was the average of these four
estimates.  As this example illustrates, the EPA model plant control,
costs were based on data from diverse sources.  They do not necessarily
reflect the situation at any particular polyvinyl chloride plant, where
the costs may be higher or lower for one or more reasons.

     12.  VC-29

Comment:  The capital and operating costs for incineration are under-
stated by a factor of two for polyvinyl chloride plants and a factor
of two to three for ethylene dichloride-vinyl chloride plants.

Response:  The costs for incineration at polyvinyl chloride and
ethylene dichloride-vinyl chloride  plants have been based on a range of
data.  Six information sources were employed:  five companies and one
EPA contractor.  The installed cost listed industry sources in Table 7-7
resulted from a least-squares analysis of the cost data from these six
sources and is intended to represent average conditions.  It is expected
that some facilities would experience lower costs and some would experience
higher costs.

     13.  VC-29

Comment:  The allowance for administrative, selling, research and
development, and interest costs is understated and overstates
the return on investment at a given plant.

Response:  Estimated costs for these items were derived after
consultation with a committee composed of industry representatives.
EPA sees no valid basis for altering any of the figures that
were used.
                                    2-85

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       14.  VC-29,  VC-32

  Comment:  Costs are grossly disproportionate  to  benefits for
  water striooing,  evacuation of compressors, double mechanical
  seals on pumps, leak detection,  and  removing  vinyl chloride from
  reactors before opening:

  Response:   The  standard for vinyl chloride is based on best
  available  control  technology.  The term "grossly disproportionate"
  was  introduced  into  the supporting documents for the standard
  because  the term  "best available control technology" could be
  interpreted indifferent ways  and EPA thought it was desirable to
  place some  limitations on it.  The first limitation was that the
  control  technology must be  in  useTn one or more plants in the
  chemical industry and be generally adaptable for use at the plants
  subject  to  the  standard within the time allowed for compliance under
  section  \\d.  Second, costs were considered only when they were
 jrojjsTy  disproportionate to the emission reduction achieved.   Technologies
 Xi£ •fP5 c°nsildere* *? not f1t i^o ^s definition of best available
  control  technology included placing a bubble around a plant to capture
 all the  emissions from it for control, using multiple incinerators on
 a gas stream, and incineration of the emissions  from  the  oxychlorination
 f^elt'   Theulrea?on for not requiring incineration of the  emissions
 from the oxychlon nation process  are  the relatively low emissions
 from it compared with the  very large  expenditure  of energy  which
 would be  required to incinerate.

      Obviously,  there is some judgment involved  in  interpreting
 which costs are  "grossly disproportionate."  In  EPA's judgment
 the cost  of controls  mentioned by.the commentator are not in the
 same category with the oxychlorination process.  Although the
 commentator may  view  these controls as not being cost-effective,
 in  hPA s  judgment  the costs  are not grossly disproportionate.

      Altougn t"*:  economic impact study included in the SSEIS, Vol. I
            °SI"er^t1veneSS'  1ts pr1mary PurP°se was to inform EPA
        nrfrfSS    ?  K35 affordable and> ^ so, what the impact would be,
       3   *d  -S n°!  b!sed on  costs-  The cost data was developed to
 Art!e th*  T*?  °f the  standard-  ^en under section  111  of the
 Act, where standards  are to  be  based on "best demonstrated control
 the s?]nH^HC°nS1^nH9K?°StSlu; the stan
-------
discharges and reactor opening is  .31 and for water stripping  is  .80.
Evacuation of compressors, double mechanical seals or pumps-, and  leak
detection are included in the cost-effectiveness ratios for fugitive
emissions.

     1-5.  'V029

Comment:  On Table 7-40, Tenneco/Flamington:, Tenneeo/Pasadena, and
Union Carbide plants were .omitted.
Response:  The comment is correct.

     1.6.  VC-29

Comment:  On Table 7-T5, the total annual i zed cost should fee $773,000
    ead of $793, 000.
Response:  The correct number is $793,000.  However » the figure of
$407,000 shown on Table 7-15 should be $427,000.

     17.  VC-32

Comment:  The number of plant shutdowns has not been accurately
estimated.

Response:  The number of plant shutdowns was inaccurately estimated,
in that three out of four plants EPA forecasted would close have
since, told EPA they will not close.  The fourth plant ho longer produces
polyvinyl chloride.  Plant closures attributable to other regulations,
if any, are not considered since they are not believed to be a direct
consequence of the proposed EPA regulation,  it would appear that the
immediate cause of the closing of the Uni royal plant is the OSMA regula-
tion, although anticipation of the EPA regulation may have influenced
the decision.

     18.  VC-32

Comment:  The economic analysis is simplistic.

Response:  The major thrust of the economic analysis; is to4
determine the impact upon, industry gr-owthi,, prices, awd p'tartf!
closures.  It is believed that these issues, are treated iii a*
full and complete manner.

     19,  VC-34

Comment:  EPA cost estimates are low.
                                 2-87

-------
 Response:  EPA cost estimates were based upon estimates provided
 by control equipment vendors and by polyvinyl chloride industry repre-
 sentatives.  As might be expected, estimates of control costs varied.
 EPA believes that its estimates reflect average costs that might be
 incurred at a typical facility.  It is expected that individual plants
 will have control costs that vary from the EPA estimate on both sides.

      20.  VC-34

 Comment:  Polyvinyl chloride plant profitability in Table 7-5
 is overstated.

 Response:  The  prices shown in Table 7-5 were published prices.
 Prices used in  succeeding profitability calculations were based
 upon consultation with industry representatives.

      21.  VC-34

 Comment:  Annualized capital  charges  do not include any profitability
 factors.

 Response:  Annualized capital  charges,  by definition, exclude
 profitability factors.   An  analysis  of  profitability impacts  is
 carried  out in  the  economic analysis.

      22.   VC-34

 Comment:   The bases  for  the direct operating  costs  for  control
 alternatives is questionable.

 Response:   The various items included in  the  direct operating
 costs were  discussed  in  Chapter  7, on page  7-9.

 The unit prices used  on  computing these various items are as
 follows:
     Fuel:
     Electric Power:
     Steam:
     Inert Gas:
     Labor:
     Cooling Water:
     Process Water:
     Caustic Soda:

     23.  VC-34
$2.Do/million BTU
$0.03/kw-hr
$3.00/thousand pounds
$.21/100 SCF
$6/man-hr.
'i.lO/thousand gallons
$.25/thousand gallons
$0.35/lb
Comment:  The process scope for estimating investment costs for
control alternatives is questionable.
                                2-88

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Examples are:  (1) rubber-lined carbon-steel slurry tanks to replace
stainless-steel vessels,  (2) reactor opening control does not include
tanks, pumps, and distribution lines for water purge or headers for
relief valve vents, and (3) no scope description for improved stripping.
Response:
follows:
The process scope for estimating investment costs is as
     1.  Slurry Blend Tanks

     As is stated on page 7-14 of the Standard Support and Environmental
Impact Statement, the existing slurry blend tanks in the model plant
are insufficient to withstand the pressure associated with venting to
an incinerator.  Therefore, they would probably need to be replaced.

     The costs in the document were based on the following assumptions:
                                                               o
     Each blend tank had a capacity of 24,000 gallons (3,342 ft ).'
     Two tanks were installed in each reactor line.
     The cost of removing an existing tank was offset by its
       salvage value.
     The tank diameter equalled the height (16.2 feet).
     The tank design pressure rating was 50 PSI gauge.
     Tanks were fabricated of a carbon steel, lined with 1/4 inch
       rubber.
     Costs were obtained from Guthrie's "Process Plant Estimating
       Evaluation and Control," 1974 edition, p. 151.

     2.  Reactor Opening Controls

     As tables 7-8 and 7-9 indicate, costs for reactor purge
water systems have been developed for controlling the relief valve
discharge and reactor opening emission points.  Each of these
systems includes a storage tank for the purge water, a header system
and pumps to deliver the water to the reactors.

     The capital costs were obtained from two sources, both of which
were polyvinyl chloride plants using these systems at the time.  The
costs - $102,000 and $310,000 were averaged to obtain the $206,000
figure for the model suspension plant,  the dispersion plant cost
($78,000) was calculated by scaling from the suspension plant reactor
capacity (90,000 gallons) to the dispersion plant capacity (18,000
gallons), using a 0.6 factor.

     Although the costs of a header system for relief valve vents was
not included under reactor opening controls, it was accounted for under
fugitive controls (see tables 7-11 through 7-14).  The cost of this
                                     2-89

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collection header system varied substantially according to each
plants' process configuration.  Based on data from four polyvinyl
chloride plants, the installed system cost ranged from $15,000 to
$229,000.  (Process capacity had no recognizable effect on the
costs).  The average of these numbers ($84,200) was used for all
form model plant costs.

     3.  Improved Stripping

     The costs for improved stripping varied considerably among the
sources from which data were obtained.  For stripping in suspension
plants, data were submitted on four plants, ranging in capacity
from 70 to 250 million pounds/year.  The installed costs ran from
$195,000 to $2,085,000.

     These costs were plotted against capacity on logarithmic
paper and the function listed in Table 7-6 resulted.

     The same approach was used for dispersion improved stripping.
Here data from four plants (ranging from 16 to 60 million pounds/
year in capacity) were used.

     For bulk plant stripping, cost data from one plant (with a
capacity of 160 million pounds/year) were scaled to the model plant
capacity, 100 million pounds/year, using a scaling factor of 0.53
(This factor was taken from the suspension and dispersion plant  cost
functions).

     The various improved stripping systems used in deriving the
cost functions differed in scope,  simply because the plants in which
they were installed had diverse process configurations.  However, a
typical system included:  stainless steel stripping vessels with
agitators, condensers, and vacuum  pumps, plus all the  required
instrumentation, piping, etc.

     The  bases for direct operating costs were as follows:

     Where itemizations were  available, the following  unit  values were
used to complete direct operating  costs:
                                2-90

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    Item

I.  Operating Labor

II.  Utilities:

     1.  Electric Power
     2.  Fuel (Natural
     3.  Process Water
     4.  Cooling Water
     5.  Steam

III.  Operating Materials

     1.  Sodi urn hydroxi de
     2.  Nitrogen

IV.  Maintenance

     1.  Incineration
     2.  Improved Stripping
     3.  Carbon Adsorption
     4.  Water Stripping
     5.  Automatic Short-Stopping
     6.  Automatic Short-Stopping
     7.  Reactor Purge Water System

     24.  VC-40
                                                  Unit Value

                                                 $6/man-hr
                                                 $0.03 kilowatt-hr
                                                 $2.00/million BTU
                                                 $0.25/thousand gallons
                                                 $Q.10/thousand gallons
                                                 $3.OO/thousand pounds
                                                 $0.35/pound
                                                 $0.21/hundred cubic feet
                                                 5% of Installed
                                                 15% of Installed
                                                 3% of Installed
                                                 5% of Installed
                                                 5% of Installed
                                                 10% of Installed
                                                 6<£ of Installed
Cost/Year
 Cost/Year
Cost/Year
Cost/Year
Cost/Year
 Cost/Year
Cost/Year
Comment:  The economic impact of the regulation has been underestimated.

Response:  A detailed company-by-company study was beyond the scope of
the analysis.  EPA believes that the estimation of economic impact is
satisfactory.

     25.  VC-47
          The projected capital cost of meeting all the emission
          is $198 million.  Of this total, $183 million falls on polyvinyl
                                      on ethylene dichloride-vinyl
                                      (including operating and maintenance)
                                      of which $58 million would be
Comment:
standards
chloride plants and $15 million falls
chloride plants. The annualized costs
are expected to be about $70 million,
borne initially by polyvinyl chloride plants and $12 million by ethylene
dichloride-vinyl chloride plants.  In addition, the fugitive emission
standards would involve another $37 million of capital costs and $25
million annualized costs.

Response:  The statement is incorrect.  The cost of fugitive emission
controls is included in the capital cost estimate of $198 million and
the annualized cost estimate of $70 million.
                                   2-91

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     26.  VC-47

Comment:  In reading through the proposed standard, there seems to
be some question as to whether or not a spare reactor can be used as
a gasholder or whether a separate gasholder is required.  If, in fact,
there is some ambiguity regarding this point, it would be worthwhile
for the EPA to complete some further economic analysis before the
issue is resolved.  If a plant already had a spare reactor, the costs
incurred to install a separate gasholder would have little benefit.

Response:  EPA is concerned only that a vessel for holding vinyl
chloride be provided.  The vessel can be either a spare reactor or
a separate gasholder.  The economic analysis took a conservative
approach and included the cost of a separately purchased gasholder.

     27.  VC-47

Comment:  An economic analysis of the trade-offs between emission
risks and prevention costs for control of relief valve discharges
at ethylene dichloride-vinyl chloride plants should have been undertaken.
These discharges  occur infrequently at ethylene dichloride-vinyl chloride
plants, as opposed  to polyvinyl chloride plants.  Based on information
received by the Council on Wage and Price Stability,  this requirement
could involve costs as much as $2 million depending on the size of  the
plant and the distances involved.

     If it is assumed that only one of the  17 ethylene dichloride-vinyl
chloride plants will incur about $2 million to vent relief valves,
$2 million in capital outlay could be saved in addition to any  operating
and maintenance costs that might be involved.  Consequently,  EPA's
analysis should have considered this alternative.

Response:  EPA agrees that relief valve  discharges  from ethylene
dichloride-vinyl  chloride plants occur relatively  infrequently
compared with polyvinyl chloride plants.  The commentator  did not
provide EPA with  the basis for  the $2 million estimate;  i.e., the
control technology which would  cost $2 million  is  not discussed.
This makes  it difficult to evaluate the  comment.   The reason for
assuming that only one plant would incur the  $2 million  cost
 is  not  clear.   In talking with  industry  representatives,  it
appears that  the  types of  controls which would  be  installed  to
 prevent discharged from these  relief  valves would  consist  of
 installing  additional alarms  to warn  an  operator  of upset  conditions,
 tying  thermal  relief valves  into  process lines,  and avoiding operator
 negligence  such  as overfilling  storage  spheres.
                               2-92

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     28.  VC-34, VC-47

Comment:  The projected costs of the standards do not incorporate
any estimates of the costs associated with the research and development
of control technology, lost production from down-time during control
equipment installation, and losses from startup.  It seems that EPA should
have incorporated some estimates of these costs if the full impacts
of the standard are to be identified a.nd analyzed.

Response:  The comment is correct in that research and development of
control technology would add some additional costs to meeting the
standard.  These costs would vary considerable from plant to plant
and are difficult to estimate.  Losses from down-time during control
equipment installation and from startup would not appear to add
significantly to costs because polyvinyl chloride production is a
batch process and it is not unusual for ethylene dichloride and vinyl
chloride plants to be shut down for maintenance.

     29.  VC-34

Comment:  The economic analysis fails to consider duplicate control
systems needed to operate at 100 percent service factor.

Response:  Costs for duplicate control equipment were not included
since the control systems were designed to operate continuously with
only routine maintenance.  It was assumed that the maintenance would
be performed during normal plant maintenance shut-downs.

     30.  Proceedings from the Public Hearing, Presentation by
Barry Castleman, p. 9.

Comment:  Some polyvinyl chloride substitutes must be available
for those uses listed by EPA as having no substitutes.

Response:  EPA attempted to list those materials that the industry
believes to be acceptable substitutes for polyvinyl  chloride resins.
It is agreed that some substitutes would probably exist for all
polyvinyl chloride uses, but the question of acceptability in
individual applications would have to be evaluated closely.

     31.  Proceedings from the Public Hearing, Presentation by
Barry Castleman, p. 9.

Comment:  The cost of vinyl  chloride emissions in terms of worker
health and community health and safety impacts has not been
evaluated.

Response:  It was beyond the scope of the analysis to attempt
to quantify in economic terms the cost of vinyl chloride emissions
to the general public.

                                    2-93

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     2.8  Environmental  Impacts

     1.  VC-21, VC-22, VC-29

Comment:  "The discussion of potential adverse environmental impacts
on page 1-24, 1-27, and  1-28 of the SSEIS, Vol. I regarding
increased water consumption seems to be overstated.  EPA expects
increased water consumption from the use of such control systems as a
reactor water purge system, improved stripping, waste water stripping,
and carbon adsorption.   We believe that there will be little, if any,
increased water consumption and certainly nothing approaching the 6-38
percent range as noted on page 1-28 and as detailed in Table 6-13 on
page 6-42.

     "The reactor water  purge control technique, according to
Table 6-13, clearly results in the greatest water consumption.  It
should be noted, however, that only a small percentage of the polyvinyl
chloride industry intends to utilize the reactor water purge control
method.  Also, there is  no technical reason that water used for reactor
purging cannot be used over and over again in a completely closed cycle.
Obviously, water used in this type of system would have to be stripped
of vinyl chloride content prior to discharge.  Recycling of such water
would minimize stripping requirements thereby conserving energy and
would also minimize the  use of our natural resource (water).  We believe
the numbers presented for reactor water purging are in error.

     "The second noted source of increased water consumption as a
result of applying the necessary controls is that noted for
improved stripping.  We  question the quantities listed in
Table 6-13.  Steam requirements of 1,500-2,000 kg of steam per
10,000 kg of product are stated on page 6-5 for improved stripping.
Using the highest amount stated (2,000) and calculating the steam
requirements for a model 150 million pound per year plant as shown
in Table 6-13, an increased water consumption of 3.6 million gallons/
year is determined as compared to the quantity of 7 million
gallons/year shown in Table 6-13.  Similarly, other numbers presented
in Table 6-13 for improved stripping are in error.  As noted on
pages 6-5, primary stripping, which is already used by most plants,
required 2,000-4,000 kg  of steam per 10,000 kg of product and
improved stripping will  require an additional 1,500-2,000 kg of
steam per 10,000 kg of product.  While these facts may be correct
for some plants, they are not correct for the industry as a whole.

     "Improved continuous stripping technology is not applicable
to dispersion resins due to the extreme differences in stability
of dispersion resins versus suspension resins.  Batch stripping
will continue to be employed for dispersion resins.  Nevertheless,
the steam quantities given on page 6-5 are greater than that
                                      2-94

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required for stripping dispersion resins.  Moreover, recipe water
and steam stripping water do not discharge to a sewer, but rather
are emitted to the atmosphere in the drying operation.  Therefore,
there is no increased waste water from improved dispersion resin
stripping.

     "For improved stripping of both suspension and dispersion
resins, the quantity of steam sparged into the slurry which would
result in increased water consumption is less than the 3,000-4,000 kg
of steam per 10,000 kg of product stated on page 6-5.  We conclude
there will be no increased water consumption due to improved
stripping, and no adverse environmental impact.

   •  "The quantity of increased water consumption, as shown in
Table 6-13, for water stripping is also questionable.  The basis
for such number is not given.  It is technically possible to strip
vinyl from these waste water sources by recycling such waste water
sources to slurry stripping systems.  By doing so, the amount of
additional steam required is negligible.

     "Increased water consumption data given for carbon adsorption
is also questionable.  First, this Table assumes carbon technology
will be utilized across-the-board for the industry.  Many producers
certainly do not intend to use carbon adsorption.  Additionally,
even if carbon adsorption is used, regeneration with hot nitrogen
is technically possible as noted on page 4-61.  Obviously, if hot
nitrogen  is used, there would be no increased water consumption.

     "Considering all other factors as noted above, it is questionable
whether there would be any increased water consumption as a
result of compliance With the proposed standard.  Thus, it seems that
EPA should make a more realistic analysis of the situation than
it presently has done.  Additionally, the percentage increase of
water consumption as noted is meaningless in itself, particularly
when based on the average of the range of numbers as shown in
Footnote  1 of Table 6-13.  The average of this range is extremely
misleading and unrepresentative of industry operations for certain
type of plants.  When considering the range of base water consumption,
the percentage increase is less than significant."

Response:  Since there is no regulatory  limit  on the amount of
water a plant can consume, EPA calculated the water consumption
impact assuming that the control systems using water would be
used and  that there would be no recycling.   It is gratifying to
EPA to  know that recycling will be used  and  that the water consumption
impact will be negligible.
                                    2-95

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       2.   VC-29

  Comment:   The  concern  for  hydrogen  chloride  emissions  is  overstated
  Incineration will  be used  only  to a small  extent  in  vinyl  chloride
  manufacture and  to a lesser  degree  in  the  polyvinyl  chloride
  industry  because of economics.
                 1s Pleased 1f the hydrogen chloride impact is overstated.
            vol.  I stated that incineration would be used only to
 a very limited  extent in the polyvinyl chloride industry.  The
 commentator did  not name the types of control which would be used
 in the ethylene  dichloride-vinyl chloride industry or explain the
 reasons for not  using incineration to a large extent.  The
 hydrogen chloride impact was calculated for an individual model plant.
 J-or those plants which do use incineration to control ethylene dichloride
 purification and vinyl chloride formation and purification, the commentator
 did not explain why the hydrogen chloride impact is overstated.

      3.   VC-29

 Comment:   The impact on solid waste stated for a carbon bed is
 conjectural.   Not enough is  known of bed life to permit an  estimate,
 and the  one to three years  presented has no  basis.   It cannot be
 regenerated if contaminated  by polymers,  since polyvinyl  chloride
 is  less  combustible  than carbon.

 Response:   Page 1-29 of the  SSEIS,  Vol.  I  states  that "since  there  has
 been  very  limited experience with carbon adsorption  in the  ethylene
 di chloride- vinyl  chloride or polyvinyl chloride  industries, it  is not
 known  for  certain at this time what the  carbon bed-life would  be or
 whether the damaged  carbon could  be regenerated."  The 1  to 3 year
 estimate was given to  EPA by a vendor of carbon adsorbers based  on
 experience with  other  substances, but is acknowledged  to  be conjectural.
 It  is  based on  the only  information available  at the  time.

     4.  VC-22

 Comment:  On page 6-5, it is stated that "the  amount of vinyl chloride
 released into the inprocess wastewater is expected to  be proportional
 to the amount of  steam used, and thus would be increased by improved
 stripping."  This statement  is incorrect.  In  a stipping operation,
 the vinyl chloride removed from the resin is not transferred to the
water but rather actually passes overhead as a gas with the steam.
The steam is condensed and recycled back to the stripping operation
                                    2P96

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 Response:   Since there is  no requirement to reuse the  steam,  it
 was  assumed that no recycling is  involved.   EPA is pleased that
 at least the company represented  by  the  commentator recycles  the
 steam.

      5.   VC-23,  VC-35

 Comment:   EPA should require recycling of sludge from  polyvinyl
 chloride  plants  if possible.   The air emissions from sludge
 disposal  sites have been subjected to preliminary investigation
 by EPA.   Vinyl chloride levels  at landfills  were as  high  as 1.9 ppm,
 and  in a  residential  area  near  one landfill  the air contained 0.4  ppm.
 This  exposure, because it  is  continuous,  actually exceeds  that
 permitted  in the workplace (1  ppm, 8-hour exposure,  40 hours  per
 week).

 Response:   The data referred  to were obtained  during a study  done
 by Battelle for  EPA which  is  entitled "A  Preliminary Examination
 of Vinyl Chloride Emissions  from  Polymerization Sludges During
 Handling and Land Disposal"  and is dated  February 13,  1976.   The
 results obtained were relatively  high but it should  be noted
 that  they  are  instantaneous measurements.   The  1.90  ppm figure cited
 by the commentator was  measured only about  5 cm from the discharge
 stream during  the discharge of  fluid sludge  to  the  landfill.   The
 next  highest measured value in  the landfill  area  was 1.10  ppm.  The
 study referred to was  a preliminary study only.   EPA's  Office  of
 Solid Waste Management  Programs is planning  to  conduct a more
 detailed follow-up  study to determine the extent  of  the problem.
 At the conclusion of  that  study it will be  determined  whether  a
 regulation  is  needed,  and  if  so, what type  of control  should be
 required.

      There  are two  sources of the  solid waste;   (1)  resin  that
 cannot be marketed  because it does not meet  certain  specifications,
 and (2) sludge removed  from centrifuges and  placed in  ponds to
 separate out additional water.  The vinyl chloride in  sludge is primarily
 due to the  vinyl  chloride  contained in polyvinyl  chloride  that collected
 in the centrifuge.   Improved stripping required by the standard will
 reduce the  vinyl  chloride .content of the  polyvinyl chloride resin, and
 thus  also of the  sludge.

      On a trip to a polyvinyl chloride plant, the plant personnel  stated
 that much of the  "off-spec" resin is  sold or recycled by blending it in
with  other  batches.  The plant had just recently begun to also recycle
 the polyvinyl  chloride sludge from the settling ponds.   Another company
 has recycled sludge when the market demand for polyvinyl chloride has
 been high.

                                  2-97

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      6.   VC-23

 Comment:   The standard should be revised to require scrubber
 control  of hydrogen chloride emitted from incinerators used to
 control  vinyl chloride.

 Response:   In the preamble to the proposed standard,  EPA indicated
 that it  has plans to further evaluate the hydrogen chloride problem.
 Before establishing standards for -a pollutant,  EPA does a study which
 looks  at  the health effects and sources  of the  pollutant and determines
 whether standards should be set,  and if  so, under the authority of
 which  section of the Clean Air Act.   The National  Academy of Sciences
 (NAS)  has  recently prepared for EPA a document  which  includes information
 on  the health effects of hydrogen chloride.   There are several
 sources of hydrogen chloride emissions.   In fact,  in  ethylene dichloride-
 vinyl  chloride plants, an incinerator used to control  vinyl  chloride
 is  only one of the sources of hydrogen chloride.   Since hydrogen chloride
 is  a raw material  in the manufacture of  ethylene  dichloride and a
 by-product in the manufacture of  vinyl chloride,  it is emitted  from
 process equipment.

     7.  VC-46

 Comment:   Pages  6-33 of  the SSEIS,  Vol.  I  discusses allowable emissions
 in  terms of pounds  of kilograms of vinyl  chloride  per hour,   rlo reference
 is  made, however,  to how the  allowable emissions  compare with the
 proposed standard.

 Response:   Pounds  and  kilograms are  both  a measure  of mass.   Pounds are
 in  English  units  and kilograms are  in metric  units.   In  its  documents
 EPA usually  gives  data in  terms of metric  units with  the English  units
 in  parenthesis.

     The standard, most  of  which  is  expressed in terms of
concentration  units,  is  related to the mass units in  the following
manner.  EPA  selected an average  plant size.  The production  rate of the
plant and the air flow rates  from the equipment in the plant  are  known.
With this information, it is  possible to calculate the mass emission
rates that would be  emitted from  this certain size facility when  the
standard is in effect.
                                  2-98

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     8.  VC-46

Comment:  Pages 6-33 through 6-39 of the SSEIS, Vol. I compare the
concentrations of hydrogen chloride in the vicinity of plants incinerating
vinyl chloride with standards for hydrogen chloride in other countries.
It is stated that EPA does not have a standard for exposure to hydrogen
chloride and thereby lacks a yardstick for comparative measurement.
Without further expansion, reference to ambient standards allowed in
other countries should be omitted and justification should be presented
for including a discussion over the ambient standards of 5 ppm which
have already been established.

Response:  In presenting information on environmental impacts,
EPA believes that it is meaningless to report a long list of
numbers without relating them to something.  It would be helpful
to compare them to an EPA standard.  If one does not exist, it
seems reasonable to compare them to standards established in other
countries.  These standards are based on health effects data.  The
5 ppm standard referred to is for occupational exposure.  All
of the other standards discussed are below 5 ppm.

     9.  VC-46

Comment:  Page 50 of the SSEIS, Vol. I discusses the caustic which would
be required to neutralize the HC1 collected in scrubbers.  The fate and
cost for disposal of the large amount of brine which would be released
after neutralizing the HC1 should be discussed.

Response:  Neutralization of the HC1 would result in sodium chloride
being released into wastewaters.  Since EPA has not deemed it
necessary to require control of dissolved solids, there would be
no additional cost associated with disposal of the sodium chloride.
As discussed in the SSEIS, Vol. I, the amount of HC1 that would have to
be neutralized would be considerably reduced by reclaiming the HC1.  HC1
is a raw material used at ethylene dichloride-vinyl chloride plants.


     10.  VC-46

Comment:  On page 6-59 of the SSEIS, Vol.  I reference is made that
plants could possibly reduce energy impact because  they are typically
located  in large petrochemical complexes.  The rationale for this
statement should be clearly stated.  Proximity to  large petrochemical
complexes will afford availability., but will not reduce the energy
required.

Response:  Incineration of hydrocarbons produces heat.  The
heat can be used in other processes in the plant.   This provides
an energy savings because otherwise the heat would  have to be
generated.
                               2-99

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      1 .   VC-46

 Comment:   On  page 6-59 of the SSEIS,  Vol.  I,  the  statement Is 'made that
 AlSSIaS'irSnT fP01^]  chloride dispersion  plants to  attain  the
 Alternate  II  control  level would be increased by  a factor of ten  over
 the  energy consumption of plants attaining  the Alternate  I control
 level.  Considering that  this .alternate  would accomplish  only  a four
 percent reduction in  emissions of vinyl  chloride, some  reference
 fS i be  ™de  *? s"ow how much  vinyl  chloride reduction  would be
 equivalent to a ten- fold  increase  in energy to accomplish  this
 decrease.
hptonfli     I-"1" ?6rc!nt diffei"ence in the emission reductions
between Alternative I and II is for ethyl ene di chloride/vinyl
chlori deviants.  For polyvinyl chloride dispersion plants
Alternative I reduces emissions by 52 percent and Alternative II
reduces emissions by 95 percent.  (See Table 6-2 on page 6-9)
                               2-100

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     2.9  Process and Control Technology  (Chapters 3 and 4 of
Volume I of the Standard Support and Environmental Impact
Statement).

   '  1.  VC-26

Comment:  Furnace tubes, in the vinyl chloride conversion from
ethylene dichloride, are not packed with  charcoal or pumice as
reported in the SSEIS, but are empty.

Response:  EPA's statement was based on a draft document which is
reference 6 in chapter 3.  EPA now concurs.

     2.  VC-22

Comment:  Vinyl chloride is a liquid below 7°F.  It could not
"float" on a pond of water as written on  page 4-52 of the
SSEIS.

Response:  EPA concurs.  The point was that the residual vinyl
chloride monomer will be evaporated from  the ponds, not staying
in the water.

     3. VC-22

Comment:  Not all pressure rises can be detected by instrumentation
in time to avert over-pressure conditions as stated on page 4-30
of the SSEIS.

Response:  Change to "In most cases, potential problems can be
quickly detected by instrumenting each reactor with temperature or
pressure alarms to alert the operator to  upset conditions."

     4.  VC-22

Comment:  Gas holders cannot practically  hold the vinyl chloride
contained in an entire reactor batch if the reactor is large.
(See p. 4-30 of SSEIS).                                          .

Response:  It is technically feasible to  construct a gas holder
to hold the contents of the entire batch  of a large reactor.  At
least one new plant is set up to discharge one reactor batch to
another reactor and thus the second reactor is a "gas holder."

     5.  VC-22

Comment:  The calculation on p. 4-22 of the SSEIS, Vol. I is in
error in using tapped bulk density of polyvinyl chloride instead
of true density (87 Ibs/cu ft).

Response:  EPA concurs with the correction.  The true density
was not available to EPA at the time of the calculation.
                                 2-101

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       6.   VC-22

  Comment:   The statement on page 4-76 "...  each of these techniques
  can reduce the vinyl  chloride content of the case being treated
  to less  than 10 ppm," should be qualified  by noting that use of
  HoL  +   lq!!eS (adsorPtion, absorption,  and incineration)  has not been
  demonstrated under production conditions for all  sources.

  Response:   EPA agrees that thdse techniques have  not been  used
  under production ^facili ties for all  sources.   However,  it  is believed
  that these  techniques can  be designed to meet the emission  limit
  even though  different production conditions exist at different plants.

       7.  VC-22                 ~

  Comment:  Table 4-3,  page  4-81  shows  achievable emission levels for
  certain controls on certain  sources  to be zero emissions.  This
  figure is inconsistent with  reported  performance  of  control  devices
  (Also same comment for Table 4-4, p.  4-83).                        '

 Response:  Where the emission factors were  less than 0.001 kq/100 kq
 they were considered zero.

      8.  VC-33

 Comment:   Double mechanical seals are fine  for vertical  vessels
 but for horizontal  vessels, a grease stuffing box is safer and
 more practicable.

 Response:   EPA concurs that the two  methods  are equivalent.

      9.   VC-34, Attachement 1, page  1


                              as  reported  1n  Tables 3~6 and  3-7 do  not
Response:   In the spring of  1974,  (the baseline for all of  EPA's
emission data) not all strippers were vented to a  recovery  unit.
EPA averaged the emissions from these plants over  the entire industry
for the factors given on Tables 3-6 and 3-7.

     10.  VC-29

Comment:  A more reasonable polymerization cycle time for suspension
polymerization than the 6 hours given in the SSEIS is 10-12
hours /batch.

Response:   EPA agrees.
                               2-102

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     11.  VC-29

Comment:  The saturation point for vinyl chloride monomer in
water is 1100 ppm at standard conditions, thus it is impossible to have
concentrations of 2000 ppm as reported on page 3-15.

Response:   The 2000 ppm figure was given to  EPA by the  B. F. Goodrich
Chemical Company in a visit  to their  Henry,  Illinois, plant on
April 8, 1975.  The estimate was  based on their own  tests of
inprocess waste water from the plant.  EPA feels that the condition
is  possible under non-equilibrium conditions with impure water streams.

      12.  VC-29

Comment:  The  origin of the  data  in  Tables 3.6-3.9 is not
reported, nor  is  the specific process for Table  3.7  identified.

Response:   Tables  3.6  through 3.9 were, developed from data  submitted
by vinyl  chloride monomer and polyvinyl  chloride producers  in
 response  to a  May  31,  1974,  section  114  request  by Mr.  Don  Goodwin.
 Table 3.7  deals with  both dispersion and latex resins.

      13.   VC-29

 Comment:   In bulk plants, the  popo reactor  may be cleaned after each
 batch and must be opened to transfer the product.   This is  clearer than
 the statemenFgiven in section  3.2.2.3 of the SSEIS, Vol.  I.   New
 data is available on emissions  from bulk plants  to update Table 3.8 of
 the document.

'Response:   EPA agrees  with  the  first comment.  While emission
 factors have changed  in bulk plants, EPA does  not plan  to  update
 Table 3 8.   The  factors  in  that table are based  on  data supplied
 to EPA in  May  1974, the  base date for the uncontrolled  plant.

      14.   VC-29

 Comment:   The estimates  in Table 3-9 for solution resins are
 incorrect since reactor opening loss and dryer loss  are both
 non-existent.

 Response:  On June 26, 1974, the sole manufacturer of  this
 type of product reported a  dryer loss.  The company also reported
 a  precipitation tank loss equivalent to the reactor opening loss.
 The category in Table 3-9,  "reactor  opening loss  should be
 considered "precipitation tank loss."

      15.   VC-29

 Comment:   According to Chapter 4, carbon adsorption is not
 applicable to streams with  low vinyl  chloride monomer  concentration,
 high in water and  particulate  and composed  mainly of air.  Untested

                                 2-103

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 technology, such as this, should not be considered in the document.
 The discussion of carbon adsorption and ion exchange resins is irrelevant
 to the study.

 Response:  Chapter 4 never said that carbon adsorption was inapplicable
 to any particular source.  The document states that carbon adsorption
 is more practical for some than for others.  There are no sources
 in ethylene dichloride-vinyl chloride or polyvinyl chloride plants
 where carbon adsorption is technically impossible to apply.   Carbon
 adsorption is used commercially on similar streams.

      16.   VC-29

 Comment:   Spray towers, spray chambers and venturi scrubbers
 are_inefficient devices as solvent adsorbers.   Ten ppm would
 be impossible.  Scrubbing vinyl chloride monomer gases to 10
 ppm using water or aqueous solutions  of sodium carbonate  or
 sodium hydroxide is  not possible using present technology.  Use
 of a  lower volatility  solvent is not  feasible  because  of  problems
 in separating vinyl  chloride monomer  and the solvent.

 Response:   EPA did not claim, in Chapter 4, that any of the
 described solvent absorbers  could achieve  10 ppm.  The chapter
 pointed out that a number of factors  affect control efficiency
 on these  devices  including temperature,  concentration,  and  design.

      17.   VC-29

 Comment:   The  figures  used in pages 4-34 and 4-35  of the
 Standard Support  and Environmental  Impact  Statement are incorrect.  The
 references  should be Table 3-6,  not 3-5  and the  reactor opening loss  is
 0.14 kg/100 kg/not 0.46.

 Response:   The table number  is  incorrect.   The figure  for reactor
 opening loss includes  the  figure  in Table  3-6 for  opening of
 0.14 and stripper loss  of  0.32.

     18.  VC-29

 Comment:  The suggestion on page 4-46 that  equipment could
 be fitted with high pressure  spray heads is incorrect for the
majority of existing .reactors which do not  have nozzles of
adequate size to  permit passage of the spray head.

Response:   EPA points out again that not all of the discussed
control procedures are applicable to all sources.
                              2-104

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     19.  VC-29

Comment:  The discussion of polyvinyl chloride inprocess waste
water should note that the suspension resin process is involved.
All data given is based on the suspension process.

Response:  EPA concurs.

     20.  VC-17

Comment:  The preamble and the document suggest that bulk
process reactors be purged with nitrogen gas and vacuum.  The
writer suggests that steam has been shown to be effective in
some cases.

Response:  EPA concurs.

     21.  VC-21

Comment:  "EPA does not define dispersion, latex, and emulsion
resins well.  Clarity is needed in the process description.  The
following is offered:  "The dispersion polymerization is discussed
as though these are basically emulsion type polymerizations.
Although the emulsion process is used, or can be used, to produce some
dispersion resins it is not the principle method used.  The comments
describing the equipment are in error.  The process is similar to
the suspension process only in that monomer, water and catalyst
are used in the polymerization.  The difference is not that more
soap is added to the slurry to stabilize the monomer droplets and
form agglomerates.  Suspension resin (p. 3-11) uses vinyl chloride
monomer, water, catalyst and suspending agents, not soap.  Dispersion
resins use a dispersing technique which does not relate to suspending
techniques as the article implies.  If the emulsion process is used,
it uses an emulsifying technique which again is quite different."

     "The particle size of the suspension resin after polymerizing
and after drying is essentially identical.  The particle size of
the dispersion or emulsion resin after polymerizing is sub-microscopic.
The spray dryer used to dry dispersion resins produces a particle
size wuich depends on the type of spray.

     "Latex resins are not produced by the dispersion process; they
are produced by the emulsion process, quite different, technically.
More soap may be used but not during the polymerization.  In some
instances soap may not be added after polymerization which results
in an unstable condition and leads to difficulty in stripping."

Response:  EPA agrees that perhaps more clarity is needed in
defining the various resins in the process description.  The Agency
points out, however, that these distinctions do not affect the
proposed standard.

                               2-105

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     22.  VC-21

Comment:  On page 3-13, polymerization pressure is stated to be
5.1-5.8 atmospheres while on page 4-30, polymer pressure is
stated to be 6.1-7.8 atmospheres.  The latter figure is more
nearly correct.

Response:  EPA agrees.
                                  2-106

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     2.10  Comments on Quantitative Risk Assessment for Community
Exposure to Vinyl Chloride

     1.  VC-22, VC-27, VC-29, VC-32, VC-34

Comment:  The risk assessment should have been based on the log-
probit model, rather than the linear no-threshold model.

Response:  A number of arguments were made by industry in support
of this comment; they are discussed in turn.

     First, it was argued that the risk assessment document was biased
in favor of the linear model.  It was the intention of the authors that
the two extrapolation methods should have equal status; any impression
to the contrary was inadvertant.  Both methods are supported in the
scientific literature, and both are equally lacking in empirical
confirmation.  It is true that the log-probit model results were
shown as a range determined from a sensitivity analysis of the
linear model results.  This was done because it is computationally
much more difficult to get a single number for the log-probit model,
and the value of the number for the decision maker did not appear
commensurate with the amount of work required to get it.  Because
the log-probit curve is non-linear and falls off very rapidly with
dose, the results will be determined by the groups with the highest
exposure and it is not valid mathematically to apply it to average
data for large groups (as several industry comments have done).  It
would be necessary to perform a separate calculation for each
community, direction, and distance category (over 2,500 combinations),
and even this might not be sufficiently fine-grained.  The only payoff
of this massive amount of work would be to know just where in the
range of, for example, 0.1 to 1 cases/year the log-probit results
fall.  Knowing this would not greatly help the Administrator in
making a responsible decision.

     Second, it was argued that the log-probit model better fitted
the actual animal data and should therefore be the basis for
extrapolation.  While it is true that the deviations of the log-
probit model from the actual data were somewhat smaller than for
the linear model, the differences are not large enough to have any
statistical significance.  And even if they were statistically significant,
that would not necessarily be a controlling consideration.  The choice
of a preferred extrapolation method should depend on one's view of
the mechanisms of carcinogenesis and on the degree of conservatism
one feels is appropriate.  Neither of these is greatly affected
by small differences in .the fit of the two curves at high doses.  And
even if it is believed that variations in susceptibility are the main
factor affecting dose-response, no information is available on
the tails of the distribution.

                              2-107

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      Third, it was argued that the "log-probit method is more generally
 accepted or that "Nature seems to operate in the normal distribution
 (log-probit) mode."  In fact, it seems more accurate to say that
 both approaches have support in the literature; support for a linear
 model is found, for example, in Hoel, et al., "Estimation of Risks
 of Irreversible, Delayed Toxicity," J. Toxicology & Environmental Health.
 Vol. 1, No. 1  (1975) and FDA Advisory Committee, "Panel on Carcinogenesis
 Report, Toxicology & Applied Pharmacology, Vol. 20, pp. 419-38 (1971).
 Support for the linear model and its variants is generally based on
 the notion that cancer occurs as the result of random events at the
 cellular level.

      Finally,  it was argued that animal  data on the metabolism of
 vinyl chloride shows that the log-probit model  is more appropriate.
 While there are some difficulties in interpreting these data (which are
 discussed elsewhere in these comments),  this argument may well  turn
 out to be correct.   The current state of knowledge is not sufficient,
 however, to prove it.

      In summary, it still  appears justifiable to present the results
 of both models and  to  allow the  decision maker  to decide what
 weight to give to each.

      3.   VC-29,  VC-34

 Comment:   Recent animal  studies  indicating a change in  the pathways
 for vinyl  chloride  metabolism at  low doses suggest that a  threshold
 dose rate exists below which cancer  is not expected to  occur.

 Response:   The metabolic studies  do  not  measure  tumor incidence,
 which is  the end result of many biochemical  reactions and  cellular
 changes which  are not well understood.   Therefore,  they are  not
 directly  relevant to the quantitative  relationship  between cancer
 incidence  and  dose  rates.  It is  not  known whether  the  malignancy
 results from the parent compound, one of  its many  possible metabolities,
 or  from some consequence of  the reactions  which metabolize the
 compound.   Since each of these possibilities is expected to  have its
 own  dependence on the dose rate,  it  is not possible  to  rule  out the
 linear, no-threshold model.   The metabolic pathways  in man may be
 different  than those in the  animals studied.

      4.  VC-22,  VC-27, VC-29, VC-32, VC-34

 Comment:  The risk assessment should have  used the much lower
ambient concentrations measured in EPA's monitoring  study, rather
than  use diffusion modeling  results.

Response:  The data referred to were not available when that part
of the risk assessment was done.   The decision was made to use the
diffusion modeling results, which were the best information available

                              2-108

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at the time.  The best available estimates of vinyl chloride emissions
were also used.  Diffusion modeling is a generally accepted technique
in the air pollution field.  The fact that two independent groups
produced very similar results added to confidence in the diffusion
modeling (although both are based on the same estimates of total
emissions).

     The risk assessment made clear that the situation with uncontrolled
plants was being evaluated.  The EPA monitoring in question occurred
after the OSHA standard had been promulgated, so that the plants may
have been operating more carefully to limit workers' exposures.  It also
occurred during an economic recession, during which production rates
may have been less than full capacity.  It seems doubtful, however, that
these factors can account for a difference as large was was observed.
In any future revision of the risk assessment, the monitoring data
will be taken into account.  It is possible that if this were done,
the risks would be approximately one-tenth of the current estimates.

     It should be noted that the risk assessment is not required by
the Act and that the standard is not derived from it in any direct
sense.  It forms part of the background information available to the
Administrator in deciding on the seriousness of the problem of vinyl
chloride emissions.

     2.  VC-22, VC-23a, VC-29, VC-34

Comment:  What importance should be attached to the negative finding
in the risk assessment document of liver angiosarcoma cases clustered
around ethylene dichloride-vinyl chloride and polyvinyl chloride plants?

Response:  The risk assessment document described a survey of liver
angiosarcoma cases in which evidence of higher than average clustering
of cases among people living near ethylene dichloride-vinyl chloride
and polyvinyl chloride plants was sought but not found.  The document
concluded that, for several reasons, the survey was not sensitive
enough to detect such clustering even if it did occur, unless the
actual rate of vinyl chloride induced angiosarcoma is many times greater
than the maximum rate predicted by the model.

     Industry comments generally interpreted the survey as evidence
that cancer is not caused by community exposure to vinyl chloride, and
a comment from an environmental group pointed out factors not considered
in the document which would make the survey even less sensitive than
stated.

     One industry comment alleged, but could not support this definite
information, that the ambient concentration at some plants could have
been more in past years than in 1974.   Another industry stated that
at one plant emissions did not change appreciably from the early
1950's to 1974, and consequently estimated that the risk to that
community has not increased in this period.

                               2-109

-------
      In order to make the risk estimate more realistic, the Agency
 would need reliable information about historical  vinyl  chloride and
 polyvinyl  chloride production rates at each factory site.   Because such
 localized  information is not available, the document draws conslusions
 only about national averages.  The comments received were  not extensive
 enough to  invalidate the assumption that the average vinyl chloride
 concentrations were proportional  to the polyvinyl  chloride and vinyl
 chloride production rates.   Therefore people in recent  years have been
 exposed to higher vinyl  chloride  concentrations and the conclusion
 still  remains that surveys  conducted now cannot detect  a large portion
 of cancers that may have already  been initiated by vinyl chloride
 exposure.

      The environmental  group commented that the latent  period is  probably
 longer for people exposed to low  community vinyl  chloride  concentrations
 than for those occupationally exposed (a factor ignored in the risk
 document), so that any  community  cases observed in the  survey would
 represent  exposures earlier, and  therefore, at lower ambient concentra-
 tions  than stated in the risk document.   If the Agency  had considered
 this factor,  a stronger  case could be made for rejecting the survey
 conclusions and,  therefore,  for being unable to rule out the possibility
 of vinyl chloride induced cancer  in the community.

     The Agency has decided  that,  since no new data on  these points
 was  submitted by  the industry groups  or the environmental  group,  the
 risk document should still leave  open the  possibility that vinyl
 chloride could have induced  cancer in people living near plants which
 is  currently  undetectable in the  population.

     5.  VC-32, VC-37

 Comment:   In  estimating  the  incidence of liver angiosarcoma  among  vinyl
 chloride and  polyvinyl chloride workers, the risk  document selected
 studies  showing the highest  incidence and  ignored  those showing lower
 incidence  in  order  to artificially increase the risk estimates.

 Response:  The  objective  of  the literature  survey  of occupational
 cases was  to  obtain the  incidence  of  liver  angiosarcoma in a  homogenous
 population of workers who were all  highly  exposed  to vinyl chloride in
 a situation where the concentration could  be estimated.  Of  the
 four studies  found  where  the  incidence of angiosarcoma  among.highly
 exposed workers could be  calculated,  one was  a  large study of  33 plants,
 each with  its own definition  of high  exposure.  It  was  rejected
 because the population was too heterogeneous  and because of  the resulting
 difficulty in establishing an exposure level  for the group.  A second
 study of two  plants with a group of workers  almost  as large as the
 first group but with no evaluation of separate job  categories  reported
 all types of  liver  cancer.   It was rejected  because  of  the large mix
of job categories in the population.  The remaining  two studies were
 both restricted to workers directly exposed  to high  concentrations of
vinyl chloride.  The incidence rates  in these two studies were similar

                              2-110

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and higher than the two larger studies that were rejected.  These
rates are consistent with the hypothesis that the larger populations
had a heterogeneous mixture of jobs with a range of exposures.
Unfortunately we had to go to a third study in order to estimate
the concentration of vinyl chloride to which this occupational group
was exposed.                                         .              ,:

     Therefore, the selection of studies was necessary, in order to
arrive at an incidence rate which was valid for a population exposed
to a known vinyl chloride concentration.

     6.  VC-23a, pp. 9-10 of EDF testimony

Comment:  The risk assessment may understate the risk because it
does not reflect the effects of pre-natal and childhood exposure,
possible synergistic effects, or the effects of adult exposure
for entire lifetimes.

Response:  Ideally, animal studies for environmental carcinogens
should involve exposure from conception to death.  Unfortunately,
the animal data on vinyl chloride were designed to simulate
occupational rather than environmental exposure.  For the risk
assessment, it was necessary to do what was possible with the
available data.

     There is no data that would make possible an estimate of .<
different susceptibility of fetuses or young children to the
carcinogenic activity of vinyl chloride, or of possible synergistic
(or antagonistic) effects of other environmental agents.  Hence,
such factors were not included in the calculations; the comment is
correct that this is an additional source of uncertainty in the
estimates.  It is not possible to be sure that they would lead to
higher estimates of effects.

     The problem of limited adult exposure duration, one year for
rats, up to 30 years or so for humans, was handled in a conservative
way in the risk assessment.   It was assumed that each period of
exposure would have the same probability of causing cancer after
correcting for species lifetime effects as that observed in the
animal experiments, where young rats were exposed for about half
their lifetime.  This leads to an overstatement of the actual risk
because of the long latency period, since pre-cancerous changes
occurring late in life are less likely to cause clinical disease
before death intervenes from other causes.

                              2-111

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      2.11  Miscellaneous

      1.  Comment:  Several commentators pointed out typographical,
 editorial, and conversion factor errors in the proposed standard.
 The errors have been corrected in the promulgated standard and are
 listed below along with the commentators that pointed them out.

      1.  The conversion factor for liters to gallons is 3.8 1/gal,
 not 4.1 or 4.4 1/gal.  VC-14, VC-21, VC-26, VC-27, VC-29, VC-32.

      2.  The word "chloride" was left out of §61.64 (e)(l)(i).
 VC-13,  VC-29.

      3.  In §61.65 (b)(3)(iii) and (iv) in the phrase "so that
 any leak that occurs is into the pump," the word "pump" should  be
 replaced with "compressor" and "agitated vessel," respectively.
 VC-25,  VC-35.

      4.  §61.70(a)(4) should refer to §61.65(a)  instead of
 S61.65(b).   VC-21,  VC-31.
 31.
      5.   §61.65(c)  should  refer to  equipment >_ 5500 1  (1250  gal).   VC-
      6.   There  should  be  a  paragraph  following  §61.67  explaining
 that  Test Methods  106  and 107  are  being  added to  Appendix  B  of
 Part  61.   VC-35.

      7.   §61.65(b)(9)(i)  should  be  corrected to say  "inprocess
 wastewater stream  is to be  reduced  to  10 ppm" instead  of "by 10 ppm."
 (emphasis  added)   VC-35.                                  -*-

      There were also some errors pointed out in supporting documents.

      1.   In the STAR document, the  nameplate capacity  of Shell Chemical
 Company's  plant in Deer Park, Texas should be 380 x  10 kg/yr instead of
 410 x 10   kg/yr.  VC-27.

      2.   In Table I of the  "Quantitative Risk Assessment for
 Community  Exposure to Vinyl Chloride," entries 65 and  66 are incorrect.
 With  regard to entry 65, Tenneco does not have a vinyl chloride or
 polyvinyl  chloride plant in Painesville, Ohio, and therefore this
 entry should be eliminated from the Table.  With regard to entry
 66, Tenneco does have a facility at Pasadena Texas, but that facility
manufactures only polyvinyl  chloride; it does not manufacture vinyl
chloride.  VC-15.
                                 2-112

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     2.  VC-18, VC-29, VC-30

Comment:  Under the provisions of section 112 of the Clean Air Act,
EPA may grant a waiver of compliance with a standard for a period
not exceeding two years from the effective date of the standard.
Plant owners and operators will need to take advantage of this
provision.

Response:  No response necessary.

     3.  VC-13, VC-25

Comment:  The definition of "in vinyl chloride service" in §61.61(1)
of the proposed standard should be revised in the following three
ways.

     (1)  Add the qualification that the equipment must be operating
under pressure.  A piece of equipment that is not operating above
atmospheric pressure cannot emit vinyl chloride to the atmosphere.

     (2)  The words contain vinyl chloride should be changed to
contacts vinyl chloride.  As an example an agitator does not contain
material, but contacts the material being agitated.

     (3)  The qualification should be added that the principle phase
of the contents of the equipment contains 10 percent vinyl chloride.
The basis for this suggestion is to alleviate problems with vessels
that contain stripped-to-specification slurries (the principle phase)
but whose vapor space at the low pressure still might contain
10 percent by volume of vinyl chloride.

Response:  The definition of "in vinyl chloride service" has been
revised to incorporate the second suggestion, but not the first
or third.  EPA intends to cover the situation described in the
third suggestion.  The benefit of adding the first suggestion is
not apparent.

     4.  VC-28

Comment:  Clarification on the following two questions is requested:

     (a)  Once the residual vinyl chloride levels of 400 ppm for
suspension resins and 2000 ppm for dispersion resins are met,
may fugitive emission sources from equipment downstream from the
reactor (reactor/stripper), exceed 10 ppm?

Response:  If the 400 ppm and 2000 ppm limits have been met in the
stripper, the fugitive emission limits do not apply to equipment
downstream of the stripper.
                                 2-113

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      (b)  Once a vessel is evacuated to the required level for
 opening, may the remaining vinyl chloride be collected to a system
 whose stack exit concentration exceeds 10 ppm.

      Response:  Yes.  The vinyl chloride removed from the equipment
 in order to meet the requirement for opening must be treated
 to meet the 10 ppm limit.   The vinyl chloride remaining in the
 equipment after the requirement for opening is met is allowed to go
 to the atmosphere.   It is  assumed that the commentator is referring
 to a purging hose which is typically used by the industry to remove
 any remaining vinyl chloride from the reactor.  Emissions from other
 sources may not be mixed with the reactor opening loss and exceed
 the 10 ppm limit.

      5.   VC-14, VC-26,  VC-32, VC-34, VC-39

 Comment:   The equipment specifications for fugitive  emission sources
 are not authorized  under section 112 of the Clean Air Act.   VC-34
 states  that the only fugitive emission regulation that is worthwhile
 is the  one requiring leak  detection.   Just requiring a leak detection
 program would allow plants more latitude than  the proposed regulation
 in controlling fugitive emissions.

 Response:   In the preamble to the proposed standard, EPA  explained
 in detail  why it had decided  to regulate some  fugitive emission
 sources with  equipment  specifications.   Numerical  emission  limits
 were used  for each  emission point where  possible;  however,  equipment
 and operating procedures are  specified  for some  of the fugitive
 emission sources from which emissions  cannot be  measured  or
 calculated or for which  it would  be  grossly  impractical to  do  so.
 Generally,  the  reason that these  emissions  cannot  be measured  is
 that they  are released  into an  unconfined  area and often  from  many
 small sources,  and  there is no  practical  testing procedure  for
 obtaining  a reliable reading  of emission  levels.   Where equipment
 or operating  procedures are specified, plant owners  or operators are
 generally  allowed to use other  equipment or procedures, demonstrated to be
 of equivalent effectiveness.  Primarily  because  fugitive emissions
 compose such  a  large proportion of the total emissions at ethylene
 dichloride-vinyl chloride  plants,  EPA has determined  that control
 of such emissions by specification of equipment and  operating procedures
 is  preferable to the alternative of leaving such emissions unregulated.

     6.  VC-46

Comment:  The environmental impact statement was prepared after
standards were proposed and published in the FEDERAL REGISTER.
                                   2-114

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Response:  Drafts of the environmental impact statement were
available to interested parties as early as March 1975.  The
information in these drafts was the basis of the proposed
standard.

     7.  VC-46

Comment:  Reference is made to one company in Chapter 2.  Naming
one plant out of several is inappropriate.  The term "Vulcan
Materials"  should be substituted by an appropriate synonym so as
to read "with the exception of one plant."

Response:  The suggestion is probably appropriate.  However,the
document is not being rewritten, so this change will not be made.

     8.  VC-46

Comment:  It should be stated that the total emissions from the
vinyl chloride plant are one-third of the emissions from the polyvinyl
chloride fabricating plants.

Response:  Table 2-1 on page 2-28 of the Standard Support Document lists
the 1974 vinyl chloride emissions from ethylene -dichloride-vinyl chloride
plants as being 11 million kg per year and from polyvinyl chloride
fabricating plants as being 600,000 kg per year.

     9.  VC-46

Comment:  In Chapter 2, it is stated that "all vinyl chloride emissions
from the fabricating plants are due to residual vinyl chloride in the
raw materials coming from polyvinyl chloride plants."  This statement is
incorrect.  Emissions in fabricating plants result from the vinyl
chloride contained  in the raw polyvinyl chloride used in the fabri-
cation.

Response:  The difference between the two statements is unclear.

     10.  VC-45

Comment:  The data from the ambient sampling program around Shell's
ethylene dichloride-vinyl chloride plant is not included under the
data for Region VI on page 27 of the STAR document.

Response:  This data ijs on page ,30.
                                     2-115

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       11.  VC-45

  Comment:  The ambient sample data reported from grab samples
  in Tedlar bags is totally unreliable.   If the grab sample
  data is going to be referred to or tabulated in the report,
  there should be some reference made to the use of a bag containing
  plasticizers.                                          3          y

  Response:   The fact that Tedlar bags contain plasticizers  should
  not be  a_problem.   EPA conducted a study  under contract on Tedlar bags
  and alunnmzed Milar bags.   Samples  containing specified quantities of
  vinyl chloride were placed  in  bath the Tedlar and aluminized Milar bags
  for a period of one month.   The  Tedlar bag showed no  loss  or increase of
  vinyl chloride.   It also did not show  peaks  due  to  decomposition
  products  from  the bag.   The Milar bag  did,  however.   Zero  concentrations
  of vinyl  chloride were  also placed in  the  Tedlar  bags and  no response
 was  observed.

      The vinyl  chloride  content  of the Tedlar  bags  used  during the
 sampling program was measured with gas chromotography and  in
 some cases cross-checked with mass spectrometry.  Based  on the
 study discussed above, it is unlikely  that the plasticizers  in the
 bags caused interference with the  vinyl chloride peak on the
 gas chromatograph.

      12.  VC-39

 Comment:  It is unfortunate that EPA could not and did not visit
 all plants.   As a result, the commentator's plant was not
 given sufficient recognition within the regulation as
 utilizing the best available technology.

 Response:   Time did  not permit  EPA to visit all plants.   The  SSEIS,
 Vol.  I does  not characterize individual plants, but only the
 average  plant.   Since the comment letter was received, EPA has  visited
 this particular plant.   The  plant does  have many of the  control  systems
 required by  the standard, particularly  for the fugitive  emission
 sources  and  relief discharges.

      13.   VC-39

 Comment:  The regulations  should  state  the  emission  reduction
 possible for  the entire  class or  category  of  point sources
within a given  range  and  should analyze those  factors  deemed
 important for the writing  of each  individual  compliance schedule
within that range.  More  consideration  needs  to be given
to formulating  a more detailed approach for the issuance  of
each compliance schedule.
                               2-116

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 Response:   The  specifics  for  the  compliance schedules are in
 §§61.10  and 61.11  of  the  general  provisions.

      14.   VC-18, VC-24, VC-335 VC-34

      The standard  should  provide  for variances for infrequent
 operations  that produce small emissions.  An example would
 be  the requirement to strip vinyl chloride from water which
 has  been used to purge vinyl  chloride from a storage sphere
 before opening  it.

      The standard  should  provide  for excess emissions during
 start-up,  shut-down,  and  malfunction.  EPA has not included
 in  its economic impact statement  the costs which would be
 incurred during a  malfunction either to shutdown production
 or  to install back-up control equipment.

      EPA should at  least  provide  for excess emissions during a
 shutdown.   If a breakdown occurs  in the emission control
 equipment,  there are  on-going reactions in a plant that must
 be brought  to completion  prior to shutdown.  This will require
 venting in  excess  of  10 ppm until a safe shutdown can be
 accomplished or the malfunction in the control system corrected.

      One option would be  to have  a steam factor of 0.9 with
 a maximum emission  limit  of 0.04 kg/100 kg. of product produced
 during noncompliance,,  This option would allow operators to
 repair, maintain, and modify operation of control devices that
 malfunctioned or required preventive maintenance without
 terminating production or otherwise seriously disrupting operations.
 In our plants (VC-18) this would cause a maximum increase in
 annual emissions of about 10 percent at the polyvinyl chloride
 plant and about 20 percent at the ethylene dichloride-vinyl
 chloride plant.

 Response:   (1)  Variances.

     There are  no provisions at the present time for variances
 for standards promulgated under sections 111  or 112.   The water
 used to purge vinyl chloride from a storage sphere would have
 to be treated only if it contains more than 10 ppm vinyl  chloride.
 If it does need to be treated, it would not appear to be practical
 to install  a larger water stripper for this purpose.   Storing the
water in  that vessel or some other holding tank until it could
be treated seems to be a more plausible solution.
                              2-117

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       (2)   Startup  and  shutdown

       Startup and shutdown provisions are not  relevant for
 polyvinyl  chloride plants because startup or  shutdown of the
 process has essentially no effect on emissions to the atmosphere
 For ethylene dichloride-vinyl chloride plants, only one comment
 mentioned  a source of  emissions during startup which would present
 control problems.  During startup the hydrogen chloride stream that
 is normally vented to  the oxychlorination process from the cracking
 furnace is vented to the atmosphere.  The commentator vents the
 hydrogen chloride stream to the atmosphere since the oxychlorination
 process is not operating.  The gas stream contains emissions in
 excess of  the 10 ppm standard.  EPA discussed this problem with
 two other  companies.   Both companies avoid venting the hydrogen
 chloride gas stream to the atmosphere by starting up the oxychlorination
 process before the cracking furnaces.  There is no apparent reason why
 this procedure could not be adopted by the other companies.

      (3)  Malfunction

      Section 112 of the Clean Air Act has been reserved for the
 regulation of pollutants,., such as vinyl  chloride, which may cause,
 or contribute to,  an  increase in mortality or an  increase in
 serious illness.   Because of  the serious  nature of the health
 effects of pollutants regulated  under section 112,  EPA has
 determined that  it  would  not  be  appropriate  to consider adding
 malfunction provisions  to  the regulation  unless the  Agency  was
 convinced  that the  additional  emissions occurring during  the malfunction
 did  not increase  the  risk  of  health  effects.   There  is  no conclusive
 evidence to this  effect for vinyl  chloride.   Therefore, when a
 malfunction occurs, compliance with  the vinyl  chloride  regulation
 consists of promptly  shutting  down.

     It could be argued that  EPA,  in  providing  for emergency relief
 discharges,  in effect provided for excess emissions  during  some types of
 malfunctions.  Emergency relief  discharges, however, are in a different
 category.   Safety considerations require the use  of  relief  valves  on
 equipment in which vinyl chloride is processed or stored under pressure
 There  are several preventive measures which can be undertaken to reduce
 the pressure in the equipment  to prevent a relief discharge.  In cases
 where  these preventive measures have been undertaken, and the pressure
 continues to build-up in the equipment, the standard allows relief
 discharges.  Relief valves discharge only the amount of vinyl chloride
 necessary to reduce the excess pressure in the equipment.  The alternative
would be rupture of the equipment and release of its total contents, and
perhaps fire.

                                  2-118

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     15.  VC-35

Comment:  Clarify what emissions are  to be measured on a continuous
basis.

Response:  A monitoring device is required to measure vinyl
chloride concentrations at certain points within the plant on
a continuous basis.  Typically this involves a central analyzer
with twenty or more sampling points.  The purpose of this requirement
is leak detection.  EPA's standard requires that sampling points
also be located  in the stacks to measure outlet concentrations on
a continuing basis.

     Reactor opening emissions and stripped resin samples are
also required to be measured on a continuing basis, but this
is not related to the vinyl chloride  monitoring device.  Testing
methods are specified for each of the sources.

     16.  VC-35

Comment:  Regarding the absence of a  proposed standard for polyvinyl
chloride particulate and EPA's determination that direct regulation
of the particulate is unnecessary, the following is provided:

     "A recent complaint received was about a polyvinyl  chloride
fabricating plant indicating that accidental  intermittent release
of polyvinyl chloride particulate emissions,  because of process
malfunction, were impacting the surrounding ambient air to which
the public has access.   Serious concern therefore is expressed for
the respiration or inhalation of the polyvinyl  chloride particulate
and any carcinogenic health effects that may result from residual
vinyl chloride in the particulates, especially where such emissions
are common occurrences and complacency is found in efforts to
correct such accidental  emissions.

     Clarification of carcinogenic health effects of polyvinyl
chloride particulate,  with appropriate regulation,  is  recommended
as soon as health effects data from NIOSH are evaluated.

Response:   In the preamble to the proposed standard, EPA stated
that additional  information may indicate a need to regulate
polyvinyl  chloride particulate.   The information  submitted by the
commentator is appreciated.
                                  2-119

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      17.  VC-32

 Comment:  The preamble to the proposed standard states
 (40 FR 59543) that studies show that polyvinyl  chloride
 particulate "may possibly" cause pneumoconiosis.   Stiles and
 Wilson [Ann.  Occup.  Hyg. 16: 241 (1973] clearly demonstrated
 no such effect from polyvinyl chloride dust.

 Response:   The studies EPA referred to include:

  1.   B.   B.  Szende,  et.  al.; "Pneumoconiosis  Caused by the
      Inhalation of Polyvinyl Chloride Dust,"  Med.  Lavoro,
      Vol.  61, no.  8-9, 1970; p.  433.

  2.   Yu.  J.  Verthin  and  Yu.  R.  Mamontov,  "On  the  State of
      the Bronchopulmonary System in Workers Engaged in the
      Manufacture of  Articles Made of Polyvinyl  Chloride,"
      Gigiyena Tudor) Vol.  14, No.  10, 1970, pp. 29-32.

      EPA will  await  additional  studies being  conducted by
 NIOSH to determine the need  to  regulate polyvinyl  chloride
 particulate.

      18.   VC-32

 Comment:   It  is not  clear  from  the  discussion in  section 4.9
 of the SSEIS,  Vol. I which decision was reached on  reactor opening
 emissions  since no statement is  made  as to the  final  conclusion,  but
 from  section  4.12.5  and  Table 7.8  It  is assumed that  the gasholder was
 chosen.  Substantially the same  effect can be obtained  by  the use of
 vacuum pumps,  which  can  reduce  the  internal pressure  well  below 100 mm
 Hg absolute,  to give a reduction of vinyl chloride  vapor in  the reactor
 of at least 87 percent.  An  expenditure of over $1.5  million per  plant
 is an excessive price  to pay for the  additional 12  percent reduction of
 an estimated  loss  of 3.6 percent of the total.  This  requirement  should
 be omitted.

 Response:  The type  of control used to  meet the reactor opening
 standard is left up  to the plants.  Water purge and vacuum are
 both  control methods that  can be used  to meet the standard.  Plants
will  be expected,  however, to have  gasholders or some other
empty  vessel for prevention  of reactor  relief discharges.

      19.  Proceedings  of Public Hearing, Presentation by
Barry Castleman, p.  30.

Comment:  I would  be interested in  knowing from EPA what the
update situation on vinyl chloride and  livestock is.

                            2-120

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 Response:   EPA and  the  Department  of Agriculture  are  co-sponsoring
 a study to  determine  whether vinyl  chloride  appears in  food  supplies
 due to livestock  living near polyvinyl  chloride plants.

     ,20.  VC-49

 Comment:  Are  all treatment  ponds  carefully  lined and sealed
 to prevent  leakage  to ground water?  If not,  the  significance
 of reported zero  concentrations  of effluents  from the ponds  may
 need to be  reexamined.

 Response:   According  to one  company,  they  have two types  of  ponds.
 For one type the  bottom is one foot thickness of  compacted
 impermeable clay.   These ponds are located in the same  area  with
 wells.   No  vinyl  chloride has been  detected  in the water  from  the
 wells.   For the second  and newer type,  the bottom is  composed
 of an  impermeable polypropylene  liner.

     21.  VC-49

 Comment:  In general  under the proposed  standard,  the low
 density of  the  vinyl  chloride is counted upon to  permit
 escape  of the  substance from water  into  air.  That is,  removal
 is  to  be accomplished by stripping  and evaporation.   The  length
 of  time that a  free water surface  is  available may require
 consideration  as the  temperature,  the flow conditions,  such  as
 turbulence,  before  infiltration  to  groundwater or confinement
 of  surface  flow can occur, should  be  assessed.  Flow  conditions
 of  water discharge  from a plant may prevent escape to the air,
 either  by confinement or local pressure  conditions. Quick
 infiltration or restraint of surface  flow  of the  water  bearing
 vinyl chloride  might  prevent escape of the chemical as a  result
 of  such factors as  pressure  condition, aquifer texture, and
 sorption properties with  respect to sediments, carbon, etc.

     Although removal is  estimated  to be essentially  complete,
monitoring  in specific  situations  is needed to verify this
 conclusion.

 Response:  As stated  by  the  commentator, there are multiple
 factors which influence  the  rate at which  vinyl chloride  is
 transferred out of water  into the air.   These factors should
 be  taken into account when designing the water stripper used
 to meet EPA's standard.    EPA has conducted studies on the
 behavior of vinyl  chloride in water.  A  report on  this
 study entitled  Dynamic  Behavior of Vinyl Chloride  in
Aquatic Systems has been prepared  (January 1976) and  is
available from  the Environmental  Research  Laboratory,  Office
of Research and Development, EPA, Athens, Georgia, 30601.   The
conclusions of  this study are discussed on page 6-45 of the
SSEIS,  Vol.   I.
                             2-121

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
 1. REPORT NO.
 EPA-450/2-75-009b
                             2.
                                                           3. RECIPIENT'S ACCESSIOt*NO.
 l-TJTLEjAND SUBTITLE .    ,  _         .  - T     ,  - ,  ,
 Standard Support  and  Environmental Impact  Statement,
 Volume 2:   Promulgated Emission Standard for  Vinyl
 Chloride
                                                         5. REPORT DATE
                                                            September  1976
                                                         6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  U. S. Environmental  Protection Agency
  Office of Air  Quality Planning and Standards
  Research  Triangle  Park, N. C.  27711
                                                           10. PROGRAM ELEMENT NO.
                                                          11. CONTRACT/GRANT NO.
 12. SPONSORING AGENCY NAME AND ADDRESS
                                                           13. TYPE OF REPORT AND PERIOD COVERED
                                                           14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
       A national emission standard  for vinyl  chloride emitted  from ethylene
  dichloride-vinyl chloride and polyvinyl  chloride plants is being  promulgated under
  the  authority of section 112 of  the  Clean Air Act.  Vinyl chloride has  been implicatec
  as the causal agent of angiosarcoma  and  other serious disorders,  both  carcinogenic anc
  noncarcinoge.nic, in people with  occupational exposure and in  animals with experimental
  exposure to vinyl chloride.  Reasonable  extrapolations from these findings cause
  concern that vinyl chloride may  cause or contribute to the same or s.imilar HisnrHpr<=
  at present ambient air levels.   The  purpose  of the standard is to minimize vinyl
  chloride emissions from all known  process and fugitive emission sources in ethylene
  dichloride-vinyl chloride and polyvinyl  chloride plants to the level attainable with
  best available control technology.   This would have the effect of furthering the pro-
  tection of public health by minimizing the health risks to the people  living in the
  vicinity of these plants and to  any  additional people who are exposed  as a result of
  new  construction.  This is estimated to  have the effect of reducing emissions from a
  typical- ethylene dichloride-vinyl  chloride plant by approximately 94 percent and from
  a  typical  polyvinyl chloride plant by approximately 95 percent.   This  document
  contains a summary of the public comments on the proposed standard and  EPA's responses
  to the comments.  It also contains updated information concerning the environmental
  and  inflationary impacts of the  standard.
17.
                               KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
Air pollution
Pollution control
Hazardous pollutants
Emission standards
Vinyl chloride
Vinyl chloride plants
Polyvinyl chloride plants
Ft.hylpnp-Hi rhl nyi HP
                                              b.IDENTIFIERS/OPEN ENDED TERMS
                                                                       c. COSATI Field/Group
                                               Air pollution control
18. DISTRIBUTION STATEMENT

  Unlimited
                                              19. SECURITY CLASS (ThisReport)'
                                               Unclassified
                                                                       21. NO. OF PAGES

                                                                           134
                                              20. SECURITY CLASS (Thispage)
                                               Unclassified
                                                                        22. PRICE
EPA Form 2220-1 (9-73)
                                            3-1

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