EXPOSURE AND RISK ASSESSMENT
             OF DIOXIN IN
     BLEACHED KRAFT PAPER PRODUCTS

                  BY

       ARTHUR D.  LITTLE,  INC.

                  TO
MONITORING AND DATA SUPPORT DIVISION
     OFFICE OF WATER REGULATIONS
            AND STANDARDS

U.S. ENVIRONMENTAL PROTECTION AGENCY
  U.S.  EPA CONTRACT NO.  68-01-6951
       WORK ASSIGNMENT NO.  18
           AMENDMENT NO.  1
           JUNE 25, 1987
             52967-02

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                           TABLE OF CONTENTS



                                                                 Page


1.0  Introduction                                                  1


2.0  Objective and Approach                                        1

     2.1  Exposure Assessment                                      2

          2.1.1     Identify consumer products made
                    from bleached Kraft pulp                       2
          2.1.2     Characterize use situations                    2
          2.1.3     Identify and characterize
                    exposure pathways                              3
          2.1.4     Evaluate dioxin concentrations in the
                    consumer products being evaluated              3
          2.1.5     Estimate exposure associated with
                    product/use situations                         3
          2.1.6     Estimate exposure associated with
                    incineration of contaminated products          4

     2.2  Hazard Identification                                    4

     2.3  Risk Characterization                                    4


3.0  Exposure Assessment                                           4

     3.1  Identification of Consumer Produces Containing
          Bleached Kraft Pulp                                      4

          3.1.1     Production of bleached Kraft pulp              4
          3.1.2     Product categories and production data         9
          3.1.3     Characterization of product use               18

     3.2  Assessment of Potential Availability of Dioxin          25

          3.2.1     Estimation of dioxin in bleached Kraft
                    products                                      2i
          3.2.2     General approach to evaluation of
                    migration rates                               26
          3.2.3     Potential release of dioxin from paper
                    products                                      29

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                           TABLE OF CONTENTS
                    3.2.3.1   Available data                      29
                    3.2.3.2   Uniaediaced diffusion processes      32
                    3.2.3.3   Migration mediated by external
                              phase                               34
                    3.2.3.4   Conclusions                         36

     3.3  Exposure Evaluation of Selected Consumer Products       38

          3.3.1     Exposure evaluation of selected consumer
                    products                                      38
          3.3.2     Estimate of potential dioxin exposure
                    levels                                        44
4.0  Risk Assessment                                              52

     4.1  Characterization of Product Uses. Users and
          Lifetime Exposures                                      52

          4.1.1     Uncoated paper plates                         55
          4.1.2     Disposable diaper                             55
          4.1.3     Sanitary tampon                               56
          4.1.4     Dinner napkin                                 56
          4.1.5     Paper towel                                   56
          4.1.6     Coffee filter  "                              57
          4.1.7     Uncoated sheet (contact)                      57
          4.1.8     Uncoated sheet (ingestion)                    58

     4.2  Risk Estimation                                         58
5.0  Dlaeuaaton                                                   59

     5.1  Uncertainties and AgSV1TO7l?Tt8                           59

     5.2  Implications of eha Results                             60

     5.3  Recommendations                                         62;



References                                                        64
                                   li

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                       LIST OF FIGURES
FIGURE                                                 £ASE
  1            End-produce manufacture of
               paper/pulp products
               Paper producing mills and the
               respective paper grades
                             ill

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                       LISTJ5EJABLES
IAS1E
  I            Consuaec produces containing
               bleached Kraft (BK) (A) (B)             11-14
               Relative percent distribution of
               bleached Kraft in selected
               product categories                        16
               Characterization of product use           17
               Qualitative exposure/relative risk
               matrix                                  20-23
               Relevant Physicochemical Properties
               of 2,3.7,8-TCDD                           33
               Evaluation of specific external
               phases                                    35
               Estimates of potential dioxin exposure
               levels based on unit consumption  of
               paper products containing bleached
               Kraft (BK)                              45-46
               Estimates of increased lifetime cancer
               risk based on dioxin exposure from
               specific use of paper products
               containing bleached Kraft (BK)          53-54
                                    iv

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 1.0. INTRODUCTION

 Results  from   the  National   Dloxin  Study  have   indicated   that
 2,3,7,8-TCDD  is  present  in  fish  and  river  sediments   collected
 downstream  from  some  pulp  and  paper  mills.   The  highest  levels
 appeared to be associated with bleached Kraft  aills.   As a  result,  a
 concern has  arisen  regarding  the  potential  exposure  and  risk  to
 consumers  using products  containing bleached  Kraft  pulp and  several
 research projects  have  been undertaken.   For example,  the  Pulp  and
 Paper study,  a  cooperative  effort  between  the  U.S.   Environmental
 Protection  Agency,  the  American  Paper  Institute,  and  the   National
 Council  of  the  Paper Industry  for  Air  and Stream  Improvement,   was
 initiated  to  determine  possible  sources  of  dioxins  and  furans  in
 bleached Kraft mills.

 Also,  the Monitoring and  Data Support Division  (MDSD) of  the Office  of
 Water Regulation and Standards  of the U.S.  Environmental Protection
 Agency requested that Arthur D. Little, Inc., as part of  its continued
 support  for the National  Dioxin  Study,  conduct an exposure  and risk
 assessment study of dioxin In bleached Kraft paper products.
2.0  OBJECTIVE AND APPROACH

The objective of this task was to evaluate and quantify, to the extent
possible with  available data, the  exposures  and the risks  to health
that may occur  through use of bleached Kraft  paper  products that may
contain dioxin.

The  general  approach was  to  define  the universe  of bleached  Kraft
paper products,  to quantify  their production and  to  determine  the
potential implications of product use on  dioxin exposure.   Because .of
the   uncertainty  regarding   the  exact  mixture   of   chlorinated
dibenzo-p-dioxin isooers contained in bleached Kraft pulp,  the generic
term  "dioxin"  has  been  used  throughout this study,  except  where

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reference to che specific isomer (e.g.,  2,3,7,8-TCDD) is made.

The potential  exposures associated with  a variety  of  use  situations
were evaluated and more detailed evaluations were  conducted for a few
selected products which appeared to represent greater risks.

There were four major steps in this task.

     e    Exposure Assessment
     e    Hazard Identification
     e    Risk Characterization
    • •    Report Production
     2.1  Exposure Assessment

The exposure  assessment was  probably the most difficult and uncertain
aspect  of  this  project  because aany  of the  issues had  never been
considered, and there was limited information to describe and quantify
product use patterns.  The assessment Involved the following steps.

          2.1.1     Identify consumer products made from bleached
                    Kraft pulp

Products  were  identified   through  review  of  the  literature  and
discussions with  staff members  of Arthur D. Little, Inc.,  experienced
in the pulp and paper  industry.

          2.1.2     Characterize use situations

Additional  data were collected  to  provide information on  the use of
these   products.    In  addition,   staff  members  from  the  Product
Technology  Section  at Arthur  D.   Little,  Inc.,  were consulted and
project  team  discussions were  held in order to  develop additional
information.   The  types  of information developed  during  this  step

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Included the potential number of users,  the  extent and/or duration of
average use and descriptions of the typical conditions of use.   It was
anticipated that use situations would include usual activities  such as
handling  sheets of paper and unusual  activities  such as oral  contact
and ingestion of paper by children.

          2.1.3     Identify and characterize exposure pathways

In this step exposure scenarios were developed from the use situations
identified in the previous step.  Limited data were available for this
purpose, and through use of related information and group discussions,
reasonable scenarios  which  were consistent with  past experience were
developed.  This  subtask produced  the  methods  which  were  used  to
calculate the exposure for each product/use situation.

          2.1.4     Evaluate dioxin concentrations in the consumer
                    products being evaluated

Although it had been  anticipated that  some data might be available to
determine   initial   product  concentrations,   no   such   data   were
available.  Therefore, with the advise  of HDSO,  it  was  assumed that
bulk  bleached  Kraft  pulp  contains  10  parts par  trillion (ppt)  of
dioxin.

          2.1.5     Estimate exposure associated with product/use
                    situations

This step was  an integration of the  results  of steps 3 and 4 of the
exposure assessment.  In step 3, the methods  or models were developed
for  the product/use  combinations  and in  step 4 rough estimates  of
concentrations were developed.   This step resulted in estimates of the
average or range of exposures for each product use situation.

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          2.1.6     Estimate exposure associated with Incineration of
                    contaminated products

Independently,  the  potential impact  of dioxin-eontaainated paper  on
dioxln  emissions   from  municipal   solid   waste   incinerators   was
considered within the limitations of this task.

     2.2  Hazard Identification

This step,  while extremely  important to a  risk assessment,  did not
represent a  large part  of the  effort.   Primarily,  confirmation was
obtained from the EPA Project Officer that the current EPA cancer risk
assessment methodology for 2,3,7,8-TCDD would be utilized.

     2.3  Risk Characterization

In  this step,  the exposure estimates developed above,  as well as the
unit  risk value  from the  hazard identification  step,  were  used  to
quantify  the risks associated  with the product/use situations.   The
need  to identify the uncertainties  associated  with the estimates was
also anticipated.
 3.0  EXPOSURE  ASSESSMENT

     3.1   Identification  of Cqnaumar  Products  Containing  Bleached
           Kraft Pulp

           3.1.1  Production of Bleached Kraft  Pulo

 Bleached Kraft pulp is a major component in  a wide variety  of paper,
 paperboard and pulp  products.   In  order  to identify  and  classify
 specific   consumer   end  products   from  an   exposure   assessment
 perspective,   it  is necessary to  understand how various  paper  and
 converted produces are manufactured.

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In  general,  pulp,  paper  and paperboard production  consists of  five
distinct  steps:   pulping, bleaching, stock  preparation,  papermaking,
and converting.  Figure 1 is a  simplified  block  flow diagram of these
processes.   In the  discussion  that follows,  each step  is  described
briefly.

In  the  pulping  process,  cellulosic  material,   primarily  wood,  is
converted by mechanical or chemical means into papermaking fibers.
Mechanical processes separate the wood fibers by attrition using large
grind stones  or metal plates.  The  lignin which  holds  the  cellulose
fibers together is not dissolved or separated and appears in the final
product.   This method  produces  a  very  economical grade  of  fiber
(groundwood) and is typically used in newsprint.

Semi-chemical  processes  combine chemical  and mechanical steps.   The
wood is  softened by  means of a chemical solution at low temperature.
Excess chemical is removed  and the wood is  defiberized mechanically,
Essentially all of the lignin remains with the pulp.  The primary use
is for corrugating medium,  i.e., the fluted  middle layer of boxes and
shipping containers.

Chemical pulping Is used to produce fiber for a wide range of products
including  printing and writing papers, tissue  and  packaging  paper,
paperboard and fluff  pulp.   The raw material  is  reduced to  a fibrous
state by cooking with solutions of various chemicals.  Essentially all
of  the  lignin  is  removed from  the  wood  fiber.   The  most  important
chemical pulping process  is the Kraft or sulfate process.

The  second step  in   the  production sequence  is  chemical  bleaching.
Typically,  the agents used for bleaching  include chlorine compounds
and  oxygen.   The purpose of this  step  is threefold:   to  remove any
coloring  matter within the pulp,  to extract residual  lignin  and. to
achieve  brightness  or whiteness, which  is desirable in printing and
writing papers, food  packaging and sanitary applications.  Fibers that
undergo  the Kraft  chemical  pulping process and bleaching sequence are

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PULPING PROCESS
* Chemical (Kraft)
* Seal-mechanical
* Mechanical (Croundwood)


BLEACHING/WASHING


STOCK PREPARATION
* Internal sizing
* Vet strength
* Dyes
                  PAPERMAKING

                  *  Dyes
                  +  Surface sizing
                  *  Coatings
                  END-PRODUCT. CONVERSION

                  Wet:              Dry:

                  *  Coating       *   Bag
                  *  Laminating    *   Box
                  *  Impregnating  *   Printing
FIGURE 1:  END-PRODUCT MANUFACTURE OF PAPER/PULP PRODUCTS

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referred co as bleached Kraft fibers or bleached Kraft pulp.

The  third  step,  stock preparation, refers  to  several  operations that
may  take place between pulping  (and  bleaching) and the  formation of
the paper or board  on a machine  and nay include heating,  refining and
repulping.    The purpose  of  these operations  is  to  shorten  or  to
hydrate  the   fiber  for   specific  paper  properties.   Fibers  from
different processes can be blended in various proportions to produce a
wide range of  products.   Fillers,  dyes,  pigments,  wet strength resins
and conventional sizing may be added during stock preparation.

As a fourth step, the prepared stock  is conveyed to the paper machine
where the paper web is formed and subsequently dried.

The final step in  the production of a  paper  or paperboard product is
the  converting  process.   There  may   be  one  or  many  converting
operations  that follow  the  papermaking process.   These  operations
include, for example, waxing, gumming,  off-machine  coating,  printing,
bag, envelope,  box and container manufacturing.  With the  exception of
tissue mills,  paper and board mills are typically not responsible for
the converting process.   This is handled by companies which  use the
different grades of paper produced at the  paper  and paperboard mills
as their raw materials.

The manufacture of  paper and paperboard products  is distributed among
three  distinct  industries:   paper  mills,   paperboard   mills,  and
construction paper  and  board mills.   In  Figure  2.  the three  mill
industries are presented along with the grades of paper and board they
produce.  The various grades of paper and board produced are, in turn,
processed by "converters" into consumer end-products.

Since  the  focus of  this  study  is limited to consumer  end-products
which  consist  primarily  of bleached  Kraft pulp,  various  paper and
board grades will not be considered in  this  analysis.  These include
all  the  grades produced  by the construction  paper and  board mills,

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PAPER MILLS
1
1 1 1 1 1 1 1

NEWSPRINT

UNCOATED
GROUNDUOOO




COATED
GROUNDUOOO




COATED
FREE
SHEET
UNCOATEI
FREE
SHEET
THIN
PAPERS




COTTON
FIBER
PAPERS
1
UNBLEACHED
KRAFT
PAPERS



1 1
BLEACHED
KRAFT
PAPERS




TISSUES



PAPERBOARD
HILLS


r 	 '
III II
UNBLEACHED
KRAFT
PAPERBOARD



BLEACHED
PAPER -
BOARD



SEN I -CHEMICAL
PAPERBOARD




RECYCLED
PAPERBOARD




WET
MACHINE
BOARD
                                       CONSTRUCTION PAPER
                                        AND BOARD MILLS
                      r
                 CONSTRUCTION
                     PAPER
INSULATION
   BOARD
  HARD
PRESSED
  BOARD
                        FIGURE 2:  PAPER PRODUCING HILLS AND THE RESPECTIVE PAPER GRADES
Source:  Arthur D.  Little,  Inc., Based on U.S. Department-of Commerce and
         Industry Paper Classification Schemes

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unbleached Kraft paperboard and specific grades from paper mills,  such
as  newsprint,  uncoated/coated  grounduood,  cotton  fibers  and  the
majority  of   packaging  and  industrial   papers   (except  glassine,
greaseproof and vegetable parchment papers).

In particular, consumption  patterns  of consumer products manufactured
from the  following  paper,  board and pulp categories  will be assessed
and used for exposure assessment and risk evaluation:

          •    coated/uncoated free sheet;
          •    thin papers;
          •    bleached bristols;
          •    special industrial papers:  glassine, greaseproof,
               etc.;
          •    tissue papers;
          •    packaging paperboard;
          •    non-packaging paperboard; and
          •    fluff pulp.

          3.1.2  Product Categories and Production Data

There are numerous  consumer end-products  that comprise  the bleached
Kraft paper,  board and  pulp categories.  Annual production data for
1985 vere acquired  from  the  published  literature,  statistics from the
American  Paper   Institute,   Bureau  of  Census  Reports,  Industrial
Outlook  and  other  in-house  sources.   Primarily,  these  data  are
restricted to the larger product categories and are not broken down as
individual produces.

The estimated production tonnages for  products whose major component
is  bleached  Kraft pulp are  summarized  in  Table  1.    Examples  of
consumer end-products that comprise the respective categories are also
listed.  As mentioned earlier,  the actual bleached Kraft pulp content
varies   among  the  categories.   The  remainder   may   be  fillers,
laminations,  and  resins.  For example,  only about 75 percent  of the

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milk carton stock  Is  actually bleached Kraft.  Alternatively,  tissue
papers are almost exclusively bleached Kraft.

Due to  the variation  in bleached Kraft content,  the  total production
tonnage is not necessarily equal  to  the consumption of bleached Kraft
pulp.   Using  an  average percent  bleached  Kraft content within these
respective categories,  the  annual pulp consumption can be estimated.
These totals are also presented in Table 1.  For the remainder of this
analysis, the per  capita usage  and percent distribution will be based
on  values  of  consumption  of  bleached  Kraft,  not  production  of
converted end-products.

Several  assumptions are implicit in the  data of  Table  1.   The  net
effects of imports  and exports on the tonnages are  assumed to be minor
(+  10  percent);  accordingly, the totals have  not been adjusted.  The
numbers also  include recycled paper  that is bleached.  Certain product
categories, such as coated free sheets, are "semi-bleached," i.e., the
Kraft  pulp  undergoes fewer bleach/wash  cycles  than  fully bleached
fiber.    However,   from   the   perspective    of  potential    dioxin
contamination in the  end product, it  is  assumed that a semi-bleached
pulp  is equivalent to a fully bleached fiber.   It  is  important  to note
that  there may  be variation  in  the bleached  Kraft  content within  a
given product category; however,  in.  this analysis  an  average value has
been  used to represent the  majority of  end-products that fall  within
each  category.   Finally,   the  examples  listed  in Table 1  are  not
all-inclusive.   There is some overlap whereby a given product  may be
found in more than one category. Nevertheless,  the example  products
are  representative of typical  consumer  products  containing  bleached
Kraft.

The relative  distribution  of bleached Kraft  pulp among  the  selected
product categories was calculated from the data  generated in  Table  1,
and is summarized in Table  2.   It should be noted that this percentage
breakdown does not account  for  the sum  total of bleached Kraft  pulp
 produced and consumed in all the grades of paper and allied products,
                                     10

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                            TABLE 1
          CONSUMER PRODUCTS CONTAINING BLEACHED KRAFT(BK) (A) (B)
                            TOTAL 1985     AVERAGE       BK
  PRODUCT                   PRODUCTION     PERCENT  CONSUHPTION(H)
 CATEGORIES                 THOUSAND         BK     THOUSAND
                            STONS/YR (I)            STONS/YR
TOTAL PAPER,PAPERBOARD.PULP       27078                   22864
** PAPER(C)(DJ**                  22198                   19121

  ^PRINTING                       1666S                   13848
     COATED FREE SHEET(E)          5875          70        4113
     E.G. PRINTED PRODUCTS
          MAGAZINES
          PUBLISHED BOOKS
          CATALOGUES
          ANNUAL REPORTS
     UNCOATED FREE SHEET(E)        9625          90        8663
     E.G. CORRESP.TABLETS
          DESK  PADS
          LOOSELEAF FILLER
          MEMO  BOOKS
          OFFICE PAPER
          TYPING PAPER
          FINAN/BUS1NESS FORMS
          ENVELOPES
          PRINTED BOOKS
          STATIONERY
     THIN PAPERS                     241          100          241
     E.G.   CIGARETTE PAPER
            BIBLE PAGES
            LENS TISSUE
            CARBON  PAPER
     BLEACHED BRISTOLS              924           90          832
     E.G. WEDDING INVITNS.
          CALLING CARDS
          FILE  FOLDERS
          POSTCARDS
                                         11

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                           TABLE 1
         CONSUMER PRODUCTS CONTAINING BLEACHED KRAFT(BK) (A) (B)
 PRODUCT
CATEGORIES
TOTAL 1985
PRODUCTION
THOUSAND
STONS/YR (I)
AVERAGE       BK
PERCENT  CONSUMPTION(H)
  BK     THOUSAND
         STONS/YR
  'PACKAGING                       593
    FOOD WRAPPING                   31
    BAG&SACK                       266
    SHIPPING SACK                   80
    GLASS1NE.CRSPRF.ETC.           216

  *TISSUE(F)                      4940
    TOILET TISSUE                 1882
    FACIAL TISSUE                  354
    NAPKINS                        579
    TOWELLING                     1700
    WIPER/OTHER                   282
    E.G.  INDUST.CLEANSING
          PACKAGING
    TOT ALL  OTHER                  143
    E.G.  UNCOATEO  WRAPPER
          CONFETTI
          CREPE PAPER
          DOILIES
          GIFT WRAP
          NOVELTIES
          COFFEE FILTERS

** PAPERBOARD **                   3948

    *PACKAGING                     3881
      MILK CARTON STOCK(G)          609
      E.G.MILK CONT.
          YOGURT CONT.
          CHEESE CONT.
          NON-DAIRY BEVRG CONT
          NON-CARB. DRINK CONT.
          JUICE CARTON
                     95
                     95
                     95
                     95
                     95

                   95-98
                     95
                     95
                     98
                     95
                     95
                     95
                      75
                 563
                  29
                 253
                  76
                 205

                4710
                1788
                 336
                 567
                1615
                 268
                 136
                 3160

                 3100
                  457
                                       12

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                           TABLE 1


         CONSUMER PRODUCTS CONTAINING BLEACHED KRAFT(BK)  (A)  (B)
 PRODUCT
CATEGORIES
TOTAL 1985
PRODUCTION
THOUSAND
STONS/YR (I)
AVERAGE
PERCENT
BK

BK
CONSUMPTION(H)
THOUSAND
STONS/YR
     FOLDING CARTONS              1780          80        1424
     E.G.TOBACCO
         MEDICINAL
         COSMETICS
         CONT.CGELS.SAUCES)
         DRY FOOD
         PREPARED/PKCD FOOD
     PAPEROJPS/LIDS                438          80         350
     PAPER PLATES/TRAYS            284       80-90         241
     OTHER                         656       75-85         525
     E.G.  OVENABLE TRAYS
           LIQUID VESSELS
           MOIST/OILY FOOD VESSELS
     LINERBOARD                    U*          90         103
   *NON-PACKAGING                    67          90          60
      E.G.DISPLAY BOARD
** PULP *
                                    932                     582
   *DISPOSABLE DIAPERS              800          60         480
   *FEK HYGIENE PRODS                66          95          63
      E.G.SANITARY NAPKINS
          TAMPONS
   *GERIATRIC ACCESSORIES            66          60          40
      E.G.INCONTINENCE PADS
                                       13

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NOTES FOR TABLE I:
A. SOURCES: AMERICAN PAPER INSTITUTE STATISTICS(1985); INDUSTRY
   OUTLOOK; PREDICASTS FORECASTS; ADL ESTIMATES. SEE REFERENCES.
B. THIS LIST IS NON-EXHAUSTIVE; SOME PRODUCTS FALL INTO SEVERAL CATEGORIES
C. INCLUDES RECYCLED PAPER THAT IS BLEACHED
D. IMPORTS4EXPORTS INCLUDED IN TOTAL; NET DIFFERENCE HAY BE +/- 10%.
E. ASSUME SEMI-BLEACHED PRODUCTS AND BLEACHED PRODUCTS EQUIVALENT
   FROM RISK PERSPECTIVE.
F. DOES NOT INCLUDE FLUFF PULP CONSUMPTION IN SANITARY TISSUE
G. TOTAL WEIGHT INCLUDES BK PLUS COATINGS.LAMINATIONS, ETC.
H. BK TONNAGE REPORTED DOES NOT INCLUDE CONTENT IN OTHER CATEGORIES OF
   PAPER PRODUCTS NOT CONSIDERED IN THIS ANALYSIS.
   THUS. ACTUAL BK CONSUMPTION EXCEEDS TOTAL LISTED HERE.
I. STONS/YR - SHORT TONS(2000 LBS/STON) PER YEAR
                                        14

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but mainly  represents the  relative consumption  among those  product
categories whose main component is bleached Kraft.  From Table 2,  it is
evident that  bleached Kraft consumption is dominated by  the printing
papers; the tissue papers are  at a distant second place,  followed by
the packaging paperboard.  The fluff pulp and packaging papers utilize
a relatively small fraction of the total bleached Kraft tonnage.

If an exposure assessment were based purely on relative tonnages, then
several  product  categories  vould  not  be  considered  for  further
analysis.    However,  the per  capita annual  consumption  for specific
products provides a more realistic perspective on bleach Kraft tonnage
consumed.    For  example,  the relative distribution of  both disposable
diapers and milk  carton  stock is about 2 percent  each.   However,  the
size  of the  population  using disposable diapers, namely infants,  is
significantly  smaller than the  size  of  the  population using  milk
carton/Juice  cartons,  etc., i.e. children,  adolescents,  adults, etc.
Therefore,  the  actual per  capita consumption  of  bleached  Kraft  for
disposable  diapers would  greatly exceed  that  of products  made from
milk  carton  stock.   This  analysis is  illustrated  for  the  various
product categories in Table  3.   Note  that the  second column "Annual
Bleached  Kraft  Production"  includes the fractional  content  as listed
in Table  1.

The  user  population,  tabulated  in the  third  column  of  Table  3,
specifies whether typical products within a given category are used by
a segment of  the  population,  or the total US population.  Products in
categories  such as tissue  or  packaging  paperboard are generally used
by  all age brackets.  For  the printing papers  and  packaging papers,
children  under  five  years  of age are excluded.   For a specific use of
an  uncoated free sheet,  which may  be  chewed and/or eaten,  such as  a
spitball,  however, the  user population consists  of children between
the  ages  of 5  and  13.   The disposable  diapers  are  specific  for
children  under  three years  of  age.    The  use  of  feminine hygiene
products  is limited  to  the female  segment  of  population between the
ages  of 10 and 50.   Finally,  the geriatric accessories  are primarily
                                    15

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                                       TABLE 2


         RELATIVE PERCENT DISTRIBUTION OP BLEACHED KRAFT IN SELECTED PRODUCT CATEGORIES
                                TOTAL PAPER.PAPERBOARD.6i PULP
                                             100.0
* PAPER **            83.6

 ^PRINTING            60.6
    CTD FREE SHEET    18.0
    UNCT FREE SHEET   37.9
    THIN PAPERS        1.1
  ,  BL. BRISTOLS       3.6

  ^PACKAGING           2.5
    FOOD WRAPPING      0.1
    BAG&SACK           1.1
    SHIPPING SACK      0.3
    CLASSINE.CRSPRF    0.9

  *TISSUE             20.6
    TOILET TISSUE      7.8
    FACIAL TISSUE      1.5
    NAPKINS            2.5
    TOWELLING          7.1
    UIPER/OTHER        1.2
    TOT ALL OTHER      0.6
** PAPERBOARO **             13.8

    ^PACKAGING               13.6
      MILK CARTON STOCK       2.0
      FOLDING CARTONS         6.2
      PAPERCUPS/LIDS          1.5
      PAPER PLATES/TRAYS      l.l
      OTHER                   2.3
      LINERBOARD              0.4
   *NON-PACKAGING             0.3
** PULP *                  2.5

   *DISP. DIAPERS          2.1
   *FEH HYGN PRODS         0  3
   *CERIATRIC ACCESS       0.2

-------
                                   TABLE  3


                         CHARACTERIZATION OF PRODUCT USE
  PRODUCT
  CATEGORY
                        ANNUAL BK  USER
                        PRODN     POPULN.
                        (000)     CATEGORY
                        STONS/YR    (A)
** PAPER **

  *PRINTING
     COATED FREE SHEET
     UNCOATED FREE SHEET

     THIN PAPERS
    BLEACHED . BR1STOLS

  ^PACKAGING
    FOOD WRAPPING
    BAGS.SACK
    SHIPPING SACK
    GLASS INE.GRSPRF, ETC.


  *TTOIL!T TISSUE
    FACIAL TISSUE
    NAPKINS
    TOWELLING

    WIPER/OTHER
    TOT ALL OTHER

** PAPERBOARD **

    * PACKAGING
      MILK CARTON STOCK
      FOLDING CARTONS
      PAPERCUPS/LIDS
      PAPER PLATES/TRAYS
      OTHER/OVENABLE BRD
      LINERBOARD

   *NON- PACKAGING

** PULP *

   *DISPOSABLE  DIAPERS
   *SANIT  NAPKINS&TAMPONS
   *GERIATRIC ACCESSORIES
8663

 241



 832
                                29
                               253
                                76
                               205
                               nn
                                 36
                               ,
                               1615

                                268
                                136
                                /e,
                                457
                                350
                                24 L
                                525
                                103

                                 60
                                480
                                 63
                                 40
5

5
5
1

1


1
1
 1
 1
 1
 1
 1
 1
 2
 3
 4
    PER CAPITA
     USAGE
    KG/PERSON
    /YR
                             PRODUCT
                             USE/
                             MISUSE
                                                  16.9
                                                  35.7

                                                   1.0
               READING/CORRESPONDENCE
               INGESTION
               READING
               SMOKING
               TYPING
               CLEANING
           3.4 CORRESPONDENCE
                      0.1 PACKAGING
                      1.0 PACKAGING
                      0.3 PACKAGING
                      0.8 PACKAGING


                      6.8 WIPING/CLEANING
                      1.3 WIPING
                      2.2 WIPING
                      6.1 DRYING
                          GREASE ABSORPTION
                      1.0 WIPING
                      0  5 CLEANING/WIPING
                       1.7  BEV  STORAGE
                       5.4  FOOD STORAGE
                       L.3  HOT/COLD LIQUID  SERVICE
                       0.9  FOOD SERVICE
                       2.0  HEATING FOOD
                       0.4  PACKAGING

                       0.2
                      40.3 INFANT CARE
                       0.8 FEMIN. HYGIENE
                      16.4 ELDERLY INCONT.
 AOTulER°POPULATIOT  CATEGORIES  DEFINED AS  FOLLOWS:

                           1- TOTAL US 1985 POPULATION
                           2- CHILDREN <  3  YEARS
                           5- TOT POPULN > 5 YRS
                           6- CHILDREN BETWEEN 5-13 YEARS
                                                                    (MM)
                                                                    S38.74
                                                                     10.82
                                                                     71.06
                                                                      2.20
                                                                    220.70
                                                                     30.11
                                             17

-------
used by the elderly population  (greater  than  age  65)  with the medical
condition of  incontinence.   The sources for  population data  used  in
Table 3 are  the U.S.  Bureau of Census  (1985)  and the National Center
for Health Statistics (1986).

Characterization  of   product  use  provides  an  estimate   of   the
consumption for a typical user  of a given product.   Referring to the
example mentioned earlier,  it is  apparent  that,  although the tonnages
of bleached  Kraft are  similar  for milk carton stock  and disposable
diapers, the  relative  per  capita consumption, as  shown in the fourth
column, indicates a  difference  in bleached Kraft  consumption of  more
than a factor of twenty.

Based on the per capita consumption for all categories in Table 3, the
printing paper  products and pulp categories  indicate  a high level of
consumption;   tissue   and  packaging   paperboard  products  reflect
intermediate  levels  and the  packaging papers  represent low bleached
Kraft consumption levels.

The  last column in Table 3  exemplifies Che use (or misuse) of typical
products.   Definitions of  product  uses provide  further insight  into
potential  routes of dioxin exposure,  i.e.,  how  is the product used,
and  how does  it come in contact with  the user?  While the bulk of the
printing  papers  are used  for reading  and  writing,   there  are  some
exceptions:   fractions of  uncoated sheets may be chewed or  ingested
and  thin  papers  may  serve  as  lens  tissue,   cigarette  papers  or
carbonizing paper.   Similarly,  in the  tissue  category,  the majority of
produces are used for  wiping or  cleaning purposes;  however, with the
increased  use of microwave  cooking,  paper towels may also be  used for
absorption of  grease,   e.g.,  in cooking bacon.  Numerous  scenarios of
product use/misuse can b* postulated.   As the exposure  assessment and
analysis  of exposure  routes  are  discussed further,  the  rationale for
selection  of  particular scenarios and  products will become evident. *

           3.1.3  Characterization of Produce  Use

In conducting a product-related exposure assessment,  the  product must

                                    18

-------
be  characterized both  in terms  of  the  type  and size  of  the  user
population and  in terns of  its  patterns of  use.   Estimation  of  per
capita  consumption  essentially defines  the  user  population that  is
exposed.  There  are several parameters- that characterize  the use of a
given paper product,  such  as  the  duration,  frequency and multiplicity
of use.  Each of these parameters can be ranked in a semi-quantitative
manner, so that  low-risk categories nay be screened our.  As a result,
further analysis can focus on potentially high-risk product types.   In
Table 4,  a  qualitative risk matrix  is presented,  characterizing both
product use and  the user.

The  first column  lists the  product categories.   The second  column
defines  three  levels  of per  capita consumption  of bleached  Kraft,
based on data from earlier  tables, i.e., low refers to less  than 1
kg/person/year; medium implies between 1 and 10 kg/person/yr; and high
refers  to use  in excess of  10 kg/person/yr.    The unit use duration,
which is  shown in the third  column,  may be short,  i.e.,  on the order  .
of a few seconds, as  with  facial  tissues.   Alternatively, the use may
be of medium duration,  on  the order of a few minutes,  as with coated
paper cups  or extended  over  one  or more hours as with a large Juice
carton.

The  relative  frequency  of use,  tabulated  in  the fourth  column,  is
based   on  annualized   daily   averages.    The  criteria  needed  to
distinguish frequency levels  are as follows:  low implies usage not
exceeding once per week,  such as  use of shipping  sacks; medium refers
to  a range between  once per  week and once  per  day,  such as  use of
paper plates; high-frequency Indicates  use  exceeding once a day, such
as use  of disposable  diapers.

The  multiplicity of  use for  each produce category  is  shown  in  the
fifth  column.    Essentially,  it  answers  the   question:   can repeated
exposure occur  from  the same product  (not product type)?  Due to  the
basic disposability of the majority of paper products, such  as  single
                                   19

-------
                                     TABLE 4
KJ
o
PAPER
PRODUCT
AND
USAGE

PAPER:

PRINTING PAPER

 COATED SHEET
  -READING
 UNCT SHEET
  -READ/CORRESP
  -SPITBALLS
 THIN PAPERS
  -READING
  -SMOKING
  -TYPING/CARBON
  -CLEANING/WIPING
 BL BRISTOLS
  -CORRESPOND.

PACKAGING

 WRAPPING
  -PACKAGING
 BAG&SACK
  - PACKAGING
 SHPNC SACK
  - PACKAGING
QUALITATIVE EXPOSURE/RELATIVE
RISK MATRIX

PER
CAPITA
CONSUME .
L.H.H(A)
H

H
»

H


>N
'ING
H

L

H

L

DURATION
PER USE
OF UNIT
S.M,L(B)

S

S
S

S
H
S
S

S

H

M

M
RELATIVE
FREQUENCY
OF USE
L,H,H(C)

H

H
H

H
H
H
H

M

L

L

L
IS USE
PER UNIT
REPEATED?
N,Y (D)

Y

Y
N

Y
N
N
N

N

N

N

Y
                                                                    EXPOSURE
                                                                     ROUTE
          DIOXIN EXTRACTION MEDIUM
                                                                             SKIN
                                                                             OILS
               BODY
               FLUIDS
NON-OILY
 FOODS
OILY
FOODS
D
I

D
I (F)
D
D
                                                                        D

                                                                        D

                                                                        D
                                                                                 *
                                                                                 *
         *

         *

         *

-------
                                       TABLE
N>
QUALITATIVE EXPOSURE/RELATIVE
DA nc*n

PAPER p£B
PRODUCT CAPITA
AND „ CONSUMP.
USAGE L,M,H(A)
TISSUE
TOILET
-WIPING
FACIAL
-WIPING
NAPKIN
-WIPING
TOWELLING
-DRYING
-CREASE ABSORP
WIPER/OTHER
-WIPING
TOT ALL OTHER
-CLEANING/UIP
PAPERBOARD:
PACKAGING
MILK CTNS
-BEVER STORAG
FOLD CTNS
-FOOD STORAGE
PAPERCUPS/LIDS
-HOT/COLD LIQ
PLATES/TRAYS
-FOOD SERVICE
OVENABLE BRD
-HEATING FOOD
LINERBRD
-PACKAGING
NON-PKGINC
M
M
M
H

M

L



M

M
M
M

L
L


DURATION RELATIVE
PER USE FREQUENCY
OF UNIT OF USE
S.M.L(B) L.M.H(C)
S
S
M

M


S



L
L
M
M/L
M

L
L
H
H
H

M


M



H
M
M
M
L

L
L
RISK MATRIX

IS USE
PER UNIT
REPEATED?
N.Y (D)
N
N
N

N


N



N
N
N
N
N

N
N


"oUTE^ DIOXIN EXTRACTION MEDIUM 	
D *
D *
D *

D *
I

D *
D *



I * *
I
1 *
1 * * *
I *
* *
i

-------
                                   TABLE 4
     PAPER
     PRODUCT
     AND
     USAGE

     PULP:

     DISP  DIAPS
       -INFANT CARE
     SAN NAP & TAMP
       -FEM. HYGIENE
     INCONT  PADS
       -ELDER INCONT
QUALITATIVE EXPOSURE/RELATIVE
RISK MATRIX

PER
CAPITA
CONSUNP.
L,H.H(A)
H
N
H
DURATION
PER USE
OF UNIT
S.N.L(B)
L
L
L
RELATIVE
FREQUENCY
OF USE
L.M.H(C)
H
H
H
IS USE
PER UNIT
REPEATED?
M,Y (D)
N
N
N
EXPOSURE
 ROUTE
D.I
      (G)
              DIOXIN EXTRACTION MEDIUM
                                         OILY
                                         FOODS
                       *

                       *
KJ
K)

-------
      NOTES FOR TABLE 4:
      A  CENSufDATA^IS^EFINEfi JsSFOLLOWS?°DUCTI°N T°NNACE &


          H- HIGH; EXCEEDING 10 KG/PERSON/YR

      B.  BASED ON ADL ESTIMATES:
         TSE S5iIIRIA USED TO DISTINGUISH THE TIME ARE AS FOLLOWS
          S- SHORT; ON THE ORDER OF SECONDS : E.C  FACIAL TISSUR
          M- MEDIUM-  ON THE ORDER OF MINUTES*: EC   CIGARETTES
          L- LONG; 6N THE ORDER OF HOURS ; E.G.? DISPOSABLE DIAPERS

      C.  BASED ON ADL ESTIMATES:
         CRITERIA USED TO DISTINGUISH THE FREQUENCY OF USE ARE AS R

         fe BtjpaRap^a^ffiJUT^^-yfs^
         AH- HIGH:  EXPOSURE TO UNfT EXCEEDS ONCE PER DAY •E C   DISPnrlpppS w""
         ANNUALIZED DAILY AVERAGES  ARE ESTIMATED BASED  ON'slcMENT^OF USEREpOPULATION



ro

      E. ^^^^"JJS^DIOXIN  FROM A GIVEN  PAPER PRODUCT INCLUDE THE FOLLOWING
         I - INCESTION

      F.
     c
     H.  "USE- IS DEFINED AS - CONTACT WITH AN EXTERNAL PHASE.

-------
  service  dinnerware,  most  of the  products are  not  used repeatedly
  However,  the  reading/writing papers  and shipping sacks may be reused,
  and exposure may occur with each use of the same product unit.

  Assuming  the  three  use  parameters  are  equally important,  certain
  generalizations can be made.  According to Table  4,  a typical user of
  printing paper product uses a large number of sheets, each for a short
  period of  time,  and so may be exposed  to the  same sheet more  than
  once.   Packaging papers, on the  other hand, are used  infrequently,  for
  an  intermediate  duration.    Tissue   papers,   like   printing  papers
  consist of  high  frequency,  short/medium  duration  uses.   Paperboard
  used for  food  packaging tends to be used  for extended periods  of time
  although  the frequency is not high.   Finally,  the  products  in  the pulp
  category  are typically used frequently and  for . lengthy period of
 time.
 In order  to determine user  exposure,  a mechanism  for  dioxin release
 from  a product  to  a  user  must be  defined.   For this  study,  an
 -external  phase matrix penetration" mechanism is assumed.  In order to
 release the  dioxin from  .  paper, board  or pulp matrix, an  external
 phase or  solvent,  such as air,  skin oil, body  fluids  or water  must
 penetrate  the  matrix,  solublize  and extract the dioxin and come  in
 direct contact with the user.  The modes of contact, termed  -routes  of
 exposure," may be via ingestion or dermal absorption.  External  phases
 chat  contact  the  outer skin,  such as  skin  oil touching a  sheet  of
 paper,  result in exposure  by  -dermal  absorption"; external phases  that
 pass  directly  to  the  gastro-intestinal  tract,  such  as by  chewing
 paper,  result in exposure  by "ingestion."  A third  route of exposure,
 where  the  external phase  may  come  in  contact with  internal mucous
 membranes, e.g.,  with a sanitary  tampon,  is  assumed to  be equivalent
 to ingestion  in this analysis.

 In Table 4, respective potential exposure routes are characterized for
each of  the  product categories.   Additionally,  one  or  more  relevant
external phases  (or extraction media) are identified for each of the
                                   24

-------
   product  categories.   For the majority  of products where outer  dennal
   absorption  is  the primary exposure  route,  skin oils are  the  extraction
   media;  the  single exception is body  fluids (urine)  on a  disposable
   diaper.   Where ingestion of  the  external phase  containing  dioxin  is
   involved, non-oily  and/or  oily foods  usually  comprise  the external
  phases.  Where  internal  dermal  absorption occurs, body fluids are the
  extraction media.

  The ultimate  risk  to the  user depends  not  only on  the  quantity
  frequency and duration of use,  but also  on  the  route  of exposure and
  extraction medium.   These   last  two parameters   lead  into   a  further
  analysis  of dioxin availability,  migration rates, and dioxin release
  from a  product.   In  the   sections that follow,  these  topics  are
  discussed  in greater  detail.

      3-2   Assessment  of
           3-2-1  Estimation of Dtqxln in ftleaeheti Ttr*f+ Produers
                                     •^'^•^••••"TiiTrift—i&MA±-+t^£ A.tfymp i^j

 The detection  of dioxin in  fi,h and sediment  samples  collected near
 bleached  Kraft  pulp  and  pap.r  mills  has  prompted many  questions
 Several studies  .„ currently underway to evaluate  the  formation and
 fate of  dioxin  in  th. bleached Kraft process  and to determine the
 potential for  dioxin  contamination in bleached  Kraft  pulp and paper
 products.   However,  th.s.  studies are not  complete and the  data are
 not yet available.

 For th. purpose, of this  exposure and risk  assessment,  the EPA has
 provided  a hypothetical contamination l.v.l of  10  ppt (pg/g) for all
 bleached  Kraft  pulp  and paper.  As discussed previously, no provision
 has  been  made  for  decreasing  or  increasing the  assumed  level  of
 contamination  for semi-bleached  or  highly bleached (several  passes
 through  th. chlorination  process)  products.   It  has been  assumed.
however, that th. 10 ppt contamination is  only  in the bl.ached Kraft
portion of th. product and, therefore, the product contamination level
                                   25

-------
  has been adjusted based on  the  estimated  percentage  of bleached Kraft
  pulp or paper contained in  each specific  product  (See  Table 1).   This
  assumption is reasonable in light of preliminary  data  indicating that
  the  highest  environmental  contamination has  been  associated  with
  bleached Kraft mills.  However, a survey of  dioxin contamination  in
  consumer paper products  is  needed  in  order  to  document the fate  of
  dioxins  formed during pulp and paper manufacture.

  There  are no available data describing the  potential distribution  of
  the  dioxin  contamination  within  the  pulp and  paper  matrices.   The
  dioxin  molecule  could be   chemically  bonded or  adsorbed  to   paper
  components,  or it could be  loosely incorporated  into  the  matrix and
  available to  migrate.   The  chemical characteristics of dioxin suggest
  that it  will probably be adsorbed to  the molecular  structure  of the
 paper  matrix;  however, in   the  absence of any  specific data  and in
 order  not  to underestimate  potential  exposure,   it has  been assumed
 that the dioxin is freely available.

 Finally,  it  is  acknowledged  that the type of  coating and  the  actual
 coating  process  used on  pulp  and paper products  may  affect  the
 contamination.  For example,  the  coating process  may actually initiate
 an extraction process resulting in . lower  dioxin concentration  in the
 paper product  its.lf and a  more  concentrated contamination in  the
 coatings;  or there may be a continual partitioning between the product
 and the coating; or the coating may be a barrier to dioxin  migration.
 Due to  the   lack  of  any  data describing  the  potential  behavior of
 dioxin  contamination  in coated paper products,  it has  been assumed
 that  there is no  transport  to  coating  materials  during or after  the
 coating  process and  that  there   is  no detectable migration from a
 coated product.

          3-2-2  general Approach to Evalu^ti^ «f *!,*»,.*«„ BMt.f1

The overall  migration rate of  a  contaminant from  «  specific matrix
depends on the rate of diffusion within the matrix and the  rate of
                                   26

-------
  dissolution and  dispersion  in an external  phase  in contact wich  the
  matrix.  Migration is Influenced by properties of  the  contaminant,  the
  matrix  and   the  external   environment;    interactions   among   the
  contaminant,  the  matrix  and  the  external  environment;  and the  use
  conditions.   Some specific  factors  potentially affecting  contaminant
  migration  during  a specific  use  include:

      •     size  of  migrant  •  molecular weight,
      •     physical and chemical properties of  the migrant,
      e     concentration of the migrant,
      •     interaction of the migrant with the matrix.
      «     characteristics  of matrix - rigidity/flexibility,
      •     contact/penetration of matrix by external phases,
      •     solubility of migrant in external phases,
      •     duration of use, and
      e     temperature.

 Migration  from a specific  matrix  is  often  controlled  within  the
 matrix.    In such cases,  migration  is  a   function  of  the  initial
 concentration  in   the  matrix  and the  diffusion  coefficient of  the
 migrant/matrix  pair.

 The driving force  for migration  is the concentration gradient of  the
 migrant  within  the  matrix  and  the  rate of migration  is  directly
 proportional to this  gradient.   According to  theory,  migration will
 continue as long as there  is  a  concentration  gradient.  However,  there
 may exist   cases In which some of  the  migrant species are bound and
 unavailable for migration.   For  example, this  has  been  reported for
 very  low concentrations of monomer in some  plastic materials.   Most
 available studies  documenting contaminant migration involve synthetic
 polymers and concentrations  of ppm  or  higher.   No information was
 found to support or refute  a  "zero migration- concentration for paper
 products.

Migration through  a matrix toward  the  surface may occur  through  a
                                   27

-------
  diffusive  process in which migrating  molecules  "jump" thermally from
  one  position to a neighboring position.  The  mechanisms  involved are
  similar  to  those  by which  solutes  move  through  liquids  and  can
  theoretically  be characterized  in terms  of  diffusion  coefficients
  Diffusion  through solid matrices  is  much  more  sensitive  to  migrant
  molecular weight  than is  diffusion in water because  the  migration of
  small molecules requires only minor shifting of  the matrix,  while the
  movement of  larger molecules from sit. to  site may  necessitate  the
  simultaneous reorientation of segments  of the matrix.   Thus,  diffusion
  rates  in  solid  matrices  (e.g.,   polymers)  are  relatively  low  and
  decrease  sharply as migrant size  increases  (Till  ec  al.,  1983).

  In  addition  to the  size  and nature  of  the migrant,  other factors
  related to  the thermal  energy  (i.e.,  activation  energy)  needed to
  stimulate  the  "Juaps"  include the  stiffness of  the   matrix  and the
  presence  of   penetrants.   plasticizers,  proc.ssing  aids  or  other
  molecules  which  may affect  the flexibility of  the  matrix or  the
  movement of the migrant.

 Elevated temperature,  are expected  to  decrease  the  activation  energy
 needed  for   movement  within  a   matrix  and   increase   diffusion
 Temperature-induced  effects may  include:   increased  migrant  vapor
 pressure,  altered  partitioning between migrant  and matrix,  altered
 behavior of  penetrants or  other processing aids  within  the  matrix   In
 a study of migration of various  contaminants in polymeric  materials
 increases  In diffusion coefficient,  of on. to  four orders of magnitude
 were observed over the temperature range of 4«C to 40'C (Till et al
 1983).

 Once  a  migrant  r.aches  the  interface  bectfeen  ^   ^^  ^  &
 contacting external phase,  it dissolve.  !„  the  external  phase and
 effects   a   partition  equilibrium.     Assuming   constant   migrant
 concentration, migration controlled  by diffusion is expected to occur
 at  a  rate  proportional  to  the  square  root  of  time.  However,  if
migrant  concentration in the matrix drop, below  50% of  the  initial
                                   28

-------
   concentrator,  or  If the migration concentration in the external phase
   approaches  10-20%  of  saturation  levels,  the rate  of  migration is
   expected to drop  below  that  which  would be associated with the square
   root of  time  relationship.   If che external phase  is not well mixed
  boundary  conditions  may  also  reduce  the   migration   rate    The
  interaction  of  the  migrant with  the  external  phase   is  generally
  defined as a solubility and  partitioning  issue; the solubility of the
  migrant in  the external  phase, volume  of external  phase  available
  time of contact  and temperature during  contact are  all  important in
  evaluating dissolution and dispersion.   External phases which are able
  to  remove  migrating species as  fast as  they appear  at the surface of
  the  matrix are considered  -sinks";  under these conditions,  migration
  is dependent on diffusion and solubility considerations in the  matrix.

  The  interaction between  external phase and  the matrix itself i, also
  important.   Penetration  of the external  phase into  the matrix  can
  accelerate and  may control  the migration process.  After the external  4
 Phase  reaches   eh.  contaminant,  solubility  and  partitioning  again
 become important issues.

           3'2'3  Potential
                     3-2. 3.1   Availabl
The  technical  literature  was  searched  for  information  that  could
provide  insight  into  the  mechanism  by which dioxin  or  any  other
chemical migrate,  fro. paper products.   Because information specific
to  dioxin  migration  was  thought  unlikely   to  exist,   the  search
encompassed  the migration  of  any chemical  fro. paper  products    Of
intereat was  th.  form and  location of  the  che.ic.1 in the paper  the
rates  at  which chemical  migrates from paper  and factors  that could
affect the migration process.

Four data bases were searched:
                                  29

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       •    Chemical Abstracts -- 1977 to present,
       •    Food Science and Technology •- 1969 to  present,
       •    Pira -- 1975 to present,  and
       •    World Surface Coatings Abstracts -- 1976 to present.

  The  first two databases  were  searched through the online services  of
  Dialog Information Services, Inc. and the latter  two  through Pergamon
  InfoLine.  Inc.  Pira  is  the Paper and  Board,  Printing and Packaging
  Industries Research Association (United  Kingdom).

 A  variety  of search strategies  and  key  words were used.  Ultimately.
 the  most productive was  the combination:  MIGRA(...)  and PAPER.  Of
 the four databases, the first two yielded  the most apparently relevant
 abstracts.  Fifteen articles were obtained and reviewed.  In selecting
 the articles for acquisition, emphasis was placed on those in English,
 French. Italian or German that could be rapidly obtained.  None  of the
 non-English articles were translated; however, they were inspected for
 useful tables and figures.

 Of the  fifteen  articles,  six  have  ,0».  pertinence  to the present
 problem,  although none  provides  quantitative  information that would be
 useful for  substantiating estimates  of dioxin migration.

 Whicfield et al.  (1984) associate the contamination  of cocoa powder
 with  the  presence  of chlorophenols in the paper of the sacks in which
 the powder was  packaged.   The  authors  cite  Voss, et  al.  (1980) who
 state  that  certain chlorophenols  are  formed  during  the  bleaching
 nrnfmam
process
The  migration  of  polychlorinated   biphenyls   (Aroclor  1242)  from
bleached Kraft to four  foods  was  reported by Stanovick et al.  (1973).
The  PCB-containing paper  was  produced  by  blending  the  pulp  with
"carbonless" carbon paper.   The foods were dry cereal, cereal grain* a
cake mix  containing  12%  shortening and  table  spread.   At  typical
commercial  ratios  of  food  weight  to  package  surface  area,   the
                                   30

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   migrations  from paper initially containing  20  and  160  pp» PCB  produced
   concentrations  in  th. foods  ranging fro» 0.1 to 4.3 ppm  after periods
   of  60 or 90 days.  Food  type  appeared to have little or no effect on
   the  amount  of  migration.   In  other  tests,  plastic  files  and waxed
   glassine  paper  were  placed between  the  contaminated paper  and the
   food.   Migrations  were  generally   reduced with  the  polyvinylidene
  chloride  film  and  the  glassin. but not  with the polyethylene  film
  Although  the  procedures  section of this  publication  indicates  that
  data were obtained  at several times  during  th. 60  or 90 day durations
  of the exposures, only  the end  point v.lu., are  reported.  Presumably
  the  time data along with  details on  th. experiments  could be obtained
  from  the  authors.    From such data  the  mechanisms  and  rates  of
  migration  might  be   discernible   and,   perhaps,   applied   to   the
  elucidation  of  the  dioxin  migration  process.

  Two  other publications  discuss  the  migration of N-nitrosomorpholine
  (NMOR)  from  paper products to food.,   s.n and Baddoo  (1986) compared
  the amounts  of  NMOR found  in margarine  comm.rcially packaged in waxed
  paper,  polymer-coat.d  pap.r  and alu.inum-b.cked  paper.   In  three of
  five  cases,  0.5,  1.1  and 1.4  ppb NMOR were found  in the margarine
 close  to  its interface  with  the waxed paper packaging.   The initial
 amount of NMOR in each packag. ranged from 5 to 34 nanograms.   No NMOR
 was  detected  in  th.  margarine ' fro.  th.  packages  of  the  other
 materials,    although  NMOR  wa,  pr.,.nt   ln  the   packaglng>    ^
 publication  is  deficient of  any infor-mtion with  which  to  estimate
 migration rat.,.  For  example,  neither  th.  storag. times  nor package
 dimensions  nor amount,  of margarine ar.  given.   Hotchkiss  and Vecchio
 (1983)  report the migration  of  NMOR  to flour at 100'C.   However,  no
 detail, on  th. ti.es  or exposure  areas are  given.

 Two foreign language  articles  that could have r.levance are laccarino
 et. al.  (1982) and Falandysz and  Ganowiak (1982).

As mentioned  earlier, these studies may  not b. directly applicable to
dioxin  migration  fro.   paper product, b.caus.  of   the  different
                                   31

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  chemicals,  higher   contamination  levels,   different   matrices   and
  different conditions used.  Therefore,  for  the  purpose  of this study,
  several assumptions regarding dioxin migration have been made  and are
  discussed below.
                      3-2-3-2  Unmediated
  Table 5 presents some physicochemical properties of  2,3,7,8-TCDD  that
  are   relevant   for   predicting  the   potential  migration  from solid
  matrices.   As  discussed in Section 3.2.2, diffusion  is expected to  be
  highly  dependent on  the size and  nature of  the migrant.   The  high
  molecular  weight and low vapor pressure of 2,3,7,8-TCDD  indicate  that
  unmediated diffusion through  solid matrices  is  not expected  to  be
  significant.   In  fact,  mobility  of  2,3,7,8-TCDD   in   environmental
  soils,  which are  generally more  porous  than  paper, has  been shown
  repeatedly  to  be very low,  e.g.,   10  c.  migration  over  12  years
  (Freeman and Schroy,  1985).   Furthermore, .t concentration levels on
 the  order   of  10 ppt,  there  may  be very  little  driving  force  for
 diffusive migration.

 External  factors  such  as  microwaving  or   exposure   to  elevated
 temperatures could possibly  affect dioxin mobility  and  increase  the
 potential for diffusion.  However, -'there  are no data  describing these
 effects  and  they have not  been  addressed within the  scope of this
 study.

 The disposition of dioxin molecules within the  paper matrix may also
 affect  it.  rate  of  migration.    For  example,  to  the  extent that  the
 dioxin molecules  may  be adsorbed or chemically  bonded to the matrix.
 the rat. of migration may be reduced.  However, there  are  no  available
 data  describing  the extent of  sorption  or bonding  of dioxin in  the
 paper matrix.   For the purposes  of this  study  and  to assess maximum
 migration potential,  it  has been assumed  that the dioxin molecule  \s
unbound.
                                  32

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                                      TABLE 5
                Relevant Phvslct
 Formula

 Molecular Weight

 Melting Point

 Vapor  Pressure  (nun Hg)

     25'C
     25'C
     30*C

 Log Octanol Water
                                                               Sourea
 CiaH4Cl40,

 321.97

 305'C
 1.5 x 10"»
 7.4 x 10"10
 3.5 x 10~»
     Partition Coefficient    6.15-6 84
     dog Kow)

Solubility (mg/L) in:

     o-Oichlorobenzene
     Chlorobenzene
     Benzene
     Chlorofona
     n-Octanol
     Methanol
     Acetone
     Water  (25*C)
     Water  (20-22'C)
     Water  (22'C)
     Water  (20-25'C)
  1400
   720
   570
   370
    48
    10
   110
3.17 x 10"*
7.91 x 10'«
1.93 x 10"«
 Schroy
                                      . (1985)
 Freeman and Schroy (1986)
 Podoll ££ al. (1986)
 Schroy at al. (1985)
 Marple fi£
2.0 x 10~«
 Schroy ££
 Schroy e^
 Schroy e^
 Schroy ££
 Schroy ej
 Schroy e^
 Schroy ej
 Schroy e^
Adaas  and
Marple ££
Mackay ££
Al.
Al-
                                       (1986)
     (1985)
     (1985)
     (1985)
     (1985)
     (1985)
Al-  (1985)
Al-  (1985)
Al-  (1985)
Blaine (1986)
Al-  (1986)
Al.  (1985)
                                      33

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   In  summary,  diffusion of dioxin within the  paper  matrix and from the
   surface of paper  products  is  expected to  be very  low due  to its high
   n-olecular weight and low vapor pressure at room temperature.  Products
   for which unmediated  diffusion represents the only  migration process
  will not be considered further.
                      3'2'3-3
  Dioxin  migration  can  be  facilitated  by  an  external   phase   that
  penetrates  and  swells  the  paper  product and then  solubilizes  the
  dioxin.   Because  air  does  not  swell  paper  and  because  the  vapor
  pressure of dioxin  is  so low.  little or no migration is expected with
  this  external phase.   It is  also  likely  that coatings  on products
  effectively  prevent  the  external  phase  fro.  contacting  the   paper
  matrix  and  solubilizing  the dioxin.   Therefore,  migration  from dry
  paper  products  and  from coated  paper products  under  normal  use
  conditions is  expected to be negligible  and  these  product categories
 have been eliminated from further consideration.

 External phases  that  are likely  to contact  and penetrate  consumer
 paper products were evaluated.  The  mass of  dioxin  estimated to  be
 available in  a  specific product  and  the  volume of  external phase
 associated  with  a specific  use were  reviewed  to  determine whether
 saturation conditions might be  expected.  Table 6 lists the  types  of
 external phases  considered,  the  types  of products  expected  to  be
 contacted, and  a  conservative estimate of the volume of external phase
 expected to be  encountered in a  specific use.

 Using  the wight  of dioxin available  in a specific product and the
 volume of external phase  shown in Table  6. estimated concentrations of
 dioxin in the external phases can be calculated.  These concentrations
 should be considered  maximum  concentrations, since  all  the  dioxins .in
 the  product  may not  be contacted by the assumed volume of external
phase: and  in an  actual product, all  the dioxin may  not  be freely
available.
                                   34

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                                                                 TABLE 6
tn
External
Phases
Water
• Aqueous foods

Body Fluids
e Saliva

• Skin oils
• Blood

• Urine
Oils
• Oily foods

Product
Contacted.8
• paper towel
• coffee filter

• uncoated sheet

• uncoated sheet
• paper towel
• dinner napkin
• uncoated plate
• tampon

• diaper

e paper towel
• uncoated plate
Dioxin (pg)
Per Unit

30
63

0.4

36
30
93
148
24

420

30
148
Approximate
Volume (raL)
External Pb,****
•an
j\j
1000

1
1.
0.001
0.001
0.001
0.001
in
JU
so

30
30
Maximum Estimated
Concentration in
External P^flfje (ne/l\

. . .6
1 x 10 *
6 x 10~8

. , -7
4 x 10
4 x 10~i?
3 x io"<
9 x 10":
2 x 10"1
-7
8 x 10
8 x 10'6

-6
1 x 10~
s v in'6
        See Table 7





               assumed to be associated with specific use of product, as discussed  in Section  3.3.

-------
  The  concentration estimates  In  Table 6  can  be compared  with  the
  solubility  data  given  in  Table  5  to determine whether  solubility
  limitations should be  considered.   The different solvents for  which
  solubility  data  are  available  do  not directly correspond  to  the
  selected external phases;  however,  some general assumptions about  the
  solubility of dioxin  can be made.   The concentrations estimated  for
  dioxin  in  aqueous solution,  are  less than  the  aqueous  solubility
  concentrations  cited  in the  literature,  and concentrations estimated
  for  dioxin  in  oily   foods  and  in  skin  oil,  «.  also  less  than
  solubility  concentrations  cited in the literature for  most non-polar
 organics.   Therefore,  for these  three  categories, solubility  i, not
 expected  to  limit the  extent to which  the  dioxin in  the paper matrix
 will be  transported by the  external  phase.  There are  no  solubility
 data available for  the other body  fluid, cited;  however, the  capacity
 of saliva, blood, and urine for dioxin  i. expected to be greater than
 that of pure water, and the maximum estimated  concentration, given  in
 Table 6  probably do not exceed  solubilities.   In  summary,  therefore
 all of the external phases  specified in  the  following  sections  of this
 report may  be  considered  -sink,-  with  respect to their ability  to
 solubilize dioxin present at  10  ppt  in the selected products
                     3.2.3.A  Conclusions
For  the  purpose of evaluating the exposure  to dioxin associated with
normal «..  of selected bleached  Kraft paper  products,  the following
observation, about  the  release of dioxin fro. the  products have been
made.

     1.   There  are no  specific migration  rate  data available  for
          dioxin-contaminated paper products.

     2.    Unmediated migration is expected to  be negligible at  10  ppt
          dioxin;  migration to air is  not  expected  to  be  signific
Leant.
     3.   Matrix  penetration/alteration  is  necessary  for  release of
         dioxin from paper products.
                                  36

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5.
 Penetration   of  representative  external   phases   through
 coating materials  is  not likely  to be  significant;  dioxin
 migration  from  coated  paper  products  is  assumed  to  be
 negligible.

 For several  representative  external phases  it is  unlikely
 that saturation  and partitioning  limitations  control  the
 migration  process;  this conclusion was based  on conservative
 assumptions  in that dioxin  availability was  maximized  and
 the  external phase  volume was minimized.

 Since the  migration of dioxin will most  likely occur under
 conditions   of   external   phase  penetration.   individual
 estimates  of dioxin availability will be made  for specific
uses of  specific  paper  products; penetration  will  depend on
 time, temperature,  contact area  and depth,   external  phase
volume and other considerations.
                           37

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        3-3  Exposure Evaluf

             3-3.1  Prpduct  Selection  Crf^frf||

   Converted  end-products which are primarily comprised of bleached Kraft
   pulp  cover   a broad  spectrum  of   consumer  use,.   The  analysis  of
   relative tonnages and per capita distribution, as described in Section
   3.1,  combined with  the  evaluation  of  dioxin  availability  and
  migration,  as  discussed   in  Section  3.2,  strongly suggest  various
  products   and  categories  that   can  be   dismissed   from   further
  consideration  in  terms   of relative  exposure  and  risk.   Specific
  products with  the highest  potential for exposure have been  selected
  based upon  a qualitative  evaluation of  the  parameters  summarized  in
  Table 4,   which  include   the   following:   per  capita   consumption
  exposure routes, product us. characterization  and external phases.

  End  products which fall in high per capita consumption categories may
  result in an increased exposure  - .ither vla  the ^^ absorpclon J
  the  ingestion route.   In  terms of  exposure  routes,  if  a user  were
  exposed  to  an available ^ of dloxlnf only  a fc
 would actually be  absorbed, depending  on  the  mode of contact.   This
 fraction,  known M  <*. .bsorption  efficiency,  range,  from about  2
 percent for direct external skin contact (Poiger and Schlatter,  1980,
 to 30 percent for  ingestion of product containing  dioxin (McConnell.'
 et al.,  1984,, to  100 percent for  inhalation  of airborne  dioxin  (ADL
 estimate).    For absorption  through  internal  mucous membranes,  an
 efficiency of 50 percent (similar to  ingestion)  has  been assumed   Due
 to the phy,icoch.Bical  nature  of dioxin.  (high molecular weight and
 low vapor  pressure)  it  has been  assumed  that  under   normal  use
 condition, dioxin would not become airborne and  thus inhaled.

 Since  the absorption efficiency  for dermal exposure is significantly
 lower than inge.tion, it is likely that chose papar productj| which ^
only touched by skin oil and which do  not com.  in  direct  contact with
food would  have  a  lower  risk.    If the  consumption,  duration  and/or
                                   38

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 frequency of use  were also low,  then the potential for exposure  and
 subsequent risk would be further reduced.   If the  product Is  contacted
 by an external phase  such  as  water,  skin oils, body fluids  or  edible
 oils,  th. matrix could absorb  the fluid; swell and release the  dioxin
 for subsequent  contact via the  skin,  membranes or via ingestion.  AS
 discussed in Section  3.2,  if  .  product  is coated or  laminated,  the
 paper  matrix has been  assumed  to  be impervious  to  representative
 external  phases and, even for extended periods  of contact time,  is  not
 expected  to result in  an increased risk.

 In  terms  of specific  product  categories  which could  potentially  be
high-or-low risk,  the  following  conclusions  have been drawn (refer to
Table 4):

     •    Printing Papers:

     -     Coated ShB«r:  Although the  per  capita consumption  is high
          and exposure to a  single unit is  repeated during the life  of
          a "page", the  route  is primarily  dermal; furthermore,  the
          coating provides . barrier  to potential  matrix penetration
          by  skin oils.  Therefore,  this category comprises a  low- risk
          group.

     -     Unseated,  h
            mr:   Although  the exposure  is  mainly  dermal,
 there  i.  a subset  of  users  who  may also  insert  smaller
 pieces   of uncoated paper  into   the  mouth  for  chewing,
 spitting,  or  swallowing  purposes.   This  user population
 introduces a secondary  ingestion- related risk.   Since the
 per  capita consumption ranks  second  highest  among the list
 of categories  (Table 3),  its  potential  risk could  not  be
 dismissed without further analysis.

Thin PflBftrii:  The consumption is low/medium; exposure occurs
primarily by touching (dermal).  The single exception is the
cigarette  paper   category  but,   as  mentioned   earlier,
                        39

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  inhalation has  not been addressed as  a route  of  exposure.
  Although  the  frequency of  use may  be high,  each unit  Is
  generally used  for  a short  period  of time.   Thus,  this
  category has been dismissed from further analysis.
  Pleaded BrUmTi:    The   product  use   characterization  Is
  similar to  that  of thin papers,  and the  bleached  Kraft
  content is  similar  to uncoated  sheets.  Since  the  latter
  category will be evaluated in further detail, these products
  do not  require additional  scrutiny.

  Packaging Papers:

 Wrappings. Rag and ,^fiy   SMpfftng;  These  three  categories
 do not  appear to  be high risk  groups  for  three  reasons:
 consumption  is  relatively  low;   exposure  is  via  dermal
 contact  since  food packaging paper generally  contacts dry
 food; and since the glassine/greaseproof/vegetable parchment
 papers  that  may contact  wet or  oily  external phases  are
 coated,  the potential risk via ingestion is minimized.

 SBftcialtY P"Win:   This  category  includes   a  variety  of
 end-user products such  as' uncoated wrappers,  doilies,  gift
 wrap,  novelties and coffee filters.   While the majority  of
 products represent  exposure via  dermal contact, one product
 in  particular,  namely  the coffee filter,  involves direct
 ingestion of  the  external phase (water).   Total per capita
 consumption  is  low;  but  frequency is  medium-high.   Also,
 this  single product  is almost  exclusively bleached  Kraft
pulp.  Due  to the product  use  characterization parameters,
i.e.,  thorough  contact  and saturation with the extracting
medium during typical  use,  an analysis of exposure and risk
of coffee filters  has been conducted.
                         40

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   Tissue  Papers:
                r
                       These  tissues have  a medium  level of
  consumption but the duration of use is momentary.  Moreover
  user exposure  is  via  skin  contact.   Although  the  bleached
  Kraft  content   is  high  in  these  categories,   the  products
  generally maintain their integrity during use,  implying that
  the matrix is not  greatly affected by skin oils.  Therefore,
  these were not  evaluated further.
            Paper napkins, like tissues, also come  in  contact
  with external  skin and skin oils.  However, unlike tissues
  the  use  duration of a typical dinner napkin exceeds  that of
  a  facial/toilet  tissue.   Assuming that skin oil penetration
  in the matrix  is  a  function  of time, this  category could
  pose  an  increased  risk.   Therefor.,  it has been examined in
  greater detail.

 Ifiwfilling:  Products in thi. category have varied uses which
 could  lead to  a  rang, of potential risks.  The  typical  use
 is for drying  or wiping  spills.   Drying  constitutes water
 absorption into  the  paper;  wiping  Holies dermal contact
 with  skin oils.   The  absorbent  nature  of  the   products
 introduces a   third  use,  i...,  greaae  absorptlon  during
 microwave cooking.   The consumption is  medium,  and the  use
 duration   may   be  on  the order   of   seconds  or   minutes.
 However,  th.  pot.ntial risks du.  to  th. different  external
 phases Justify  additional  analysis.

 Packaging  Paperboard:
HliK C
               rfr:  There are three reasons that products in
this category may be  of high-risk:   consumption  is medium,
use  is  for  an  extended  duration,  and  exposure  is  via
ingestion of fluids contained within  the  cartons.   However.
there is  one  overwhelming reason  to  dismiss  this  category.
                         41

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  I.e.,  coatings.   Since dairy  and  non-dairy  (juice)  carton
  stock  is  laminated,  the  coating  provides  an  effective
  barrier  for  the paperboard matrix,  thereby minimizing  the
  potential  risk.   One  implicit   assumption  is  that  the
  effectiveness of  the coating  is not time- dependent,  i.e..
  there is no penetration of  the liquid into  the  matrix over
  several days of contact  time.   This category  has not  been
  further evaluated.

  Pmr  PlflrMflTHYi:    The  presence  of   laminations  has
  eliminated  consideration  of coated  plates.   For uncoated
  Plates,  consumption and duration are medium;  exposure may
  occur by  touching the plat, surfaces or by inge.tion of food
  that  contacts  the  plate.   Due  to  the  potential  range  of
  risks in this category, it has been evaluated further.
       ftgfffl.tth;  Consumption  and use duration of  uncoated
 cups  .re  relatively  low.   Cups  coated on  the inside  for
 hot/cold beverages are analogous to the packaging paperboard
 products:   the  coating has  been assumed  to eliminate  the
 potential  exposure via ingestion.  The exterior surfaces  of
 the cups,  uncoated,   are  exposed  to  skin oils  and dermal
 contact.    However.   since  the  uncoated   paper   plates
 constitute  a  similar  exposure  scenario,  this category has
 been exempted  from a detailed analysis.

 friable. Bftflrd.  Linftrhoarda  flnd  r^dln*  ^rr»nr   7^ ^
 characterization,   external  phases   and  exposure  route
 features   of   products   from  these   categories  are   all
 considered   in   other   product   categories.    Moreover.
 consumption  is  low  for  ovenable  board  and  linerboard.
 Folding  carton products  are  typically used  for dry  goods
storage  such  as medicines,  cosmetics  or  prepared/packaged
food.  Thus,  the matrix  is  not  penetrated by an external
fluid  phase.     Hence,   these  categories  have  not   been
                        42

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considered for further evaluation.

Pulp:

Ptsppsabje
                                 The  product use parameters,  i.e.  high
            frequency and per capita  consumption,  imply  a high ejcposure
            level.   Although  the  mode of contact  is  dermal absorption
            the extended duration for external  phase saturation  in the
            pulp matrix may  increase  the potential  dioxin availability
            to a significant degree.   Accordingly,   this category  has
            required further  analysis.
           Feminine  HYy1fne
                                             sanltary  napkin produ
-------
       o    dinner napkin,
       o    paper towel,
       •    coffee filter, and
       •    uncoated free sheet.
            3-3-2  Estimate of Potantt^  P1ftfftn
  Assuming a  dioxin  concentration  level  of  10  ppt or  10  pg/gm  of
  bleached Kraft  fiber,  the  amount  of dioxin mass  available for exposure
  can  be  calculated for a prototypical product as a function of several
  estimated factors which  include  the  following:   MSs  of  the  unit
  product,  surface area contacted,  external  phase penetration in the
  matrix  and  fraction  of the external  phase  ingested  or absorbed.   For
  the  seven products  representing  potential high-risk  categories,  the
  total  dioxin mass  available  for  exposure  following  a  typical  use
  situation is  summarized in Table 7.  The methodology  for  estimating
  the potential exposure levels is outlined in this section.

 Column  (A)  of  Table  7 list,  the  seven  sample products  and  their
 associated bleached Kraft content.  Although the primary component  in
 each product i, bleached Kraft fiber, the actual  fraction ranges  from
 60 to 100 percent, appending on the quantity of  other components  such
 as fillers or  resin..  Also  it  i. important to  not.  that  for three
 product, (th. uncoated paper plate,  paper  towel,  and uncoated  sheet)
 multiple u.. situation,  have  been  postulated.   Each use effectively
 result,   in  a  different  potential  exposure  level.    !„  subsequent
 analyst.,  only  th.  highest  exposure level  i.  considered.    For  the
 remaining product.,   a single  us.  situation  adequately defines  the
 potential dioxin mas.  to which a user  could be exposed.

 Although  the  dioxin  concentration in bleached Kraft fiber has baen
 assumed  to be constant,  the amount of dioxin in each  product varies
with the  mass of bleached Kraft fiber in a product unit.  Column  (B)
presents  the  mass  of each  prototypical  unit as measured during this
                                  44

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                                                 TABLE 7
Ul


PRODUCT
PERCENT
BK/UNIT
(A)
UNCOATED
PAPER
PLATE
90.0
DISPOSABLE
DIAPER
60.0
SANITARY
TAMPON
95.0
DINNER
NAPKIN
98.0
PAPER
TOWEL
95.0
COFFEE
FILTER
100.0
UNCOATED
SHEET (L)
90.0
ESTIMATES OF POTENT]

UNIT EST.
MASS DIOXIN
WT/UNIT
(CM) (PC)
 (C)
16.5 148.5
70.0 420.0
2.5 23.8
9.5 93.1
3.2 30.4
6.3 63.0
4.0 36.0
0.04 0.4
iAL DIOXIN EXPOSURE LEVELS BASED ON UNIT CONSUMPTION

PRODUCT
SURF
AREA
324.0
826.0
16.1
1865.0
671.0
881.0
603.0
1.6
UUNIAINIHU
BLEACHED
FOR A TYPICAL
EXTERNAL
PHASE
(EP)

SKIN OIL
OILS
URINE
BLOOD
SKIN OIL
SKIN OIL
WATER
OILS
WATER
SKIN OIL
SALIVA
EXPOSURE
TIME
(F)
30 MIN
30 MIN
4 HRS
4 HRS
30 MIN
15 SEC
15 SEC
3 MIN
5 MIN
15 SEC
30 SEC
i KRAFT (BK)

USE SITUATION 	
CONTACT
AREA
PERCENT
(C)
23
16
60
100
80
100
100
100
100
10
100
DEPTH
PENETRN
FRACTION
(H)
0.01
0.50
1.00
0.50
0.01
0.01
1.00
1.00
1.00
0.005
1.00

	
DIOX MASS
IN EP VOL
CONTACTED
(I)
0.3
11.9
252.0
11.9
0.7
0.3
30.4
30.4
63.0
0.01
0.4

-----...
EP
EXPOSURE
PERCENT
(J)
0.1
25.0
5.0
10.0
0.1
0.1
0.1
1.0
99.0
0.1
95.0



DIOX MASS
AVAILABLE
FOR EXPOSURE
(PC/UNIT)
|K /
3.4E-04
3.0E+00
1.3E+01
1.2E+00
7.4E-04
3.0E-04
3.0E-02
3.0E-01
6.2E+01
l.OE-05
3.4E-01

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 NOTES  FOR TABLE 7:
    SSI S^Kfiyr^S^SIM^^
 c-
 D. BASED OH ADL ESTIIUTED VALUES AND MEASUREMENTS .
 B. SEE TOT RK DISCUSSION OH EXTERNAL PHASE UNITATIONS.
 t. EXPOSURE TIME IS BASED OH ADL ESTIMATE OF TYPICAL PRODUCT USE
                                                                 .
                                                                ,v
                                                                >Y
                                                              ™E
J-                                            PHASE
K. BASED ON THE TOTAL MASS OF DIOXIN IN A PRODUCT  AND

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   analysis.   The product of the percent bleached  Kraft,  unit mass  and
   10  ppt concentration,  as shown in Column  <«.  provides the estimated
   dioxin mass per unit.

  Based on the physical geometry, a single surface area for each product
  is calculated  and summarized in Column (D).  The  specific dimensions
  and geometric  assumptions are  discussed  on a p.r-product  basis  later
  in this section.

  The  characterization of a typical use situation  is defined in  Columns
  (E)  through (H).   The primary  external phase,  as shown  in the Column
  (E). may be water  or a water-based solvent, skin oil, edible oil  such
  as hamburger or bacon grease,  or  body fluid such as saliva, blood or
  urine.  As  discussed in Section 3, the quantity of dioxin  solubilized
  is not  a function of the  solvent  type since it ha. been assumed  that
  dissolution is  not  limited by  solubility.   Inatead,  the  differences
  among the solvent, represent the relative ease with which a pulp/paper
 matrix  could be penetrated, so  that  the dioxin could become available
  for  exposure.   For  example,  the  relative  volume  of  skin oil  that
 touches a sheet of paper is much less than the volume of urine that is
 absorbed in a diaper.  Accordingly, the amount of bleached Kraft fiber
 penetrated  by  the external  phase varie.  between  the  two  products
 Although  the exact  volumes  of  'each  external  phase  for  all   the
 scenario,  have   not  been  quantified,  the  differences   in   matrix
 penetration are accounted for  using  factors defined in Columns  (E)
 through  (H).

 The exposure time,  .8 ilsted ln column (F),   is not used  in  the actual
 calculation  scheme;  however,  it provide,  a basis  for  a  reasonable
 estimate of the contact  area percent  and depth penetration fraction
 which are  tabulated  in  the two  column,  immediately  following     For
 several  product, and  uses,  it would be unrealistic  to assume that an
external phase contacts the entire  volume of bleached Kraft fiber and
saturates  the entire matrix.   If that  were  the  case,  then  every
occurrence of touching a page would result in a  soggy sheet with none
                                   47

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  of its initial integrity.  In  fact,  only a portion of  the  surface  is
  contacted,  and  only  a fraction  of the  depth is  penetrated by  the
  external phase in most instances.   Only in a few select cases  does  the
  entire product volume  (area  x depth)  encounter a volume of  external
  Phase.   The  estimated available  dioxin per  unit has  been  adjusted
  accordingly for each  product  and summarized in Column  (I) .

  Of the  total  external phase chat is absorbed into  the  matrix,  there  is
  always  some fraction  that remains in the  web.  Th. portion in direct
  contact  with  the  user  accounts for  the fraction of  dioxin  that   is
  potentially available.  This exposure percent  is listed  in Column (J)
  For  example,  given the total  volume  of urine  in a diaper  it   is
 estimated that  about  five  percent comes  in direct contact with  the
 infant's skin surface.  On  the other hand,  about  ninety nine  percent
 of  the  water passing through a coffee   filter  i.  recovered  and
 subsequently ingested.  Assuming the dioxin  ha.  been removed from  the
 matrix and solubilized in  the  external phas., a larger  fraction of  the
 dioxin mass in the water  is available  for  exposure than the  aass  in
 the urine.

 The  last  Column  (K)  contains  the  actual  mass of  dioxin that  is
 potentially available  for ingestion or dermal absorption.  In summary
 the total  estimated dioxin mass in'-th.  product unit has been  reduced
 first  by  the  fractional volume of  product contacted,  then  further
attenuated by  the  portion  of external phase  exposed to the  user   In
the  disc«.sion  that   follow,,   the dimension,  of  each product  and
assumption, of usage are outlined.
              Pflpftr  Plnrti:   A sample  eight- inch dinner  plate  weighs
     16.5 gas,  and the surface area of one face is 324 sq cm.   The two
     specific use .cenario. considered are (i) holding  the  plate,  and
     (ii)  eacing  a  hamburger which  is on the plate.   Note  that  no
     cumulative  effects will  be considered in this analysis.
                                  48

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  For  the  first  situation,  assume  a  one-Inch  annular  ring  is
  touched  for about half  an hour; therefore,  skin  oil encounters
  about 23% of  the total available surface  area.   For typical skin
  011-matrix  contact  scenarios, assume  a  one-percent  penetration
  into the depth of the plate surface.  Of the total volume of skin
  oil  that  enters  the  paper web.  a small  fraction of a percent
  returns to  the user.  This  assumption has  been maintained  for
  other products where  the  typical  use Involve, dermal contact/skin
  oil.   Given this use  situation, of the  total dioxin mass  of 148.5
  pg.  about 3.4  x 10-   pg has  been calculated to be available  to
  the  user.
 The  second scenario  assumes  a four- inch hamburger  eaten from a
 paper plate.   Hamburger oil covers about 16% of the top surface
 and  penetrates about  half the  depth of  the plate.   About one
 fourth  of the oil  that contacts the  pl.te  is removed with the
 burger and ..ten.  In this ca.e, 3.0 pg of the total 148.5 pg has
 been assumed to be available for exposure.

                      Although the weight  of a  diaper (70  g)  is
 high compared to other paper products,  its bleached Kraft content
 is only  60%.   The  remainder is  fillers,  plastic  lining,  tape
 •tc.   A  st«dard absorbent  diaper,  when  spread open,  measures
 •bout 8 in wide  and 16  in  long.   The  resultant surface  area  is
 826  sq cm.   The external phase  1. urine,  which may have  contact
 with  the  diaper  over  several  hours.   About   60%  of  a diaper
 surface 1, generally wet, and it is reasonable to assume  that the
 entire depth of the  diaper i, saturated.  The extended period of
 u,.  allow,  for repeated  contact  with  urine;  therefore,  It has
 been  estimated  that  the infant is exposed  to  about 5 percent of
 the volume.

Given these us. conditions,  an Initial dioxin content of 420 "'pg
per diaper is reduced to 13.0 pg available for exposure.
                              49

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                     This product  consists primarily  of  bleached
  Kraft pulp.  Its  mass  (including the string,  but not the  outer
  cardboard liner)  is  about  2.5 g.  The  geometry of a  compressed
  tampon is  a solid cylinder  with an  outer  area  of  16.1 sq  cm.
  Over a  period  of 4 hours,  blood,  the external phase,  is  in
  contact  with the  entire outer surface and is  generally  absorbed
  through  half  the  tampon  thickness.   About  one- tenth  of  this
  external  phase  may  come  in contact  with   the inner mucous
  membranes.   Applying  these  assumptions,  a total mass  of 23.8 pg
  dioxin  per  tampon has  been  reduced to  1.2  pg  available  for
  exposure .
 Ptnner  papMn:   This  paper producc  haa
 resin content.  A typical napkin, 17 in. square, weighs about 9.5
 gms and has a single surface area of 1865 sq cm.  For a half-hour
 use time, skin oils touch about  80 percent  of  the total surface.
 As with the uncoated plate,  the depth penetration is estimated to
 be 1 percent and 0.1 percent of  the skin oil remains  on the  skin
 surface of the user.  For this  scenario,  93.1 pg of dioxin in the
 product have been reduced to 7.4 x lO'4 pg available to the user.

 faper Tgve.1;   The  presence  of wet strength resins reduces  the
 bleached Kraft  content  slightly for  this  product.   A  typical
 single  unit  has  dimensions of 11.25 in  x 9.25 in,  resulting in an
 available surface area  of 671 sq  cm.  The potential  use scenarios
 which have  been postulated  to illustrate  the  range  of  results
 are:  (1)  wiping up  a spill,   (2)  drying hands,  and (3) using  the
 towel for bacon  grease  absorption during microwave cooking.

 Th«  first use  situation involves skin contact  for a short period
 of  time.   Essentially,   an entire surface is touched,  and depth
 penetration  is  1  percent,   as  assumed  earlier.    Less  than 1
 percent of the skin oil re-contacts the user; thus 30.4 pg in  £he
product has been reduced to 3.0 x 10'4 pg available for the user.
                              50

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  The  second  scenario postulates  water  as  the  external  phase.
  Although the use  duration  is  short,  the total area and depth are
  saturated with  water.   Since the  function of the product  is to
  dry, a  fraction of a percent of water returns to the  user   In
  this case,  3.0 x 10'2  pg of  dioxin  hav.  been  assumed to  be
  potentially available.

  The  third  us.  situation  involves  edible  oils.  namely  bacon
  grease,  as  the  external  phase.  In the  three-minute cooking  time.
  the entire  paper towel is  saturated with  the grease  and about  1
  percent  remains  on  the  bacon  strips  to be  eaten.   For   this
  example,  the  dioxin mass  calculated  to  be  available  is   the
  highest  of  the  three scenarios:   0.30 pg  from  the  initial   30.4
  PS-

  frf-fte "inn   Of the seven  selected  products,  this  is the  only
  example  of  100  percent bleached Kraft content.  A  medium-sized
  filter,   11  3/8   in x 12  in,  with a surface  area  of 881  sq  cm
 weighs about 6.3 gms.  in a five-minute  period of use,  hot water
 literally acts  as  an extracting solvent,  contacting  100 percent
 of the area and depth of the  filter.  The  bulk of the  water is
 recovered a. coffee, and only  about 1 percent is retained on the
 wet filter.   For this product, 62 of the  total  63  pg have been
 assumed  to be  available  for  exposure.

 Vncoated  iffiMr;   This product, which contains  about  90  percent
 bleached  Kraft,  can have two very different use situations.   The
 first  involves routine touching or handling of sheets/pages;   the
 second' scenario  involve,  chewing of paper fragments which may be
 followed  by ingestion or expectoration.

A typical sheet,  8.5  in x 11 in.  has a surface area of about 103
sq  cm.   For  reading/writing applications,  skin oil touches  the
sheet for about 15 sec, and generally is in contact with about 10
percent of the  area.  Due to  the momentary nature  of use,  the
                              51

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       assumed  depth penetration Is less than  I  percent.   Accordingly,
       the 36 pg of  dioxin In the sheet of paper has been reduced to 1.0
       x 10   pg available for user exposure.

       A fractional  piece of a  sheet  of paper used for a  spitball.  on
       the other hand,  constitutes a  potential ingestion  exposure.   A
       half-inch square  piece  of paper  weighing 0.04  ga  has a  single
       surface area  of 1.6 sq  cm.   Given 30  second,  in the mouth,  the
       wad of paper  is  totally surrounded on .11 sides by saliva   the
       external  phase.  Of the  total external phase  contacting  the paper
       mass,  a major  fraction,  about 95 percent  ..y  be ingested -  the
       remainder leaves with  the  paper.  Thus,  the total mass of dioxin
       0.4  pg have  been slightly reduced  to  0.34 pg available for user
       exposure.
 4.0  RISK ASSESSMPMT
 The process  of risk  assessment  for exposure  to dioxin  contained  in
 bleached  Kraft paper  products involve,  estimating average  lifetime
 daily exposure  to dioxin.  the efficiency  of the  exposure route  in
 absorbing dioxin,  the  estimated  seventy-year lifetime use  pattern  of
 the product and the average  weight of  the  product user  to calculate
 the average lifetime daily dose per kilogram of body weight  (U.S.  EPA.
 1984a, Eschenroeder. et al.,  1986).

 The dose  is tran.l.t.d into risk by applying a potency factor or  unit
 risk multiplier *lch  yields an estimate  of  the  increased lifetime
 cancer riak due to  the  particular exposure scenario.
     4-1
          Exposure^
For each type of paper product  scenarios  have  been quantified and are
outlined in Table  8.  Column B  in Table 8 wa.  previously generated in
                                  52

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                             TABLE 8

 UNIT
           DIOXIN
                              DIOXIN  NO. OF
   U)
 UNCOATED    3.0E-09
 PAPER
 PLATE
Sffi""  »-3E-08
?»"    l"-<"
DINNER     7.4E-13
NAPKIN
PAPER      3 OE-10
TOWEL
COFFEE
FILTER
           6.2E-08
UNCOATED    1 OE-14
SHEET      3.4E-10
                          50   1.5E-09





                         1.5   1.9E-10




                          50   5.9E-10




                         1.5    1.1E-14



                          50   1.5E-10



                          50   3.1E-08
                        1.5   1.5E-16
                         50   1.7E-10
                                             1   1.5E-09
                                            3   3.4E-14
                                            2   3.0E-10
                                            1   3.1E-08
                                         1000   1.5E-13
                                            5   8.6E-10
                                                                   as™   spisT  ilsiTi"'
                                                                   ^INC   ESffiF SPSS1

                                                              70    2.1E-11
                                             6   1.1E-09      10.2    1.1E-10

                                               i


                                             t   5.9E-10       60    9.8E-12
                                                              70    4.8E-16
                                                              70    4.3E-12
                                                             70    4.5E-10
                                                              60   2.5E-15
                                                            3^.8   2.5E-11
                                                                                  70
                                                                                 50
                                                                                        (J)
                                                                                         2. IE- 11  6.6E-06
                                                                                   3    4.8E-12  1.5E-06
                                                                                  40    5.6E-12   1.8E-06
                                                                                  70     4.BE-16   1.5E-10
                                                                                  70     4.3E-12    1.4E-06
                                                                                        3.2E-10   1.0E-04
50     1.8E-15   5.6E-10
 9     3.2E-12   9.8E-07

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        NOTES & ASSUMPTIONS FOR TABLE 8:

        A- £25 oSSS^n1?11! 9N PROTOTYPICAL PAPER PRODUCT  DIMENSIONS
        c
                  INTERNAL CONTACT           50 PER CENT
                  INGESTION                  SO PER CENT
       °  ABSORPTION EFFICIENCY!1" °F PR°DUCT REFLECTS ™E «™CTI« DUE TO THE

       E. THE NUMBER OF UNITS USED PER DAY ASSUMES  A TYPICAL USER OF THAT PRODUCT.
       F. THE DIOXIN DOSE PER DAY  - DOSE/UNIT X  NO.OF UNITS USED/DAY
Ul
*"      H
       •• •  »•••* vawn AM uudn uun. mm* i np. n^w ftftf • im • c TUP iv« «* «•  IVlCP
       C.  THE AVERACETWEIGHT OF THE TYPICAL USER IS INPUT ON THE FOLLOWING  BASIS:
                 ADULT FEMALE               60 KG
                 CHILD UNDER 18      3.14 + (3.52 X MEDIAN AGE)
       J.
      K-  EXroSURE^^THFMmllJL^^^^IS^FSSeyCT OF THE LIFETIME

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   Table  7 and  indicates the mass  of dioxin  (converted  from pg to  o,g)
   which  is ingested or  contacted.  The  following sections address each
   product  and  discuss  how  this  dioxin  exposure  estimate  has  been
   translated  into an average lifetime daily dose.
            4-l-l     Uncoacsd
 This potential  exposure  scenario  for use  of  uncoated paper  plates
 involves ingestion of dioxin  in food oils,   it ha.  been assumed that
 50  percent  of  the  ingested  dioxin  is  absorbed by  this   route
 (McConnell,  et al.,  1984). that one uncoated paper plate is  used each
 day  and that  the duration  of paper  plat,  use Uses  for a 70  year
 lifetime.   It  ha. also been  assumed  that the user ha. an  average  adult
 -ale weight  of 70 kilograms and that  the  av.r.g.  lifetime daily  dose
 is equal to the  dose per day during use.  A, .hown ln Column  , of
Table . «. a  lifetime  dioxin dose for u..  of uncoated paper platM of
2.1 x  10    milligram, per  kilogra. body weight per day  (»gAg/day)
has been esti
 has been estimated.

           4.1.2.
 This  potential  exposure  scenario  for  use  of  disposable  diapers
 involves skin contact with dioxin in urine.  It  has  been assumed that
 1.5  percent of the contacted dioxin i, absorbed  by thi.  route  (Poiger
 and  SchUtter, 1980),  that  six disposable diapers are  used each  day
 and  that the  duration  of diaper us. lasts  for  three years. It   has
 also  been  as.umed  that  the  user ha.  an  average  weight of  10  2
 kilogram  and that the  average lifetime daily  dose  is  equal  to  the
 dose  p.r  day during  u.. multiplied  by  the fraction  of  a 70 year
 lifetim. during which the product i. used.   A. shown in Column J of
Tabl.^8. .  lifetime dioxin dose for u.. of disposable diapers of 4  8 x
10      milligram, per  kilogram body weight  per day  (mgAg/day)  has
been estimated.
                                  55

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              • 1 • 3     Sanitary Tanraon
  This potential exposure scenario  for  use  of sanitary tampons Involves
  mucous membrane  contact with  dioxin  in blood.   It has been  assumed
  that 50 percent of the contacted dioxin is absorbed by this route (ADL
  estimate).   It has also been assumed  that  thirty  sanitary  tampons are
  used each month,  representing  an annual  daily use of on.  tampon per
  day;  the duration  of sanitary tampon  use  has been  assumed to be  40
  years.  The  user  has  an assumed average weight of  60 kilograms  and the
  average lifetime  daily dose is  equal  to the  dose  per day  during  use
  multiplied  by  the  fraction of a  70  year  lifetime  during which  the
  product is used.   As  shown in Column J  of Table 8, a lifetime  dioxin
  exposure  for use  of  sanitary  tampons  of 5.6  x 10'12 milligrams per
  kilogram body weight  per day (mg/kg/day) has been estimated.
             • 1.4     Dinner
 This potential  exposure scenario for  use  of dinner  napkins involves
 skin contact  with dioxin in  skin oil.  It has been  assumed that 1 5
 percent of the contacted dioxin  is absorbed  by  this  route (Polger and
 Schlatter, 1980), that thr.e dinner napkins are used each day and that
 the duration  of napkin us.  lasts for  70   years.  It  has  also  been
 assumed that  the  user  has  an average weight of 70 kilograms and that
 the average lifetime daily dose  is  equal to the  dose per day  during
 use multiplied by the fraction of a 70 year  lif.tlm.  during  which the
 product i. used.   A. shown in Column J  of  Table 8,  a lifetime  dioxin
 exposure  for  users  of dinner napkins  of 4.8 x 10'16 milligrams  per
 kilogram body  weight per day  (mgAg/day) has  been  estimated.
          4.1.5     Pacer Towel
This potential exposure  scenario  for us. of paper towels in microwave
cooking  involves  inge.tion of  dioxin  in food  oils.   It has  be'en
assumed that  50  percent of the contacted dioxin is absorbed  by this
rout. (McConn.ll,  .t  al.,  1984),  that two  paper  towels  are used each
day and that  the duration  of  towel use  lasts  for  70 years.   It  has
                                  56

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  also  been  assum.d   that   the  user  has  an  average  weight  of  70
  kilograms and that the  average  lifetime daily  dose  is equal  to the
  dose  per day during  use  multiplied  by the  fraction of a  70  year
  lifetime during  which the  product is used.  As  shown in  Column  J of
  Table 8, a lifetime dioxln exposure for users of paper towels of a 3 x
  10    milligrams per  kilogram body weight per  day (mg/lcg/day)  has ben
  estimated.
                      Coffee Filter
  This  potential exposure  scenario for use  of coffee filters  involves
  inges-tion  of dioxin in coffee.   It has been assumed  that  50  percent  of
  the  contacted dioxin  is  absorbed by  this route  (McConn.il,  et al
  1984),  that  one coffee filter is used each day  and  that the duration
  of  coffee  filter use  lasts for  50  years.   It has  also  been assumed
  that  the user has  an  average  weight of  70  kilograms  and  that the
  average  lifetime  daily dose  is  equal  to the dose par day during us.
 -ultipled  by the fraction of  a 70 year  lifetime  during  which the
 product  is used.  AS shown in Column J  of  Table  8,  a lif.tim. dioxin
 exposure for  users  of coffe. filters  of 3.2  x  10'10 milligrams per
 kilogram body weight per day (mgAg/day)  has been estimated.
           4.1.7     Uneoated
This  potential exposure  scenario for us.  of uncoated sheet  involves
skin  contact with dioxin in  skin oil.   Ic has  been assumed  that  1  5
percent  of the contacted dioxin is absorbed  by this route (Poiger  &
Schl.tt.r,  1980),  that  1000 uncoated sheets are  used each day  and that
the  duration of  this  intensive  us.  of  uncoated sheet lasts for 50
years.   It  has  also  been assumed that th. user  ha.  an average weight
of 60  kilograms and that the average lif.tim. daily dose  is equal to
the dos. p.r  day  during us.  multilpll.d by th.  fraction of a  70 year
lif.tim. during which th. product  is  us.d.   AS shown  in Column J "of
Tabl.  8.  a  lif.tim. dioxin  .xposur.  for  int.nslv. us. of uncoated
sheet  of 1.8  x  ID'    milligrams per  kilogram body waight  p.r  day
                                 57

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   (mgAg/day) has been estimated.

            4-l-«     Unseated sheet
  This potential  exposure scenario  for  use of uncoated  sheet involves
  ingestion of  dioxin in saliva or  in the paper  itself.   It has  been
  assumed that  50  percent of the  contacted dioxin is absorbed by  this
  route  (McConn.ll,  et.  al.,  1984),  that  five  fragments  of  uncoated
  sheet are  used in this  manner,  each day,  and that the duration of  this
  type of paper use  last,  for 9 years.  It has also  been assumed  that
  the  user has an average weight of  34.8 kilograms and that  the average
  lifetime daily dose Is  equal to the dose per  day  during use multiplied
  by  the  fraction  of a  70  year lifetime  during  which the  product is
  used.   As shown in  Column J  of Table  8, a lifeci«i dioxin exposure for
  this  type  of  use  of unco.ted sheet  of  3.2  x   10'12 milligrams  per
  kilogram body weight per day (mgAg/day) has been estimated.
           Risk EgPimarion
 The U.S. Environmental Protection Agency (EPA) has calculated an upper
 95% confidence limit of the carcinogenic potency of 2,3,7,8-TCDD which
 Is equal to 1.6 x 10  per mgAg/day of exposure (USEPA,  1984a,  1985).

 Since this potency factor  is  based upon the administered dose   it  is
 multiplied by  2 to  give a potency of  3.1  x  105 per  mgAg/day  of
 absorbed dose (U.S.  EPA.  1984b, Eschenroeder. et .1., 1986).  The EPA
 has  also  developed  procedure,  for estimating  risks  associated with
 mixture, of .pacific  i.omer, of dioxin. and furans; however, for this
 risk  calculation it ha. been ...umed that all of the contaminants are
 equivalent to   2,3,7,8-TCDD  (USEPA,  1987).

 The upper 95% confidence  limit of exc.s. cancer  risk  resulting from
 the  dioxin dose 1,  calculated by  multiplying the  absorbed potency
 factor  of  3.1   x  10   (mgAg/day)'l by  the  average daily  lifetime
dose  expressed  as  mgAg/day  to  yield  a  unities,  expression  of
                                  58

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   individual  excess  risk.   When multiplied  by  the  size  of a  user
   population, this  individual  risk yields  the  expected number of excess
   cancers  which will result  over the  lifetime  of the population  as a
   result of  the exposure.   An estimate  of the annual number of excess
  cancers  to be expected in the population can  be  obtained by dividing
  by the 70 year average lifetime.

  Column K of Table 8 provides the estimated  lifetime cancer risks for
  an individual  product user.   Demographic data can b. used to evaluate
  population-based risks (e.g.,  user  population data in Table 3).

  Overall,  these individual risk  estimates range from 1.5  x  10'10  for
  dinner  napkin, to 1.0 x  10*4  for  coffee filter..  Coffee  filters  are
  the  only product  category which results in  a  risk  greater than  the
  conventional benchmark of 10'5.  Using  10'6 a. the cut-off,  four other
  products  are  included:   uncoated  paper  pl.tes,  disposable diapers,
  sanitary  tampons and paper towels.
 5.0  DISCUSSION
 In  this  section  the -sumption,  underlying the  analysi. have  been
 summarized and the result, and th.i* implication, have been discussed
 Recommendations for  additional  work which  may  reduc. some  of  the
 uncertainty associated  with  thi.  preliminary  study  have  elso  been
 provided.
     5-l  UncertaintyM *** A.11wr1
Throughout  thi,  ,tudy a,,u»ption, have been Mde.   m some cases EPA
report,  or .cientific  literature  have been  u..d  to .upport  these
assumption,.  Where such support wa, lacking or unavailable, estimates
have been  made using p.se  experience  and Judgment.   For  example,  In
the absence of data, important assumption, have been made about:
                                  59

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        o    potential levels  of dioxln contaalnatlon,

        •    the  surface  area  of product contacted,

        •    the  depth of penetration of the external phase,

       •     the  availability of dioxin  to the external phase,

       •     the extent of absorption or ingestion of external phase, and

       •    the duration and frequency of product
use.
  Accepting  the  assumption  that  consumers  may  be exposed  to  dioxin
  through us.  of paper  products,  a  rationale  by  which such  exposure
  could occur has been developed.  The scenario, ar. reasonable and  are
  in accord  with current  understanding  of  the chemical  and  physical
  behavior  of  dioxin; however,  there is  in.uffici.nt  information to
  estimate  the magnitude  of the uncertainty.

  In  addition  to the  uncertainty  inherent  in  the  evaluation of  the
 potential for exposure, there also exists  substantial  uncertainty in
 the   calculation  of  carcinogenic  potency   factors.   The  final
 uncertainty associated with this analysis would thus be the product of
 the uncertainty In the  exposure estimates and the uncertainty in  the
 risk factor.
      5-2   Implication* of t*.

 The   result.  pr...nt.d   in  Table   8   imply   that   md,r  certain
 circx».t««:..  bl.Mh.d fcmfe  product „,.„ My  be  ^^ ^ ^^
 and,  under  the  definition of  zero  thre.hold  risk  and  using  the
 assumption.  o«tlln.d in this  report,  will  have  a calculable lifetime
 risk of cancer.

Although  the  risk, calculated  in  this  study  are relatively  low.
                                  60

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   ranging approximately from  lO'4  to  10'10.  they are totally  dependent
   on  the  assumptions  of  the  exposure  scenarios.   In  the  actual
   population  of product  users,  there may be group, who us. products more
   or  less intensively than has  been  assumed and, thus,  have  higher or
   lower   risks.   Furthermore,  the  combined  risk  from using several
  bleached Kraft paper products has not been considered.

  Potential contamination  of  consumer  paper  product, with dioxin raises
  questions about  the impact  of that contamination on emissions  from
  municipal solid waste  (MSW)  incinerators.   A complete summary  of the
  literature on  dioxin emissions from incinerator., dioxin content  in
  waste feed  streams  and  generation  of dioxin  during the combustion
  process  is  beyond the scope of  this  exposure  and risk  assessment
  However,  several   observations  can  be  made,  and  these have  been
  outlined below.

  During  the 1970's  and  1980's,  dioxins  and  furan.  were identified in
  precipitator  fly  ash  samples  fro.  MSW  incinerators  in the  U S
  Canada.  Europe and Asia.   The  rn.ctumi.rn of formation  of  dioxins and
  furans  ha, been  studied  extensively,  but  the  relationship  between
  dioxin/furan  emission, and  the  type of waste incinerated  is  still
  controversial.   There  are   essentially  no  data   to  confirm  that
 dioxins/furans  In  the  wast,  f..d'- material,  result  in  dioxin/furan
 emission,.   Generation  of dioxins/furan,  a.  product, of  incomplete
 co«bu.tion  appear,  to be  more  closely  correlated  with  facility
 operating condition, and  with the availability of  precursors  such as
 organochlorine compound, and  po.sibly inorganic chlorine.

 Paper i. a  Mjor  fraction   of  the  wa.t.  stream,  of typical  MSW
 incinerator..   Domalski, et .1.  (1986) reported that paper  represented
 approximately  50%  of the   ma,,  of the  MSW  at a Brooklyn. N.w York
 facility  during  8ne  week in early  1984; 42.5% w.. unbleached paper  and
 4.6%  wa,  bleached paper.  Ac  a  Baltimore  County,  Maryland, facility.
 approximately  60% of the waste stream during a week in early 1983 was
 classified as paper materials.  The amount, of chlorine contributed by
MSW component, at the  two  facilitie.  were  also determined.   The major
                                 61

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  amounts  of chlorine in MSW  were contained  in  the paper  and plastic
  fractions.

  The paper fractions contained approximately one-quarter to one-half of
  the  weekly  average  total   chlorine  content  (0.45  -  0.89%  mass)
  One-third  to  two-thirds  of  the  total chlorine  content in pap.r  was
  determined  to be  water-soluble  chlorine  which  is  more  likely  to
  represent inorganic materials.   On the other hand,  greater than 90% of
  the chlorine  in  the  plastic  fraction  was  water-insoluble  chlorine
  compounds.

  Although  paper is a major portion of typical MSW feed streams and  may
  represent a source  of chlorine,  there  is no evidence linking increased
  paper  content  in  MSW to  increased  dioxin  emissions  fro.   an  MSW
  incinerator  or documenting  that dioxin  in a waste  stream would be
  likely to survive the combustion process.

 Another important implication of  the results  is  that  they may  be used
 as  a  basis  for regulation or legal action, or they may unduly alarm
 the public.   It cannot be stated too strongly that  these results have
 been based  on  numerous  assumptions  and  are  intended  to guide  EPA
 planning  for data  collection  and relevant  research  studies    The
 following section identifies  some areas  where additional research  may
 help to resolve some of the uncertainty surrounding  this  subject.
      5.3
 In  order to resolve  some of the uncertainty  regarding the potential
 for exposure to dioxin  in bleached Kraft paper products, several areas
 where   information  is   particularly  lacking  or   where   there  are
 significant  uncertainties   have   been  identifi.d.    For  example
 additional  data  are  needed on  how dioxin  may be  generated  in  the
bleached Kraft process,  on  the relative levels of  dioxin  in bl.ache'd
and semi-bleached Kraft product  and  on the  dioxin content  of consumer
products.
                                 62

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 There   are  some   fundamental  questions   regarding   the   physical
 distribution  of  dioxin  contamination  in  the  paper  matrix.   For
 example, is dioxin incorporated or bonded into the paper matrix, is it
 adsorbed to the surface of  the matrix,  or  is it free within the paper
 as has been assumed in foregoing analysis?

 Another  fundamental  area  of  uncertainty  concern,  the migration  of
 chemicals at very low (ppt)  concentrations.   Dioxin at 10 ppt may have
 such a low migration rate  that exposures, under normal scenario,  will
 not occur.  Finally,  it  has been assumed  that conventional  coatings
 act as  a  barrier and  prevent exposure.  One  could also  hypothesize
 mechanisms  by which  the dioxin would be  concentrated in the coating.

 Another  area  which  is  important  for  accurate  risJc  assessment is
 determination  of  usage pattern,  for  consumers  of  p.p.r products.
 Marketing  data,  consumer survey,, and  focu, group, could  be used to
 develop  a better understanding of the extent of exposure, in terms of
 both  frequency and duration, and of the nature of any high risk user  *
populations  such  a,  children or user,  of multiple  type, of  bleached
Kraft products.
                                  63

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                                REFERENCES
  1.    Adams.   W.   and  K.M.   Blaine.    1986.   A  water   solubility
       determination of 2.3,7,8-TCDD.  Chejnosphere 15  (9-12):  1397-1400.

  2.    American Paper Institute.   1986.  Statistics  of Paper,  Pap.rboard
       and Word Pulp Data Thru 1985.  New York.

  3.    Domalski,  E.S.;  K.L.  Churney; A.E. Ledford,  Jr.  and S.S. Bruce.
       1986.  Monitoring the  fate  of chlorine from MSW sampling through
       combustion.   Part  1:  Analysis of the  waste stream for chlorine.
       Chemosphere 15(9-12):  1339-1354.

 4.   Eschenroeder,   A.,  R.J.  Jaeger,  J.J.  Ospital and  C.P.  Doyle.
      1986.   Health  risk  analysis of human  exposures  to  soil  amended
      with   sewage   sludge   contaminated   with    polychlorinated
      dibenzodioxins and  dibenzofurans.   Vet.  and  Human  Tox.  28(5)-
      435 -  442.

 5.    F.landysz,  J.  and Z. Canowiak.  1982.   Sources of contamination
      of   food   with   polychlorinated   biphenyls   (PCB).    (Polish)
      Bromatologia i Chemia Toksykologiczna 15  (3),  161-166.

 6.    Freeman, R.A.  and J.M.  Schroy.  1986.   Modeling the transport of
      2,3,7,8-TCDD   and other   low   volatility  chemicals   in  soils.
      Environ. Prog.  5(1): 28-33.

 7.   Freeman, R.A.  and J.M.  Schroy.   1985.   Environmental  mobility of
     TCDD.  Chemosphere 14 (6/7):  873-876.

8.   Hotchkiss,  J.H. and A.J. Vecchio.  1983.  Analysis of direct
     contact paper  and paperboard  food packaging  for  N-nitrosomor-
     pholine and morpholine.   J.  Food Sci.  48:  240-242.
                                 64

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                                REFERENCES
  9.   laccarino, T. . L.  Croci.  S.  Gizzarelli,  A. Fcrrara,  G.  DeFellp
       and M. Morgantini.  1982.  Precise definition  of microbial tests
       on migration of antiseptics from food wrapping  paper.   (Italian)
       Bullettino  dei  Chimici  dell'Unione  Italian*  dei  Laboratori
       Provincial! 33  (S6), pp 629-637.

  LO.   Mackay,  D,  S.  Paterson  and  B.  Cheung.    1985.   Evaluating  the
       environmental fate  of chemicals.  The fugacity level III approach
       as applied to 2.3.7.8-TCDD.  Chemosphere  14  (6/7): 859-863.

  11.  Marple, L.,  B.  Berridge and L.Throop.   1986.  Measurement of the
      Water-octanol   partition  coefficient  of  2,3,7,8-t.trachloro-
      diBenzo-p-dioxin.  Environ. Sci. Technol.  20(4): 397-399.

 12.  McConnell,  E..  G.  Lucier,  R.  Rumbaugh, et al.   1984.  Dioxin in
      soil: Unavailability after  ingestion by  rats  and guinea  pigs.
      Science.   March 9.

 13.  National   Center for Health Statistics.   1986.   Aging  in  the
      Eighties,    Prevalence   and  Impact   of   Urinary  Problems   in
      Individual, Age 65 Years and Over.  Advance Data from Vital  and
      Health  Statistics.   No.  121.  DHHS Pub. No.  (PHS)  86  .  1250.

 14.   Podoll. R.I., H.M. Jaben and T. Mill.  1986.  Tetrachlorodibenzo-
      dioxin:   rate,   of  volatilization   and   photolysis   in    the
      environment.  Environ. Sci. Technol. 20(5): 490-492.

 15.   Polgor, H.  and  C.  Schlatt.r.   1980.   Influence  of solvents  and
     adsorbents  on dermal and intestinal  absorption of  TCDD.   Food
     Cosmet. Toxicol. 18(5):  477-481.

16.  Predicast Forecast:  Paper, Paperboard and  Pulp.   1985.  p.  B-183
     thru B-192.
                                  65

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                                REFERENCES
  17.   Schroy,  J.M.,  F.D.  Hileman  and  S.C.  Cheng.   1985.    Physical/
       chemical   properties   of   2,3,7,8-TCDD.    Chemosphere   14   (6/7)-
       877-880.

  18.   Sen,  N.P.  and P.A.  Baddoo.  1986.  Origin of N-nitrosomorpholine
       contamination in margarine.  J. Food Sci., 51 (1): 216-217.

  19.   Stanovick,   R.P.,   S.I.   Shahied  and   E.   Missaghi.    1973.
      Determination   of  polychlorinated  biphenyl    (Aroclor   1242)
      migration  into  food  types.  Bulletin of  Envir.  Contain,  and Tox
      10 (2): 101-107.

 20.  Till,  D.E.,   D.J.  Ehntholt,  A.D.  Schwope,  K.R.  Sidman,  RH
      Whelan and R.C. Reid.   1983.  A study of indirect food additive
      migration.   Arthur  D.  Little,  Inc. report to Department of  Health
      and  Human  Services,   Public  Health  Service,   Food   and  Drug
      Administration;  FDA Contract No. 223-77-2360.  July,  1983.

 21.   U.S.  Bureau of  the Census.  1987.  Statistical  Abstract of  the
      United States.

 22.  U.S.  Department  of  Commerce.   1987.  Paper  and  Allied Products,
     U.S.  Industrial  Outlook, p. 5-1 thru 5-24.

23.  U.S.  Dep.rtm.nt  of  Commerc.,  Bureau  of  the  Census.   1985.
     Current Industrial Reports: Pulp, Paper and Board, HA 26A <85)-l.

24.  U.S. Environmental Protection Agency.  1987.   interim Procedures
     for Estimating  Risks  Associated with Exposures  to Mixtures  of
     Chlorin«t.d Dibenzo-p-Dioxins  and  - Dlbenzo  Furans  (CDDs  and
     CDFs).  EPA/625/3-87/012.
                                  66

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                               REFERENCES
 25.  U.S.  Environmental  Protection   Agency.    1985.   Health   Risk
      Assessment Approach for 2,3,7,8-TCDD.   EPA/600-8-85/013.

 26.   U.S.  Environmental  Protection  Agency.   1984a.    Ambient  Water
      Quality  Criteria  Document  for  2,3,7,8-TCDD.  EPA  440/5-84-007.

 27.   U.S.  Environmental  Protection Agency.   1984b.  Risk Analysis of
      TCDD Contaminated Soil.  EPA-600/8-84-031.

 28.  Voss. et.  al.   1980.   Chlorinated  Organic,  in  Kraft Bleachery
     Effluent.  Proceedings Third International Congress on Industrial
     Waste Water and Wastes.  Stockholm. Sweden. February. 1980.

29.  Whitfield.  F.B..  C.R. Tindale. K.J.  Shaw and G.  Stanley.   1984
     Contamination of cocoa powder  bichlorophenols and chloroanisoles
     adsorbed  from  packaging  materials.   Chemistry   and  Industry
     5 Nov 1984: 772-774.
                                 67

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