United States
               Environmental Protection
               Agency
               Office of
               Toxic Substances
               Washington, DC 20460
EPA 560/13-80-034a
August 1980.
vvEPA
               Toxic Substances
Chemical Use
Standard
System (ChemUSES)
               Volume 1
               Introduction and  Instructions

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CHEMICAL USE STANDARD
ENCODING SYSTEM (ChemUSES)
Volume I — Introduction and Instructions
Final Report


July 1980


EPft 560/0,3*80-G34a
Prepared by:
Steven L. Wilhelm
John N. Gevertz
Jon J. Kaufman
Office of Pesticides and Toxic Substances
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460

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                                  PREFACE

     The purpose of the Chemical Use Standard Encoding System (ChemUSES)
is to provide a standard format and nomenclature for use in collecting
and exchanging information about chemical uses.  ChemUSES is a system
for describing a chemical use by the function the chemical serves and
the setting or application in which it serves that function.  For exam-
ple, a chemical use could be described as a solvent (function) in paints
(application).  ChemUSES thus consists of a list of function terms and a
list of application terms.  ChemUSES also includes user instructions and
user aids.

     ChemUSES is presented in four volumes:

     I    User Instructions
     II   Function List and Index
     III  Application List and Index
     IV   User Aids

Volume I describes the purposes of ChemUSES and gives directions for
using the system.  Volume II presents a list of terms that describe
chemical functions and an index to the function list.  Volume III pre-
sents a list of terms for describing the products and activities in our
economy that represent potential applications for chemicals.  Volume III
also includes an index to the applications list.  Volume IV presents
aids for using ChemUSES.  These user aids consist of (1) a table that
relates the ChemUSES application list to the SIC system, (2) a list of
examples of application/function combinations, and (3) a list of func-
tion/application combinations.
                                    xix

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                               Acknowledgement s
ChemUSES was developed by the Environmental Protection Agency's  Office  of
Pesticides and Toxic Substances.  Mr.  Steven L. Wilhelm was  the  EPA Technical
Monitor for this study until 4 April 1980, when Mr.  John N.  Gevertz became  the
Technical Monitor.  Mr. Wilhelm, Mr. Gevertz,  and Mr. Jon  J.  Kaufman, all in "
the EPA Office of Pesticides and Toxic Substances,  played  an active role  in
the study.  They defined the objectives of ChemUSES,  contributed ideas  for
constructing the lists, identified  sets of terms  to be  included, reviewed and
commented on the work in progress,  and prepared the introduction and
instructions contained in this volume.   '

This study was conducted primarily  in  the Center  for Resource and
Environmental Systems Studies  (CRESS)  and  the  Chemical  Industries Division
(CIO) of SRI International.  Dr.  Stephen L. Brown,  Director  of CRESS, was  the
project supervisor.  Mr. Richard L. Goen,  also of CRESS, was the project
leader.

Dr. Eugene C. Coyner (CID)  led the  work on  the Function List, the Function
List Index, the chemicals section of the Application List, and the
application/function combinations  lists.   Dr.  Thomas Gibson (CID) also  played
a major role in those activities,  and  Mr. Arnold  J. MiHard  (CID) participated
in  preparation of  the Function List.  Dr.  Coyner  and Dr.  Gibson also
contributed to the  paper and petroleum sections of  the  Application List.   Dr.
Kirtland E. McCaleb and Ms.  Janet  R. Hardy both of  CID, participated  in
development of the  function  index.   Dr. McCaleb also participated in  planning
the study effort.

Mr. Goen and Dr. Robert V.  Steele  were primarily responsible for development
of  the Application List  (exclusive  of the  chemicals section) and the
application index.   Several  other SRI staff members who are experts on the
industries represented  in  certain sections of the Application  List also
contributed to  the development of those sections.  In particular, Mr. James C.
Croudace (Forest Products  Industries Department)  contributed to  the sections
on  wood  products  and  paper;  Mr.  Eugene Thiers (Minerals and Metals Center)  to

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the mining and metals section; Mr. Gerald Shroff  (Mechanical  and  Electrical
Industries Department) to the machinery  and  electrical  and  electronic
equipment sections; and Mr. Philip D. Uinholtz  (Mechanical  and Electrical
Industries Department) to the transportation equipment  section.

Dr. Oliver W. Whitby (Computer Science and Technology Division)  led  the data
processing activities and developed  the  procedures  for  preparing  the
indexes.  Mr. Robert L. Gofer (CRESS) conducted the initial programming and
data file manipulation.  Ms. Karen A. Suttinger (CRESS)  performed the  initial
data entry.  Ms. Reddy Dively (Computer  Science and Technology Division)
developed the format for the lists,  edited the lists, and  entered the  data and
changes.  Mr. John F. Whitby (Computer Resources  Group)  developed special
programs for the indexing and for generating check  digits.

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                                   CONTENTS

PREFACE	iii

ACKNOWLEDGEMENTS  . . . . .	 . v

I.    INTRODUCTION  .		1
II.   INSTRUCTIONS  	 9
III.  ChemUSES CHECKLIST  .	27

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Introduction

I.   Purpose
     The Toxic Substances Control Act (TSCA) *, which became effective on
January 1, 1977, gives the Environmental Protection Agency (EPA)
responsibility for regulating chemical substances "whose manufacture,
processing, distribution in commerce, use, or disposal may present an
unreasonable risk of injury to health or the environment."
     TSCA authorizes EPA to collect from manufacturers, importers, or
processors of chemical substances certain types of data,.including information
on uses or use categories in which these chemical substances are employed.  In
order to carry out this mandate, the Agency has developed the Chemical Use
Standard Encoding System (ChemUSES).  ChemUSES provides a standard format and
nomenclature for use in collecting and exchanging information about  chemical
uses.
     The standard format and nomenclature provided by ChemUSES will  enable EPA
to make more efficient and effective use of the information it obtains.  It
will also aid EPA in meeting its TSCA responsibility of  improving coordination
between the several Federal agencies concerned with chemicals and health by
facilitating computer storage and retrieval of use information.

II.  History
     EPA's development of a use classification system began prior to passage
of TSCA in October 1976.  The Agency carefully evaluated  the ability of
existing classification systems to classify information  required  under TSCA.
Systems that were evaluated by the Agency include the  following:
          Standard Industrial Classification Manual, Office of Management  and
          Budget, 1972.
          Numerical List of Manufactured Produces, Bureau of the Census,  1973.
          Tariff Schedules of the U.S., Annotated, U.S.  International Trade
          Commission, 1975.
     -    Schedule A—Commodities Imported  into  the U.S.,  Bureau  of  the
          Census, 1960.
    USC  2601 et.seg.

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          Schedule B--Commodities Exported from the U.S., Bureau of the
          Census, 1971 (with revisions through 1975).
          Classified Index of Industries and Occupations, Bureau of the
          Census, 1971.
          U.S. Foreign Trade Statistics:  Classifications and Cross-
          Classifications, 1974, Bureau of the Census.
     -    Standard International Trade Classification, Revised, United
          Nations, 1961.
     -    Nomenclature for the Classification of Goods in Customs Tariffs
          (Brussels Tariff Nomenclature), Customs Cooperation Council
          (Brussels), 1955.
          International Standard Industrial Classification of all Economic
          Activities, United Nations, 1968.
          Commodity Classification for Transporation Statistics, Office of
          Management and Budget, 1972.
          List of Materials Consumption Items, Bureau of the Census, 1972.
          Federal Supply Classification, Defense Supply Agency, 1975.
     Although some systems were valuable in the development of ChemUSES, the
Agency concluded that no single existing system could meet the special
requirements for a use classification system to support TSCA.  As a
consequence EPA developed this classification system.
     In the course of developing a use classification system the Agency
published a Chemical Use List in the Federal Register* and solicited public
comment on the applicability, utility, and technical merit of the some 850 use
terms that were included in the List.  Concerns expressed by EPA staff
staff members and public comments received in response to publication led EPA
to ask SRI International to evaluate the system.  The results of this work
were published by EPA in June 1979 as Report No. 560/12-79-007, "An Analysis
of the EPA Chemical Use Classification System and the OTS Exposure Estimation
Methodology."
243 FR 32222, July 25, 1978

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After reviewing this analysis and considering additional comments  from  a
variety of sources, EPA decided that  the  concept of  the Use List remained
sound, but that considerable improvements were needed to make  it into an
effective tool for systematically classifying chemical uses.

     The new ChemUSES is greatly changed.   It consists of  the  following
elements:
                                            \ :
     1.   Function List with scope  notes,
     2.   Index to the Function List,
     3.   Application List with scope  notes,
     4.   Index to the Application  List,
     5.   Table showing the relationships between  the ChemUSES Application
          List and the SIC system,
     6.   List of functions associated with selected application  terms,
     7.   List of applications associated with each  function  term.

III. Design and Philosophy
     A complete and detailed description  of a single chemical  use  could fill a
small volume.  Therefore, it is a challenging task to describe a  chemical  use
adequately in a few words or phrases.   For  purposes  of ChemUSES,  "use"  is
defined in terms of two parameters,  function and application.
     The  function of a chemical is  described in  a  single  word  (or small group
of words) which identifies the purpose the  chemical  serves.   Examples  are
"solvents", "dyes", and "gelling  agents."  Similarly the  application of a
chemical  is described by a single word (or  small group of words)  which
identifies the setting in which the chemical is  used.   Examples are "dry
cleaning  operations", "industrial  finishes", .and "inks."   A use is defined
when both the function and application are  specified.
     ChemUSES is composed of two  lists of terms:   the  Function List and the
Application List.  Terms  from  these lists are  selected  to describe functions
and applications.  This approach  describes  a chemical  use simply and conforms
to commonly accepted notions about  the nature  of chemical use information.
     EPA  sought to develop a system that  could  capture  a  level of detail  " \
consistent with the Agency's intended use.   The  two-parameter system will
provide EPA with sufficiently  detailed use  descriptions  at an affordable

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 development and maintenance cost.  Such a scheme will also reduce the time and
 cost involved in reporting.
      Most important, the two parameter system is easy to use.  It was designed
 to  be used by persons with limited technical expertise.  This was necessary
 due to the variety of backgrounds and professions of the people who will  use
 the system.  Even in a two parameter system, there are some complications in
 selecting the appropriate function and application terms.  Becoming familar
 with this system is the biggest difficulty to overcome.  The two lists, their
 indexes,  the other user aids, and the instructions will require some study.
 In  designing the user aids and instructions every effort has been made to make
 the system easy to grasp and simple to use.
      The  Function List was developed in accordance with the following
 principles:                                 .
      o    Structure
           -    No hierarchy of terms        """
           -    Terms not arranged in alphabetical order
                Cross-references appear only in the index, not in the Function
                List                                                ;:   .
      o    Uniqueness
           -    Any function is referred to by only one term
           -    Each term refers to only one function
      o    Descriptions
                Terms for functions applicable to a particular technology
                include a parenthetical expression identifying that technology
                Scope notes describe the terms concisely, and if necessary for
                clarity,  identify mechanisms of action or methods of
                application
           -    Terms and scope notes use common industry terminology.

      The  absence of hierarchies in the Function List may help to prevent
substitution of a more general term for a more specific term.  It also makes
the  system  less  complicated.   One reason for not arranging the terms in
alphabetical  order is  to permit addition of new terms without changing the
numbers of  the  old  terms.   The primary reason is to force the user to refer to
the  index  and thus  to  examine the cross-references.  Cross-references appear
only  in the  index,  to  permit  simplification of the instructions and easier and

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more accurate use of the Function List.  The  only way  to  ensure  that  the most
accurate function term  is  selected  is  to refer  to  the  Function List  Index.
     The Function List  contains  385 terms,  including 46 terms  designated as
general terms.  The general  terms are  intended  for  use only if an appropriate
and more specific term  is  not available.  The scope notes were developed to
                                                    i
aid in making the terms conform  with common industry terminology, and to
eliminate ambiguity.  They also  clarify words that  might  be unfamiliar, by
identifying mechanisms  of  action or methods of  application when  necessary.
     The Function List  Index contains  extensive cross-references of  the
following three types:
     (1)  For all terms in the Function List:  "See also" the  related terms
          that are also in the list.
     (2)  For general terms  in the  Function List:   "Use more specific term if
          appropriate," with a list of the  specified terms.
     (3)  For terms not, in the Function  list:  "See" related terms that  are in
          the list.      ^X
     In cross-references  to  a  general  function  term, we replaced the number of
the general term with the  words  "general  term"  so  that the user would have to
look it up  in the index and  thus be exposed to  the related specific  terms.
     Index  terms that are  in the Function^List  have the initial letter
capitalized; others do  not.  These  terms  can also  be readily distinguished
from the terms in the Function List by the  absence of a function number.
     The Application List  is basically a new list, though it was derived in
part from the Standard  Industrial Classification Code (SIC).  Like the SIC,
the Application List  is hierachically arranged.  Many ChemUSES application
terms have  the same  first  two  digits as  related SIC terms.  A detailed
explanation of the  correlation is  presented  in the user aid titled
"Relationship of the ChemUSES  Application List  to  the SIC Code."
     The Application List  describes the products and activities  of our
economy.  The list  provides  a  standard system  for classifying the context in
which chemicals  are  used.   We  developed the  list with a hierarchical  structure
to provide  a way of describing uses at the appropriate level of  detail.
     We included  scope  notes for terms,  when it was necessary to  clarify what
the  term encompasses.   The Application List may be used  sometimes without
reference  to  the  Index.  Therefore, cross-references have  been  included in
                                                                   /
some of the scope  notes to indicate the location of related terms.

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     During development of the system,  it became  obvious  that  each  category
could not appropriately contain  the  same number of  levels.   Because many
related terms do not occur close to  each other in the  list,  use  of  the
Application List Index may be necessary in  order  to identify related terms.
Reliance on the hierarchical nature  of  the  Application List  alone may lead  to
errors in describing uses.
     Different kinds of hierarchical structures were developed for  Application
List categories.  Three types of hierarchies  can  be distinguished:
     (1)  Product classes and products
     (2)  Basic products and converted  products
     (3)  Products and activities.
     Furniture is an example of  a  two-digit group that can be  logically
structured only by product class (e.g., office furniture) and  product (e.g.,
desks).  Paper products is an example of a  group  that  divides  into  basic
products and converted products.   The basic products in the  Paper  sector are
pulp, paper, and paperboard, with  subclasses  of products  in  each.   The
converted product group can be divided  into converted  paper  products and
converted paperboard products such as notebook paper and  dress boxes.  An
example of a sector that logically divides  into products  and activities (or
processes) is petroleum refining.   Processes  include distillation  and
catalytic cracking.  Products include gasoline and  jet fuel.  In this and
similar cases, the activities (or  processes)  cannot be uniquely associated
with a single product.  In most  of the other  manufacturing  sectors, the
"activity" is the manufacture of the product  itself.
     In some two-digit categories  the SIC  structure was largely followed, but
other categories reflect substantial departures.   In particular, an effort was
made to avoid classifications that would permit listing a product  in two or
more different categories.  The  SIC  system is structured  by  type of
establishment, and frequently the  same product may  be  produced in  different
types of establishments.  For example,  in  the SIC,  sweaters  are listed under N
both Textile Mill Products and Apparel. We separated  these  categories into
the two categories of (1) basic  textiles  and  (2)  apparel  and other  fabricated
textile products.
     The major use of chemicals  is to make  other  chemicals  and chemical
products.  Hence the chemicals section of  the Applications  List is of

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particular importance, and special attention was devoted to the development of
that part of the list.
     The basic inorganic and organic chemicals presented the major
difficulties in structuring the chemicals section.  One problem was  in
specifying a clear distinction between organic and  inorganic chemicals.
Consideration was given to classifying all chemicals containing carbon as
organic, in order to  provide an unambiguous distinction.   However, that
classification rule would have led to classifying as organic compounds such as
carbon dioxide and carbonates that are commonly  considered inorganic.
Therefore, all chemicals containing carbon were  classified organic except
those commonly considered inorganic.  Exceptions are indicated  in  the  scope
note.
     Another major problem was to develop a hierarchical  structure  for the
basic chemicals that  would provide a unique category for  each chemical.   To
achieve that objective, basic organic chemicals  were divided  into  the
following composition categories:  (1) hyrdrocarbons,  (2)  monofunctional
organic compounds, (3) heterocycles, and  (4)  polyfunctional organic  chemicals.
     During development of ChemUSES, EPA  came  to realize  that  there  was  no
practical limit to the detail involved in describing many applications.   The
application area of paints, for example,  could be  subdivided  into  dozens of
different types of paints.  These could be  further  subdivided  according to
method of application, type of pigment, etc.   Eventually,  continued
subdivision becomes impractical.  The Application  List alone could easily have
grown-to more than 20,000 terms,  and with cross-references and  synonyms, the
index to  the Application List could have  surpassed  100,000 entries.
     However, the problem remained that chemical use  information is  very
                                     x.
frequently known in  finer detail  than  can be  handled  by.a list  of a few
thousand  terms.  Nearly as often, this additional  detail  is useful or even
critical  to accurate  and  adequate understanding  of chemical uses.   To resolve
this problem, EPA added a narrative  section to ChemUSES.   In this  section, a
respondent may  submit a  limited  amount  of narrative information in addition to
the basic function/application description  of a  use.   Use of narrative
information is  explained  in  detail  in  the Instructions section.
     ChemUSES will never  be  complete.   Each aspect of  ChemUSES was designed to
allow for potential  expansion and improvement.  Expansion of ChemUSES should
not  result  in  the addition  of thousands  of  very detailed  terms.  Some new

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                                     - 8  -
terms, similar in detail  to  the  current  ones,  may be  necessary due to
innovation in the chemical and allied  industries, or  due to initial oversights
in developing ChemUSES.
     Finally, it should be noted  that  the  Function List  and the Application
List are not developed in certain  areas, such  as  pesticides and cosmetics,
which are not regulated under TSCA.  Limited  treatment of such areas appear in
one or both of the lists, to serve the purpose of holding a place  in the list
as a "reserved" category*  Should ChemUSES be  adopted by other Federal
agencies, as hoped, these sections will  be expanded.

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                                    -  9 -
INSTRUCTIONS
    This section contains descriptions of  each  of  the  components  of  ChetnUSES
and instructions for their use.  The Function and  Application Lists  and  their
indexes are described first, followed by the user  aids.   Finally,  specific
instructions for developing chemical use descriptions  are given.
    A chemical use is defined as a combination  of  a  function  and  an
application.  A chemical function is described  in  a  single word or small
groups of words which identifies the purpose the chemical serves.  Examples
are "solvents", "dyes" and "dust control agents".  The application of a
chemical is the activity or product in which the chemical is  used.  The
application is also described by a single  word  or  small  group of  words chosen
from the terms on the Application List.  Examples  are  "Inks", "Metal cans" and
"Dry cleaning operations".

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                                    -  10  -
I.  FUNCTIONS
    A.  The Function List and Scope Notes
  ,  The Function List contains 385 terms.   The  order  of terms  on the Function
List is intentionally random.  Each term on the list  is followed by a scope
note that contains explanatory or descriptive information.   These scope notes
are user aids, not technical definitions of terms.
    The scope notes state whether a function term is  one of the small number
of general terms included.  General terms  are to be used only  when a more
specific description of  the function  or  functions is  not appropriate.
Specific terms should be used for the most  part, even if several such terras in
a general category must  be  listed.

    B.  The Function List Index
    The entries in the Function List  Index consist  of terms from the Function
List, as well as referral or locator  entries.   Each  term from  the Function
List appears in the index with its code  number.  For  each valid function term,
cross-references to related valid terms  are given by  "see also..." entries;
e.g., "see also Sequestrants" appears after "Chelating agents."  Synonyms and
closely related terms that  do not appear on the Function List  may not be used
as ChemUSES codes; they  appear in the index to  assist users in identifying
valid function terms.  Every non-valid  term is  followed by "see" and one or
more cross-references to valid function  terms,  e.g.,  "see Film-forming Agents"
is listed as a cross-reference under  the synonym entry "Binders."
                                                               i   - .
    Index terms that are in the Function List have their initial letters
capitalized.  These terms also have a ChemUSES  code number in  the left
margin.  Non-valid terms are neither  capitalized nor  numbered.
    When a general term  appears on the  Function List  it is followed by the
statement, "use more specific term if appropriate" and, then,  the specific
terms.  When a general term appears as  either a "see" or "see  also" reference,
it is followed by the phrase "general term" instead of the ChemUSES code
number.  The user should then refer to  the general' term in the index to note
whether any of the specific terms  listed under  the general term are
appropriate.

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                                    - 11  -
                                           I

    C»  Selecting a Function Term
    The function of the chemical should be  expressed  as  one  of the  terras  in
the Function List.  To use the Function List  Index  to select  a valid  function
terra, begin by identifying possible  function  descriptors in  your own
terminology.  One or more of these terms  should  appear in the Index.   If  not,
attempt to identify more  specific or more general  terras.  Select the  Index
entry or entries that best match the function being described.  Using the
ChemUSES code numbers, look  for valid terms  on the  Function  List and  use  the
scope notes to select the most appropriate  term(s).
    As an example, suppose that a respondent  manufactures hydroxy-
ethylcellulose to be used as a thickener  in interior latex trade sale
paints.  The user examining  the Function  List Index to see if "Thickeners" is
a valid function term, or whether a  related  term would better describe the
chemical's function.  If  there are related  terms,  they should be listed under
"Thickeners".
    "Thickeners" is a valid  function term and is assigned the number  272.
Therefore, one can next look for the term in the numerically ordered  Function
List, and read the scope  note.  The  user  should also look up the related  terras
"Emulsifiers", "Gelling agents", "Thixotropic agents", and "Viscosity
adjusters".  Because the  user  knows  that  the chemical does not perform its
function in textile technology there is  no  need to look up the related term
"Vat  printing assistants  (textile  technology)".
    After examining the scope  notes  for  all related terms, the user should
choose the term which best describes the  function  the chemical serves.   In
this  case, it may be assumed that "Thickeners" was the best term.  The
respondent should note both  the Function term and  its code number.  This
example will be continued  in the  section  of the instructions which deals with
selection of application  terms.

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                                     - 12  -
II.  APPLICATIONS
     A.  The Application List and Scope Notes
     The Application List contains several thousand terms at  five levels of
 hierarchical detail.  Products, processes, and other activities are all
 potential applications.
     The least specific level of hierarchy contains such broad terras as
 "Chemicals" and "Machinery."  These terms will rarely, if ever, appear in use
 descriptions.  They are included to clarify the organization of the list.
 Each of these categories is divided into several sub-categories which are then
 subdivided, and so on—up to a fifth level of hierarchy, when necessary—to
 reach an appropriate level of detail.  Terms at the same level of the
 hierarchy, but at different locations in the list are not necessarily
 comparable in detail.
     Many terms on the Application List are followed by scope notes that
 contain explanatory, descriptive or instructional material.  In the majority
 of cases, the scope note is intended to clarify what the term encompasses
 and/or provide an illustrative list.  None of the scope notes should be
 thought of as definitions or exhaustive lists.  Some Application terms are
 self-explanatory and no scope note is provided.  When selecting a term from
 the Application List, the most specific term available should be used rather
 than a less specific term.
     The Application List is numbered by assigning two digits to each level of
 the hierarchy.  Each pair of digits is separated from the next by a decimal
 point.  For example, 04.03.02.01 denotes a term at the fourth level of
 hierarchy,  and 04.03.02 denotes the less specific term at the third level.
 Care must be taken in transcribing the codes to ensure that digits are not
 inadvertently deleted or transposed.
     To reduce the likelihood of transcription errors, a "check digit" has been
 added  to  the end  of each code number.  A check digit is a number which the
 computer  can decipher to "check" for errors  in transcribing code numbers.  The
 check  digit  is preceeded by a hyphen.  While the check digit does not reflect
 the  Application List hierarchy, it is an intergral part of the code number and
 must not  be  left  off when recording the number.
     Many  instances  occur when a term or group of terms could be located in
more than  one  place  on  the list.   Such occurences are unavoidable due to the
 complexities and  overlaps of industries,  products, and processes.  While

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                                    -  13  -
duplicative entries have been eliminated,  closely  related  terms  do not  always
appear in the same section of the  list.   Thus,  use of the  Application List
Index is recommended to ensure that  the most  appropriate  term is selected.
    Application terms are basically  of two types that may  be called "products"
and "activities".  Products are generally items that  can be purchased,  such as
"Laundry detergents," "Wire springs" or "Storage batteries".  Activities are
processes or services, such as "Automobile repair" or "Medical services".  The
distinction between these two types  of terms  is not always clear.  First, all
"product-type" Application terms have a dual  meaning.  They refer both  to the
product and to the activity of manufacturing  or processing that  product.  In
making "Steel castings" in foundaries one uses  steel.  The steel is
incorporated in the final product.   Thus, "Steel castings" refers to the
product.  However, other chemicals are used in  foundry operations, such as
binders for making sand casting molds.  Such  chemicals are not part of the
final product, and thus are not used in steel castings in the same sense that
   ;el is.  In this case, the  application  term refers  to the activity of making
   :eel castings."  In general, if  a  chemical  is not intentionally incorporated
in the end product to perform a  function, it  should be specified as serving in
the activity.
    An analogous  situation exists  for many "activity-type" terms.  They may
indicate either an activity or a product  used in conducting that activity.
    Whenever there might be some confusion regarding products or activities
the user is requested to append  an "A" to the Application term code number to
designate an activity, or a "P"  to designate  a product.  For example,
"30.01.02-3P'Tires and innertubes" implies that the application is in the
product tires, whereas "30.01.02-3A  Tires and innertubes" implies that the
application refers to manufacturing  tires. The need to make such distinctions
should not arise.^often.   It will usually  be necessary when the user desires to
specify whether or-not the chemical  substance is intentionally incorporated in
the final product.

    B.,.  The Application List  Index
    The Application'List  Index  contains  valid terms  from the Application List,
   well as some,common synonyms.   Because of  the length and hierarchical
Vature of the Application List,  not  all  terms on the List appear  on  the
Index.  Terms that contain identical first words,  or similar roots do not  all
I!

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                                    - 14  -
appear on the Index.  For example, "Clothing" appears in the Index, but ,
"Clothing, Men's" and "Clothing, Women's do not appear.  This is because the
entry "Clothing" refers the user to the section containing both men and
women's clothing*  However, "Men's clothing" and "Women's clothing" do appea
in the Index.

    C.  Selecting an Application Term
    The application of the chemical should be described by one or more of th<
terms in the Application List at as detailed a level of the hierarchy as
possible.  To find the appropriate term, look for ptential descriptor terras
in the Application List Index, and then find these terras on the Application
List.  It may be necessary to try a variety of descriptors to find the propel
section of the list, and to examine all the scope notes in that section to
determine the most appropriate; term( s) .  Also, examine the sections of the
Application List that contain cross-referenced terms and read any scope note
provided.  This  should make selection of the .most appropriate terra straight
forward.
    Returning to the example used above, one can select an appropriate
application term for the use of hydroxyethylcellulose as a thickener in
paints.  The user should first examine the Application List Index and check
for paints.  The user is referred to both "(39.06.03.02-0) Paints, artists"
and "(28.08-6) Paints and Allied Products".  Assuning the application is onl
in "Paints and allied products", the user should then refer to section 28.08
of the Application List.  If, however, the thickener is also used in Artist'
paints, the user would be required to list both function and application
combinations as  separate use descriptions.
    The "Paints and allied products" section contains a variety of sub-
sections that must be examined in order to select the most accurate use
description.  First, one must choose (at the next level of hierarchy) between
"(28.08.02.-7) Trade sales .finishes" and "(28.08.0272) Industrial finishes".
In this example, "Trade sale finishes" is selected,,
    At the next level of detail, one must decide whether the Application is
"(28.08.01.01.-8) Exterior trade gale  finishes", or "(28,08.01,02.-9 ) Interior
trade sale finishes".  In this case, "Interior trade sale finishes" is
selected.

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                                    -  15  -


    Finally, one would  specify  the  application  term "(28.08.01.02.02-1)  Water
based interior paints and  enamels".  Additional  detail  may be provided by
describing the application in the narrative  section of  the ChemUSES reporting
form, as will be discussed later.
    It is possible  that  the  application may  not  be  known to the level of
detail described in  the  example.  In these cases,  the most specific
Application description  which conforms with  the  user's  knowledge should be
provided.

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                                      - 16  -
III.  THE USER AIDS
      To assist individuals in searching the  function and application  lists  for
  appropriate terms, three user aids have been developed.  The  first,  a parallel
  table relating the Standard Industrial Classification Code  to  the Application
  List, will be helpful for those familiar with the SIC system.  The other us'er
  aids are lists of common uses which indicate frequently encountered
  combinations of functions and applications.

      A.  Relationship between the ChemUSES Application List  and the SIC
      The ChemUSES - SIC table is a simple parallel table that makes explicit
  the  relationship between the Application List and SIC codes.  While  the
  Application List was developed in part from the SIC codes, many deviations
  from the general organization of the SIC system were necessary.  Because many
  users are already familiar with the SIC system and are aware of the  location
  of an industrial section in the SIC hierarchy,  knowledge of SIC codes may^e
  valuable in using the Application List.
      The table is arranged by SIC codes and terms, which appear in the left
  column.  In the right column appears information indicating where the
  industrial segment or its products may be located in the Application List.
  Because of its simple organization according to SIC code numbers, use of this
  table should be straight forward.

      B.  Application/Function and Function/Application Combinations
      The purpose of the Application/Function and Function/Application lists is
  to provide a starting place for determining what kinds of chemical functions
  might be employed in a known application, or the converse.  The two
  combination lists also serve as examples that illustrate how to employ
  ChemUSES to specify chemical uses.
      Function terms are listed only for selected terms in the Application
  List.   For our purposes,  a comprehensive listing of combinations is not
  needed;  nor would development of comprehensive  lists be feasible.  Many of the
  application terms  in the same section of the list will have a common set of
  chemical  functions.   The Function/Application List is a list of all  functions
  followed  by one  or more  related applications.  Returning to the previous
  example,  the  respondent  may know that the chemical is used in paints, but does
  not know  the  proper  ChemUSES term  for the function this  substance serves.  By

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                                    -  17 -
locating "Paints and  allied  products"  in  the  combination Application/Function
list, a list of common  functions  that  chemicals  perform in paints can be
examined.'  Because the  combination  list is  arranged  numerically,  the user must
first find.the valid  Application  code  number. By examining the listed
function terms and comparing scope  notes  in the  Function List,  the user can
select the/appropriate  function term.
    If a user knows the function  of the chemical, but not the proper ChemUSES
Application term, a review of the Function/Application combination list; should
provide assistance.

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                                     - 18  -
IV.  DEVELOPING A USE DESCRIPTION
     This section provides specific guidance for building & use description by
 combining function and application terms, and adding narrative material where
 necessary.  Instructions for handling simple cases are given  first,  followed
 by instructions for uses which are slightly more complicated.  Finally,
 instructions for inclusion of narrative material are given.   To understand
 this section,  the user must have reviewed the material presented in  the
 preceeding sections.

     A.  Basic Structure (F/A)
     As noted in the Introduction, "use" is defined in ChemUSES as  the  function
 a chemical serves and the application in which it serves that function.  The
 basic structure of a use description) is a function term preceded  by its code
 number and an application term preceded by its code number.   The two terms are
 separated by a slash*  The example of methyl ethyl ketone used as  a  solvent  in
 paints would appear as:

         (271) Solvent8/(28.08.01.02-9) Interior trade-sale finishes*

     B.  Function or Application Unknown
     In some pases, a respondent will not know the setting in  which a chemical
 is used.  In many cases, the respondent will be able to make  use of  the  less
 specific levels of hierarchy in the Application List.  In pases where  the
 application is completely unknown, the code "(98) Application Unknown" may be
 used*
     It is less likely that a respondent will be unaware of the function  a
 chemical serves.  However, for such cases, CheraUSES includes  the category
 "(980) Function Unknown."

     C.  Function or Application Not Found
     Every effort has been taken to ensure that function and application  terms
 are provided for all uses of chemicals.  With careful examination  of the
 indexes, appropriate terms should be found.  However, should  the respondent
 remain unable to locate appropriate terms, the categories "(990) Function  Not
 Found" or "(99) Application Not Found" may be used*
     If one of these categories is used, the respondent must also employ  the

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                                    - 19  -


narrative section (specific instructions are provided  in  Part  J  below).  The
respondent should briefly describe  the  function or  application in his/her  own
words.  A brief indication of why existing  terms did not  seem  appropriate  is
also suggested.
    The EPA- will review all narrative material accompanying  functions  or
applications not found.  The EPA may decide to add  new terms or  alter  scope
notes in future editions of ChemUSES.

    D.  Multiple Functions (F-F/A)
    Occasionally, a chemical, serves  two or  more purposes  simultaneously in a
product, or may serve any of several functions depending  on  its  concentration
or some other parameter. . An example of the latter  is  sodium nitrite which at
low concentrations serves as a preservative in meat products,  but  at higher
concentrations can also serve as a  color enhancer.
    ChemUSES permits specification  of multiple  function terms.  The function
terms with their code numbers should be separated by hyphens.   To  use this
format, the proper application term must be identical  for all  of the function
terms.  An example is the use of carbon black  in  automobile  tires  where it
serves as a.pigment and protects the rubber from  ultraviolet degradation.
This use would be described as follows:

        (125) Pigment. - (36) Ultraviolet  absorber/(30.01,02-3) Tires and inner
        tubes*

    E.  Multiple. Applications - Different  Uses  (F/A, F/A)
    Frequently a chemical serves  the .same  purpose (function) in several
applications.'  For purposes of ChemUSES these  are considered separate uses and
are coded separately. . For example, acetone is  a  solvent in many applications
such as paints,  adhesives, and  patching fillers.   These uses would be coded as
follows:

        (271) Solvent/(28.08-6) Paints  and allied products
        (271) Solvent/US.13.02.02-5)  Synthetic organic adhesives
        (271) Solvent/US.01.03.04-6)Extender  pigments and fillers.

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                                     -  20  -


     F.   Multiple Applications:   Activity-Product Combinations
     In  the nine sections of the Application List discussed below the user is
 instructed to combine two application terms; one which describes an activity
 and  one which describes a product.  The activity code number and term should
 be listed  first followed by a hyphen,  then the product code number and terra.
 If a substance functions in more than one activity or with regard to more than
 one  product,  these  uses should  be coded separately.
     In  some instances, the user may know only that the substance functions in
 the  activity  and be unaware of  the products  involved.  Sirailarily, the user
 may  know only that  a substance  is involved in the production of one of the
 products discussed  below,  but be unaware of  the activity or process
 involved.   In these cases, the  user should code only the known activity or
 product.

         1.   (10) Mining
     In  this section,  one shpuld specify an activity from "(10.07.) Mining and
 related  activities" and a  product from the categories:  "(10.01) Metallic
 ores";  "(10.02) Oil and gas'1;  "(10.04) Nonmetallic minerals"; or "(10.05)
 Construction  minerals".  For instance, xanthates serves as collectors in the
 beneficiation of zinc ore.  This use would be coded as follows:

         (283)  Collectors/dO.07t04) Ore benefication - (10.01.04) Zinc ore.

         2.  (15) C ons true tion
     In  this category  one should choose an activity from "(15.03) Special
 construction  activities",  and,  if appropriate,  a product from "(15.01)
 Building construction" or  "(15.02) Construction other than buildings"*  For
 instance, methyl borate serves  as a flame-retardant in insulation for.
 residential housing.   This use  would be coded as follows:

         (332)  Flame retardants/(15.03,07-5)  Insulation-(15.01.01-7)
        Residential buildings.

        3.  (22)  Textiles  and Textile  Finishing
    In this category  one should specify,  when appropriate, an activity from
"(22.03) Textile  finishing and  coating",  and a  product from "(22.01) Fiber and

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                                    -  21  -
 fiber products",  or  "(22.02)  Textile  goods,  n.  e.  c.".   For instance,
 hexaraethylene  diamine  serves  as  an  antistatic  agent  in  the finishing of man-
 made knit  fabrics.   This  use  would  be coded  as  follows:

         (328)  Antistatic  agents/(22.05.01.04-2) Chemical finishing n.  e. c.  -
         (22.01.04.03-0) Man-made  knit fabrics.

         4.   (27)  Printing and Publishing
    In  this  category one  should  specify, when  appropriate, an activity from
 "(27.02) Printing and  related activities",  and  a  product from "(27.01) Printed
 products".   For instance,  Yellow 12 serves  as  a toner in gravure printing of
 catalogues and directories.   This use would  be  coded as  follows:

         (225)  Toner/ (27.02.01.04-4)  Gravure-  (27.01.05-3) Catalogues  and
         directories.

         5.   (30.02)  Plastic Products
    In  this  category one  should  specify, when  appropriate, an activity from
 "(30.02.16)  Plastics forming  processes", and a  product  from sections
 (30.02.01) through (30.02.15)  For  example,  carbon black serves as reinforcing
 agent in injection molded  plastics.   This use would  be  coded as follows:

        ?(250)'  Reinforcing agents/(30.02.16.01-9)  Injection molding -
         (30.02.02-4) Plastic  rods,  tubes and other stock shapes.

        6.   (34)  Fabricated Metal Products
    In  this'category,  one  should  specify, when  appropriate, an activity from
"(34.09)' Metal processing", and  a product from  sections  (34.01) through
 (34.08).  It might also be appropriate to select  a product from sections such
as "(37.01.01) Motor vehicles" or "(33.01.05.03)  Steel  castings".   For
example, zinc  serves as a corrosion inhibitor  in  hot dip coated metals.  This
use would be coded as  follows:

        (323) Corrosion inhibitors/(34.09.05-8) Galvanizing and other  hot dip
        coatings - (34.03.01-8) Fabricated structural metal.

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                                    - 22  -


        4.  (80) Building Application^
    In this category one should specify, when appropriate, an activity  from
"(80.02) Building-related activities", and a product from "(80.01) Building
categories".  For instance, 1,2- dichloroethane serves as a degreaser in
service station cleaning operations.  This use would be coded as  follows:

        (229) Degreasers/(80.02.01-3) Cleaning -  (80.01.05-6) Service stations
        and garages.

        8.  (32.01) Glass
    In this category, one should specify, when appropriate, an  activity from
"(32.08.01.-4) Glass finishing", and a product from "(32.01.02-5) Flat  glass",
"(32.01.04-7) Glass containers", or  "(32,02.05-8) Glassware".   For example,
Fe203 serves as a coloring agent in  the staining  of glass.  This  use would be
coded as  follows:

    (86) Coloring agents/ (32.01.01.01-5) Chemical treatment-  (32.01.02.03-8)
    Sheet glass.

        9.  (95) General Processes
    The general process terms in this category describe  activities that are
not limited to a single industry, but are common  to a number of industries.
These terms should  only be used if  the activity cannot be  accurately described
in a specific section of the Application List, or if the respondent is  only
aware that  the substance functions  in the general process.
    The terms should be used in combination with  a particular  application
where specification of a process would help clarify the  use  of chemicals in
the manufacture of  a product.  An example is magnesium perchlorate which serve
*s a dehydrating agent in the reactions of ethers.  This use would  be  coded  as
follows:

        (73) Dehydrating.agents/(95.01.08-4) Reaction -  (28.02.02.03-5)
        Ethers.

    G.  Specifying  Product or Activity Applications  (P or  A)
    As discussed above, it will occasionally be necessary  to distinguish

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                                     - 23  -


 between the product and activity meanings of an application tern.  Due to  the
 existence of the sections described in Part F, only in a few cases should  it
 be necessary to explicitly make the distinction.  Most cases will be obvious.
     The key element in making a distinction between product and activity
 hinges on whether or not the substance is intentionally incorporated in the
 final product.  If a substance is used only in manufacture or processing and
 is not intentionally incorporated in the finished product, an "A" for activity
 may be specified.  If the substance is intentionally incorporated in the
 finished product, a "F" should be specified.  The A or P should be added to
 the use description following the code number (including check digit).
     For example, parting agents are used in the manufacture of rubber tires.
 This use would be coded as follows:

         (144) Parting agents/ (30.01.02-3A) Tires and Innertubes.
     On the other hand, pigments are included in tires.  This use would be
 coded as:

         (125) Pigments/(30.01.02-3P) Tires and Innertubes.

     H.  Multiple Applications;  Additional Application Term*

     1.  General discussion
     Frequently, a use description may be improved by (an) additional
 application term(s) which serves to limit the scope of the application.  For
 example, acetone is used as a solvent in special glues for making plywood.
 This would be described as follows:

         (271) Solvents/(28.13.02.02.03-8) Synthetic organic adhesives T
         (24.03.01-8) Plywood veneer.

     As the example indicates, the application terms are separated by
 hyphens.  When multiple application terms are used, the function term may  only
 be relevant to the first application.  In this example, for instance, the
 solvent only functions in the adhesive.  Function terras, applicable to each
^Bp in the application chain should not be strung to$*ther,' but rather listed
 as separate use descriptions.

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                                    - 24  -
    2.  .(30.02.07) Industrial Plastics Products
    In one section of the Application List, the user is specifically
instructed to use additional application terms.  This is section "(30.02.07)
Industrial plastics products" which includes four broad categories of
applications such as housings and cabinetry, and mechanical components and
parts.  Additional application terms may be used to specify the industry
segment involved.  .For example, acrylonitrile-butadiene-styrene is used as a
raw material in the production of housings of car stereo equipment.  This use
would be coded as follows:

        (224) Plastics for shaping/ (30.02.07.01-0) Plastic housings and
        cabinetry - (36.03.03.03-5) Audio components

    *•  (28) Chemicals and Allied Products
    This section of the Application List contains two parts.  The  first is
composition terms:  "(28.01) Inorganic chemicals" and "(28.02) Organic
chemicals".  The second is end-use terms: (28.03) through  (28.14).  The end-
use terms include categories, such as explosives .and inks, and refer to end-
products produced to meet specific performance characteristics.  A chemical
composition term refers to a specific molecular and elemental arrangement of
atoms.
    The composition section is used when a substance is used  in the
manufacture or processing of a chemical product or class of chemical
products.  The user may know,  for example, that a substance is used in  the
manufacture of "(28.02.02.02) Acyclic hydrocarbons".  If the  specific acyclic
hydrocarbon is known, the user must provide the IUPAC (International Union  of
Physicists and Chemists) name  in the narrative section  (described  below), and
must also provide the CAS (Chemical Abstracts Service)  number.  Whenever  a
specific chemical identity of  an application is known,  a CAS  number must  be
provided if one has been assigned.
    The end-use section is to  be used if the particular chemical  composition
is not known, or if the substances functions in a wide-category of chemical
products.  For example, diphenylamine is used as a stabilizer in  explosives.
This use should be coded:

        (54) Stabilizers/(28.11.04-3) High explosives

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                                    -  25 -


 In cases where  a  composition  term  and  an end-use  term are  both appropriate,
 the  respondent  must  give  both*

     J.  Use of  Narrative  Material
    If  the  terms  on  the  Function  and Application Lists  and  the formats
described above are  inadequate, either  because  they fail  to convey some
critical detail or because  they imply more  than they should,  narrative
material may be appended to  improve the overall use description.
    One particular type  of  information  that may be  useful in a narrative is a
product number from  the  Numerical List  of Manufactured  Products (NLMP) which
is an extension of the SIC  system to  the product level.  It contains nearly
20,000  specific product  descriptors.  Users of  NLMP descriptors are required
to use  the  code number for  the product  preceded by  the  acronym NLMP, e.g.,
NLMP 22	.  Narrative descriptions of  products are acceptable as  well as NLMP
codes.  In  the example of a  paint thickener, for instance,  the respondent may
wish to write in  the Narrative section  NLMP 28514-11-5, to  indicate that this
thickener is used exclusively in  flat interior  latex trade  sale paints.
    As mentioned  above, Category  28 of  the  Application  List,  "Chemicals and
allied  products"  contains terms for describing  applications in which chemicals
are used in the manufacture  or processing of other  chemicals.   The terms
necessarily represent categories  of chemicals.   When using  a term  from this
section of  the Application List to refer to a specific  chemical, the Chemical
Abstract Service  (CAS) number for the chemical  must be  supplied, if one has
been assigned.  If the CAS number is used,  it should be prefaced by "CAS",
i.e., CAS 7647-01-0.  When no CAS number has been assigned, the IUPAC name of
the chemical substance or substances must be specified.  An example is
magnesium bromide used as a  catalyst  in the production  of methyl ethyl
ketone.  In the narrative section, the  respondent would write:

        Catalyst  in  production of Methyl ethyl  ketone.           CAS 78-93-3.

    If users wish to describe the chemical  use  in their own words  in addition
to describing it with a  function/application combination, they may do so in

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                                    - 26  -
the narrative section.  However, the respondent must  always  provide a valid
ChemUSES code.
    If the valid ChemUSES code  contains  either  the  terms  Function Unknown  or
Not Found,, or Application Unknown or Not Found, respondents  must describe  the
use in the narrative  section.                               .

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                                 - 27 -
                              ChemUSES Checklist
1.    Examine Function List Index and  record name  and  code  number  of candidate
      function terms.             x
                <   '
2.    Look for candidate terms by number  in Function List.   Read  all scope
      notes and choose best valid function term(s).

3.    Examine Application List Index*   Record  name and code number of
      candidate application terms*  You may wish to refer to SIC  - ChemUSES
      relationship table;

4.    Examine relevant sections  of Application List.   Read  all scope notes and
      choose appropriate terms.   Provide  as much detail as  possible*  Record
      selected term(s) and number(s).

3.    Combine function and application terms as instructed*

6.    If application  is an identified  chemical, write  CAS number and IUPAC
      name in narrative section.

7.    Describe the chemical use  in  your own  words  in  the narrative section, if
      appropriate.

8.    When necessary  consult  the combination lists for suggested
      function/application combinations.

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